XXHighEnd

That's the problem with summer. I usually have a few weeks off work and try to spend as much time at home as possible. But on Thursdays and Fridays, my wife goes to work and my 20-month old son goes to nursery. I'm at home... with way too much time on my hands...

My two NOS1s should be back at some point and I'm eager to get everthing ready for them. One of the tasks is to get an ultra-fast amp sorted for my office system, with my small Quad electrostatics. I've been looking at some possible solutions, but the one that I keep on coming back to is to simply buy another Sanders Magtech amp for my office, just like the one I already have in my main room, with my big Quad electrostatics. I've tried a number of amps in my main room now, and none of them sound as good as the Magtech with the Quads. The sound comes alive with the Magtech - it's 3-dimensional, tight and really quite dynamic (for electrostatics at least).

But buying an identical amp just seems too boring. So the search recommenced today. Of course, this is nothing new for me. I've been at this before (http://www.phasure.com/index.php?topic=1274.0). But this time, I'm looking for a real end-game, so that I can focus on other elements of my system. Anyway, to cut to the chase, I have an opportunity to buy a used (but absolutley mint) Soulution 710 amp (http://www.soulution-audio.com/en/serie7/710/index.php). The idea would then be to put the Magtech in the office (with the small Quads) and the 710 in the main room (with the big Quads).

But even used, the 710 will cost me 14K UK pounds! Now, I'm not a rich man and this is a totally absurd amount of money for me. But, I can just about afford to buy it without putting my family in a state of total poverty.

Someone... anyone... please give me a compelling arguement as to why I shouldn't do this. Please...

... but you've got to convince me that the USB-NOS1/710/Quad combination won't be heaven on earth, because I'm totally convinced it might well be.

Mani.

Ok, you are obessed. Can't be helped. You *have* to do it. But :

What about the way too high power ?

Also, output seems to be 22V-p with a rise time of 330ns. Roughly this means a slew rate of 66V/us.
Let's say I didn't make too many mistakes here, and let's say the slew rate of the NOS1 of 650V/us is something to take into consideration.
Does this look good to you ?

Then, I don't like the graphs;
I can't see the FFT depth, but from the two pictures -one with noise only, one with signal- there's already a 20dB difference. Besides, something like -165dB for the noise floor ? haha. Well, the specs in the end talk about -110dB, so I guess that's the figure, but that's no good figure at all.

The noise-only figure shows harmonics which I don't like to see. I know, amp manufacturer judge this as very good etc., but I just don't want to see it. From the NOS1 comes exactly silch (the noise floor being at a real better than 140dB), and the only thing my Gainclones add during playing the test signal is a 3rd harmonic which isn't higher than the harmonics coming from the DAC. See ? it can be done.


So Mani, I did my best to trash this amp, which most probably is totally unjustified for the normal situations. Even in your situation it may not be justified at all. But at least you now may have a reason to not spend 14K GPB.

Peter

PS: You can always try to dig up similar figures from the Magtech. :)

Hey Peter, thanks for your thoughts. I know you're busy, so appreciate your spending time on my 'obsession'.

I don't think 130W into 8 ohms is a problem - the Magtech is 500W into 8 ohms.

Actually, I think the slew rate is 31V/0.33µs = ~90V/µs. Now the Magtech operates at plus/minus 92 volts and is quoted as having a slew rate of 500V/µs. The operating voltage becomes important when considering an amp for electrostatics because these speakers are 'voltage operated devices'.

Now this is where I'm getting a little confused. In the recent Stereophile review of the 710, John Atkinson ends his measurements by saying, "... the Soulution 710 is definitely one of the best-measuring amplifiers I have encountered." I've attached some of his measurements - any comments about these?

Incidentally, the Magtech's noise is also rated as, "More than 110dB below rated output."

Yeah, but I need an amp that will drive my Quad 2905s 'properly'. On paper, they're pretty benign. But their impedance dips sharply at the frequency extremes and I'm sure that this is why they sound woolly low down and too smooth up top with most amps. But the Magtech seems to cope very well.

I think with your help, I'm on the road to convincing myself to buy another Magtech... and save >10K UKP! Thank you!

But any additonal thoughts (from Peter or anyone else) would be really welcome. I have to make a decision as to whether I buy the Soulution pretty quickly.

Cheers, Mani.

A slightly different topic, but I think I'll keep it in this thread...

Yesterday, I was testing some other old amps that I have lying around, and I ran out of interconnects. I went down to the basement and pulled out the only pair of XLR interconnects that I could find - 'PureNote Epsilon' interconnects. These have ultra-high purity silver conductors housed in a stiff a metal sheath. I bought these ICs years and years ago, tried them, didn't like their forward/bright sound and put them away for I guess 8-9 years! I convinced myslef that silver was a bad metal for audio. But you know what, they sound incredible now, with much better low-level detail than any other ICs I have. And they just sound 'faster' - better transients and overall boogie factor.

Does anyone have any idea as to why a silver cable might sound 'faster' and more detailed than a copper cable? I'm not sure I buy into the simple "better conductivity" argument, because you can always just increase the amount of copper in a cable for significantly less cost...

Mani.

Hi Mani,
have a look at this amp: http://www.audionet.de/main/elektronik/endverstaerker/max/charakteristik/page.html?L=en
I did not heard it but they have a very good reputation to have an excelent value for money. I like their philosophie and this is the amp I would look first for, if I would try to finish the search for an high end amp. 400W into 8ohm and a bandwidth of 0-500kHz should be fast enough, plus a dampinfactor of about 10000 should control every speaker. New "only" 12500€ and used it goes for about 8000€. Here you actually find one for 8300€ 3 years old: http://www.audiomarkt.de/_markt/
Greetings
Adrian

Hi Adrian, thanks for this - much appreciated. I've looked into Audionet before but have never heard any of their gear. I remember the owner of Wilson Benesch recommending Audionet with my then Chimera speakers, which were hard to drive. I'm not sure how easy it is to get hold of, and sell if/when necessary, an Audionet in the UK.

