Schiit Valhalla Tube Rolling thread.

[jonathan c]

You must be a fan of this guy then

Warning! Warning! ….. sibling! sibling!

 

[Novik tube]

The question I have though relates to the screen on Pin 9 in the 6922. Presumably, the screen is connected to some part of Valhalla's circuit. For isolation between the two triodes??? And I would guess at some high negative voltage so the electrons don't just stream from the cathodes to it instead of the anodes. Assuming that, then wouldn't not having a screen lead to noise between the two sections or coupling of their signals? Maybe it's moot if the two sections are wired in parallel. Or am I just being ignorant? (Always a high probability!)

I saw your post with a question about the screen in the 6922 tube and realized that I was mistaken in my post!
I didn't have time to edit, so I temporarily deleted it!
In all types of converter 12AT7 to 6922 glow plugs 4 and 5 are connected together and inserted into pin 4 6922
And pin 9 to pin 5
Pin 9 in socket 6922 is not used. This is the converter standard for 6.3 volts
The role of the screen in the 6922 has almost no effect on the operation of the tube. therefore, the replacement with 12AT7 has been repeatedly confirmed by real experiments
Thanks for @GumbyDammit223

 

[bcowen]

I will not be surprised that after a successful connection, cv4033 will be at least as good as CV455

You're right. I have a couple of the Footscray CV4033's from Pulse where they have affixed a noval base with pins. It's difficult to hear much difference between those and the CV455. What little difference there is could just be sample-to-sample variation, it's really that minor. Pulse does a superb job putting the bases on, but they're also asking $131 per tube versus the $56 Langrex is asking for the CV455. Kinda not that hard to make a decision.

https://pulsetubestore.com/products...play-ready-to-use?_pos=2&_sid=e15fcb619&_ss=r

 

[LobalWarming]

You're right. I have a couple of the Footscray CV4033's from Pulse where they have affixed a noval base with pins. It's difficult to hear much difference between those and the CV455. What little difference there is could just be sample-to-sample variation, it's really that minor. Pulse does a superb job putting the bases on, but they're also asking $131 per tube versus the $56 Langrex is asking for the CV455. Kinda not that hard to make a decision.

https://pulsetubestore.com/products...play-ready-to-use?_pos=2&_sid=e15fcb619&_ss=r

Indeed. The $131 Pulse CV4033 needs another $50 of Fedex 'handling' charges to really make it worth it.

 

[TBBZ8X8]

I'll help where I can, but I'm not absolutely positively totally sure with this particular tube so please feel free to ask around for verification.

The link @Novik tube posted is about all I see (without a lot of searching) on the CV4033. I've added a graphic layout of a 12AT7 (below) which is the analog to the CV4033 and as far as I can see the element/pin assignments are the same. Logical enough, but with this stuff you never know for sure. Remember that the pin numbering scheme is looking at the bottom (pin side) of the tube. The 12AT7 (and presumably the CV4033) is a dual heater voltage tube, meaning the heaters can be operated at either 6.3V or 12.6v depending on how you wire up the heater pins. Your Valhalla will only send 6.3v to the sockets, so the tube pins will need wired for 6.3v by wiring pins 4 and 5 together and tie one heater leg to that, and connect the other heater leg to pin 9. The neat thing here is that the 12AT7/CV4033 pin assignment is the same as the 6922 (2nd picture) that is native to the Valhalla input tubes, so as long as you get things wired up right (and for 6.3v operation) you won't need any adapters. Just be sure you plug these into the 6N1P (6922) sockets, and not the 6N6P sockets.

Wow! Thank you so much!

So it sounds like I buy those adaptors @Mr Trev mentioned (https://www.ebay.ca/itm/193443011307). Solder all of the pins straight down (no crossed wired), bridge pins 4 and 5 and then I am in business?

2 questions. How do I know the pins on the adaptors are for the 6922 socket? And am I able to test my adhoc tubes with a multimeter or am I going to need to borrow an oscilloscope?

You guys are absolutely awesome! I can see why I have heard such great things about this community!

 

[Novik tube]

Wow! Thank you so much!

So it sounds like I buy those adaptors @Mr Trev mentioned (https://www.ebay.ca/itm/193443011307). Solder all of the pins straight down (no crossed wired), bridge pins 4 and 5 and then I am in business?

