[ThatMatt437]

Hi all,

Recently picked up a Vali 2 (based off of recommendations from this forum!), and I really like the sound of it. However, I’m getting quite a bit of a hiss when listening. I’m using a Rega P2 into a Cambridge CP-1 phono stage, and Hifiman HE-400i’s. I find I have to use the amp in high gain mode, since it isnt loud enough for my tastes otherwise.

Is this normal for this amp? Would changing to a better tube solve this? Any help is greatly appreciated!

 

[dncnexus]

Tubes have a hiss on high gain if the headphones are getting too much power. I would try low gain, which will get rid of the hiss. Other than that not sure what to say, it shouldn't be the tube as far as I know

 

[ProtegeManiac]

Recently picked up a Vali 2 (based off of recommendations from this forum!), and I really like the sound of it. However, I’m getting quite a bit of a hiss when listening. I’m using a Rega P2 into a Cambridge CP-1 phono stage, and Hifiman HE-400i’s. I find I have to use the amp in high gain mode, since it isnt loud enough for my tastes otherwise.

Is this normal for this amp? Would changing to a better tube solve this? Any help is greatly appreciated!

Tubes tend to have higher noise than solid state, especially on high gain. That's why most tube models known for low noise tend to have lower gain as well, like the Mullard ECC83.

You could try that or other compatible tubes on your Vali2 and see if there's less noise at high gain mode on the amp, but note that it will still not be as loud on high gain. Reissues are eaasy to find and are cheap, and while NOS Mullard 12AX7 are better, they can be expensive and you have to get them from reputable dealers who will test how well they perform for their age (or really more of the storage conditions since they left the factory than outright age).

That said...do you really need it on high gain? Why not set it on low gain and just crank it up more? In some cases that might still have less noise, and not necessarily get you more distortion or closer to clipping.

 

[ThatMatt437]

Tubes tend to have higher noise than solid state, especially on high gain. That's why most tube models known for low noise tend to have lower gain as well, like the Mullard ECC83.

You could try that or other compatible tubes on your Vali2 and see if there's less noise at high gain mode on the amp, but note that it will still not be as loud on high gain. Reissues are eaasy to find and are cheap, and while NOS Mullard 12AX7 are better, they can be expensive and you have to get them from reputable dealers who will test how well they perform for their age (or really more of the storage conditions since they left the factory than outright age).

That said...do you really need it on high gain? Why not set it on low gain and just crank it up more? In some cases that might still have less noise, and not necessarily get you more distortion or closer to clipping.

Thanks for the reply. Unless I put it on high-gain, the volume is not really where I want it to be, which surprised me since I was under the impression that HE-400i's were not very hard to drive headphones. Are there tubes that generate more power so that I would not have to go to high gain but still get more volume?

 

[ProtegeManiac]

Unless I put it on high-gain, the volume is not really where I want it to be, which surprised me since I was under the impression that HE-400i's were not very hard to drive headphones.

Even if you set the volume higher? Like max out the volume knob on low gain.

That said, yes, it's only at 93dB/1mW. That's nowhere near the HD650 at 98dB/1mW. You need both power and higher gain.

Are there tubes that generate more power so that I would not have to go to high gain but still get more volume?

The tube in the Vali2 (or the tubes in Vali, Lyr, Mjolnir, etc) does not produce power. It's a gain stage - part of the preamplifier circuit. That is a hybrid amplifier so you have a solid state amplifier output stage mated to a tube gain stage.If you want an amp that gets its output power from tubes you need a pure tube amplifier, but the cheap ones are Output Transformer-Less amps that produce most of their power at 300ohms. Transformer-coupled amplifiers are more expensive - like the WooAudio WA22 - because it has to be really good iron and in the case of that amp, you need one for each channel.

You can get a tube with higher gain but unless Schiit is using a really crappy tube that will just mean more noise. Maybe try a Mullard ECC83, however all I can partially guess is that high gain with it will have less noise while still being louder than the low gain on the stock tube. I can't tell if the noise will be low enough.

Past trying a $25 tube, your safest bet is to get a new amp. If you want a lot of power with very low noise, check the Meier Jazz FF.