From a purely technical point of view, I guess what I'm looking for is the following:

- high voltage output (is there any other good audio amplifier that operates at 90V and not 30V?)
- at least 100W into 8 ohms
- power that doubles with every halving of impedance (down to at least 2 ohms) - to keep control at frequency extremes with the Quads
- ~500V/µs slew-rate (and therefore high bandwidth) - although many people would say this is 10 times higher than is necessary...
- low THD* at 100W ouput
- something that won't depreciate massively and that I can sell if/when necessary

* Unless it's a true single-ended output amp. You see, you can theoretically reverse the speaker polarity and use the amps HD to cancel that of the speaker, which should have a similar HD spectrum to a single-ended amp. But, I've never come across a single-ended amp that has all of the other requirements above.

Any thoughts anyone?

Mani.

Briefly :


I didn't look it up again, but I think the amp bears 31VRMS. If I (again) don't make mistakes, this is 42V-pp (from bottom minus to top plus).
Slew rate (I think), is measured from zero to plus (or from zero to minus, but that shouldn't make a difference; btw fall time (opposed to rise time) can be different again). So, 42-pp would be 21V-p (from zero to top only). And now *that* rises in 330ns ...

If this is wrong and slew rate would be measured from bottom minus to top plus, then my figure has to be doubled. So, then it would be 133V/us. You can always count on me being wrong. :)


a. This is not related to bandwidth, but the sheer being able to follow transients;
b. 10 times higher than necessary is the common electrical engineer's rule.

Ad a. If the frequency of the high transient (think synths) becomes so high that the fall time is longer than the next rise is to start, yes, then it is related to bandwidth.

An additional notice : the NOS1 also is rated 10 times higher than necessary; Only last week I tried with 2 times only, and it didn't sound good anymore ...


I never understood Stereophile (DAC) measurements. John Atkinson is "able" to judge a random 16/44.1 CD player or DAC to be not worth while for even playing CD's, when the dynamic range is worse than 130dB or something. Well, I don't know what dither he applies around the player (or expects it to be active somewhere) to achieve something like 130dB which inherently has 96dB only, but as I said - I just don't understand it (and looked HARD for the explanations, which I can't find anywhere).

Peter

Shouldn't have an high power amp also have an high output voltage? Because P=U*I,  and I=U/R so P=U^2/R. R is constant for the speaker. Hence you need more power to have a higher output voltage.
Also if you think it the other way around: An Amp deliveres an high output voltage but does not have the power to deliver the current, it would make no sense to have the high voltage.

Does anybody know how to calculate slew rate from bandwidth and vice versa? (My preamp has bandwidth of 0-1.5Mhz :showoff:)

Corrections: Ups... It must be Mhz not Ghz haha :)

I read an article once, where it was said there is a connection between slew rate and bandwidh. I think it must.

and here it is...http://www.amplifier.cd/Verstaerker/Wald_und_Wiesen_hifi_Verstaerker_Test/what_are_open_loop_slew_rate_bandwidth.htm

I do not have the time to read it myself at the moment, I should work now....

If only! My Quads have pretty much 4 ohms in the bass, 8 ohms in the mid, and 2 ohms in the treble (falling to 1 ohm at ~18KHz). The current required in the treble will be 4x that of the mids (8x at ~18KHz). Of course, this assumes all sorts of things which I'm sure aren't really valid... reactive vs. capacitive loads, etc.

Another complication with my Quads is that being electrostatics, they are not driven by current but by voltage. The Soulution outputs 31V RMS, which I'm sure is fine for 'normal' magnetic speakers. My Magtech outputs 62V RMS, which the Quads should prefer.

EDIT: This voltage I guess is dependent on the operating voltage of the amp. High voltage parts are more expensive, so it's not in an amp manufacturer's interest to have a high operating voltage... unless they were designing an amp for electrostatics  :)

Mani.

Mani, regarding the silver interconnect question you raised, I have also done a lot of experimentation over the years with silver cables.  Initially they have typically wowed me with their sense of speed, greater detail, etc.  But then after listening for a few days I end up concluding they are too thin and lacking in tonal balance.  And I go back to a copper based cable (or at least a hybrid).

I remember George Cardas telling me that his conclusion after much experimentation with silver was that they were like a beautiful woman with no soul.  YMMV.

I love it!

I'm sure many of us have had a similar experience - I know I have. But this simply goes totally against the 'human bias' and 'double-blind' argument. I mean, 8-9 years ago, I knew I had silver ICs in place, I knew they were 5x the price of my copper ICs, and yet I still returned to the copper ICs, for much the same reasons as yourself.

Today, the silver ICs still sound 'thiner' than my copper ICs. But for the first time, they sound more right. Why should this be? If I had to guess, it's because my new mains circuit has gotten rid of all the hash that in the past has been accentuated by the silver ICs. Just a guess...

Mani.

Up to some degree, sure yes. I mean, in order to suffice a certain bandwidth, first the slew rate has to be sufficiently high to not let mix up the subsequent "samples" (but notice this is about analogue). When this is met, next the slew rate can still be very much higher, while the bandwidth does NOT increase. Something like : nice that we have an overly high slewrate, but in order to really comply to that bandwidth which is "implied" by the slew rate, many more things have to happen. Like inherent bandwidth in other places of the device, it will be more hot (and burn without special precautions) and probably a few more things I don't know myself. Anyway, if you look at datasheets of devices with slew rate and bandwidth, you will see that both are totally unrelated, BUT, a device with bandwidth of 200Khz for sure will not have a slew rate of 1uV/uV because that will allow for a frequency of 1 (I guess). So, when you work this out, the 200,000 needed implies for 200,000uV/uV which is 200mV/uV at 1V output (am I doing this right ?). So, for e.g. 30V this takes 6V/uV. Is the needed bandwidth 1GHz ? than multiply this by 5. Now we have 30V/uV and we come close to reality.
But we are not there, because any transient will have some sustain (otherwise it's nothing), and don't ask me what to add for that. But it will be something like 1/1GHz sec to be realistic. Now things change a bit, because that 1/1GHz already consumes the time it is given, which makes the rise time infinitely high. Also the fall time has t be added to the lot.
After this has been done, the logical conclusion should be that an original 1GHz bandwidth decreases to less because of the "overhead" needed. Thus, rise time consumes, fall time consumes, and the sustainment of whatever is the length of the pulse also consumes (should be a wary formula on the latter).
One can maybe also say : multiply whatever you think the needed bandwidth is by 10 (only for the slew rate number !), and you're good. But this is from another angle, and a not much official one.

