Vari-Mu tube compressor PCB for DIY project based on Altec 436c, RS124, VK1

The listing is for PCB to build tube compressor. I have four of them, contact me if you need more (for stereo build, for example).

The schematic of the compressor is based on Altec 436c / RS124 / VK1 compressors.

Tubes used for this build:

- 6BZ7 input tube (alternative is 6BQ7),

- 6EV7 output tube (alternatives are: ECC85, 6BZ7),

- 6AL5 rectifier tube.

Input transformer is Lundahl LL1540 but you can use anything you prefer, PCB just has LL1540 footprint for convenience.

Output transformer is UTM Industry UTM3580 but you can wire anything you like, from what fits the design.

With the PCB you will receive the QR code which you can scan, open link to the Drive and get BOM file from there.BOM file is a reference, feel free to experiment and enjoy! Calibration guide included.

I have made the compressor using exact this PCB and recommended from BOM parts. It is noiseless and smooth.

Power supply is not on the PCB, for flexibility and more modular approach. I have ordered proper PSU with 6.3V for filament and 240-260V for B+ voltage at fyfaudio, see pictures.

Works as it should and sounds amazing. You can find 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.

No returns, the sale is final.