[Pharmaboy]

So with regard to dropping or increasing gain on the unit, what is the best approach to take with a difficult to drive pair of cans such as the Hifiman He-6 (Sensitivity - 83.5 db ; Impedance - 50 Ohms)? I've always kept my v281 at unity gain, and it has performed adequately with many of my cans, but if some messing with the gain system can improve performance with the power-hungry He-6, I wouldn't mind trying it.

The HE-6 is legendary for being difficult to drive. Not sure if my experience with other headphones on the V281 will have much relevance to that one...

How does the unity gain V281 do with the HE-6? Does the sound live up to your expectations? I guess what I'm asking (based on my own uniformly positive experiences w/the V281 on 3-4 headphones, including ZMF Ori [planar] & Eikon [300 ohm dynamic])--does the V281 do as much good for the sound of the HE-6 as it probably does for your other headphones?

Here is what I can tell you at this point:

• Until yesterday my V281 was at unity gain, like yours.
• That was clearly too much gain for the powered monitors; it also was too much for relatively efficient, low-impedance headphones like the Fidelio X2. They sounded wonderful on the V281 (sounding good is never the issue w/the V281). The real issue is I had to keep the volume pot very low in its range (ie, 7:30-9:00 o'clock on the dial). That meant I had relatively few steps available, and each step caused a relatively large/coarse change in volume.
  
• My power-hungry planar (ZMF Ori), of course, played by different rules on the V281, like every other amp on hand. At unity gain I could run it comfortably between 9-10:30 on the dial, but pushing it up to 11:00 o'clock produced too-loud volume.

Yesterday I reduced the overall gain (via external & internal dip-switch settings) by 26 dB below unity gain. The effect on listening to the powered monitors at lower gain has been 100% good--better gain match across the system, more steps available to adjust volume, listening done at a higher portion of the dial, and no change in the basic sound of the V281 that I can detect.

Tomorrow I'll listen in depth to the Ori at the lower gain. My hope is the V281 will be in the 10:00-2:00 o'clock range for moderate-to-loud listening w/the Ori. I expect these headphones will sound at least as good w/the lower gain than they did at unity gain. As Arthur from Violectric USA put it, "The less resistance in the circuit the better. This goes for all volume controls" (ie, higher up on the volume pot dial is better). I doubt the sound would be noticeably less good at lower gain, and it may be a bit better. I'll report back w/whatever I hear. In my expeirence, headphones, way more than monitors, allow me to disciminate relatively small sonic differences.

Getting back to the HE-6...if they sound good at unity gain on the V281, you win--in the sense that plenty of other above-average SS designs are said to not really be up to driving it. I somehow doubt lower gain would benefit the HE-6 (though it's not impossible it would); and that higher gain would only help the HE-6. In fact, it's just the only headphone I can think of that might need above-unity gain on the V281.

 

[sahmen]

On Unity gain, the He-6 gets loud enough for me between the 11 o'clock and 12 o'clock mark on the volume dial, and I can't tolerate higher than that... The sound is good in every respect, except that it seems to lack very slightly in bass impact/extension as compared to the He-6 driven by my Bryston 2b-LP, and hooked up with speaker taps. I am talking about a difference that is very slight, without being entirely inaudible, and not implying that the He-6's bass on the v281 is "thin" or anything like that.

The Bryston 2b LP is a 60 wpc into 8 ohms speaker amp, of course, so there is that. It is only in relation to the bass impact/extension of the He-6 when hooked to the Bryston, that it sounds very slightly less impactful on the V281. In fact, if I didn't know about the Bryston experience, I would most likely find nothing to complain about regarding the way the v281 handles the He-6, especially since the v281 also drives all my other cans (incl. the HD600, Hd700, HD 800, the Hifiman He-k, and the He-500) very well without giving me the impression that anything is missing.

In fact I could probably even resolve the minor bass impact issue of the He-6 with some EQing, but I thought I should investigate the gain change solution first. With that being said, I am not sure what good upping the gain on the v281 will do in this case though, since the v281's power seems more than adequate when it comes to getting the He-6 to play loudly... At unity gain, 12 O'clock on the volume dial begins to sound much too loud for me with the He-6...With all of my other cans, the dial does not go beyond the 10 O'clock mark... In short, I do enjoy my v281 a lot, when all is said and done, but I am curious about what, if anything, the gain-adjustment thing can do for the He-6.