Peter (hoping he's not too much off on this all)

Referring to amps, I think 'telstar' had an interesting take on things. His feeling was that you need 1V/µs for every 1W of amplifier power (presumably at 8 ohms). My Magtech amp is 500W at 8 ohms, and coincidentally has a slew rate of 500V/µs. The Soulution is 120W at 8 ohms, so I guess all other things being equal, it 'should have' a slew rate of 120V/µs... no?

Does this make sense, or does it just confuse things further?

Mani.

Mani,

What about Spectron class D amplifiers to drive your Quad?. I used it with big SoundLab A-1 electrostatics and worked fantastically well.
Now I´m using the Spectron as monoblocks to drive my Von Schweikert VR-9SE and I´m very satisfied with the smooth and detailed sound, terrific bass and huge soundstage. The Spectron works in perfect combination with the NOS1.

You can get the Spectron Musician III MK2 for around $3.500 (at today currency rates that means less than 2.500€ or around 2.125 UK Pounds) and you can buy two and get them as monoblocks.

Here you have some technical information:

http://www.spectronaudio.com/tech1.htm (http://www.spectronaudio.com/tech1.htm)

here as well:

http://www.spectronaudio.com/musicianIII.htm (http://www.spectronaudio.com/musicianIII.htm)

and here as monoblocks:

http://www.spectronaudio.com/monoblocks.htm (http://www.spectronaudio.com/monoblocks.htm)

I hope it helps, Juan

Hmmm... I have a slightly different take on Soulution. I heard 700 monoblocks and 710 stereo amp a few times with Magico Q5 and Q3 in that order.
First of all, I am not sure why the two are often shown together as I don't like the combination at all. My theory is that damping factor on Soulution is credibly high (> 10,000 per spec sheet). With Magico, I don't think I ever heard a drum that start and stop as quickly in real life. Listening to it for awhile, I felt that the sound was rather unnatural. I heard Quads a few times but not well enough and don't know if it would benefit from high damping factor or not. Magico Q3 sounds more natural to me with Lamm M2.2 (damping factor 82 if I remember correctly). On the other hand Lamm M2.2 could not quite control dual 12 inch Eton woofers in Usher Be-20 quite as well as would most likely benefit more from amp with more damping factor.

Soundwise, this really depends on the person. I find Soulution hyperdetail but in a good way, not very fatiguing but I really like my music a bit more sugar coated. Vocal music on Soulution just did not quite do it for me unlike Lamm M2.2. So I hope you will have a chance to take a good listen to Soulution with Quads yourself before making up your mind. It is definitely an excellent amp but not with a sound that is universally good for everybody.

So you can calculate the minimum slew rate from bandwidth but not the maximum. The calculation should be:
Maximum Frequency fmax=1.5 Mhz
Maximum output voltage Vmax=30V
Minimum Slew Rate [V/us]= fmax*Vmax=1.5MHz*30V=1.5*10^6[1/s]*30V=1.5[1/us]*30V= 45 V/us
It has to be considered, that the amplifier has to change the voltage from peak to peak in half of a period. So the result must be multiplied by 2.
Makes a slew rate of 90V/us
If the maximum voltage is given in RMS and not PP, which is the normal case, you have to multiply by 2*SQRT[2].
The minimum slew rate would be then 254,5 V/us.

Well, at least I made a mistake here :


This, of course, should have said 1MHz (because I wanted to calculate that - and did).

But


I don't see any of the subjects I brought up in your math ...


Nope. This is not difficult for an amplification because this is a "swing". Maybe not exactly true for a square wave form (what this will be about), but if the length of the high voltage sustainment is short enough (the highest frequency = the highest bandwidth) it comes close to that. But since you leave this out of the equation anyway, it can go in all directions ...
It is to be from zero to peak and back. If this weren't so, what would be "fall time" ? it would be the same as rise, but in the other (voltage +/-) direction.

Peter

I used the unit V/us becuase it is more intuitive. I derived this based on the definition of the slew rate, which is the rise time from voltage "a" to voltage "b" in a given time. If you start with this definition, the maximum frquency and the maximum voltage is directly linked to the minimum slew rate.


It has nothing to do with the amp or how the total signal could look like, it is just math. If you have a sine, and that is what we always have no matter how the total signal looks like (because every signal is just a linear combination of sines), and this sine is at the maximum frequency your amplifier can handle (in this case 1.5MHz), the steepness of the curve, in other words the slew rate, you need to reproduce this sine is dependent on the "voltage change" per "time" unit. If you use one period as the time the voltage should change from Vo=0V to Vmax=30V, you use a number that is only half as big as what is actually needed.
I have made a scetch. You can see that to reach the first maximum of the sine you have 1/4 of one period. This maximum is at a voltage off pp/2. Hence your slew rate is PP-Voltage/2 times 4*Maximum Frequency or simplified PP-Voltage times 2*Maximum Frequency.

Hi Adrian - You make a nice difficult outlay of this !

I think if you go this direction, it is waaay too simple. Not that I would be able to make the story complete (on the real math I mean), but if you talk like this you'd have to give definitions for overshoot (limits), allowed ripple and what not, and I am not sure it works like this for the functional aspects we are trying to talk about.
If you, for example, want to talk about the as good as possible representation of 20KHz (assumed that is audible or at least senseable), you'd have to start with what comes out of the D/A converter. You'd have to start with no filter at all (and the amp representing that sh*t because it is good (on the slew rate)) vs. common filtering as needed and applied (I'm not talking NOS1 now), that not demanding anything from the amp (because it's stupid 20KHz sines always without real "impulse" data).

What we have been doing/trying, is approaching it the other way around : the amp has a bandwidth, and what does that mean without context. I think this is useless, because a figure comes from that which won't say whether it is good or bad for our purpose.

