Search found 127 matches

by aionios
18 Dec 2020, 18:19
Forum: Parts Sourcing & Trading
Topic: j201 substitute
Replies: 30
Views: 10767

Re: j201 substitute

J201 in TO-92 though hole in stock at Mouser currently. https://www.mouser.com/ProductDetail/InterFET/J201/?qs=OxRSArmBDfyvD8SbvWteMw%3D%3D Just a heads up... all the classic pedal applications for the J201 were developed with Fairchild/ON Semi parts, which up until recently was the only manufactur...
by aionios
19 Nov 2020, 19:07
Forum: Boutique Stompboxes dissected...
Topic: Catalinbread - SFT [traced]
Replies: 280
Views: 111229

Re: Catalinbread - SFT [traced]

Add 1M resistor between Q1 gate and GND. This is missing component on schematics. This is on pedalpcb schematics https://www.pedalpcb.com/docs/SOFTii.pdf With this pedal works consistently, there is no need to "reset" it after each 10 seconds, tone is not dark anymore and different transi...
by aionios
18 Nov 2020, 17:38
Forum: Boutique Stompboxes dissected...
Topic: Crowther Audio - Hot Cake Overdrive [traced]
Replies: 306
Views: 129620

Re: Crowther Audio - Hot Cake Overdrive [traced]

It's the 2008 revision, but the specific model I traced was from 2014. As far as I understand, the next revision after 2008 was the 2020 one that released this summer, with toggles on the outside.
by aionios
16 Nov 2020, 21:59
Forum: Boutique Stompboxes dissected...
Topic: Crowther Audio - Hot Cake Overdrive [traced]
Replies: 306
Views: 129620

Re: Crowther Audio - Hot Cake Overdrive [traced]

We were sorely missing any info on the post-2003 models, including the XLF and Bluesberry variants, so I traced a post-2008 Hotcake which includes internal switches for XLF and Bluesberry modes. Crowther goops these pedals pretty effectively, so it was a pain, but hopefully worth it! crowther_hot_ca...
by aionios
16 Nov 2020, 20:06
Forum: Boutique Stompboxes dissected...
Topic: Dinosaural - OPA 101 overdriven preamp
Replies: 21
Views: 10838

Re: Dinosaural - OPA 101 overdriven preamp

I was finally able to get one of these and trace it, so we're now 3 for 3 on Dinosaural designs (the Tube Bender and OTC-201 are the other two pedals he designed). Here's how it looks: opa101_trace_schematic.png Not an exact copy of the Tube Bender by any means, although it does share the same overd...
by aionios
14 Oct 2020, 13:05
Forum: Software Room
Topic: Gaussmarkov Eagle and LTspice tutorials
Replies: 6
Views: 1940

Re: Gaussmarkov Eagle and LTspice tutorials

Don't use the gaussmarkov Eagle libraries... they're super outdated and not very well designed by today's standards. They were a game-changer when they first came out, the first pedal-friendly set of libraries for Eagle, but they don't hold up well in 2020. His tutorials aren't great either - for ex...
by aionios
14 Sep 2020, 22:08
Forum: Boutique Stompboxes dissected...
Topic: Pete Cornish - CC-1 Crunch
Replies: 4
Views: 1262

Re: Pete Cornish - CC-1 Crunch

Ben N wrote: 14 Sep 2020, 19:32 Nice. Looks like a worthwhile build. Might NE5532/NE5534 be a good substitution for TL072/TL071?
Yep, will be a little higher current draw but on paper it’s a better audio chip. Should work fine!
by aionios
14 Sep 2020, 02:22
Forum: DIY Stompbox designs
Topic: Guitar Distortion Pedal, Popular Electronics, September 1999
Replies: 4
Views: 937

Re: Guitar Distortion Pedal, Popular Electronics, September 1999

Not dissimilar to an AC/RC Booster! Tube Screamer frontend (op-amp feedback diodes) with a 2-band Baxandall tone control. This is only a couple years before the AC/RC appeared in 2002, so I wonder if Xotic got any inspiration? Popular Electronics was an American magazine. It's not a terribly origina...
by aionios
11 Sep 2020, 21:42
Forum: Boutique Stompboxes dissected...
Topic: Pete Cornish - ST-2
Replies: 0
Views: 1052

Pete Cornish - ST-2

The Cornish ST-2 was originally designed for David Gilmour, and released as a standalone pedal in 2007. David is notably associated with the Colorsound Overdriver and so it was suspected that the ST-2 was Pete's take on the Overdriver, although some ST-2 owners of course swore it had to be a complet...
by aionios
11 Sep 2020, 21:38
Forum: Boutique Stompboxes dissected...
Topic: Pete Cornish - CC-1 Crunch
Replies: 4
Views: 1262