 

[Pharmaboy]

On Unity gain, the He-6 gets loud enough for me between the 11 o'clock and 12 o'clock mark on the volume dial, and I can't tolerate higher than that... The sound is good in every respect, except that it seems to lack very slightly in bass impact/extension as compared to the He-6 driven by my Bryston 2b-LP, and hooked up with speaker taps. I am talking about a difference that is very slight, without being entirely inaudible, and not implying that the He-6's bass on the v281 is "thin" or anything like that.

The Bryston 2b LP is a 60 wpc into 8 ohms speaker amp, of course, so there is that. It is only in relation to the bass impact/extension of the He-6 when hooked to the Bryston, that it sounds very slightly less impactful on the V281. In fact, if I didn't know about the Bryston experience, I would most likely find nothing to complain about regarding the way the v281 handles the He-6, especially since the v281 also drives all my other cans (incl. the HD600, Hd700, HD 800, the Hifiman He-k, and the He-500) very well without giving me the impression that anything is missing.

In fact I could probably even resolve the minor bass impact issue of the He-6 with some EQing, but I thought I should investigate the gain change solution first. With that being said, I am not sure what good upping the gain on the v281 will do in this case though, since the v281's power seems more than adequate when it comes to getting the He-6 to play loudly... At unity gain, 12 O'clock on the volume dial begins to sound much too loud for me with the He-6...With all of my other cans, the dial does not go beyond the 10 O'clock mark... In short, I do enjoy my v281 a lot, when all is said and done, but I am curious about what, if anything, the gain-adjustment thing can do for the He-6.

By dropping the gain on your V281, as I have done on mine, the main effect would be that you would be running the HE-6 in (I would guess) the 12:00-2:00 o'clock area of the dial. I suppose this could theoretically affect the sound, as the resistors used at each step in that range are lower value than in the 10:00-12:00 o'clock range.

Clearly the V281 has more than enough power to do this for you. I'd be interested to learn if you could hear any difference...

 

[S Crowther]

On Unity gain, the He-6 gets loud enough for me between the 11 o'clock and 12 o'clock mark on the volume dial, and I can't tolerate higher than that... The sound is good in every respect, except that it seems to lack very slightly in bass impact/extension as compared to the He-6 driven by my Bryston 2b-LP, and hooked up with speaker taps. I am talking about a difference that is very slight, without being entirely inaudible, and not implying that the He-6's bass on the v281 is "thin" or anything like that.

The Bryston 2b LP is a 60 wpc into 8 ohms speaker amp, of course, so there is that. It is only in relation to the bass impact/extension of the He-6 when hooked to the Bryston, that it sounds very slightly less impactful on the V281. In fact, if I didn't know about the Bryston experience, I would most likely find nothing to complain about regarding the way the v281 handles the He-6, especially since the v281 also drives all my other cans (incl. the HD600, Hd700, HD 800, the Hifiman He-k, and the He-500) very well without giving me the impression that anything is missing.

In fact I could probably even resolve the minor bass impact issue of the He-6 with some EQing, but I thought I should investigate the gain change solution first. With that being said, I am not sure what good upping the gain on the v281 will do in this case though, since the v281's power seems more than adequate when it comes to getting the He-6 to play loudly... At unity gain, 12 O'clock on the volume dial begins to sound much too loud for me with the He-6...With all of my other cans, the dial does not go beyond the 10 O'clock mark... In short, I do enjoy my v281 a lot, when all is said and done, but I am curious about what, if anything, the gain-adjustment thing can do for the He-6.

It has often been noted that changing the gain on the V281 changes the SQ slightly also. I think it was suggested due to change in impedance.

 

[Pharmaboy]

Well, last night I listened to the lower-gain V281 through an efficient, low impedance dynamic HP (Yenona Adapter-Free DJ Headphone); and for most of that time through the ZMF Ori (inefficient planar design).

They both sounded really good, as good I ever recall. I really didn't notice a change in SQ, though. Beyond the volume pot operating at a different range at lower gain, I couldn't reliably say the sound was any different.

As for V281's output impedance changing at at low gain, I hadn't heard that. Does output imedance go up at lower gain, or down?

This raises the related issue of how certain headphones respond to somewhat higher output impedance in HP amps. I've read in various HF threads that the Ori is not particularly sensitive to an amps's output impedance. It is said, however that ZMF's 2 new dynamic designs, Eikon and Atticus, are somewhat sensitive to this, particularly the Atticus, which reported "opens up comsideraby in midrange presence/dynamics when output impedance is over ~30 ohms. The Atticus was the topic of an experiment by several technically adept Head-Fi'ers to insert resisters of variouis values in an adapter (1/4" output of amp to 1/4" headphone jack). Results from that haven't been reported yet.