Theoretically one could start off with 30KHz as a "senseable" frequency because it easily can be there in properly done HiRes. But use 50KHz to be on the safe side, although I still must see a properly done HiRes which can represent that. This is the easy one. The more difficult one is 50KHz of impulses (On/Off sound) because that theoretically can exist too. Synthesized at least. But, stupid, plus I don't believe much in the "senseable" thing. So, maybe better stick to 18KHz as a realistic On/Off which can be audible for some. *Now* do that math ...

Don't forget in your math to incorporate the distance between the pulses, because one sample space in between them will physically be impossible and it will become a mess (it would need infinite rise and fall time). But, the better the "slew rate", the less soon it wil become a mess, or IOW the more close the pulses can be without disturbing eachother.
Once you are done with it, you will find to have done it without reason, because your DAC will never spit out those pulses, because the filter will have been ahead of it all and will have flatten it (to normal sines). Not so with the NOS1, but now there's the problem of images at higher frequencies. Aha. How high ? at what level ? and they sure are at higher frequencies ...
The higher the bandwidth, the more is let through. The lower the bandwidth, the more is nicely filtered out, that is, while in some frequency band (like 200KHz) the amp will distort. At what level ? dangerous ?

There is all a bit more to it.
Regards,
Peter

It should be that simple because it is just an estimation of the minimum slew rate. The real slew rate must be meassured. But I think it is good to calculate a lower limit of what is to be expected from the amp. The real slew rate should be always higher than the calculated number. So we are on the safe side.

If the amp should reproduce a perfect sine wave at a certain frequency, the slew rate must be higher than estimated, because the sine has a maximum slope at the point of zero crossing, that is slightly higher than what I have assumed.
I think it gets too complicated if you incorporate other equipment and it is not necessary. There are simple boundary conditions. The maximum Voltage and the maximum frequency. If you want to fullfill this boundary condtition, the amp must have a slew rate, that is high enough to reach the voltage in the expected time. The amp could have a higher slew rate but not a lower, otherwise the datasheet would say something wrong.

I am not sure what you mean by the on/off thing. You mean you have an outputvoltage of 0V and than suddenly you switch the siganl (music) "on" and imedeatly "off" again?
If this would be so, the shape of this pulse would be determined by the bandwidth you have. For very short pulses you would need very high frequencies. If your amp can not represent this frequencies, the sharp pulse would get flatter and wider. It depends of the frequency content of the puls, if anything will come through. The basic principle is, that no matter if we have digital data or analog data, the slope of any puls should be stricly limited by the bandwidth of the equipment. This also should be true for the "resolution" the amp has, to make it possible to differentiate between two pulses, which are seperated by a very small time. If the pulses are so close to each other that it crosses the maximum frequency your amp has, or what ever hifi equipment you want to look at, it will not be reproduced as two peaks. It will be smeared and maybe reproduced as one peak or it will not be reproduced at all if the bandwidth is too small.
There is this philosophie of having a high bandwidth, which is much higher than what you can hear. Reading the article I mentioned earlier, I would say this high bandwidth is a byproduct of getting the amplifier fast to get the negative feedback work well. Having higher bandwidth also should prevent phase changes in the "used" frequency range.
For the math so far, nothing should change, because we only have used basic principles that hold true under any situation.

Hi Mani,

in the German HiFI Magazin Stereo they tested the 710 in the beginning of 2010, and a Acoustic Arts AMP II MK2 a couple of month later

(http://www.accusticarts.de/pages/de_amp_ii.html)

The 710 was by a very, very small margin superior but the Acoustic Arts AMP II MK2 costs new appr. € 9.000,00 only.

best

Joachim

Hi Juan, thanks for the suggestion. Well, they certainly look interesting... and they're capable of driving a 0.1Ω load!

But if going the class-D route, I kind of feel a slight loyalty towards Hypex. I already have 8 of their UCD700HG modules that I used to use to quad-amp my previous speakers. And the yet-to-be-released Hypex 'Ncore' modules look very interesting (http://www.hypex.nl/docs/papers/ncore%20wp.pdf).

But maybe I need to re-evaluate this loyalty...

Mani.

I've read similar comments from other people. I haven't heard that particular combo but did hear the Magicos being driven by a pair of Spectral amps at the Munich High End last year. And I can't say that I was particularly impressed by that combo either... but then again, I wasn't impressed by anything there!


I think I know what you mean. When I listen to a real instrument, I want to be able to 'hear' the size of the instrument being played. Too often, instruments like violins sound as if the strings have been placed on 2D MDF, rather than a gorgeous 3D waxed body.

BUT... ultimately, I'd rather have a 'thin' sound with 'accurate' timing and touch than a 'blossomed-out' sound with just beautiful harmonics - I mean, I'd rather listen to Keith Jarrett playing a cheap stand-up than me playing a Steinway!

Mani.

Just in case here you have a nice review of the Spectron:
http://www.positive-feedback.com/Issue44/spectron.htm (http://www.positive-feedback.com/Issue44/spectron.htm)

Juan

Hi,

The combination 710 stereo amp with Magico Q5 or Q3 (metal housings - no resonances from the casing) is a very fast, super detailed system with an unheard fine resolution. You will not hear this fine resolution with any other speaker (except YG Acoustics).

If you like a fast, clean, detailed, analytical sound this is the combination. (preference Jazz music)
The most musical power amp is the Dartzeel NHB-108, but with 100W at 8 Ohms only. (favoured by many active musicians)

If you like a warm sound, tubes is ...............  !

Peter has an amazing, warm sounding system with a floor shaking bass.

best

Joachim

I like to add to this that Joachim has more experience than listening to Magico's on some show. So, FWIW in here, I think we can very well trust his help.

Peter


PS: Joachim, it seems offtopic (but it is not) ... what about your relocating ?

And except the Von Schweikert VR-9SE  ;):

http://www.stereotimes.com/showreport05cespage6.shtml (http://www.stereotimes.com/showreport05cespage6.shtml)

Hi Joachim, yes the Dartzeel still holds a lot of appeal for me. But it performed pretty badly on John Atkinson's bench, so I'm wondering whether it simply has a 'nice' distortion characteristic that makes it sound euphonic. If so, this isn't really the route I want to take... for now.

What I really want is to be able to hear the NOS1 with as little added by the amp and speakers as possible.

Mani.

