[bcowen]

DISCLAIMER: These are my own thoughts and should take them as such. Listening perception is unique and individual, and in no way shape or form am I saying this is any sort of truth for anyone else.

All right guys... I hate to say it, but my thoughts on rolling tubes in the Vali 2 has completely changed. I'm calling it de-bunked. I spent all weekend A/B'ing my Vali 2's and I can't tell a difference. Maybe it's my ears, maybe it's my cans, but there is no noticeable difference between any of the tubes that I used, including the stock one. The difference between my Modi2 Uber vs Modi Multi-bit is perceivable. The difference between the Vali 2 and my Jotunheim is (barely) noticeable. The tubes... not so much. Maybe I am doing this wrong, but I just am not seeing it.

Maybe I am doing this wrong, but I just am not seeing it.

Well, there's the problem...your eyes obviously can't hear very well. (groan)

Differences between tubes in my setup are pretty dramatic, especially when changing tube types (ie: 6DJ8 to 6SN7, etc). A few thoughts:

1) You have a whole lotta wire, adapters, and connections between the source and your cans. With every connection and interconnect there's a better than average chance that information gets lost or altered, especially when dealing with the more economically friendly products we're all talking about here that don't sport connectors with pure metal and costly platings. Might be worth paring down to the bare minimum of Airport ->Modi -> Vali -> Cans and give some tube swaps a listen. I realize that kills the A/B thing, but you might be surprised at the difference.
2) I have not tried the Optical input on my Modi so I'm kinda talkin' outta my butt here, but in lower cost components I've found (in general) that the coax (S/PDIF) typically sounds better. I don't know the Airport Express...does it have an S/PDIF out? If so, and if you have a spare 75 ohm cable you can use, try that between the Airport and the Modi.

You certainly have some nice tubes...it's just surprising the differences aren't there.

 

[snafu1]

Having recently made my own 3.5mm AB switch, I don't necessarily doubt RustyPitchfork's conclusion. We can easily fool ourselves to hearing something we expect to hear. At least I can.

I had 2 DACs that I thought had a noticeable difference. But when AB'ing them, I couldn't hear an appreciable difference at all. This really surprised me.

Those of you that say that there definitely is a noticeable difference between tubes - have you ever done a blind test? You know, maybe have a friend swap the tubes out behind your back and have you pick out which was which?

As an example: There's a YouTube video I saw a couple of months ago of a guy upgrading from the Schiit Modi 2 to the Gungnir. He admits that when he first listened to the Gungnir he thought it sounded better than the Modi. But then he had his girlfriend do a blind test between the two and he tried to identify the DAC., He was correct only 40% of the time. When we know what we're listening too, it's so easy to fool ourselves.

The thing is, with just one Vali, in order to compare two tubes you have to turn the Vali off, swap the tubes and give it a few minutes to warm up. That's a long time for our "audio memory" to retain what we previously heard. I'm no expert, but I find this a tough thing to do. The best way to do this is the way RustyPitchffork is doing it.
Yes, has has a lot of extra cabling - the final sound may be slightly altered by this. But both sources are going through the same path (in my opinion) any potential sound signature difference in the two sources should still carry through to the headphones.

I know there are a lot of variables here, but I think this deserves some more testing.

 

[RustyPitchfork]

Having recently made my own 3.5mm AB switch, I don't necessarily doubt RustyPitchfork's conclusion. We can easily fool ourselves to hearing something we expect to hear. At least I can.

I had 2 DACs that I thought had a noticeable difference. But when AB'ing them, I couldn't hear an appreciable difference at all. This really surprised me.

Those of you that say that there definitely is a noticeable difference between tubes - have you ever done a blind test? You know, maybe have a friend swap the tubes out behind your back and have you pick out which was which?

As an example: There's a YouTube video I saw a couple of months ago of a guy upgrading from the Schiit Modi 2 to the Gungnir. He admits that when he first listened to the Gungnir he thought it sounded better than the Modi. But then he had his girlfriend do a blind test between the two and he tried to identify the DAC., He was correct only 40% of the time. When we know what we're listening too, it's so easy to fool ourselves.

