Volume Control

[glynnw]

Hi Peter - Thought I'd start a new thread on your suggestion that I simply remove my preamp from the playback chain.  I did so today using a passive I built a couple of years ago (it has remote volume control     ).  First though, I tried to use the volume control on XXHighend.  My Wavelength Brick is a 16/44 NOS DAC - the volume control on XXHighend really worked poorly with it - sometimes not working and then suddenly changing volume.  Also, too few steps.  As I read the Tooltips, I believe you are saying I would have better results using the volume control if I had a 24 Bit DAC.  The Brick can be upgraded to a 24/96 Wolfson chip, but it is not NOS.  In your opinion, would an upgrade improve my sound and also allow me to use the volume control of XXHighend or is it more important that the DAC be NOS?

By the way, the sound today through my passive is quite good, but I have played with these things over the years and found myself happier with the increased dynamics I perceive as being a benefit of an active preamp.  I will run the passive for a couple of days and then switch back to an active preamp to see if this bias of mine still holds true (for me).

Ultimately any longterm decision has to involve a remote with both volume and balance controls.  I installed a Welborne Labs unit in my Bottlehead preamp and find I use the balance control all the time.

[PeterSt]

Hi Glynn - Too many questions ! but I'll try ...

First of all, if you remove your preamp, you, well, remove your preamp. And not put a passive one in place ! (not even a resistor).

Next, using the volume from XXHighEnd is a matter of getting used to. But, if your system is too slow it will disturb you.
It should respond within a second. Notice that if you try to give further commands without the previous being processed, things may go wrong, or work counteractive for speed. In normal circumstances this just works, but to keep in mind : when the command can be processed within a second. Thus for example, when this takes 5 seconds, it has become unworkable, and you wouldn't know what you're up to (didn't it work ? let's try it again -> thus now two commands are pending).

I have played with these things over the years and found myself happier with the increased dynamics I perceive as being a benefit of an active preamp.

How can an active preamp let increase dynamics ? it can't unless it's fake. So, let's keep that in mind !
Then, how can a passive preamp DEcrease dynamics ? haha, it sure can to begin with. But this is because your passive preamp will be a TVC, and a TVC is not linear (per frequency) and, well, I don't like the sound coming from it. It's a nice trick which doesn't work.
Here too : first learn how the sound IS by means of using NO preamp (remember, no = no haha), and next learn what your TVC or whatever means of preamp does to the sound.
The problem, of course, is that it is not said that all will match, and this starts at the DAC. If there's not enough drive, well, there it ends. Not really, because you can buy a buffer (this is a unity gain device which drives), but a good buffer too will cost you, and could be more than the DAC ($700-900 or so).

Next point is your 16 bit DAC. Indeed, that is not allowed to work with digital volume control. Maybe up to -18dB, but that's it. And, this usually is not sufficient as an operating range (but if your main amp is calibrated to produce "your" full sound level at full gain, it may).
Also to keep in mind (but I guess you pointed that out yourself) : with a 16 bit DAC the "legal" (say, losless) steps are 6dB. Way too rough !

In your opinion, would an upgrade improve my sound and also allow me to use the volume control of XXHighend or is it more important that the DAC be NOS?

Tough question, which I officially should not answer, because it is personal (some like NOS some like OS). But I think it can be answered to like this : If you like this DAC, you will like it (a.o.) for its NOS "capabilities". Thus, if you'd change to OS you sure won't be happy. The other way around is not the same, because most "OS people" just never tried NOS and they don't know (yet).
Either way : I would not buy another type (NOS vs OS) of DAC just because I told you to try without preamp. This should be approached differently :

Don't do it at all if it doesn't work in your setup (like with the 16 bits DAC) or turn it into a complete project of improvements. In your case this comes down to :

- A 24 bit DAC allowing for decent digital volume control
- A DAC which can drive interlinks for the necessary length
- A faster PC if the volume is quite inoperable at the moment
- Gain adjustment of your main amps, so the least as possible digital attenunation will occur
- Possible new main amps and speakers because now you hear everything.

