PCB Guitar Mania Appetite for Distortion

[RICHB555]

Build Rating

5.00 star(s)

I’ve heard it said before that sometimes the 2 and 3 knobbers sound the best, and this one’s no exception! This build, a Bajaman design, is PCB Guitar Mania’s take on Slash’s signature Marshall AFD amp. Replicates the Appetite for Destruction tone very well. All high gain on tap. Of course I had to bring a Lester down to the shop to test this one to get the full effect and what fun it was. Basic Level and Gain controls are all you need here, unless your build connects to PCB Guitar Mania’s EQ sections. Pretty straightforward build - 2 J201s, one BC547B and a TL064.

Not much gain variance - seems like it’s on or off with the B100K gain pot. One tip - you gotta jumper the Send & Return pads if not using an external EQ, which is what I elected to do with my build.

Tayda 125b, Tayda ripple knobs, top hat decal is Cricut vinyl. If you’re a GnR fan, put this one on your radar!

 

[micmac]

Thanks for posting! Made me curious, because I like Appetite for Destruction! And I had never built anything from Bajaman before, but always wanted to. So, in the past days I drew a vero layout and built this thing. My soldering wire roll has about 10 centimeters left now, but I'm done.

I used what I had, so TL072 and a BC327. For the buffers I used PN4393.

The electronics store in the city is closed in the afternoons, because of summer vacation. Will have to wait some time till I get the TL062s. I doubt that the BJT makes much of a difference. But I'll get one anyway. With the TL072 it sounds good, though. For me anyways.

It sounds pretty believable, I'd say. And it's not noisy. Has a lot of treble, but that was to be expected I reckon. Using the tone stack of your amp it's controllable. Note decay is really nice, cleans up OK, too. Lows are tight.

The gain pot I find OK. I read somewhere some guy wrote that it's controlling the gain for low frequencies. I think the guy was onto something. It's fine.

The volume pot I'll swap for log taper. Unity is at 9 o'clock with a linear taper.

Thanks again! Cool pedal.

 

[micmac]

Just saw that you also used MLCCs for the 1u caps I read Bajaman did the same, so I did the same. Also to save some space on the vero. Nine 1u caps is a bit crazy

 

[RICHB555]

Thanks for posting! Made me curious, because I like Appetite for Destruction! And I had never built anything from Bajaman before, but always wanted to. So, in the past days I drew a vero layout and built this thing. My soldering wire roll has about 10 centimeters left now, but I'm done.

I used what I had, so TL072 and a BC327. For the buffers I used PN4393.

The electronics store in the city is closed in the afternoons, because of summer vacation. Will have to wait some time till I get the TL062s. I doubt that the BJT makes much of a difference. But I'll get one anyway. With the TL072 it sounds good, though. For me anyways.

It sounds pretty believable, I'd say. And it's not noisy. Has a lot of treble, but that was to be expected I reckon. Using the tone stack of your amp it's controllable. Note decay is really nice, cleans up OK, too. Lows are tight.

The gain pot I find OK. I read somewhere some guy wrote that it's controlling the gain for low frequencies. I think the guy was onto something. It's fine.

The volume pot I'll swap for log taper. Unity is at 9 o'clock with a linear taper.

Thanks again! Cool pedal.

Thanks for sharing your experience, and glad you found some inspiring tones from this one. Interesting substitutions- thanks for that as well!

I hope you’ll share photos of your vero build as well as any enclosure aesthetics that were part of your build.

 

[RICHB555]

Just saw that you also used MLCCs for the 1u caps I read Bajaman did the same, so I did the same. Also to save some space on the vero. Nine 1u caps is a bit crazy

Funny you mention the 1uf MLCCs - total coincidence that I used these. With so many builds on my bench lately, I was out of box film caps. But as you say, saves space on the board which is always convenient!

 

[micmac]

I got to admit I slacked on the "enclosure aesthetics", didn't do anything in that department. Do I really need to bother with a decal if the pedal only has two knobs? Still on the fence... On the other hand I will take the thing out of the case anyway, so I might as well do up the looks a little bit.

Apart from getting a log pot for volume I think I'll also change the source resistors of the buffers. 10k looks a bit too high for buffers where the gate is tied to VREF. Looks a bit starved, me thinks. I think I'll replace them with 3k9 or something.

 

[RICHB555]

I got to admit I slacked on the "enclosure aesthetics", didn't do anything in that department. Do I really need to bother with a decal if the pedal only has two knobs? Still on the fence... On the other hand I will take the thing out of the case anyway, so I might as well do up the looks a little bit.

Apart from getting a log pot for volume I think I'll also change the source resistors of the buffers. 10k looks a bit too high for buffers where the gate is tied to VREF. Looks a bit starved, me thinks. I think I'll replace them with 3k9 or something.

View attachment 123162

Beautiful build!