A couple of months ago I found a Chinese M77 replica on eBay and was kinda curious to try building one myself.
When I started soldiering everything together I noticed that some parts where missing or had slightly different values that the labels on the PCB.
And for Chinese DIY kits usual… it did not come with any manuals whatsoever and all the pictures have diferent parts and part values…
The resistor in the Power supply part of the PCB for example is slightly of.
Has anyone assembled one of these M77 Clones before and has some advice for the missing parts / wrong resistor values ?
It woud be hugely appreciated.
I recently built one of these and a M7 clone. Some resistors and capacitors values may be different. For the resistors, check that the “combined” value of the parallel resistors match the expected combined value on the board. The capacitor value may be different but it’s neither here or there. If you need the exact values, you can always buy them at hificollective. Resistors are cheap enough. Hope it helps.
Nino. Which missing components are you struggling to find? The ones that are missing in your picture? The values required there are labelled. There’s some scope for choice regarding which flavour of coupling & cathode by-pass caps you choose. With regard the power supply, which power transformer are you using and are you trying to incorporate a choke?
I do want to add a choke to my build but I have not settled for one as of now.
As for the power supply I ordered this transformer.
Since this is my first Project regarding any Tube Amps I was just curios what more experienced people would recommend for the coupling and cathode caps that are missing in the picture.
What actually confused me is that the cathode caps have different values marked on the board and some pictures of the sale page again had other values as the labels on my PCB.
Since I already wasted quite a lot of money on this project I don’t really care what these parts cost as long as they are good.
Thanks again for helping a clueless tube amp newby out