Valve Itch phono

So we’re in business. Populated the board and brought it up to full voltage and nothing exploded or caught fire. Test points as listed on the v1.2 schematic are all within a couple of volts.

Any other checks I should run with a DMM or scope before I try putting any music through it?
 

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diyAudio Chief Moderator
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Congratulations. We we will be waiting to see it finished.

Use shielded signal cable in the end, at least for input. Also don't forget to check your channels gain to be almost equal when you will finish. Less than a decibel difference will do. There's no NFB loop in the Itch so differences in tube sections mu are not governed by a preset ratio in the circuit. Sometimes you get lucky, sometimes the bottles can use a swap around in channels to equal better. If not lucky yet, replace one or two with extras to swap around again. Both the small and big ones contribute gain.
 
I anticipate having three extra of both the amp and the heater PCBs from the prototype order. Based on how much help I’ve gotten from your posts on this thread, PM me and I’ll gladly send you a set just for the cost of shipping if you’re interested. It’s not perfect, but the voltages measure well. I won’t know how quiet it really is until I can get the chassis work done. It was humming like crazy in the cardboard setup, but the sound was great. Head and shoulders above the 834 clone I swapped out when I powered the Valve Itch up.
 
The Valve Itch phono PCB experiment is nearly complete. I wanted to share the resources in case anyone is interested in taking it from here with another round of PCBs or modifications.

In addition to attaching the Gerber files for the amp and heater boards (which I ordered from JLCPCB with no complaints), I am making available the original projects via EasyEDA if anyone wants to fork them and make changes.

I’m also attaching the BOMs for both boards, which include most of the other parts necessary to build out the power supply. The one essential item not reflected is the need to source your own SSHV2 or other HT regulator. It would be great to add that feature to the PSU board, but I’ve got a real SSHV2 and I’m not inclined to try to clone it right now.

Access to the main board schematic and PCB:
Valve Itch Phono -
EasyEDA


Access to the Heater PSU Schematic & PCB:
VI Phono Heater -
EasyEDA


Additional odds and ends for this build I've used (also not on the BOM):

Tubes of your choice (6N2P-EV from EBay/6SN7 from PCX for me)
2x Modushop Galaxy 2U 230x280 chassis (tight fit but I was constrained by a max width)
1x Glass-Ware Select AC switch
2x 7 pin umbilical connectors
Belden 8777 (3 pair shielded conductor wire for umbilical)

Pics to follow by the end of the weekend I hope.
 

Attachments

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  • VIP Heater PSU BOM.pdf
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  • VIP Main Board Gerber.zip
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  • VIP Heater PCB Gerber.zip
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I have been so busy that I have not been able to scratch my head but that is not to say I have not had this Itch ever since I came across this post which I must unabashedly admit I have not fully read. Many thanks to you Jake for the help in scratching my back! You have alleviated some of the Itch by sending me the boards which should arrive any day. Posting and sharing thorough documentation on the work you have done so far is truly commendable. I cannot wait to begin this project. Many thanks also to Salas, and all others for your most remarkable efforts in supporting and in assisting others build this design. And that's all I could not help saying for the time being.