Either way, the Atticus is said to sound its best w/OTL tube amps, which usually have higher output impedance than SS designs.

 

[Badas]

Yes, there definitely is more gain control--it's under the case. First get the manual, if you don't already have it.

http://violectric-usa.com/downloads

The download will start when you click the "Violectric Audio HPA V281" line.​

There are are 2 general tactics available to you, to further decrease gain on the V281

External dip switches:

• Can I assume you have already flipped to "ON," the -12 dB dip-switch on each channel? That gives 12 dB less gain overall.
  
• If yes, then also switch to "ON" the -6 dB switch (ie, result is that both -12 & -6 dB switches are now "ON"), the result is an additional -2 dB gain, for a total -14 dB reduction in gain.

Internal dip switches:

• Per pg-31 of the manual, first unplug the power cable. I found it expedient to unplug all input/output cables, then relocate the V281 under a watchmaker's flourescent lamp w/4.5X diopter clear glass magnifier (very handy).
• Then...

1. screw off both upper screws on the front panel
2. screw off both upper screws on the back panel.
3. unscrew both lower screws on the front panel by a few turns in order to tilt the front panel a bit
4. now lift the upper lid
5. make your personal jumper settings
6. reassemble the unit in reverse order​

• Your "personal jumper settings" are made per the diagram on bottom of pg-33 ("GAIN ON THE LINE INPUT")
• Again, you can start by switching to "ON" the dip-switch for -12 dB (that's what I did on the internal dip switches for each channel)
• Or for absolute max gain, you could switch to "ON," both the -12 dB & -6 dB dip-switches for each channel.
  
• However, I recommend you start w/-12 dB on each channel for internal settings. You can always come back for more later.

I suppose there's such a thing as "too little gain"--but I haven't found it yet with the V281. This thing is a 2-stage rocket. It bristles with power...

My system is sufficiently complicated that it would be unfair to hold the V281 solely responsible for the system gain mismatches I've experienced--especially since switching to powered monitors recommended to be run in balanced mode only (Yamaha HS7's). Balanced operation typically is 6-12 dB higher output gain than unbalanced...that's at least part of my problem.

Still, for the first time, I'm now using the V281 for listening via the monitors, where my effective range (lowest typical volume to highest comfortable volume) is ~9 o'clock to ~12 o'clock on the volume pot. And that is a tremendous difference. In effect, I have twice the steps (out of the 128-stepped volume pot) to adjust volume with now.

While listening to my tube amp this morning I took the lid off my V281 and lowered the gain using the internal dip switches as suggested.
Thanks for the info.

I had to use -12 and -6 on the internal and external switches. It doesn't really make much difference.
I've got the volume position from about 9.30 to 11.00 O'clock position on my Ether Flows. Night Hawks
Are at about 9.00 O'clock.

I think my DAC (Yggy) overdrives the amp inputs. My last DAC (Auralic Vega) was excellent as you could control the volume so it
could be set to allow good volume control on the amps.

 

[Pharmaboy]

While listening to my tube amp this morning I took the lid off my V281 and lowered the gain using the internal dip switches as suggested.
Thanks for the info.

I had to use -12 and -6 on the internal and external switches. It doesn't really make much difference.
I've got the volume position from about 9.30 to 11.00 O'clock position on my Ether Flows. Night Hawks
Are at about 9.00 O'clock.

I think my DAC (Yggy) overdrives the amp inputs. My last DAC (Auralic Vega) was excellent as you could control the volume so it
could be set to allow good volume control on the amps.

You know, I'm glad you mentioned your DAC. That's something I've been meaning to comment on in posts above, but forgot.

There is quite a variation in the voltage coming out of DACs. Most of them seem to fall in the 2.0v range (+/- .1 volt). For example, the DAC I ran up to ~1 year ago, the Peachtree Audio DAC iTx, has a rated output of 1.9v. And that was pretty much what I was used to in my desktop system, where the volume pot on my Swan M200 MKIIIs could be run at 90-100%, and system volume would be controlled by a passive volume controller or 1 of several headphone amps/preamps on hand. Whatever device I used as a system preamp, the volume pot settings were comparable: a touch below 9 o'clock on the dial for low-volume classical streaming; all the way up to ~12:00 o'clock for loud stuff. And when listening to headphones, the volume of whatever amp I used acted predictably, similar to the same volume pot controlled speakers (ie, lower range for efficient/sealed HPs, higher for ZMF Ori/inefficient planar design).

