How much dose preamp matter?

[Vapor9]

I'm able to to put the single-ended into the STP and it is then converted to balanced and then out to the Peachtree.

 

[andreasmaaan]

I'm able to to put the single-ended into the STP and it is then converted to balanced and then out to the Peachtree.

Ok I see, but it's the single-ended input impedance of the STP that is relevant here, and this is very similar to the Peachtree's, and moreover likely hundreds of times higher than the output impedance of the S2.

Whatever it is you're hearing, it's not to do with impedance.

If I were you, I'd try a level-matched blind test.

 

[Daverz]

It's the Pre Box S2 Digital.

Worth a watch

Always useful. Whatever Paul says, it's most probably nonsense.

 

[Vapor9]

I've done quite a bit of listening to it before the S2 arrived and also tried out my older Peachtree DAC-ITx. The difference is not that subtle. In fact, I believe even someone without any experience with my system would readily tell the difference. I'm still at a loss to why. I just can't explain the loss of air and space when not using the preamp.

Do you use a preamp?

 

[andreasmaaan]

I've done quite a bit of listening to it before the S2 arrived and also tried out my older Peachtree DAC-ITx. The difference is not that subtle. In fact, I believe even someone without any experience with my system would readily tell the difference. I'm still at a loss to why. I just can't explain the loss of air and space when not using the preamp.

Are you able to do a level-matched blind test?

Do you use a preamp?

Not in any of my current systems.

 

[orangejello]

I couldn't find a spec for the output impedance of the S2 - do you have a link?

This Stereophile measurement page... https://www.stereophile.com/content/pro-ject-pre-box-s2-digital-da-headphone-amplifier-measurements

He claims it is .5 ohms for balanced and unbalanced.

 

[Vapor9]

I'm not sure how I'd be able to wire that up so that it was button-switchable.

 

[Daverz]

I have a BAT 3iX tube preamp. But I prefer going directly from my Auralic Vega to my Bryston 3B-SST and using the digital volume control on the Vega. The 3iX just swallows up too much detail. Since I'm already doing digital room correction on the music server, bit perfect playback is not an issue for me.

 

[Vapor9]

Before getting my STP-SE, I read plenty of reviews and this one stuck out and pretty much solidified my effort to get this preamp. I was contemplating getting some sort of passive much like this review had tried.

http://www.stereotimes.com/amp082912.shtml

 

[Vapor9]

I'm probably going to get a hypex ncore amplifier in the next few weeks so maybe I'll try out the whole preamp testing soon since I'll need to rewire anyway.

 

[March Audio]

All things being equal, ie appropriate voltage drive levels and impedances a pre amp can do nothing to improve the sound.

It can of course add noise, distortion and colour the sound. At best a pre can only be transparent. Of course if it changes and colours the sound you might like what it is doing, but then it's an effects box

Digital volume when performed at 32 or 64 bit resolution does not degrade the sound and you are rid of the issues of analogue pots.

If you need to switch between various sources then a pre or a switch box is obviously required.

 

[andreasmaaan]

I'm not sure how I'd be able to wire that up so that it was button-switchable.

It's difficult. You'd need a switching device. A simple version of the test could simply be done with a friend or partner, a screen, and a voltmeter.

 

[andreasmaaan]

Digital volume when performed at 32 or 64 bit resolution does degrade the sound and you are rid of the issues of analogue pots.

I know you meant to say doesn't there, right?

 

[March Audio]

I'm probably going to get a hypex ncore amplifier in the next few weeks so maybe I'll try out the whole preamp testing soon since I'll need to rewire anyway.

My range hypex amps driven directly from the dac with digital volume work very well.

 

[March Audio]

I know you meant to say doesn't there, right?

Hagagaha. Phone typing

Yes Doesn't degrade the sound

 

[Vapor9]

All things being equal, ie appropriate voltage drive levels and impedances a pre amp can do nothing to improve the sound.

It can of course add noise, distortion and colour the sound. At best a pre can be transparent.

Digital volume when performed at 32 or 64 bit resolution does not degrade the sound and you are rid of the issues of analogue pots.

S

All things being equal, ie appropriate voltage drive levels and impedances a pre amp can do nothing to improve the sound.

It can of course add noise, distortion and colour the sound. At best a pre can be transparent.

Digital volume when performed at 32 or 64 bit resolution does not degrade the sound and you are rid of the issues of analogue pots.

So, if I experience a degradation without the preamp, could it just be because of digital problems? I'm using Audirvana on my mac out to the S2?

 

[March Audio]

S



So, if I experience a degradation without the preamp, could it just be because of digital problems? I'm using Audirvana on my mac out to the S2?

I doubt it very much. First thing you need to do when comparing is precisely match volumes. Then you need to swap between the two without knowing which is which.

As mentioned above it may be that you just like the colouration of the pre.

 

[andreasmaaan]

So, if I experience a degradation without the preamp, could it just be because of digital problems? I'm using Audirvana on my mac out to the S2?

I can't imagine how this could be TBH. The digital source, drivers, etc. are identical in each case...

 

[Vapor9]

I doubt it very much. First thing you need to do when comparing is precisely match volumes. Then you need to swap between the two without knowing which is which.

As mentioned above it may be that you just like the colouration of the pre.

Hmm, I would like to try a blind test. I'll have to work on this. If it is colouration, I'm loving it.
BTW, I'm Kirk - I just wrote you regarding the P252. Were you able to gather any specs on that yet?

 

[March Audio]

Hmm, I would like to try a blind test. I'll have to work on this. If it is colouration, I'm loving it.
BTW, I'm Kirk - I just wrote you regarding the P252. Were you able to gather any specs on that yet?

Hi there Kirk

I'm typing on phone at 5he moment, I will get back to you when I am back in the office in about 3 hours

Level matching is critical, best done with a test tone and a multimeter at the outputs. Louder always wins even if identical