And here it is, finished!


Although I'm suspecting I should replace the MPF102 because there's some strange underlying distortion I didn't have before. I accidentally had the DC-DC converter board set to 25v and fried the first LM386 amp board, but I'm not sure if the J-Fet didn't also get nuked. I'll do it tomorrow cus it's midnight right now.

Maybe this one (corrected version)

You trust our divination skills too much 

WHICH Amp? Brand and model?

Post a picture of headphone out.

Is it a Guitar or a Hi Fi amplifier?

Show the speaker output jacks/terminals too.

Any speaker selector switch on the front panel?

LOTS of questions.

Good!!!

No need go get *exact* cap values if not available, +/-20% is always close enough.
At least it was close enough for Leo Fender

We are pampered by modern parts availability and precision; but way back then ... not that much ... yet they made killer amps.

Please continue posting your experiments 

I had some free time at work today so I drew this perfboard layout for the buffer, and made it once I got home - worked first try.

Attached are the layout and some pictures of the project so far.

Only difference between the Hiwatt/Bassman mod I drew and the actual build is that I didn't have any 18nF caps (to get 15nF in series with 100nF for the Hiwatt mode), but I do have a bag of 33nF caps, so 2x of those in series gets me in the right ballpark (~14nF) for this mod.

I have OneOdio A70 fusion headphones and I plugged it into my amp and sounds coming out of both the headphones and amp? Both the amp and headphones were gifted so maybe I just need to get better, not so cheap headphones/amp but I'm hoping maybe it's just the settings or something.

Thanks for posting, this one looks much cleaner.

There is an error at the power supply: the -12V rail is shown feeding 4558 Op Amp pin 8, it should go to pin 4

Maybe there are others, will check the full schematic later.

You place too much trust in our divination skills

We don´t even know what *Country* you are in, let alone state or province  

Just checked your YT video: killer sound 

Congratulations

Recently I got a handful of those LM386 module boards peeps seem to like turning into fuzz boxes, and got very dissapointed with how they sounded right away, but then I thought "what if I added the input buffer from the Ruby to it?", and went to work.


It's night and day. More gain, better dynamic response, and the "Hiwatt" and "Bassman" mods work as expected.

So, if you have one of these lying around, try adding that buffer to the input and see how it works for you.

For a "full Ruby conversion", on top of adding the input buffer, you can remove C1 on the board and attach a couple wires to it's pads to connect the 1K gain pot, remove the volume trimpot and wire up a 10K volume pot to it's pads, and change C3 from 100uF for a 220uF.