Then I got the Audio GD NOS 19, which outputs 2.5v (more than 25% more voltage than the DAC iTx), and those system volume controls inched up somewhat. But still not to a point where I felt there was a real gain mismatch in the system...ie, I wasn't at or near the bottom-most gain setting w/any amp/preamp.

But when I got the V281, all that changed. It had way too much gain, forcing me into the bottom-most portion of its volume control, both for system (powered monitors) and headphones. That troubled me, since the V281 is the best amp/preamp I have.

Thankfully, dropping the V281's gain by 26 dB has pretty much restored stability & balance to my system.

I can't find the line-out voltage for either the Vega nor the Yggy. But you're quite right that the Vega's onboard pot could moderate gain for you.

The only other solution I can think of (was going to try this in my system 'til I managed to drop the gain on the V281) is to pick up a good quality passive volume controller (w/or w/o additional inputs/outputs) and put that in line between Yggy & your V281. Yes, it's an additional device (albeit passive) + 1 set of interconnects. But that would create way more flexibility in adjusting system (or just headphone out) gain.

 

[Badas]

You know, I'm glad you mentioned your DAC. That's something I've been meaning to comment on in posts above, but forgot.

There is quite a variation in the voltage coming out of DACs. Most of them seem to fall in the 2.0v range (+/- .1 volt). For example, the DAC I ran up to ~1 year ago, the Peachtree Audio DAC iTx, has a rated output of 1.9v. And that was pretty much what I was used to in my desktop system, where the volume pot on my Swan M200 MKIIIs could be run at 90-100%, and system volume would be controlled by a passive volume controller or 1 of several headphone amps/preamps on hand. Whatever device I used as a system preamp, the volume pot settings were comparable: a touch below 9 o'clock on the dial for low-volume classical streaming; all the way up to ~12:00 o'clock for loud stuff. And when listening to headphones, the volume of whatever amp I used acted predictably, similar to the same volume pot controlled speakers (ie, lower range for efficient/sealed HPs, higher for ZMF Ori/inefficient planar design).

Then I got the Audio GD NOS 19, which outputs 2.5v (more than 25% more voltage than the DAC iTx), and those system volume controls inched up somewhat. But still not to a point where I felt there was a real gain mismatch in the system...ie, I wasn't at or near the bottom-most gain setting w/any amp/preamp.

But when I got the V281, all that changed. It had way too much gain, forcing me into the bottom-most portion of its volume control, both for system (powered monitors) and headphones. That troubled me, since the V281 is the best amp/preamp I have.

Thankfully, dropping the V281's gain by 26 dB has pretty much restored stability & balance to my system.

I can't find the line-out voltage for either the Vega nor the Yggy. But you're quite right that the Vega's onboard pot could moderate gain for you.

The only other solution I can think of (was going to try this in my system 'til I managed to drop the gain on the V281) is to pick up a good quality passive volume controller (w/or w/o additional inputs/outputs) and put that in line between Yggy & your V281. Yes, it's an additional device (albeit passive) + 1 set of interconnects. But that would create way more flexibility in adjusting system (or just headphone out) gain.

Yeah! The range in output voltage between DAC's is annoying. Vega had a crazy 3.5 volts. Fortunately being a preamp it had volume control so you could set it at 2/3's volume and it would be at that 1.9 volts. Which to me is about right.
I don't know the volts on the Yggy however from my listening and system experiences I would guess it is very high. It would be nice if they built a function into DACs to set output from high to a standard 1.9 volts.

I do have one thing in my system to help me out. I don't use computer. I use a iPod classic (I know terrible) with everything ripped at red book CD standard in a Arcam dock. The dock has volume control. So I can lower the volume to allow volume control on the V281. Unfortunately when I turn the dock off and on it defaults to full volume. So I need to adjust every session. However it is helpful when using the V281. I don't have issues when using my tube amp. The tube amp volume has enough scope.

 

[JacquesDewitt]

Hello, that dac would be a good companion for this amp?
I am evaluating Yggdrasil, 2qute, gungir multibit, V850 and hugo2

Best regards

 

[PleasantSounds]

[..]
The only other solution I can think of (was going to try this in my system 'til I managed to drop the gain on the V281) is to pick up a good quality passive volume controller (w/or w/o additional inputs/outputs) and put that in line between Yggy & your V281. Yes, it's an additional device (albeit passive) + 1 set of interconnects. But that would create way more flexibility in adjusting system (or just headphone out) gain.

