I will start building this design on Jake's PCBs as soon as I receive the boards. In the meantime, I am gathering some parts. It would have been nice to integrate the SSHV2 in the power supply but I have not been able to find a source for the SSHV2 PCB. Does anyone know of a source? Would appreciate any assistance.
Salas thank you for referring me to Tea Bag. I contacted him and was advised to sign up on his subscription list to receive the board which contains many other attractive projects highly recommended to all DIYers. The SSHV2 with its remarkably low output impedance is a practical implementation to any power supply. If like me know have been out of touch with the forum or are new to the forum, look up SSHV2 and sign up on Tea Bag's list to receive your board(s). I searched the web to source an SSHV2 PCB but it seems like everyone who at time point carried the board is out of stock. Seek Tea-Bag!
By the way, many thanks to Jake. I received the Valve Itch Heater and Phono boards today.
By the way, many thanks to Jake. I received the Valve Itch Heater and Phono boards today.
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Congrats. Do the big valves pop out through the top in a 2U case? Did you measure the channel balance?
He said it was a graphical mistake in his schematic but ok in the actual board I think. He will confirm this or not.
Divide 0.5V RMS 1kHz sinewave output from a function generator by hundred times first. Make 10k series 100R to ground L-Pad from resistors you have around. Keep the divider small and neat. Use coax. The divided signal will represent a 5mV MM cartridge. Don't get tempted to use the generator directly as source at 5mV because it will be much noisier. Between the 100R and ground send input signal to both Itch channels.
Connect the Itch outputs to a dual channel scope. Compare them. Then do swaps with the valves as I wrote to you in post #3269 and try to match the sinewave outputs amplitude the best possible on the scope's screen.
If it sounds not obviously unbalanced in volume between channels its probably good enough already. But surely check sometime. Because there is no negative feedback loop gain control to guarantee a matching gain ratio for L&R in this design. Channels nearness is based on the μ nearness of the tubes themselves.
Certainly don't adjust anti-skating to center the stereo image before knowing that the electronics have a good gain match between the channels.
Certainly don't adjust anti-skating to center the stereo image before knowing that the electronics have a good gain match between the channels.
Thanks -- it's definitely close enough for now. I'm also thinking I'll move toward some NOS 6SN7. Now that it's up and running, I think it deserves something better than the new stock Sovteks.
What do people like for less than $50 for a matched pair?
The performance is very accurate from brief, non-critical listening last night. I'll need some more time to evaluate, but I did like what I heard. Not as "tubey" as my 834 clone, but I think it will be a good balance paired with my all tube integrated.
Hmm... Good rep NOS are really expensive these days and you never know if in good spec. Tung-Sol 6SN7 GTB reissue maybe. Can hold its own against many decent NOS. Meeting your price range new from main online stores. Even if chancing on a noisy sample you can return it. The second stage does contribute in this circuit's SQ a lot by the way.
Thanks -- I really should let it cook a little while before I make any changes anyway..
More 6SN7s than you can shake a stick at. Use neutral headphones...
Schiit Freya Preamp - Tube Rolling 6SN7 Quads Listening Test
6SN7 Amperex/CBS-Hytron/PhilipsECG/Sylvania Tube Rolling Quads Listening Test Part 2
Tung-Sol Battle - American NOS vs Russian New Production 6SN7 Quads
Schiit Freya - JJ Electronic vs Electro-Harmonix Tube Rolling 6SN7 Quads Listening Test
Schiit Freya Preamp - Tube Rolling 6SN7 Quads Listening Test 6SN7 Amperex/CBS-Hytron/PhilipsECG/Sylvania Tube Rolling Quads Listening Test Part 2 Tung-Sol Battle - American NOS vs Russian New Production 6SN7 Quads Schiit Freya - JJ Electronic vs Electro-Harmonix Tube Rolling 6SN7 Quads Listening Test 
