Testing a few amps

[manisandher]

But with the electrostatics, the Hypex is better [than the Pass Aleph 4].

I'd like to retract this statement.

I didn't feel like working today and have spent the whole day reading (currently getting through 'Fooled by Randomness' by Nassim Taleb) and listening to music.

I've also been comparing amplifiers again. The main reason for this is that I've had a couple of offers for my Pass Aleph 4 power amp and X1 preamp (around a third of what I paid for them new 9-10 years ago). Before saying 'yes', I just wanted to make sure that I was doing the right thing. And boy am I glad I did! The Aleph 4 is MUCH better than the Hypex amp. The Hypex amp sounds ultra, ultra smooth... but pretty dead and boring in comparison to the Aleph. It also has much lower resolution - it sounds smeared in comparison. The Aleph is SO musical - it sings. Its top end is WAY more extended than the Hypex. But across the range, it's just better in every respect.

Indeed, I concure with everything that Pedal and Telstar have said - I'd now only recommend the Hypex modules for bass and not for full range duties.

I really don't know what happened when my friends were around a few weeks ago. We all agreed that the Hypex sounded better then. There must have been something seriously wrong with the way I set things up... that's all I can think of.

... a faster amp than Pass designs is needed to keep up with the Quads.

I’ve mentioned before that the Pass has a slew rate of 30 volts/microsecond – in Nelson Pass’s own words: “... which is about 30 times faster than the fastest signal you will ever see, and about 100 times faster than what you will be listening to.”

So how ‘fast’ is fast enough?

Mani.

[Telstar]

I’ve mentioned before that the Pass has a slew rate of 30 volts/microsecond – in Nelson Pass’s own words: “... which is about 30 times faster than the fastest signal you will ever see, and about 100 times faster than what you will be listening to.”

So how ‘fast’ is fast enough?

Mani.

I know Nelson's quote (it's also in a book that i have), but I think much more is needed, something like 1v/us per Watt.

And especially one thing: current slew rate, not voltage slew rate.
One day i'll find a mean to measure it

[PeterSt]

I didn't calculate it, but I'm sure Telstar is right although I again look at it from another angle. I think mr. Pass didn't incorporate the possible transients from digital, and then I mean *after* good filtering. This is ns level ...

Btw, I had over a fine engineer, who was the most sure nothing like a GainClone (which I use) could ever produce good sound. He tried in the past with many attempts, so he was the most sceptical I could have anything like good sound, let alone something coming close to "reality" - and which I dared promising him in advance;
First he had to withdraw the latter, but next he (thus !) couldn't find anything wrong with the GainClones. What in the world could he have done wrong at his attempts in the past ?

I only want to say : there is so much more involved. All has to match, and in order to get there you have to understand all elements and how they influence.
It can be done ...

Peter

[manisandher]

I’ll begin by apologising for this post from the outset – it’s probably of absolutely no interest to any of you...

Speed, speed, speed. This is what people seem to be saying really matters. OK, I’ll buy into this. So, I’ve been looking into an ultra-fast and reasonably powerful amplifier to drive my Quad electrostatics. ‘Spectral’ amplifiers seem an obvious choice, to try at least.

So, I called a Spectral dealer in the UK called Steven Harper (of ‘The Audio Consultants’) to have a chat. His first question was, “What are you using as a source?” This kind of surprised me because I would have thought that the obvious first question to ask when you’re considering an amplifier is, “What are your speakers?”... but there you go. I explained that I have a PC/DAC as my main source and before I could go on to give any details, he scowled at me. I then had a 30 minute lecture (really, a one-way lecture) on how a CD played back on a £20K Spectral or a £10K Nagra CD player (both of which he sells) will beat any other digital source. During these 30 minutes, I listened as politely as I could muster while he recounted all the occasions where he had demonstrated the superiority of these CD players to his customers over their “terrible-sounding USB DACs”, and where he also made some pretty dodgy statements about digital audio in general (he obviously didn’t know what ‘bit depth’ and ‘sample rate’ meant). I did actually agree with some of the points he made - he believed that the best sounding labels on CD are ECM and Reference Recordings – I think they sound great too.

So, 30 minutes into the ‘conversation’, once I could get a word in, I mentioned that my PC wasn’t actually connected to my DAC via USB. He was taken aback. “So how else can it be connected?” he asked. After I’d explained how my PC and DAC were connected, the ‘conversation’ then went on to why I would want to use a PC/DAC anyway, as opposed to a good CD player. I mentioned that one of the advantages is that I can play back hires material. As an example, I cited the Reference Recording 24/176.4 hires files. According to RR, these are direct copies of the digital masters which have been derived by digitising the analogue master tapes. But he believed that his CDs had a higher native resolution that my 24/176.4 files. His reasoning was that these hires files contain higher jitter than the CDs because jitter is introduced when files are downloaded from online (???). I mentioned that my files were not actually downloaded at all, but were copies of the digital masters put onto DVD-Rs and sent to me via the post (I don’t think he believed me). In a really condescending manner, he implied that I was mistaken if I thought that my PC/DAC combo playing any files could even come close to his Spectral CD player. At this point, I pretty much had enough and let him know that actually my DAC was an ADC also, and actually the very machine that was used to create the RR CDs that he thinks sound so wonderful. Oh and that the £20K Spectral CD player’s output stage is based on the DAC section of my machine.