Ah but none of these can produce a 1KHz square wave like an electrostatic can. Electrostatics still remain the cleanest speakers I have heard...

BUT... they're a right royal pain in the ass to live with.

Mani.

Hi Mani,

please see

http://www.dartzeel.com/PDF_Files/NHB108_HiFiPlus_Iss_41_for_web.pdf

Try to get the Soulution 710 or any other amp for a test into your listening room for one day and then decide. This is the only way to avoid a false investment.

An amplifier with the value of the Soulution 710 is a lifetime investment !!!


joachim

Hi Mani,

now we are in the academic circle.

We are listening to reproduced music. Measurements can't replace listening sessions at home.

I know that Quad owners likes the typical sound over all and that is ok. But in the meantime there was a certain evolution in speaker, crossover and driver design. See the new drivers by YG Acoustics, CNC machined out of a full metal aluminium block. Unbelievable!!!

Everything depends on the component which you like most.
If you like the Quads, then you have to build the system around the speakers. If you like the sound of tube amps then you have to build the system ............... .

My request, please test the Soulution 710 at your home. I would like to read your opinion, which would be interesting, because we read the reviews from HiFi magazines until now only.

Joachim

Well, all that I can say on this regard is that I lived for around four years with the big electrostatics SoundLab A-1. Of course the sound was very clear and big but in my experience it was a little diffuse and a little too big. I had them in a room of 70 square meters.
When I changed to a smaller apartment in downtown I couldn´t take with me the A-1 and then I looked for the same clarity and soundstage but in a more appropriate size. What I found was the Von Schweikert VR-9SE and what I can say is that they have at least the same clarity than the A-1 but with much more precision in the delimitation of the sound images which in my opinion contributes to give a sensation of even more clarity. The soundstage is also huge and I can see here some similarities with an electrostatic speaker because of the way this VR-9SE are built with a rear ribbon following the principle of what Von Schweikert calls ACOUSTIC INVERSE REPLICATION: 
Additional research led to my further discovery that recording microphones encode the musical signal with their overlaying pickup response patterns. After making a series of recordings, using several different microphones, it was obvious during playback that the mics not only had tonal differences related to frequency response errors, but also created different types of imaging patterns. The perception of depth and space was not only dependent on the recording environment and mic placement, but also on the mic's off-axis polar response. For this reason, I decided to engineer an adjustable ambience retrieval system radiating from the rear of the VR speakers, in able to recreate the space and depth heard in the concert hall when the spaced omni method of recording is used.
 Thus, a correctly designed speaker system should project the inverse of the mic signal, acting as a decoder to translate the original sound field. I have termed my design for this decoding as Inverse Acoustic Replication, and the Virtual Reality series of designs was developed from several important concepts related to microphone pick-up patterns. These concepts are based on the consistent phase/frequency relationships in the polar response pattern of the mics, which was later reverse engineered into the VR speaker systems.

For the ones interested I recommend to read the complete article:Speaker Design Theory by Albert Von Schweikert (see beneath the VR-9SE Specifications): http://www.vonschweikert.com/techspecs/5.php (http://www.vonschweikert.com/techspecs/5.php)

At the end, and in my humble experience, the electrostatics are not the last word in clarity, not always at least, of course it depends also of the rest of the system. Sound is also a personal thing and you can perceive it in a different way than me. If the Quads, or any other speakers, give you what you like, then they are the perfect speakers for you, and that´s what counts.

Juan

That is 100% correct!!!!!!!!!!!!!

Yes, I agree. Even though the Soulution is a private sale, the seller has agreed to bring it over to my place for me to try before I commit to buying it.

However, like many people here, I usually have to live with something for a while before I 'know' whether it's for me or not. So even a home demo for an hour or so isn't going to be totally conclusive.

Mani.

Juan, I think this is where the genius of Peter (Walker, not St) comes in. He found a way to convert a 'large' panel speaker into a point source. Their sound, especially from the lower mids upwards, is absolutely pin sharp.

Mani.

Of course, this was said slightly tongue-in-cheek. However, there is a serious connotation.

PeterSt spends years on perfecting his DAC. He gets it to a point where it can pass through the signal totally unadulterated. Square waves are not converted to sine waves by the massive sigma-delta filtering of most other DACs. The output stage is massively fast. The recommendation is then to use ultra-fast amplifiers to preserve the signal. And then what do we do? We feed this amplified signal to speakers that haven't got a chance of replicating the signal exactly...

In fact, I'm convinced this is why sigma-delta DACs actually sound 'OK' to most people on the majority of systems. They are just doing to the signal what the speakers will do anyway - turn squares into sines. And what does this do to the sound?  Well, just listen to a sigma-delta DAC... :)

Furthermore, I'm convinced that the 'time domain' is far more important in audio than the 'frequency domain'. Is there another speaker that can match electrostatics here (see attachments)?

But look I agree with you all. If you have a pair of speakers that you like the sound of, then that's great.

Mani.

Wow Mani. Now you have just been ahead of me;
I am preparing a topic about these kind of graphs, but really ... lack of time.

Later ...
(but you are so right)

Yes, I am also very familiar with Magico quite a bit more than at show or showroom. Got Q3 in my living room for almost 2 months now :)

Hmm... personally, I don't give much value to measurement per se. My Playback Design MPS-5 also did not measure well on JA's report but it sounds great. A great concert hall is a great concert hall because it has its unique attribute of sonic signature, not because it is close to a perfect anechoic chamber. PUt any great orchestra in there, you will still hear its sonic signature.  I would value stereo equipment sound quality as being life like, sounds great or whatever over a perfect measurement any day perosonally.

Show environment is never ideal, unfortunately. I think any system that is capable of showing 30-40% of what it can do in an ideal environment at a show is already quite a feat.
Recently I went to a major hifi show in Hong Kong and I did not find any room that I like over my own listening room and there were plenty of big toys there, Wilson Alexandria, Rockport Arrakis, Avalon Time etc etc.
I heard Spectral with Magico V3 in a good environment that was spectacular.