So you see, from one comes the other. But notice this goes by itself once you hear the real music coming from your DAC (or how it interprets that anyway), if you can only trust me this is so. But if you sit back and think about what really happens ... there is no such thing as improving sound. Nothing does that. You can only destroy, and many things in the chain can do that. Eliminate them where you can, and keep realizing that you need some gain in the end ...

Peter

[Per]

Excellent answer, Peter.
Learned a lot from it.
Thanks.

Per

To be (amplified) - and not to be (amplified) - that's the question 

[listening]

Hi Peter,

tried immediately and will stay with it. I will post some test tracks next time - so much more to hear. Awesome. But there is some additional sports too when trying to get optimal gain for the different tunes  . Is it possible to save the optimal gain with the tracks?

Georg 

[PeterSt]

Oh Georg, yes, but the story is almost too difficult to explain ...

It is related to the Normalized Volume, and how you set and use (!) the settings for that. Let's hope this topic suffices, where it was anounced : XXHighEnd Model 0.9y-5-00 (New Kernel Streaming Sound Engine).

So, this is one part of it, the other part is the gain of your main amps;
Now, when you have a 24 bit DAC and never have to attenuate more than 48dB all will be right. But if you have to attenuate more the "trick" is to (let) de-gain your main amp. Usually this is possible, but as usual you can't do it yourself. And notice this should NOT be done with a resistor or anything in the signal path. That filters and creates noise again.

But nice to hear that somebody tried with good results !
But to keep in mind : this may be at first sight, and sharpness may be a first negative you may perceive some later (fatigueness). When you perceive that, don't give up and go back, but instead try to find the source of it. Here your miles will vary ...

In all cases, I hope this gets others on this track as well ! (and many already are of course)
Peter

[glynnw]

Well, Peter, I have continued to rearrange things and after a couple of days I will agree that my system sounds better when I remove the preamp entirely.  With my 16 bit DAC, I have too few volume choices, but I could listen enough to appreciate the improvment in SQ.  Of course, things are never this simple.  I am very perceptive of channel imbalances, and have installed a volume control in my preamp that also gives me remote balance control, and using tube amps I have enough channel imbalances to need to make balance adjustments on almost every album I may play.  So to be able to adjust the channel balance without my preamp, I have sinned a bit and have placed an EVS Ultimate Attenuator at the input of each amp.  This is a shunt passive control which places just a single nude Vishay resistor in the signal path.  I know you hate the idea, but this does give me the ability to adjust the balance, and frankly, I hear no degradation in sound from having this single resistor in the signal path. In a perfect world, yada yada yada.
Another issue is that I use 2 subwoofers, each with a built in amp.  I should be able to create a dual output for each channel of the DAC, so this is no problem.
But to get better volume control, with smaller steps, I need to switch to a 24 bit DAC.  So here is my first question.  Do I need 24/192 to take advantage of the quad oversampling?  I might as well get something that lets me use the oversampling while I am making this change.
And my second question at this time: is it possible to incorporate a balance control into XXHighend, or must this always be done in the analog domain?
Thanks, as always.

[PeterSt]

Hi Glynn,

Of course my advice to get some amps which don't require the balance control is inappropriate, right ? haha Ok.
But really ... needing a balance control to set things once sounds allright to me (still not good, but good to go), but when you need to change this per album, I really would go for another pair of amps. Why ? because it will imply that certain frequencies are surpressed (or more profound) in one of the amps. And *this* can't be good ! It will create a vague sound stage the least ... IMO.
Just keep this in mind.

A balance control in XXHighEnd won't be possible because of the too rough steps. So, I could make it, but the steps would be ~1.5dB and I don't think that can work. Notice that the steps are ~1.5dB because this won't loose any data (call is a lossless digital volume). So, it can be as fine as you want, but it will be no good (just as I could allow the 1.5 steps for 16 bit data (which I actually do I think, with the red buttons), but it is wrong).