The thing is, with just one Vali, in order to compare two tubes you have to turn the Vali off, swap the tubes and give it a few minutes to warm up. That's a long time for our "audio memory" to retain what we previously heard. I'm no expert, but I find this a tough thing to do. The best way to do this is the way RustyPitchffork is doing it.
Yes, has has a lot of extra cabling - the final sound may be slightly altered by this. But both sources are going through the same path (in my opinion) any potential sound signature difference in the two sources should still carry through to the headphones.

I know there are a lot of variables here, but I think this deserves some more testing.

Thanks snafu1! Some of the stories of audio memory are why I went down this road. I have not had the chance to do a blind test. I will have to coordinate with someone to help out.

 

[RustyPitchfork]

Well, there's the problem...your eyes obviously can't hear very well. (groan)

Differences between tubes in my setup are pretty dramatic, especially when changing tube types (ie: 6DJ8 to 6SN7, etc). A few thoughts:

1) You have a whole lotta wire, adapters, and connections between the source and your cans. With every connection and interconnect there's a better than average chance that information gets lost or altered, especially when dealing with the more economically friendly products we're all talking about here that don't sport connectors with pure metal and costly platings. Might be worth paring down to the bare minimum of Airport ->Modi -> Vali -> Cans and give some tube swaps a listen. I realize that kills the A/B thing, but you might be surprised at the difference.
2) I have not tried the Optical input on my Modi so I'm kinda talkin' outta my butt here, but in lower cost components I've found (in general) that the coax (S/PDIF) typically sounds better. I don't know the Airport Express...does it have an S/PDIF out? If so, and if you have a spare 75 ohm cable you can use, try that between the Airport and the Modi.

You certainly have some nice tubes...it's just surprising the differences aren't there.

A) Dramatically different tube types may help.
1) Yeah, that was the setup I was using and I was doing straight swaps out of my first Vali 2 for months. Started to really question what I was hearing. FYI, I did a plugin direct and could not tell a difference.
2) For the Airport Express, no it does not have coax. It's just analog or TOSLink. If you want to read a great in-depth review in a human readable fashion, check out this review... http://www.kenrockwell.com/apple/airport-express-audio-quality-2014.htm I have no problems relying on how good the output is of the TOSLink.

B) YEAH! I'm surprised too. I have read enviously about some of these tubes and to hear NO difference is a bit shocking. Maybe it's Schiit's design. I'm no electrical engineer, but I would have expected something more.

 

[roshambo]

If I understand correctly Vali 2 is a hybrid tube amp, so the tube is only the preamp stage, so it's not going to be as tubey as a pure tube amp. Vali 2 power stage is solid state. Rolling has an effect, but not as much of an effect, as possibly in other tube amps.

 

[chef8489]

Yes I have done blind testing. Thing is my results were close to the same results to a friend that sent me a lot of these tubes. He did not give me any notes on how these tubes would sound, I did not read up on them before trying them, and they were all vintage. I listened to them and made my own notes and my notes were spot on to his notes. SO that tells me that they made a difference and our hearing and sound preferences are quite similar. We also used the same headphones when testing the tubes. K7xx, hd650, th-x00. I used Oppo pm-1 for a bit while he uses the Aeon open and now I use the LCD2C.

 

[Mr Trev]

A) Dramatically different tube types may help.
1) Yeah, that was the setup I was using and I was doing straight swaps out of my first Vali 2 for months. Started to really question what I was hearing. FYI, I did a plugin direct and could not tell a difference.
2) For the Airport Express, no it does not have coax. It's just analog or TOSLink. If you want to read a great in-depth review in a human readable fashion, check out this review... http://www.kenrockwell.com/apple/airport-express-audio-quality-2014.htm I have no problems relying on how good the output is of the TOSLink.

B) YEAH! I'm surprised too. I have read enviously about some of these tubes and to hear NO difference is a bit shocking. Maybe it's Schiit's design. I'm no electrical engineer, but I would have expected something more.

