[zhgutov]

No matter how much i turned wolume on -5 setting, it never sound as good as 0 db setting.

Oh, you have V280 instead of V281. It seems like these amps have slightly different implementation of pre-gain.
According to the scheme in manual, the pre-gain section in V280 is placed before the volume control, while the pre-gain section in V281 is placed after.
This might be due to the pre-amp inside V281, which has it's own gain switches, but shares the volume control.
So, it is possible that you can have different effect of the pre-gain in your amp.

In my experience with the V281 when I just switch the pre-gain it seems like I have a difference which is easy to notice.
This is because the standard volume control, which I have, has the "steps", which change the volume by the different value.
So, it is easy to think that the level is nearly the same, but actually it is not. This lead to the perceived difference in sound.
But when I try to match the volume the difference becomes less noticeable when the volume levels are closer.

This is interesting effect when the starting volume, and the sequence affect the result.
You need to start with the same loudness trying the different sequences in comparison.
Otherwise it is easy to fool yourself.

 

[Pharmaboy]

I wasn't aware the V280 has a different pre-gain implemention than V281 (I have the V281). Also never heard the HE1000 or Utopia.

Comments about gain on the V281:

1. I have both the headphone & pre-gain adjusted to -12dB. Even so, my system gain (powered monitors + sub) falls below 9AM on the big dial for low level listening & never even gets near 11AM for loud listening.
   • For efficient, low-impedance headphones, I can't get near 10AM w/o blowing brains/eardrums out. My power-hogging planar (Ori) can get near 12 o'clock on the dial before emergency services get the "bleeding from eardrums" call...
   • It seems that I'm in no position to explore different sound at different gain on the V281...it's too powerful even at low gain to allow it.
2. However, I did play around with gain on 2-3 other amps (Burson Soloist, the bigger pre-amp capable 4W/ch version); Audio GD SA-31SE; M Stage HPA-1. Hardly a scientific experiment, but w/hit-or-miss gain-matching at each gain level, I could not detect qualitative/subjective differences in sound at different gain on any of the 3 amps w/a given headphone.
   • A couple times I did hear slightly more noise distortion (very efficient headphones)...not sure whether I was hearing the amp, the headphones, or both.

Net/net: this "better sound at higher/lower" gain idea is quite appealing ("my amp has a sonic "secret weapon" in the gain switch!"). But my own listening has never borne this out....

 

[zhgutov]

I wasn't aware the V280 has a different pre-gain implemention than V281 (I have the V281).

I am not sure about that. This is just according to the manual.

I have both the headphone & pre-gain adjusted to -12dB. Even so, my system gain (powered monitors + sub) falls below 9AM on the big dial for low level listening & never even gets near 11AM for loud listening.

You have the different volume control (stepped relay), which increments equally by 0.75 dB per click.
So, if you don't use the remote control, you can set the volume with the same accuracy with any pre-gain, but probably you need to turn the volume knob with more care in the case of the higher pre-gain.
In my case I need to go between the steps, and I still don't know exactly how much gain I get. But you can count the clicks and multiply by 0.75

 

[Pharmaboy]

You're correct about the stepped relay, which can be adjusted manually or by remote. However, the "clicks" are pretty subtle--not as easy to hear or feel as w/other stepped pots, such as the one on Lake People G109-A

Another confounding factor in my case is that the pot on my V281 seems to be malfunctioning (I won't bore you with the various symptoms). The amp sounds amazing, as always--but adjusting volume is an uncertain exercise w/mine. I really need to send it in for service...

Final point: what happens w/higher gain settings on the V281 (at least for me), is there are very few "clicks" to play with, soft-to-loud, for a given headphone. At higher gain settings, I'm forced to listen at ~7:30 on the dial, @Near complete attenuation--w/"loud" is only 3-4 clicks above that.

 

[zhgutov]

I agree, with +12 dB (for example) I need to go to the similar volume pot positions too.
With 15 dBu input level I use -14 dB pre-gain, and this allows me to use LCD3 with the volume pot close to 12 o'clock (11 o'clock in the most cases, higher with the quiet recordings).
With more sensitive headphones (like Shure SRH940) I live between 9 and 11 o'clock with such settings.
What is your DAC output level?

 

[Pharmaboy]

I use either the Audio GD NOS 19 or DAC-19 (right now it's the DAC-19). Both output 2.5v.

I have another DAC (Peachtree Audio DAC iTx) that outputs 2.1v, which would probably work better w/V281. But that DAC, though very good for the price, isn't in the same league as either of the multi-bit DACs.

