That doesn't look like my idea of fun...
That doesn't look like my idea of fun...
FrankenLab
Hand crafting guitars, because Death Rays are expensive.
To me, it looks like a relatively simple enough amp circuit to understand, a lot of it is pretty standard, the tone-stacks for the two input channels appear to use typical Fender component values, so the schematic seems to be a bit Fender-ish, with a different type of power tube used in the power amp, a pair of 6DQ6A tubes rather than 6L6 tubes, all the preamp and phase inverter tubes are 12AX7, so my guess is that Maton based the amp on one of Fenders models, so once it's back up and running again it should have a Fender-ish tone.
Last edited by DrNomis_44; 11-02-2020 at 11:59 AM.
From the very few reviews I've been able to find it is very clean and bloody loud.
It's called an STB 75 which I assume means Super Twin ( Chanel ) Bass 75 W, but there is a switch on the front that is labeled 50/50-100 and they talk about it being a half power switch
Looks like you're limited to using a 16 ohm load, so a single 4x12" cab or 1x12" cab (or 2x8 ohm speakers in series).
Of course you could change the output transformer to a multi-tap one, but that would change the character of the amp.
Ah Simon that's pretty much the conversation I had with Scott, we both like 10s but he's thinking a single 12.
Maybe a 10 & 15 in series if there's suitable options
Indeed. Probably best to get the amp working first, see what it sounds like, and then start thinking about custom cab options.
Those 6DQ6A were mainly used as TV valves, so in plentiful supply back when the amp was made. You're reliant on finding NOS valves now, so it might well be worth getting some spares for the future whilst you can. At lest you have the option of using 6DQ6B valves as well, which widens the options slightly.
There are other more modern valve options that don't require major mods.
Anode to socket rather than cap and obviously rebias plus a bit but not rocket surgery
But then it's not quite the same amp.
So it all depends on whether your mate just wants a nice working amp or an original looking and sounding Maton. I don't regret having all the changes made to my Sound City head so that it's a very different amp now to the original and sounds so much better (and quieter). Had the OP transformer not required replacing (with a Marshall one for availability reasons) then I'd probably have kept it all original.