One more option you may have (if you don't do that already) is lower the volume at your source. It won't affect the resolution if your DAC is receiving 24-bit signal.
Generally most of the digital material is mastered too hot anyway and many DACs don't cope with this too well. The result may be not only better range of the volume pot, but less clipping.

 

[Pharmaboy]

Hello, that dac would be a good companion for this amp?
I am evaluating Yggdrasil, 2qute, gungir multibit, V850 and hugo2

Best regards

My vote would be an Audio GD DAC-19. It's not only one of the cheapest R2 R DACs around, but sounds absolutely terrific, praised by many here. They retail for a little over $900 + shipping. I just checked Magna Hifi in the Netherlands, where I bought both my Audio GD DACs. Shocked to find they still have stock on the DAC-19 (it won't last/product being phased out by Audio GD):
http://www.magnahifi.com/en/webshop/product/audio-gd-dac-19

Also very surprised they also have stock on the non-oversampling version of the DAC-19, the NOS 19 (same story--it won't last long):
http://www.magnahifi.com/en/webshop/product/audio-gd-nos-19

You should be able to get a quality used DAC-19 for $600-$700. Here's a typical Head-Fi listing (not shilling this Head-Fi member or his F.S item...just illustrating availability):
https://www.head-fi.org/f/threads/for-sale-audio-gd-dac19-600-usd.853426/#post-13561021

You might see a used NOS 19 come up every 18 months or so. Historically, just a fraction of Audio GD DACs sold are the NOS. Most are DAC-19s.

I own both the DAC-19 and NOS 19. The latter is my favorite DAC and the least "digital" sounding digital device I've ever heard. But they're both terrific DACs, in a class by themselves IMO.

And if you buy new, you can configure it w/o the ACCS connection--just ask them to convert it to a 2nd RCA output pair. And let me tell you, having 2 outputs on your DAC is when things really get interesting (ie, run two completely different HP amps; or 1 HP amp for headphones and a HP/preamp for speaker system + 2nd HP amp listening option).

Yes, I'm a total Audio GD fanboy, R2 R digital fanboy, and lover of non-oversampling R2 R (proud to be all 3, because now digital files/CDs, etc sound like real music).

 

[fixated]

Hi Ya'll,

Seeing as there are discussions about gain and how much voltage the DAC should output via lineout, I'm curious to see if anyone is using a Hugo TT with their V281 and at what setting they have it on? I believe when the Hugo TT is on lineout mode it's at 3V so it might be "too much" for the V281. I'm waiting for my Hugo TT purchase and I'm just doing some research for later usage! TYIA.

 

[novicez1]

@lonerboy13

That will largely depend on your listening volume and the track's gain. Personally, I use +15db on my RS06 with -12db on my V281 and my listening volume's around 10~11 oclock for -6 to -3db tracks and 12 oclock for 0~+3db tracks.

 

[S Crowther]

Hi Ya'll,

Seeing as there are discussions about gain and how much voltage the DAC should output via lineout, I'm curious to see if anyone is using a Hugo TT with their V281 and at what setting they have it on? I believe when the Hugo TT is on lineout mode it's at 3V so it might be "too much" for the V281. I'm waiting for my Hugo TT purchase and I'm just doing some research for later usage! TYIA.

I have this set up. Violectric advised me to reduce the output from the TT by 10%. Luckily the TT has a volume control so this is no problem.

 

[Pharmaboy]

I have this set up. Violectric advised me to reduce the output from the TT by 10%. Luckily the TT has a volume control so this is no problem.

I sorta get the feeling based on comments here about Auralic Vega & Hugo, that DAC/amps w/volume pots are designed to have high output voltage (3-4v or more).

(possibly to allow maximum system and/or HP volume at full rotation of volume dial?)

I've only owned 2 DAC/amps v/volume pots:

• FiiO E10K, which I still have. It's hardly a powerhouse amp & I've only used it on headphones, where it never struck me as "too hot" in output.
  
• Audio GD NFB 15.32 (since sold): Now that I think about it, it was very difficult to get the volume over ~10:30 o'clock, either w/powered speakers or any headphones. It struck me as way more powerful sounding that its specs suggested. So perhaps this DAC/amp was set up w/higher output voltage.