I think this is where analog still trumps digital in spades. You get this nice 3D body of the instrument so easily. Now, it is unlikely that analog has more resolution than digital especially high rez or DSD. Heck, I could hear this even on vinyl that was transferred from digital recording more so than CD itself. My theory is that this is a part of analog distortion that somehow just give a more realistic and pleasing presentation. True or false, I would not really know but I'll take it :)



Heh heh, this is one of those thing. One man's perfect amount of blossom is another man's way too thin and lean.
One man's perfect bloom is another man's bloated and overly warm. Me.... I prefer Kissin on a nice big Steinway rather than myself on a little upright :)

Yes, ultimately me too.

However, right here, right now, I want to hear the specific character of the NOS1, with as little changed as possible. Once I've got this done, if the sound doesn't suit me, then I'll 'tune' it to something that does.


I'm taking the red pill - I want to hear how deep the NOS1 rabbit-hole goes...

Mani.

My view (if not known by long) :

First of all, measurement tells all. Yes, I know look like a stupid engineer without thinking, but mind you, ever back I was not like this. I'm not sure I was from the leage "a nice tube sound will improve the sound", and all I know is that I ever hunted for "being able to measure". Even the stuff which can't be measured, I made measureable. Not only for sports, but merely because it would be non-sense not being able to measure what we hear/perceive.

Next thing, is that I *know* that when things measure better, sound will improve. It *will*. But this is a most dangerous thing.  I mean, if I measure one device and that measures better than yesterday (because of some tweak, whatever) it is not said at all that the whole system now performs better. Read back on Mani's post with the little graphs. That really tells it all. Thus, improve on the impulse response on one side, and tear up your speakers diaphragms on the other (so to speak). That did NOT turn out for being the better (solution).

For this reason the real moral is to have the reference. And here again Mani hits the hammer on the nail, because he knows that at least the NOS1 is such a reference device. I know that too, and only if one doesn't trust that things will become more difficult.

By now I know that my amps (the GainClones) are a reference just the same. This is 200% important, because now all what's left is the speakers (ok, assuming the software does a nice job as well, and which I *do* assume these days).
While there's now only one part left in the chain, it is theoretically the most easy to improve the chain, because it's only about the speakers. Not that I'm working on that though ...

I can't emphasize enough that everone who is using a preamp or even single resistor to attenuate the volume CAN NOT know what he is talking about. He may think he knows, but all he does is implying measurement results which WILL look totally wrong. What's the bet ? 1000 ? 10000 ? I am ready for it.
Besides that you will loose the bet, you will be the most sad that you thought you were listening to a fine system, while actually you were listening to a bunch of filters, them masking all the other stuff being wrong. The test is so easy : take out your preamp and notice that the sound gets worse. In that case, it *is* worse, and something *is* wrong.

But then, don't even attempt with an OS DAC. You really won't know what you will be listening to.
Ok, I will attach two graphs, because I made the graphs anyway. No real text. Not yet.

Both graphs are from the same playback file. Same scales (and both cover 5ms of music data, though they don't start both at the 0ms point which does not matter).

Look at the mouse pointer in the second graph which is key to the distortion in the first. Notice that there are two more of these sneaky points (the first graph shows 4 of them in total).

I don't need to ask you which is which, and hopefully I also don't need to ask you which one you'd prefer for listening. But I can guarantee you (by 100%) that any DAC not being the NOS1 will let you listen to the graph NOT of your choice. That bet too is on.
While this is the analogue output from the DAC, I just could have taken it from the LS outputs from the amps. It most probably will look the same, although I never tried it. Point is, when the slew rate of the amp is too low, very nasty things will happen, up to a an almost flat line. Well, looking at the graph you do NOT prefer, that might just as well work out for the better, right ?

Now, let loose your imagination on this.
I have prepared dozens more of these graphs. For later ...

Peter

The ROOM is the thing!!!!!!!!!!!

Room acoustics and placement of the speakers is the top priority and have the most effective result.

I visited a highend freak with the best McIntosh equipment you can think of. His room has the dimensions 5m x 5m and hard walls all around. Right side glass walls, back side a board with glass doors etc.
The sound was horrible, no focus, booming bass etc.

With a very good acoustic you can save a hell of money in hardware.

Hi Mani,

what is your motivation / reason to replace your Bernings?

Is it the highend drug / virus?

Joachim

Joachim, my Berning 300B is not used to drive my speakers - it's used purely as a headphone amp. I hardly ever use it and have decided to put it up for sale.

Your question should address my motivation/reason to replace my Sanders Magtech amp, which I've said I really, really like drving my Quads. Well, I am NOT getting rid of the Magtech - it's a phenomenal amp.

What I am looking to do is replace the Rotel Michi amp in my study (where I also have a NOS1 and the smaller Quad speakers). I could take 'the path well trodden' and buy another Magtech. Or I could take 'the path less worn', put my current Magtech in the office and buy an even 'better' amp for my main room.

So in a way, you could say that it's the highend drug/virus at work. Although maybe the 'highend' label is not accurate. If I can get bridged gainclones to work well, I'll happily go with them over a Soulution or DartZeel... hardly a 'highend' solution.

Mani.

Hi Mani,

from my experience over 30 years go straight to the top end in the second hand market. (the maximum amount of money you are willing to invest)
and buy it.
This saves you a lot of money, because the other solutions are always intermediate and you have to sell the "old" components with losses.

The decision is hard / difficult but the most economical.

Joachim

Yes I tend to agree. That's why I have two NOS1s  ;)

Of course, getting the best value for money is a big consideration (again why I have two NOS1s). But for me, like many other people here I'm sure, time is a big consideration also. It takes me an inordinate amount of time to think these sorts of things through. Luckily, it's been summer and I've had a lot more downtime than normal. But that all changes in a week or so, and I'm kind of keen to have at least made a decision on the way forward before then.

Mani.