2 questions. How do I know the pins on the adaptors are for the 6922 socket? And am I able to test my adhoc tubes with a multimeter or am I going to need to borrow an oscilloscope?

You guys are absolutely awesome! I can see why I have heard such great things about this community!

Hello.
We all want the result of your work to be positive! So don't rush to buy anything.
You have asked a very valid question, how to check what you are going to do! My simplest answer is no way to check!
More: With a tester, you can only check the correct connection of the filament section to pins 4 and 5. And that's it. An oscilloscope won't help at all! You must absolutely solder the carefully labeled leads from your tube to the specific pins on the adapter and that is the only real guarantee!
That adapter, the photo of which, along with the cv4033 lamp, was sent to you by a forum member is technologically very difficult to manufacture and therefore it is so expensive!
But, this is only an adapter, not a Converter! there is no transition from 12AT7 to 6922
The one you are about to buy is also just an adapter!!
Technologically, with the help of this adapter, the converter can be made, but this task is definitely not solved by two clicks on the computer!

Further: If you nevertheless made this converter and found a master who would risk (there is a possibility of damaging the device if you incorrectly connected the conclusions) check it on your special device for testing radio tubes, How do you insert it into Valhalla and then dismantle it back?

Those photos that my colleague sent had a significant height of the body, namely, you need to hold on to it to insert or remove your converter, and not by the tube glass!
I hope @bcowen will correct me if I'm wrong!

 

[Shane D]

Hello.
We all want the result of your work to be positive! So don't rush to buy anything.
You have asked a very valid question, how to check what you are going to do! My simplest answer is no way to check!
More: With a tester, you can only check the correct connection of the filament section to pins 4 and 5. And that's it. An oscilloscope won't help at all! You must absolutely solder the carefully labeled leads from your tube to the specific pins on the adapter and that is the only real guarantee!
That adapter, the photo of which, along with the cv4033 lamp, was sent to you by a forum member is technologically very difficult to manufacture and therefore it is so expensive!
But, this is only an adapter, not a Converter! there is no transition from 12AT7 to 6922
The one you are about to buy is also just an adapter!!
Technologically, with the help of this adapter, the converter can be made, but this task is definitely not solved by two clicks on the computer!

Further: If you nevertheless made this converter and found a master who would risk (there is a possibility of damaging the device if you incorrectly connected the conclusions) check it on your special device for testing radio tubes, How do you insert it into Valhalla and then dismantle it back?

Those photos that my colleague sent had a significant height of the body, namely, you need to hold on to it to insert or remove your converter, and not by the tube glass!
I hope @bcowen will correct me if I'm wrong!

That seems like a lot of work and risk just to save a few bucks on tubes.

 

[bcowen]

Hello.
We all want the result of your work to be positive! So don't rush to buy anything.
You have asked a very valid question, how to check what you are going to do! My simplest answer is no way to check!
More: With a tester, you can only check the correct connection of the filament section to pins 4 and 5. And that's it. An oscilloscope won't help at all! You must absolutely solder the carefully labeled leads from your tube to the specific pins on the adapter and that is the only real guarantee!
That adapter, the photo of which, along with the cv4033 lamp, was sent to you by a forum member is technologically very difficult to manufacture and therefore it is so expensive!
But, this is only an adapter, not a Converter! there is no transition from 12AT7 to 6922
The one you are about to buy is also just an adapter!!
Technologically, with the help of this adapter, the converter can be made, but this task is definitely not solved by two clicks on the computer!

Further: If you nevertheless made this converter and found a master who would risk (there is a possibility of damaging the device if you incorrectly connected the conclusions) check it on your special device for testing radio tubes, How do you insert it into Valhalla and then dismantle it back?

Those photos that my colleague sent had a significant height of the body, namely, you need to hold on to it to insert or remove your converter, and not by the tube glass!
I hope @bcowen will correct me if I'm wrong!

Your caution is warranted and should be taken seriously. My experience with flying lead tubes is that they are a gigantic PITA to deal with. To be fair I've only messed with the subminiature tubes and not any noval tubes, but I'm guessing they will still be a PITA, maybe just not as painful.

That said, as far as the CV4033/12AT7 is concerned, it makes things easier since the pinout is the same between it and the 6922. In the 6922 Pin 9 is not used, where it will need to be for the CV4033 to run at 6.3v. That and pins 4 and 5 are tied together in the CV4033. Another option would be to wire the CV4033 "straight through" (pin 4 to one heater connection, pin 5 to the other....like the 6922) and pin 9 not connected. Then use an adapter for a 12A*7 to a 6922 socket as the adapter will rearrange the connections so that the tube is wired for 6.3v.

