Search found 374 matches

by mmolteratx
11 Jul 2014, 00:59
Forum: Boutique Stompboxes dissected...
Topic: Ramble FX - Marvel Drive 1.0 [traced]
Replies: 90
Views: 50025

Re: Ramble FX Marvel Drive 1.0 [Schematic Inside] [traced]

FWIW, you could substitute it with a cap as small as 10µ and have the exact same operation in the audio range, which extends pretty far below the guitar range. 330µ is crazy. Just means full gain extends down to .6Hz. 10µ means it goes down to 19.4Hz.
by mmolteratx
25 Jun 2014, 03:00
Forum: Boutique Stompboxes dissected...
Topic: Rothwell Switchblade [traced]
Replies: 6
Views: 2718

Re: Rothwell Switchblade [traced]

mirosol wrote:Layout works, but my guesses on the values aren't exactly spot on.. Anyone have better guesses?
Try

C1 - 100n
C2 - 220n
C4 - 1n
C6 - 470n or maybe even 1µ
C8 - 1n
C9 - 220n or 470n
C10 - 100p or 220p
by mmolteratx
24 Jun 2014, 01:38
Forum: Boutique Stompboxes dissected...
Topic: Dumbloid [traced]
Replies: 471
Views: 125753

Re: Dumbloid [traced]

Well, increasing the value of the attack pot increases the gain of the second stage, so not surprised that it exacerbates the problem.
by mmolteratx
21 Jun 2014, 00:14
Forum: Boutique Stompboxes dissected...
Topic: Oddfelow Effects - Caveman Overdrive [traced]
Replies: 23
Views: 9665

Re: caveman overdrive [traced]

Did this pretty quick, but I looked over it and it looks good, as long as the schematic is good. Uploaded to OSH Park. I don't guarantee that it works, but it's very likely that it does. Might be up to organize a group buy after it's verified and if there's enough interest. Will fit in a 125B for su...
by mmolteratx
20 Jun 2014, 19:37
Forum: Boutique Stompboxes dissected...
Topic: Oddfelow Effects - Caveman Overdrive [traced]
Replies: 23
Views: 9665

Re: caveman overdrive [traced]

Here's a redraw of the schem with a slightly less retarded boost control. Might do up a PCB later today.
by mmolteratx
16 Jun 2014, 05:01
Forum: Boutique Stompboxes dissected...
Topic: Dumbloid [traced]
Replies: 471
Views: 125753

Re: Dumbloid [traced]

Enough talking about the farty decay, I thought it was time to record it. The following clip consists of 3 parts. The first section is played through my dumbloid clone on the breadboard with a strat through a deluxe reverb reissue dry with no effects or processing. The second part is played through...
by mmolteratx
15 Jun 2014, 21:52
Forum: Boutique Stompboxes dissected...
Topic: Dumbloid [traced]
Replies: 471
Views: 125753

Re: Dumbloid [traced]

Correct me if I'm wrong but wouldn't lowering the value of those resistors give Q1 and Q2 a much hotter bias? Do you suppose the designer is using them as boosts or to contribute to the distortion in some way? I've read in a couple of earlier posts that these changes seemed "arbitrary" bu...
by mmolteratx
15 Jun 2014, 18:20
Forum: Boutique Stompboxes dissected...
Topic: Death by Audio Kill Kill Filter
Replies: 9
Views: 4210

Re: Death by Audio Kill Kill Filter

Uggh. Every time I see guts of their pedals, I just can't help but wonder what fuckwad thinks that's even remotely acceptable, especially for the prices they charge.
by mmolteratx
15 Jun 2014, 18:18
Forum: Boutique Stompboxes dissected...
Topic: Dumbloid [traced]
Replies: 471
Views: 125753

Re: Dumbloid [traced]

Correct me if I'm wrong but wouldn't lowering the value of those resistors give Q1 and Q2 a much hotter bias? Do you suppose the designer is using them as boosts or to contribute to the distortion in some way? I've read in a couple of earlier posts that these changes seemed "arbitrary" bu...
by mmolteratx
14 Jun 2014, 23:00
Forum: Boutique Stompboxes dissected...
Topic: Vemuram - Jan Ray [traced]
Replies: 69
Views: 38029

Re: Vemuram Jan Ray (Traced) [traced]