Peter, while I appreciate your standpoint basically about having system that is utterly transparent to the source, in this case digital recording, I feel that deep down, this is a losing battle.
Unfortunately, majority of commercial recordings available, are not exactly made with absolutely flat and transparent audio system in mind. The sound was already tweaked, altered, manipulate with multi tracking recording, equalized to death and playback during editing through what I would considered to be inferior equipments and is aimed at mass market consumers with average audio playback system.
Only a small percentage of recordings are truely audiophile, meant to be played with true highend system.
Personally, I much prefer to listen to Kissin, Arrau, Brendel, Perahia etc recordings through mainstream recording company rather than John O'Cornor, Arthur Pizarro and the like through audiophile recording as their music making is so much better.
For me, I would rather have a stereo playback that would let me enjoy the music without the equipment getting in the way rather than trying to hear everything good and bad that sound engineer managed to add. I love Zimmerman's Chopin Ballades recording on DG very much  and would love to kill whoever that recorded the session for ruining the sound of the recording. However, since I only am aware of one version of Zimmerman's recording of this piece, I rather try to enjoy the music rather having all the bad sound screaming at me in full daylight. When I have access to all the great music that I love where listening to a totally transparent system does not make my easr bleed then I shall strive for those system. Till then......  :)

I can not let you away with this :) Why should on the one hand meassurments tell everything and than if you use a preamp, with meassurements that say that this preamp has such low distortion, noise and high bandwidth that you just cannot say there is something filtered out or added you will ever be able to hear, make things worse?  It is quite the contrary. It gives the signal comming from the dac voltage gain and lowers outputimpedance. Plus it is an easy to drive load for the dac. If you use a digital volume control you will always have a 20-40db higher noisefloor because you can never listen at full gain. And just because not any dac is designed to drive a power amp directly, there is something wrong with it. It depends on the design goals you have. There are more variables than producing a perfect square wave and to have a good impulse response. It is nice for sure but these kinds of signals never occur in real music. So, it at least can be doubted how important this realy is. It is not right to judge the whole concept of a dac or any system just by one or two parameters. And it will not work. You have to listen in the end.

Hi Adrian,

I just removed two posts of mine. Didn't fit in the atmosphere of Phasure.

All I'll say now is that I dont agree much with anything ...

Peter

Hey Peter, you must be working (too) hard on something?

I read your posts before you deleted them, and tend towards your way of thinking. However, I think we've got be careful not to alienate anyone who doesn't.

I wonder if your comments would be more suitable in a thread/area dedicated to the optimisation of a whole system that uses a NOS1 specifically as its source? But then again, we don't want the forum to become one for just NOS1 users... although, quite frankly, I have no idea why anyone who can afford one hasn't yet bought one...

Mani.

At the momen I can't. But it wont be long until there is a steady and higher money flow to my bank account. Then the fun begins :)
My last investion was a CD Transport, a DAC and a  Preamp. It all was used...If I would have combined all the money I also could have bought the NOS1 but then I would had nothing to compare to. I just need the extra money for the NOS1. Then there would be several options how to use it in my system or build up a second one. There are only two things which could come in the way before buying the NOS. I have the itch for building new speakers and a new poweramp would be nice. But sooner or later the NOS WILL come.

Ok, nontheless it would have been interesting to discuss about it. So if you have the time sometime to share your meassurments and your thoughts, it would be nice.

Hi Mani,

any news on the amplifier front.

Joachim

Hi Mani,

I'm probably pretty late joining this topic but my 2 cts would be for a second setup to go for a boutique kind of amp, SET or OTL (I used to drive my quads with an Aitos 803 OTL) to create a whole different musical experience.

If you would like to stay at solid state, another brand you might consider is KARAN. Soulution and Dartzeel may make the 'best' high-end amps according to many magazines, but for sure they have a the 'best' marketing, which also makes them extremely expensive.


- Quint

Hi Bigear,

I feel you have a good system to run your NOS1. But your signature is so short. May be you may like to expand.

Praphan

Hi Joachim. Ahem...

Well, I didn't buy the Soulution. Actually, I was going to and it was all arranged, but then the seller pulled out a couple of days before the amp was due to be delivered. Apparantly, someone (the UK distributor, I think) phoned the seller and told him that £14K was too cheap for an amp which now costs ~£30K in the UK (due to the Swiss exchange rate). If it were the UK distributor who made the call, then this would just reaffirm what I think about the whole hifi industry... But really, I should be thanking whomever made that phone call - £14K is just a crazy amount of money to be spending on an amp (let alone £30K!).

I'm currently in talks with Bert (from BD Design) to see if he could make something up for me, based on his gainclone boards. I'm really eager to pursue this route. The only issue we're facing is finding nice enclosures for the amps - it seems these are not so easy to source when considering very low volumes (i.e. just 2 units).

But I'll let you know what transpires...

Cheers, Mani.

Hi Quint. Wow, these look gorgeous. Very interesting philosophy too.


I've really set my mind on Bert's amps for now - I've just got to hear what a powerful gainclone sounds like with a pair of Quads (I wonder if it's ever really been tried before??).

But thanks for both suggestions - really. This is what I love about the Phasure forum - like-minded people trying to help each other.

Thanks again.

Cheers, Mani.

Hi Praphan,

I added some to my signature...

Cheers  :grin:

What makes you think they haven't?

I haven't, but that's because no matter how hard I try to justify it, it still comes out totally beyond even my excellent justification ability. And I'm afraid it always will.  :(

But I bet every believer in NOS dacs that knows of the NOS1 and can easily afford it has ordered one (or more:).

-Chris

Hi Mani,

from your activities during the last 12 month I can see that you are  searching for the final "medicine to kill the highend virus". Your weak point seems to be the power amp.

My gear hasn't changed since 5 years and the "highend virus" is dead , except the DAC, which is with the NOS1 the final unit.

There is a nearly identical power amp to the Soulution 710 available from the manuf. Accoustic Arts, the AMP II - MK 2. second hand for € 5700,00 at www.audio-markt.de
or a Dartzeel, also second hand for € 8900,00  from  www.highend-broker.com.
The Accoustic Arts amp has an output power of 2 x 260 Watts at 8 Ohms. The weight is 56 kg!!
The AMP II - MK 2 got amazing reviews, and the Soulution 710 was in a review by a very, very small margin superior only. The value for money of this AMP II - MK 2 is .................. .

Nevertheless it is very interesting to follow your journey to ...... and read your ideas and impressions of the components.

best

Joachim

Hey Mani,

The offer of a return session to come down to mine and listen to my humble system still stands. NOS1 is away for a short break in Holland (apparently having a good time  :)) but when it returns (should be soon) you are most welcome to come and listen to my el cheapo (in high end hi fi terms) gain clones. They are by far the biggest surprise I have had in hifi. Bring your OTL Berning I think it will be very enlightening.

