move the 820 ohm resistor from col 8 to 7, double-check that the 33k is connected to the gate of Q1, and you can tag this one, sir :) thanks for the layout! I'm already in love with this one
Finished mine up late last night and was floored by it! I used 2N5457s instead of J201s, and clipped that last 2n2 cap at the end (opened it up for more treble). It's ridiculously quiet as well. Far and away the best MIAB for that classic 'kerrang' in the chords. Would love to know if there's a way to reduce the overall bass (a little) in the circuit; it's a little thick as-is and I'd like it a little 'leaner' for lower-to-medium-gain playing. My only problem now is that I want to build another with tweaks to the circuit to perfect it for my needs; seriously don't think I'll look at another box for classic Marshall sounds (high gain/hot-rodded is another story).
I've not built this one so my advice is based simply on a quick look-over of the schematic that Anders linked to above the drawing. You might try changing the value of the 22nF cap that connects to pin 1 of the tone control to a smaller value, like maybe 15nF?
If it were my build, I'd try to add an SPST to put a 5n6 cap in parallel so I could get it back up to stock bass levels at the flick of a switch if I wanted to. That's assuming that reducing that capacitor size gets you the tone you want in the first place, of course...
I'd actually start by clipping the 100u cap between the source of Q1 and ground; that'll massively reduce the gain on the "normal" channel, but because that's where all the woofiness comes from, you might actually get a more useful sweep. (I've built this too, and I rarely have the "normal" channel above 8 o'clock.) Maybe replace it with a 22u cap for a happy medium.
That was fast!!Thanks man!!
ReplyDeleteEmulating the schematic I see a big boost in the mid-bass, not much fine. Are we sure there's no mistaken in the schematic?
ReplyDeleteI don't know but as far as I know Bugg traced this one himself and his traces haa salways been accurate.
Deletemove the 820 ohm resistor from col 8 to 7, double-check that the 33k is connected to the gate of Q1, and you can tag this one, sir :) thanks for the layout! I'm already in love with this one
DeleteSo it sounds fine?
DeleteMy emulator is a liar with some schematic, or maybe by ears it sounds better than the frequency I see.
Excellent! Layout is updated and tagged.
DeleteElijah-Baley i haven't played an original, but comparing it to demo videos it seems pretty spot on.
ReplyDeleteI think it should be ok, then.
DeleteHi, looks like a Marvel Drive
ReplyDeleteBy far the best MIAB i ever built and played
ReplyDeleteCan I replace the J201 with 2N5457?
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteSounds beautiful! Thank you so much.
ReplyDeleteHere's a sound sample of my build, fed into a Fender-style preamp: https://youtu.be/-fnT5RjNVPE
Finished mine up late last night and was floored by it! I used 2N5457s instead of J201s, and clipped that last 2n2 cap at the end (opened it up for more treble). It's ridiculously quiet as well. Far and away the best MIAB for that classic 'kerrang' in the chords. Would love to know if there's a way to reduce the overall bass (a little) in the circuit; it's a little thick as-is and I'd like it a little 'leaner' for lower-to-medium-gain playing. My only problem now is that I want to build another with tweaks to the circuit to perfect it for my needs; seriously don't think I'll look at another box for classic Marshall sounds (high gain/hot-rodded is another story).
ReplyDeleteI've not built this one so my advice is based simply on a quick look-over of the schematic that Anders linked to above the drawing. You might try changing the value of the 22nF cap that connects to pin 1 of the tone control to a smaller value, like maybe 15nF?
DeleteIf it were my build, I'd try to add an SPST to put a 5n6 cap in parallel so I could get it back up to stock bass levels at the flick of a switch if I wanted to. That's assuming that reducing that capacitor size gets you the tone you want in the first place, of course...
I'd actually start by clipping the 100u cap between the source of Q1 and ground; that'll massively reduce the gain on the "normal" channel, but because that's where all the woofiness comes from, you might actually get a more useful sweep. (I've built this too, and I rarely have the "normal" channel above 8 o'clock.) Maybe replace it with a 22u cap for a happy medium.
Delete