 

[PHC1]

The new Chord Qutest DAC will offer a 1V, 2V, 3V selectable output. With all the pre-gain settings on the V281, that combo should allow for ultimate range of preference on the volume pot. I also suspect the Chord Qutest would pair up very nicely with the V281. I am enjoying my Gungnir Multibit but may be tempted to try the Qutest.

 

[Pharmaboy]

Re: "The new Chord Qutest DAC will offer a 1V, 2V, 3V selectable output." If we're collectively obsessing about the sound of V281 & other amps at different gain settings, imagine the tsunami of audio navel-gazing the Qutest will unleash!

Seriously, besides my appreciation of multi-bit sound (a total relief to my ears vs any d-s design I've heard), there's another reason I won't be changing DACs any time soon: each of my AGD DACs was modified by addition of a 2nd RCA output pair on back (an upgrade at time of purchase, converting ACSS pair to RCA). This has transformed my desktop system. At any given time:

• I always have 1 of the 3 pre-amp capable HP amps in the system as pre-amp + amp
• And 1 other HP amp running off the 2nd (sonically equal) DAC output

I can easily compare headphones on 1 or 2 amps; change/rotate amps; listen to powered monitors only, headphones only, or both.

There are other multi-bit DACs that interest me, but lack of a 2nd RCA output (and high purchase price) mean I never get very far w/the idea...

 

[PHC1]

The multiple DAC outputs is a nice feature indeed. My Gungnir Multibit has 1 XLR and 2 RCA outputs and they are all being used. V281, Audeze Deckard and SPL Phonitor are all hooked up, powered up and ready to go. I also have the built in DAC in the V281 and the Audeze lol. All of them are selectable through Roon, can be zoned together or play separate.

One thing I recently discovered and have not been able to confirm from Violectric yet, is that the V281 seems like it shorts/mutes the inputs when turned OFF! What this does is overloads the DAC outputs and causes distortion in all the outputs. I was not able to figure this out for quite some time, why some of my amps sounded like they were distorting at different times and actually sent a Schiit Lyr 2 back because I thought it was defective! Nope, when I discussed this problem with Schiit tech support, we came to the same conclusion, must be the V281 shorting its inputs when OFF. Go figure... Now I make sure it is on when I listen to any other amp.

 

[Pharmaboy]

very interesting...didn't know that. I probably haven't discovered this because when the V281 is in my system, it's usually the preamp, not a 2nd HP amp; and it's always on while amp #2 is on.

one of my other amps (Audio GD SA-31SE) was set by 1st owner to short all inputs but #4 while ON. This led to interesting sonic discoveries; when the SA-31SE is my preamp, any 2nd amp must be on for power monitors to sound best at normal volume....also for HP output of SA-31SE to sound best.

Sometimes I forget and listen to headphones or powered monitors on the SA-31SE while 2nd amp is powered off. Result is always the same:

1. It starts with "Why is the bass distorting? This sounds like dogsh*t!"
2. (then I remember--gotta turn on the 2nd amp). Instantly the sound elevates noticeably. "Ahhhh....that's more like it."

 

[PHC1]

I'll be adding a pair of XLRs to piggyback from V281 to SPL Phonitor since it only has XLR inputs. Then I can use the V281 as a pass through and have 2 amps on the XLR DAC output and have 2 more amps from the DAC RCA outputs.

 

[zhgutov]

One thing I recently discovered and have not been able to confirm from Violectric yet, is that the V281 seems like it shorts/mutes the inputs when turned OFF! What this does is overloads the DAC outputs and causes distortion in all the outputs.

Just measured impedance of the inputs.
When it turned on XLR inputs have 10 kOhm between pin 2 and 3.
When it turned off it has couple of MOhms between pin 2 and 3 (not sure how much exactly).
RCA inputs always have 47 kOhm.
No short circuit here.

 

[Pharmaboy]

I'll be adding a pair of XLRs to piggyback from V281 to SPL Phonitor since it only has XLR inputs. Then I can use the V281 as a pass through and have 2 amps on the XLR DAC output and have 2 more amps from the DAC RCA outputs.

My god, that's an epic system...I thought mine was complicated!

BTW, I have used simultaneous RCA outputs + XLR outputs from my V281 w/no detectable sonic consequences.

 

[PHC1]

Just measured impedance of the inputs.
When it turned on XLR inputs have 10 kOhm between pin 2 and 3.
When it turned off it has couple of MOhms between pin 2 and 3 (not sure how much exactly).
RCA inputs always have 47 kOhm.
No short circuit here.

Then I don't understand why my other amps would distort when I switch the V281 OFF. That's a mystery...

 

[PHC1]

My god, that's an epic system...I thought mine was complicated!

BTW, I have used simultaneous RCA outputs + XLR outputs from my V281 w/no detectable sonic consequences.

It is fun!