In between the lines it may be good to recall that I didn't tell you to play without preamp from now on ... it was only in order to judge which of your preamps works out for the best, which you can only judge if you first know how the sound it without preamp at all. Next you can possibly "hear" where the preamp of choice can be improved. IOW, it is not the intention to end up with various other problems because you're not using a preamp ...

But to get better volume control, with smaller steps, I need to switch to a 24 bit DAC.  So here is my first question.  Do I need 24/192 to take advantage of the quad oversampling?

Yes, because 4 x 44.1 ~ 192.
But it is not so easy ...
If you don't hate OS DACs there officially shouldn't be a reason to use the Quad Upsampling, because the OS DAC will do it anyway. It will do it in a wrong way, but if you like the sound from it, why not (listen listen listen). One problem though : the Arc Prediction Quad Upsampling still seems to work out for the better with most of the OS DACs. So, YMMV, but still it comes down to whether you like the sound, one way or the other (you don't need the Quad upsampling if without it sounds better ).
The real point would be : you would need 24/192 NOS filterless to do it right, if it were up to me. Those DACs are hard to find (if existing at all), and this is where the Phasure NOS1 is for. Next problem : you don't have it yet. But if you can survive some more time, you will.

Don't make yourself crazy with this all. There are many ways to improve, and maybe there are also ways coming up to make the best out of it currently possible. But keep in mind : says me.


Peter

[glynnw]

Peter- Sorry, but I will hopefully never sell my amps - I built the amps and preamp from Bottlehead kits.  Yesterday I went to the Bottlehad forum and asked about adding passive outputs to my preamp, got advice, and added them.  So now I have passive putputs that retain volume and balance control, also keeping the active part of the preamp to drive my long Sub cables. At this time I have 2 resistors in the passive chain, and it's the best I can do.  The passive signal gives me a lower moise floor and more detail, but even with all controls at their highest, I want more volume for loud rock n roll.  So the preamp remains, although I can now do passive lstening just by switching a couple of cables, whenever I feel like it.  And it was your advice that led me to do this, so thanks.

Next I want to pick up an 24/192 DAC to see if I like how it works with XXHighend batter than My Wavelength Brick, which does 16/44.  Can a USB DAC deliver true 24/192 perfromance when used with XXHighend or should I look for an SPDIF DAC?

[PeterSt]

Of course a USB DAC can ! as long as it supports 24/192 !
I'm not sure they come at an affordable price though (it may be too new).

But in either case it is very good that you are happy so far !
Peter


PS: Sorry if it looked like I wanted to talk you out of your amps. I hope I merely said to use the preamp, but now with more knowledge how it sounds, hence how it can be improved. Or at least that has been my intention !

[bhobba]

Hi All

There is no way a pre amp can increase dynamics - it can only decrease it.  I can never add anything - only degrade it - with one exception - impedance matching.  However for that you don't need a pre-amp - a Busron Buffer which is utterly transparent will do that no problemo:
http://bursonaudio.com/burson_buffer_160.htm

And it is not just hype either.  Hugh Dean, an amplifier designer here in Aus, whose amplifiers are top notch, and whose opinions I greatly respect, tried the Busron buffer on his amp and it did have a positive benefit

Personally I am a big fan of connecting directly to amplifiers.  Some of the best DAC's around like the overdrive are designed to be used that way.  This can save you quite a bit of money by not requiring a pre amp which can run into many tohusands of dollars.  The pre amp I am interested in (the Burson) for example costs $2200 here in Aus:
http://bursonaudio.com/Burson_pre160.htm

However an excellent DAC with built in digital volume control for direct connection to an a amp can be had for about the same price:
http://www.wyred4sound.com/webapps/site/74030/117839/shopping/shopping-view.html?pid=457975

For me that makes it close to a no brainer.  However I must also add having run the idea by some others one issue is that some of the very best DAC's such as the tranquility dac cant be used that way.  They may exceed the performance of the DAC above (then agian they may not - I am unsure if any dac could appreciably exceed the Wyred for sound Dac but that is a discussion for another time) but I don't think they will exceed the performance of top of the line DAC's that can direct connect like the overdrive.

Thanks
Bill