My speakers now have hemp base drive units. Boy have they needed some burning in!!! but now they are really beginning to sing. I have to say that at times I have felt more like smoking them than listening to them  :( - well maybe not but they sound so much better now with a few hours on them (I was warned).

As I posted elsewhere I used to have Quad 57's driven beautifully by a 12watt DNM transistor amp for many years and they sounded great. Very room dependent though (no surprise there).

Maybe you could even bring your small Quads with you and see what they sound like on the end of gainclones.

All the best

Paul

That is a good idea! Mani has one NOS1 in "spare" too.
It would be interesting for us to read Mani's opinion.

Joachim

Not talking about this amp or any other specific one ...

I just tell you and everybody : all reviews are totally moot as long as the standard remains as it is, and it is totally sh*t.

Again I experienced today's standard, last Saturday. I was at some demo, but coincidentally that was hosted by the Turtle Records recording engineers (and I think Turtle Records is a superb label were it for SQ). Quite some other audio geeks and gurus were there.

Maybe not everybody agreed the sound was 100% for various reasons, but there was no way that I could find even 1 person who said it was total-sh*t. And I really tried everybody (could be 40-50 persons).
Mind you, there will be a review about this on CA. Now, watch this coming ... (maybe it's already there, I didn't look).

The sound : total non-sense. TO ME. But not to the others. Not that I could find.

So the funny thing and message is : what review ? what will it tell ? IT SHOULD TELL TOTALLY NOTHING because all audio is used to standards which are completely obsolete.

And for Joachim, better take my listening room as a reference - and even that is totally obsolete as well (since you were there to collect your DAC ever back). You will see ... (2 days before Christmas).

I have so much more to say about this, that I will spend a topic about it. And let's say it was also proven;
I sold an NOS1 right from the trunk of my car. Right there at this event. Let's say I could do that because sometimes it works to talk about sound and how it should be - and can be these days. The man was an engineer himself (but video) and maybe I could bring the real message across.
Later (which was only last Tuesday) I invited him to my place (while normally auditioning or something is not allowed). Just because we had such a nice talk (and not because he bought an NOS1). Well, I hope I can say it on his behalf : he was floored for 5 hours in a row.

So, things have really changed, and no single current review of whatever it is will say one thing. So, be warned ...

haha
Peter

Well said Peter. Last year I sold my record deck (to raise funds for my NOS1 ha ha) and agreed to meet the purchaser at the Heathrow Hi Fi show. I went with my hifi friend David who knows the sound of my system very well. As we were in the car park we thought we might as well go into the show. I had not been to a hifi show for over 20 years.

The sound quality in most rooms was poor. I was not surprised and is why I stopped wasting my time at hifi shows years ago. But the real surprise to me is that the presenters / sellers of the systems and most of the audience seemed to have no appreciation of how poor the sounds were. There was one demonstration in a large room in which it should have been possible to get a good sound. We both agreed that the mid / high was good but the bass was truly dreadful (& looking at the way the speakers were set up not surprising). The timing in the upper bass was just totally ruined and there was no lower bass at all (just a wash of muddled sound). Well OK but the truly astounding thing to me was that so many in the room thought it was good. The Emperors clothes?.

All I know about hifi is that the only things I can rely on are my own ears (and Peter & Phasure of course) - they are the only things in hifi that I trust. There is no way ever that I would rely on any review of any equipment.   

P

Selection of highend music components in general

There are thousands of audio manufacturers around the world and it is impossible to select ……… .
The starting point to select components is an advice by friends and catching informations from online and paper publications and whispers inside the scene.
All reliable authors (TAS, Stereophile, HIFI+, sixmoons, ToneAudio etc) are writing the reviews about the components heard in their own reference room. So these guys can write about the differences compared with their own audio gear. There is a tendency to favour equipment from certain manufacturers due to economical pressure (advertisements).
With all this informations you have an idea/ a tendency for the brand/unit you intend to buy (do not forget the WAF), and then the component shall be tested/listened to in your OWN environment.

Prices /Value for money.
I heard someone saying, that the sales price of his unit is just above the material and working investment and his margin is very small. When we are comparing the interior inside / and the research of a DAC for appr. €3.500,00 with the construction of a Soulution 710 the price difference is quite obvious. But the sales price of more than € 28.000,00 for a Soulution 710 is extraordinary and nobody is buying. (The former German distributor for Soulution Audio is advertising his demo units with a high discount without any success since a year)

The highend manufactures have problems with their sales of the expensive units around the world, except in some countries of Asia. The main problem is the distributor, his margin is extraordinary and the profit for the dealer is between 10% and 20% only (without sales discount).
The only chance for the highend industry to survive is to get rid of the distributors, selling the components via AMAZON etc. for a reliable price (the buyer has a 14 days return guarantee by standard already) and to perform REAL HIGHEND DEMONSTRATIONS during the trade shows around the world. Most of the demonstrations at the Munich Trade Show 2011 were not on the level necessary to encourage the visitors to buy. The lack of quality of the highend demonstrations seems to be a major problem on all fairs.

Joachim

Hi Paul. I very much doubt you system sounds 'humble'. In any event, I definitely want to take you up on this. It looks like I might have some time available in 4-5 weeks, so will PM you to organise.

Yep, happy to bring the Berning 300B OTL, but will really struggle to get the Quads (even the small ones) into my little Honda :)

Mani.

Yes, I would love this. But hang on... this isn't very far-removed from how I've bought my Sanders amp and of course NOS1 DAC. Even my speakers were factory direct from Quad, albeit through a UK dealer (with his margins).

I'm not sure that shows are the only outlet to evaluate products. I know that I myself am increasingly looking to people such as you lot on this forum, with interesting setups, to hear what's out there. Paul is a case in hand. When I get some time, I'd definitely like to visit Peter again. And I'm sure many of the rest of you also...

One thing I know for sure is that I'll have a much more productive and pleasant time doing this than spending time with dealers or at shows.

Mani.