Finished my MEQ0-5 build last night. All seems to be working as expected. Yay!
Checked all voltages marked on the schematic I have. No issues. No distortion, buzzes, hums or other artifacts found or being presented so far...
I inadvertently wired the bypass switch backwards - off was on, on was bypass, so had to re-wire that, but after making that fix, the unit sounds amazing!
My first point-to-point build...
My capacitor planning / execution leaves a little to be desired. Might re-look at that. It wasn't clear to me where or how the caps and inductors were mounted in vintage units, so I ended up throwing caution to the wind.
That aside, I used a vintage Triad HS-56 input transformer (had three of these in my parts cabinet), but so far haven't found a HS-50, so using a Sowter 1290 that I ended up mounting internally.
The bypass switch is a NOS Switchcraft and the frequency rotary switches are ceramic NOS parts sourced from Eastern Europe.
Vintage Windings inductors.
Of course, as soon as I nearly finished my build, I found a NOS Traid R-7A transformer in the original box and another used (?) R-7A which are both in the mail at the moment. Debating whether or not to replace the current Hammond in favor of a vintage R-7A?
With the exception of the reverse pot, the rest are NOS Allen-Bradley pots .
The 2k5 reverse log pot is a Mouser sourced modern part which unfortunately is a mini pot that I kludged into fitting with a home made shim around the bushing to make it fit properly in the chassis. I recently learned of and ordered a small number of full sized 2k5 rev log pots from Blore Edwards Limited in the UK. I'll probably swap that part out just to have a full sized pot in place even though the mini pot is working.
Thanks to Martin for making this chassis available. Great project! A second build is likely ahead of me in the near future! ;-)