Anyway, it was 45 minutes into our ‘conversation’ by now and I’d had enough. I had called as a genuine buyer for an amp. True, I wasn’t going to buy the top-end Spectral amp, but the one that I was considering was still £10K! And rather than trying to understand what I was trying to achieve, he went off lecturing me about how cr*p computer audio is – something that he patently knows very little about. So, I said that I’d buy the Spectral amp from someone else and I put the phone down on him...

What a strange interaction.

Mani.

[Per]

I’ll begin by apologising for this post from the outset – it’s probably of absolutely no interest to any of you...

On the contrary, Mani. I always enjoy reading your posts and this too was a VERY interesting read - to me at least.

Thanks for sharing. I fully understand your frustration.

Per

[Telstar]

I enjoy them too. There is just so much of bulls*t in the audio market today, that along with crazy pricetags.

[Gerard]

I put the phone down on him...

 

Ps:Very nice story! 

[DannyD]

Mani,

After A/B’ing my current model Spectral 4000 CD player to several generations of XXHE (and Berkeley Alpha) over more than a year, I finally sold the Spectral.  I felt that Peter’s good work finally pretty much caught up to the Spectral, and by getting rid of the Spectral I was also able to get rid of c-j pre-amp by which I improved the sound considerably more than the Spectral ever did.   Granted, I don’t have Spectral amps but current model VTL 450 tube monoblocks which are undoubtedly a lot slower but still quite nice in their own right.  As you rightly pointed out to the dimwitted Spectral rep, high rez material is a completely different ball game.  Spectral is known to very arrogant.  Good for you hanging up on them!

[PeterSt]

I like long-threaded posts with ambience and the real story in it.
Ah, you know.

[Telstar]

Granted, I don’t have Spectral amps but current model VTL 450 tube monoblocks which are undoubtedly a lot slower but still quite nice in their own right. 

Don't be so sure of the slowness of tubes.

[Calibrator]

... while he recounted all the occasions where he had demonstrated the superiority of these CD players to his customers over their “terrible-sounding USB DACs”, and where he also made some pretty dodgy statements about digital audio in general ...

Hi Mani,

it's reassuring to read that dickheaditis (tm) is not confined to the southern oceans and has proliferated worldwide .. haha. Seems like that company needs to change their name to "The Audio Insulters". Your patience exceeds mine by a long margin, as I would have hung up after a couple of minutes. I enjoyed the read

Cheers,

Russ 

[manisandher]

For anyone who's interested, I've ordered a 'Sanders Sound Systems' Magtech amplifier: http://www.sanderssoundsystems.com/products/amplifiers/magtech-amp. I think this should be a pretty good substitute for a Spectral amp. And you know the great thing? I don't have to deal with any hifi dealers or distributors. Joy!

Mani.

[christoffe]

For anyone who's interested, I've ordered ................. .

Hi Mani,

highend is a long journey and it will never end.

If you have a chance you should listen to a Dartzeel NHB-108B (www.dartzeel.com). This is one of the best amps in musicality terms and can drive your speakers easily.


Joachim

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Windows VISTA SP2> XXHE 09z-2 - Adaptive mode -  Q1/2/3/4/5 = 1/0/0/0/0 / No Invert / Playerprio = Low / ThreadPrio = RealTime / Scheme = 3 @ UnAttended / Arc Prediction * > Acer , Intel i750>|- Weiss Minerva -|- Dartzeel NHB-108B > speakers: Anat Referenz II Studio>

[PeterSt]

Looks great and fresh. But maybe it's a current (driven) amp ? I'm not sure how that would work out with "regulators", but it could be something like "the current is not derouted but the voltage is".

I would look for the most not-obvious anomalies. Not that I can think of any !
Specs sure look good to me ...

Keep us informed !
Peter

[Telstar]

For anyone who's interested, I've ordered a 'Sanders Sound Systems' Magtech amplifier: http://www.sanderssoundsystems.com/products/amplifiers/magtech-amp. I think this should be a pretty good substitute for a Spectral amp. And you know the great thing? I don't have to deal with any hifi dealers or distributors. Joy!

Mani.

That should be fast
Let us know how it sounds.