[socks mk2]

[redacted]

 

[zhgutov]

I made a big rant post about this on the LCD-4 thread. Tyll doesn't measure balanced. Only single ended afaik. That doesn't represent the V281 at its best.

Yes, it is for SE mode, but:
1. We don't know if this noise is in phase at the balanced output.
2. I think SE mode will be used for the sensitive IEM's (correct me if I am wrong, I don't have any of them).
 
Anyway, I don't think this noise is the problem for big headphones, because the noise is constant, and I don't hear it at all.
I think the IMD (without noise) or something in this area is much more important, and this is the area in which this amp works well.

 

[socks mk2]

[redacted]

 

[zhgutov]

"A V220 or V200 is a stereo amp with one power supply. The V281 is two stereo amps each with its own power supply. Two stereo amps or four mono amps are needed for a balanced headphone connection. Each stereo amp is bridged, one in phase, one 180 degrees out of phase. In phase is + on the driver and out of phase is - on the driver."

If I use balanced source, the signal comes to the amplifiers as is without splitting, inverting, or something else.
So, almost for sure, the noise is in phase and will be virtually subtracted. Maybe you're right in this case.
Now I want to get the corresponding cables and make my own measurements to check that...
 
Another thing what is interesting to me is the balanced<->single ended jumper.
Does it change the 6.3 jacks mapping only, or it makes something more (maybe changes the amps mapping), and what can it do with crosstalk, for example.

 

[mulder01]

Why are you looking at a powerful desktop amp for sensitive IEMs? I think you'll find most big powerful amps have the same noise floor problem. Maybe look into the new Schiit amp if you need lots of juice but also to power sensitive IEMs. Well, Jude's video made it seem suitable for both the very sensitive and very power hungry ends of the market anyway. Or if you specifically want a Violectric product, just email Fried and tell him what gear you have and he may be able to suggest a product from their range to suit your requirements.

 

[sahmen]

You mean zip?

Yup!  that too, and all the others.

 

[phonomat]

That is quite a lot. 

 

[zhgutov]

A V220 or V200 is a stereo amp with one power supply. The V281 is two stereo amps each with its own power supply. Two stereo amps or four mono amps are needed for a balanced headphone connection. Each stereo amp is bridged, one in phase, one 180 degrees out of phase. In phase is + on the driver and out of phase is - on the driver.

I made some measurements with the E-MU 0404 USB. Please note, what this is not the Audio Precision 

 
Test chain: E-MU 1010 PCI > TOSLINK > Violectric V800 > XLR > Violectric V281 > 6.3 stereo to XLR > E-MU 0404 USB microphone inputs > coax > E-MU 1010 PCI
 
Everything is grounded. Jumpers inside V800 / V281 are set to GND.
 
I changed the channel mapping for 6.3 jacks via jumpers in V281 to be able to use the existing cables.
That's it:
 

 
 
The noise floor of the E-MU 0404 USB:
 

 
 
Now I turn on the V281 with 0 dB pregain, and the volume at 12 o'clock:
 

 
0 dB in this graph is somewhere near 8 dBu.
The different position of the volume pot changes the noise floor slightly.
 
 
That's because I want to see the graph for -12 dB pregain (volume at 12 o'clock):
 

 
Pregain changes the noise floor! Maybe that's why I personally prefer 24 dBu / -12 dB mode with the V800 / V281.
 
 
Now I can turn V800 on to get some signal with this settings (volume turned down to about 8 o'clock, or even lower):
 

 
So, it looks like the balanced connection does not affect the noise (at least in the 100-500 Hz area), measured by innerfidelity.
 
P.S. Please note what I use 220V / 50 Hz power source.

 

[musicbuff]

  How well does V281 pair with Sennheiser HD650?
I've tried V100 some time ago and it was boring, lack of dynamics etc. Cheaper tubes like Valhalla2 or Laconic NBM (own it at the moment) drive HD650 much better.
Thinking of one all-purpose amp instead of several amps / combos one for its own headphones...
Looking at V281, Mjolnir2 or may be Jotunheim now... hm.

Very well! I found the improvement was even more exceptional when connected with a balanced cable. YMMV The V-281 Improved the HD 650's imaging and clarity on all levels; highs were more pronounced and extended, mids were oh, so, rich, and the lows were present and tight. IMHO the V-281 will bring out the best the HD-650 has to offer.
 

 

[senator52]

Hi everyone,
 
I've been trying to understand the difference between the volume control options. I will be using the V281 within arms length if I buy it. 99% of use will be via the pc (currently tossing up between this and the ifi Ican Pro) and was thinking that the no remote option is likely sufficient for my uses since I won't ever use a remote. Am I correct in assuming that the higher options will have minimal sonic impact and it's just implementing the remote control in a polished fashion? 
 
Thanks for your help in advance, the amp is going to be my first step in upgrading my rig significantly (looking at a v850 in a few months as well). 

 

[project86]

The base option with no remote is essentially the same as the remote version, except for the motor which gives it remote capability. Then there's the relay-based upgrade which is a very slight audible improvement. Honestly even though I went for it, I wouldn't recommend it for most people. If you've got an uber-expensive DAC, music server, cables, power conditioner.... then yeah, get the relay option. Other than that, and if you don't need remote, the basic volume is fine.

 

[senator52]

  The base option with no remote is essentially the same as the remote version, except for the motor which gives it remote capability. Then there's the relay-based upgrade which is a very slight audible improvement. Honestly even though I went for it, I wouldn't recommend it for most people. If you've got an uber-expensive DAC, music server, cables, power conditioner.... then yeah, get the relay option. Other than that, and if you don't need remote, the basic volume is fine.

 
Thanks very much, sounds like I can put the $500 towards the v850. 

 

[Eruditeswine]

What about V281 with V850 against V280 with (Lake People) DAC RS 06? Especially on a desk and within reach.

 

[socks mk2]

[redacted]

 

[Fegefeuer]

V281 is less warm than the V280 with a slightly bigger soundstage, you also have the power advantage. Can't say anything about those DACs in comparison though. However if you have the money then go for the V850. Much more sophisticated build and a superior PSU.