There was a lot more interest in this project than I expected, so here is a help thread.
Schematics, BOM and instructions can be found here. In case I don’t pay server hosting fees, backup is here.
Scott2000 has already built his and he should have some extra boards to sell. He might also have kit/partial kit to sell. He is located in the US so anyone in that part of the world still interested getting boards should contact him. He will probably chime in here how best to contact him.
Black Market thread for boards
https://groupdiy.com/threads/transformerless-vari-mu-pcbs-for-sale.79539/
Big thanks to Scott for helping with the instructions. Now the instructions should make at least some sense.
Here is a RightMark Audio Analyzer test report made with using Focusrite Scarlett 2i2. (Using the line input where 0dBFS = +22dBu)
Sound samples, same song with different amounts of compression.
Mouser cart which should have almost all of the components needed. Missing are tubes, tube sockets and the 36V wall wart. Double check everything before ordering! Does NOT have all the components needed for the rotary switch sidechain version!
https://www.mouser.fi/ProjectManager/ProjectDetail.aspx?AccessID=af87d40971
Here is a Mouser cart for the rotary switch version. Best double check everything is there! Lorlin CK1054 rotary switches can be probably gotten cheaper somewhere else.
https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=1b27f61fbf
This is the type of tube socket I recommend using.
https://www.tube-town.net/ttstore/socket-octal-7-8-long-leads.html
Some hints and tips
C9 on the power supply board can be omitted
C29, C30, C31, C32 on the main board can be replaced with jumpers. Read Post #84 and Post #86.
Read post #30, how to balance the channels.
Read Post #80, modifications for mastering use
Round shaft Lorlin rotary switches
Post #156
Post #158
Some components needed seem to be nearly ot of stock and have long factory lead times. Get them while you can.
edit: digikey seems to have plenty in stock!
Recom R24-150B
https://www.mouser.com/ProductDetail/RECOM-Power/R24-150B?qs=3sBZtWOgbie4PqVOrFomEQ==https://www.tme.eu/en/details/r24-150b/dc-dc-converters/recom/https://www.digikey.com/en/products...B/3776803?s=N4IgTCBcDaIE5gCwFoCMBWADAIxAXQF8g
DCWN06B-15
https://www.mouser.com/ProductDetail/MEAN-WELL/DCWN06B-15?qs=lYGu3FyN48dlyOt5/46H9A==https://www.tme.eu/en/details/dcwn06b-15/dc-dc-converters/mean-well/https://www.digikey.com/en/products...55?s=N4IgTCBcDaICYGMDuA7ADANgEYFoCMArCALoC+QA
GE40I36-P1J
https://www.tme.com/en/details/ge40i36-p1j/plug-in-power-supplies/mean-well/
Alternative power supply here!
In this post some gut shots from Manu Laudic’s build.
In this post pictures from paolomunarini's build.
Schematics, BOM and instructions can be found here. In case I don’t pay server hosting fees, backup is here.
Scott2000 has already built his and he should have some extra boards to sell. He might also have kit/partial kit to sell. He is located in the US so anyone in that part of the world still interested getting boards should contact him. He will probably chime in here how best to contact him.
Black Market thread for boards
https://groupdiy.com/threads/transformerless-vari-mu-pcbs-for-sale.79539/
Big thanks to Scott for helping with the instructions. Now the instructions should make at least some sense.
Here is a RightMark Audio Analyzer test report made with using Focusrite Scarlett 2i2. (Using the line input where 0dBFS = +22dBu)
Sound samples, same song with different amounts of compression.
Mouser cart which should have almost all of the components needed. Missing are tubes, tube sockets and the 36V wall wart. Double check everything before ordering! Does NOT have all the components needed for the rotary switch sidechain version!
https://www.mouser.fi/ProjectManager/ProjectDetail.aspx?AccessID=af87d40971
Here is a Mouser cart for the rotary switch version. Best double check everything is there! Lorlin CK1054 rotary switches can be probably gotten cheaper somewhere else.
https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=1b27f61fbf
This is the type of tube socket I recommend using.
https://www.tube-town.net/ttstore/socket-octal-7-8-long-leads.html
Some hints and tips
C9 on the power supply board can be omitted
C29, C30, C31, C32 on the main board can be replaced with jumpers. Read Post #84 and Post #86.
Read post #30, how to balance the channels.
Read Post #80, modifications for mastering use
Round shaft Lorlin rotary switches
Post #156
Post #158
Some components needed seem to be nearly ot of stock and have long factory lead times. Get them while you can.
edit: digikey seems to have plenty in stock!
Recom R24-150B
https://www.mouser.com/ProductDetail/RECOM-Power/R24-150B?qs=3sBZtWOgbie4PqVOrFomEQ==https://www.tme.eu/en/details/r24-150b/dc-dc-converters/recom/https://www.digikey.com/en/products...B/3776803?s=N4IgTCBcDaIE5gCwFoCMBWADAIxAXQF8g
DCWN06B-15
https://www.mouser.com/ProductDetail/MEAN-WELL/DCWN06B-15?qs=lYGu3FyN48dlyOt5/46H9A==https://www.tme.eu/en/details/dcwn06b-15/dc-dc-converters/mean-well/https://www.digikey.com/en/products...55?s=N4IgTCBcDaICYGMDuA7ADANgEYFoCMArCALoC+QA
GE40I36-P1J
https://www.tme.com/en/details/ge40i36-p1j/plug-in-power-supplies/mean-well/
Alternative power supply here!
In this post some gut shots from Manu Laudic’s build.
In this post pictures from paolomunarini's build.
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