As you note, these can't be tested with a DVM or O'scope. They can be tested with a tube tester, which is what I do with all of mine prior to putting in the amp. If something is miswired, either the tube won't light up, or I get a shorts/leakage reading if it does light up and something else is wrong. Of course if you don't have a tube tester, then this is not of much help.

 

[Novik tube]

I post a photo of my collection of old 6N1P (50-60 years of different factories)
I would be grateful for the possible feedback from the owners of Valhalla (strictly a tube OTL amplifier, not a hybrid) who have tried these types of tubes
Of particular interest are experiments with a boxed black anode.

NOTE the selection intentionally only 6N1P without additional E (E) .EB (EV) .B (V) .ВИ (VI)

 

[TBBZ8X8]

Hey guys! Sorry for my brief absence. Just had a couple more questions on the wiring. Currently I am confused on what pin gets soldered where. The diagrams @bcowen supplied seems to imply that the flying lead 1 gets soldered to pad 1, flying lead 2 gets soldered to pad 2, lead 3 to pad 3, etc (except I don't connect pin 9?). It sounds like I need to bridge pins 4 and 5 as well?

At that point I should have an adhoc 12at7 tube and will need at 12at7 to 6922 adaptor?

Sorry for all the questions and confusion guys. This has piqued my curiosity and I want to learn what I can!

Thanks all!

 

[Fertamblez56]

Hello,

What are the general recommendations under 50 and 100 at this point in the thread? Looking for neutral, don't like the JJ gold pins. Want slam for metal. Looking at EH 6922 but they're expensive now. Also considering GE 6DJ8. Stocks are great for older music with creamy mids. The Val is just too syrupy for metal with the stocks for me.

Any help would be appreciated. I want slam and bass.

 

[regaet]

Hello,

What are the general recommendations under 50 and 100 at this point in the thread? Looking for neutral, don't like the JJ gold pins. Want slam for metal. Looking at EH 6922 but they're expensive now. Also considering GE 6DJ8. Stocks are great for older music with creamy mids. The Val is just too syrupy for metal with the stocks for me.

Any help would be appreciated. I want slam and bass.

Valhalla 1 or 2? I've never heard the Valhalla 2 with stock tubes being described as too syrupy.

 

[Fertamblez56]

Valhalla 1 or 2? I've never heard the Valhalla 2 with stock tubes being described as too syrupy.

The 2. I just mean the transients are too slow for metal. I want the tube flavour but none of the trappings when it comes to metal, I want it to be a neutral tube amp away from NOS when it comes to that genre.

Has anybody rolled the power tubes? Are the stocks the cheap fotons or are those different/better?

Or maybe this amp will never be as fast as the hybrid Vali/Lyr in the Schiit lineup. I want to try though.

 

[jonathan c]

Hello,

What are the general recommendations under 50 and 100 at this point in the thread? Looking for neutral, don't like the JJ gold pins. Want slam for metal. Looking at EH 6922 but they're expensive now. Also considering GE 6DJ8. Stocks are great for older music with creamy mids. The Val is just too syrupy for metal with the stocks for me.

Any help would be appreciated. I want slam and bass.

Slam and bass? For the Valhalla 2, skip the 6922 / 6DJ8 / 7308 / E88CC / ECC88 category. Use these: Mullard 6201 (gold pin) with Pulse Tube Store adapters (12Axx —> ECC88). I have used this pairing in Schiit Mjolnir 2, Schiit Valhalla 2, Woo Audio WA3.

 

[Fertamblez56]

Slam and bass? For the Valhalla 2, skip the 6922 / 6DJ8 / 7308 / E88CC / ECC88 category. Use these: Mullard 6201 (gold pin) with Pulse Tube Store adapters (12Axx —> ECC88). I have used this pairing in Schiit Mjolnir 2, Schiit Valhalla 2, Woo Audio WA3.

Wow, those look pretty deluxe. $150 for the pair was probably the max for me. I got the EH anyways but I assume the 12AXX stuff with converters have a higher gain or something?

Maybe if I think the EH are weak I'll consider converters and the 12AXX stuff. I was using the 6CG7 EH in my Vali and thought it was pretty darn good.