Old post.... but full of infos :-) wondering about capacitor types ( mojo mojo... ) ref to post pag1, I never seen/don't know the type of 44.9pF capacitor (C8) 20.9pF capacitor (C3) Also, into the schematic C7 and C2 are 47nF while the images state 50nF. Is it just a tolerance matter right ? Thanks...
by mmolteratx
14 Jun 2014, 22:57
Forum: Boutique Stompboxes dissected...
Topic: Dumbloid [traced]
Replies: 471
Views: 125753

Re: Dumbloid [traced]

If you're using the op amps in their linear (and recommended by the manufacturer) part of their operating area, they're more or less the same. But as clipping goes, each one is quite unique, especially in the decay part of the signal envelope. What I'm trying to say is that fizzy decay is common (s...
by mmolteratx
14 Jun 2014, 20:35
Forum: Boutique Stompboxes dissected...
Topic: Dumbloid [traced]
Replies: 471
Views: 125753

Re: Dumbloid [traced]

I haven't had the time to test the newest revision boards that came in, and won't be able to for a few weeks at minimum. So in the mean time, for those of you who have been waiting, I've put the first verified revision up on OSH Park if you don't want to wait any longer. https://oshpark.com/shared_p...
by mmolteratx
30 May 2014, 06:21
Forum: Boutique Stompboxes dissected...
Topic: Dumbloid [traced]
Replies: 471
Views: 125753

Re: Dumbloid [traced]

I have no idea. I was commenting to what the other poster said about a thing he remembered reading from some unnamed engineer at some point. It's highly possible that something's been glossed over. Whoops. Quoted the wrong person. Searched the quote on Google, and he was definitely referring to a b...
by mmolteratx
29 May 2014, 22:29
Forum: Boutique Stompboxes dissected...
Topic: Dumbloid [traced]
Replies: 471
Views: 125753

Re: Dumbloid [traced]

Isn't there already a 10K from both non-inverting inputs to Vref? Yes there would be. He said 1M to ground. I've never done that before. It would be creating a voltage divider with the bias setting resistor, but with it being 100 times the size of the 10K bias resistor, you shouldn't see too much o...
by mmolteratx
29 May 2014, 03:07
Forum: Boutique Stompboxes dissected...
Topic: Dumbloid [traced]
Replies: 471
Views: 125753

Re: Dumbloid [traced]

All those op-amps have been tried and they don't help the fizzy decay. I have had both Hotcakes and they have the same problem. :hmmm: thanks, I see there is no quick fix to solve the fizzy decay problem. Sure there is. Put a diode in. The op amp rail is at 4.5V, right? Most of the tone you're gett...
by mmolteratx
14 May 2014, 23:04
Forum: Boutique Stompboxes dissected...
Topic: Fairfield Circuitry - Four Eyes Fuzz
Replies: 49
Views: 9967

Re: Fairfield Circuitry - Four Eyes Fuzz

Man I wish I still had this one. Would be a fun afternoon or two reversing it.
by mmolteratx
14 May 2014, 22:45
Forum: Boutique Stompboxes dissected...
Topic: Free the Tone - Gigs Boson V1.1
Replies: 3
Views: 1981

Re: FREE THE TONE GIGS BOSON

It seems to me that, looking at the topology and after hearing many of the Free the Tone pedals, many of them are based on the Tube Screamer. That said, this demo makes me want to trace at least one of them: https://www.youtube.com/watch?v=-KDOWJ2mxdM The Providence and FTT ODs are all Tubescreamer...
by mmolteratx
14 May 2014, 22:38
Forum: Boutique Stompboxes dissected...
Topic: Dumbloid [traced]
Replies: 471
Views: 125753

Re: Dumbloid [traced]

Anyone waiting on a PCB, apologies for the delays. I got totally swamped with school work towards the end of the semester, and just finished. The boards are here (and awesome), but I'm out of town on vacation for two weeks before I start up again. I'll let you guys know when I'm back and start sendi...
by mmolteratx
14 Apr 2014, 20:46
Forum: Boutique Stompboxes dissected...
Topic: Dumbloid [traced]
Replies: 471
Views: 125753

Re: Dumbloid [traced]

Reordered, but I didn't go for the speedier service this time. Could be as long as a month from last Wednesday, though hopefully they'll be here sooner.
by mmolteratx
12 Apr 2014, 03:54
Forum: Boutique Stompboxes dissected...
Topic: Oddfelow Effects - Caveman Overdrive [traced]
Replies: 23
Views: 9665

Re: caveman overdrive [traced]

FET clipping in the feedback loop. It's a boring op amp clipper with basic frequency shaping. Maybe Zen Drive ish. Not worth tracing, IMO.