DIY partial kit PCB for tube program equalizer, mastering grade

This listing is for set of:

• 2 EQ PCBs (35 Euro each)
• 1 four deck single pole with eleven positions configurable switch (20 Euro)
• 3 one deck two poles five positions switch (10 Euro each)
• 2 6Ж8 (6SJ7 direct replacement) tubes made in USSR, tested in my own EQ (15 Euro each)
• 2 octal sockets for tubes

All switches are NOS and sealed, military grade made in USSR. They are great alternative to expensive Grayhill rotary switches (approx. 30 Euro each).

Proposed switches may show silver oxide signs on contacts after long storage, which has no negative impact on the operation (opened on pictures are for the reference). If you want to buy the kit without the proposed switches, let me know.

PCBs are able to accommodate different lead spacing capacitors (in case you want to opt for something different than orange drops - cheaper or just an alternative, see pictures).

You will receive BOM file as well.

This EQ is basically passive EQ with great signal loss, and requires make-up gain stage after the EQ.

I have another listing where the EQ goes with the make-up gain stage if you want to use same tube type for the amplification after the EQ.

This listing is only a partial kit and the ready EQ on pictures is just for the example of ready build, I am using this build to check tubes now. I call my EQ "Hmara".

The schematic is from September 1947 issue of RADIOCRAFT magazine.

EQ is harmonics-rich and sounds fantastic.

Check the demo on youtube @HappinessMastering.

Disclaimer: the listing is for PCB only and it is up to you how you are going to build it and use it. Remember, that the anode voltage is high in this build so you need to be careful. This is not the very beginner build.