Pete Cornish - CC-1 Crunch

The CC-1 is an original circuit by Pete Cornish, or at least as original as you can get with op-amps and diodes, but not a clone of anything else. He had said the OC-1 was an original design, and he was definitely correct to say so, so I decided to take a chance that the CC-1 was worth tracing too. ...
by aionios
01 Sep 2020, 14:21
Forum: DIY Stompbox designs
Topic: Royal Albert Hall schematic
Replies: 9
Views: 1221

Re: Royal Albert Hall schematic

Nice to have, unrelated to the audio. D4 is polarity protection, R20 is the LED current-limiting resistor (the LED will blow without it) and then of course the indicator LED itself.
by aionios
31 Aug 2020, 11:09
Forum: DIY Stompbox designs
Topic: Royal Albert Hall schematic
Replies: 9
Views: 1221

Re: Royal Albert Hall schematic

That would be the switched ground for the LED. The other thing is just a net label and can be ignored.
by aionios
30 Aug 2020, 18:11
Forum: DIY Stompbox designs
Topic: Royal Albert Hall schematic
Replies: 9
Views: 1221

Re: Royal Albert Hall schematic

Here's one to compare it with -

https://www.madbeanpedals.com/EP/schematics/Ankh.gif

I know people have successfully built the PCB that this schematic is paired with, so if you cross reference this with yours, you can see if there are any possible errors in the one you're working from.
by aionios
29 Aug 2020, 20:17
Forum: Boutique Stompboxes dissected...
Topic: Dinosaural/Lovetone Tube Bender [traced]
Replies: 38
Views: 12629

Re: Dinosaural/Lovetone Tube Bender [traced]

I've been really hoping to get one of the original Tube Benders so I could trace it and see if it was different from the magazine version. There are only 150 of them out there so it seemed pretty unlikely, but it was on the wish list anyway. Well, this summer I found one, and after tracing it I can ...
by aionios
22 Aug 2020, 13:30
Forum: Boutique Stompboxes dissected...
Topic: KMA - Tyler The Freq Splitter
Replies: 6
Views: 923

Re: KMA - Tyler The Freq Splitter

SMD capacitors have to be completely desoldered to measure, unfortunately... there’s no other way since they’re not labeled. Measuring them in-circuit won’t tell you the real value with any degree of certainty.
by aionios
21 Jul 2020, 19:06
Forum: Boutique Stompboxes dissected...
Topic: Catalinbread CB30 [traced]
Replies: 85
Views: 29173

Re: Catalinbread CB30 [traced]

So uh - this is interesting. I grabbed one of these just to get a concurring trace since there were some unresolved questions about the original schematic and I thought we should solve it once and for all. But mine is different - it has 8 transistors (all 2N5457). The PCB layout is completely differ...
by aionios
20 Jul 2020, 17:51
Forum: Boutique Stompboxes dissected...
Topic: Catalinbread - Formula No. 55 [traced]
Replies: 23
Views: 4688

Re: Catalinbread - Formula No. 55 [traced]

The carbon comp resistors must be NOS or something because the resistances I'm measuring are way off. This isn't my area of expertise, but I was shocked to find 10k resistors with 5% tolerance (gold band) measuring at 15k. Almost every carbon comp resistor I measured was around 20% off. There are a...
by aionios
28 Jun 2020, 20:44
Forum: Boutique Stompboxes dissected...
Topic: Xotic - AC Booster [ goop-alarm ] [traced]
Replies: 129
Views: 42976

Re: Xotic - AC Booster [ goop-alarm ] [traced]

See attached. You can see that the diode polarity is always cathode down, anode up, for all five of the diodes. The underside photo is small, but you can make out the corresponding jumpers in the upper left. So I still think the schematic I drew is correct, but I do welcome a second set of eyes!
by aionios
26 Jun 2020, 20:25
Forum: Boutique Stompboxes dissected...
Topic: Xotic - Bass RC Booster
Replies: 0
Views: 828

Xotic - Bass RC Booster

I couldn't find any record of anyone cracking open a Bass RC Booster, so I did one along with the AC and RC traces. (They all share the same PCB, so the second and third ones go pretty quick once the first one is down!) xotic-bass-rc-booster-trace-schematic.png Not much changed from the standard RC ...
by aionios
26 Jun 2020, 20:21
Forum: Boutique Stompboxes dissected...
Topic: Xotic - RC Booster [traced]
Replies: 110
Views: 38006

Re: Xotic - RC Booster [traced]

I traced a recent RC Booster since there are a few different schematics out there and I wanted a definitive trace. xotic-rc-booster-trace-schematic.png The only real change from earlier schematics is that the input capacitor C7 is 1uF instead of 47n. No real difference in tone since the cutoff frequ...