From the reading I've done on hybrid amps and how the Vali is engineered. Your experience does make some sense. The VAli 2 uses negative feedback in the amp. Apparently using negative feedback can minimize how much the tube will affect the sound. From what I've gathered low gain uses much higher negative feedback (in order to lower the level) and will make those differences even smaller. My suggestion… use high gain and see if that makes a difference.
Here's one of the write ups I read: https://diyaudioheaven.wordpress.com/amplifiers/hybrid/

 

[volly]

@RustyPitchfork - Commendable effort on the A/B testing mate, I'd imagine that would have taken a fair bit of time and effort, good job!

I feel your conclusion is sincere and honest, I'd say sit back and relax to your favourite music and just switch off (You've probably got ear fatigue!).

Also everyone's impression here is subjective and their own, exaggerated more so by the English dictionary.

Compared to your other amps, how does the Vali 2 rate?

 

[bcowen]

From the reading I've done on hybrid amps and how the Vali is engineered. Your experience does make some sense. The VAli 2 uses negative feedback in the amp. Apparently using negative feedback can minimize how much the tube will affect the sound. From what I've gathered low gain uses much higher negative feedback (in order to lower the level) and will make those differences even smaller. My suggestion… use high gain and see if that makes a difference.
Here's one of the write ups I read: https://diyaudioheaven.wordpress.com/amplifiers/hybrid/

Thanks for that, Mr Trev. I knew the Vali used negative feedback, but had no idea the amount differed between low and high gain settings. Now I'm gonna have to go listen to all those dang tubes again in high gain. Oh, and the 12AU7 converter came in today, so I have a primo RCA clear-top on deck to try. In both gain settings.

 

[volly]

@bcowen - Looking forward to your thoughts on the 12AU7 path on the Vali 2, safe travels!

 

[luckybaer]

I'm going through my tube collection, and it is really, really hard to pick out differences between tubes. The differences are there, but for the most part, you've got to really try hard to notice a difference. At least that's what happens with my tin ears.

 

[snafu1]

So, earlier I posted that my new Vali 2 was having issues with the right channel. Schiit sent me out a replacement tube - 6BQ7A (made in USA). That seems to have resolved the problem.

So, now I guess I should try purchasing another tube and see if it really makes a difference. I don't want to spend too much. I was thinking of getting a Matsush*ta 7DJ8 for $35. Any other suggestions?

 

[luckybaer]

So, earlier I posted that my new Vali 2 was having issues with the right channel. Schiit sent me out a replacement tube - 6BQ7A (made in USA). That seems to have resolved the problem.

So, now I guess I should try purchasing another tube and see if it really makes a difference. I don't want to spend too much. I was thinking of getting a Matsush*ta 7DJ8 for $35. Any other suggestions?

You could buy that Matsushita and be happy if curiosity doesn't get the better of you. I got mine from Upscale Audio, and it is a terrific tube. Works great with every headphone I have, but especially works well with the neutral- to bright- headphones (like DT880, K601, and even Denon AH-D2000). I'm only speaking about headphones with which I am familiar, though, so as usual in this subjective world, YMMV.

 

[bcowen]

So, earlier I posted that my new Vali 2 was having issues with the right channel. Schiit sent me out a replacement tube - 6BQ7A (made in USA). That seems to have resolved the problem.

So, now I guess I should try purchasing another tube and see if it really makes a difference. I don't want to spend too much. I was thinking of getting a Matsush*ta 7DJ8 for $35. Any other suggestions?

Glad to hear it was just the tube. Schiit happens with tubes, no matter how well they're screened or tested upfront. Kinda like getting married...despite proper diligence and even pre-testing, they start screeching and spewing static long before they should. Much easier to replace a tube though.

My favorite low cost tube in the Vali (so far) is the 6N3P-E. A couple dollars per tube (or even less with small quantities) on Ebay. But you have to be patient on shipping from Russia, and you need an adapter to use this tube in the Vali. Also inexpensive, but now you'll have to wait for shipping from the far east. You can get both (including shipping) for about $25.

 

[bcowen]

@bcowen - Looking forward to your thoughts on the 12AU7 path on the Vali 2, safe travels!

Yes, this will be interesting. I would never have come up with this combination on my own, so thanks (I think?) to Mr Trev for bringing it up. I have 2 or 3 billion 12AU7's in the stash (perhaps a slight exaggeration), so this may take a while.

Did you ever order another 396A/2C51/5670 adapter? If not, PM me...