Search found 401 matches

by mauman
04 Nov 2024, 15:01
Forum: Amplifiers
Topic: Anyone Had Any Luck With TPA3116D2 Power Amp>?
Replies: 27
Views: 1044

Re: Anyone Had Any Luck With TPA3116D2 Power Amp>?

...If someone was to point me in a direction of learning, where would you point me? As someone said, the internet is very wide but very shallow, and it's not the best place to build a solid foundation of knowledge like you are seeking. For that I would recommend two or three books. First, Practical ...
by mauman
01 Nov 2024, 15:58
Forum: Announcements and Forum Rules
Topic: Report Forum Problems and Make Forum Wishes Here...
Replies: 273
Views: 683506

Re: Report Forum Problems and Make Forum Wishes Here...

Thank you for the detailed description. I'm puzzled. I could not make it appear. That's a phpBB debug message and the debug mode is not even activated. Also, nothing in the logs :hmmm:. The code causing the message extracts post images parameters, includind their post text as descriptions. I just ...
by mauman
31 Oct 2024, 17:24
Forum: Announcements and Forum Rules
Topic: Report Forum Problems and Make Forum Wishes Here...
Replies: 273
Views: 683506

Re: Report Forum Problems and Make Forum Wishes Here...

It seems to occur in a specific context. Please, do try to replicate it and let us know the specific URL address. I could do a blanket fix, but I'd like to know more about why. It happened again just now, navigating to this very page - https://www.freestompboxes.org/viewtopic.php?t=106 The sequence ...
by mauman
30 Oct 2024, 14:00
Forum: Announcements and Forum Rules
Topic: Report Forum Problems and Make Forum Wishes Here...
Replies: 273
Views: 683506

Re: Report Forum Problems and Make Forum Wishes Here...

I've seen this banner at the top of my screen twice in the last few days, I believe it's while I'm doing a search. If you need more details, I'll try to replicate it. [phpBB Debug] PHP Warning: in file [ROOT]/ext/alfredoramos/seometadata/event/listener.php on line 119: Undefined array key ...
by mauman
30 Oct 2024, 00:04
Forum: Pedal Debugging & Troubleshooting Support
Topic: PedalPCB sproing [SOLVED]
Replies: 9
Views: 7166

Re: PedalPCB sproing [SOLVED]

Late to the party for sure, Just finihed this board, only my 2nd pedal PCB build. Always been Tayda or Madbean boards. Like you I've always rocked before boxing with my test rig. Tried that no sound, then wired in jacks and power, still nothing, Went through with DMM, Then audio prob, no sound past ...
by mauman
25 Oct 2024, 03:57
Forum: Boutique Stompboxes dissected...
Topic: Rockett Allan Holdsworth Overdrive
Replies: 12
Views: 7060

Re: Rockett Allan Holdsworth Overdrive

MoonWatcher wrote: 22 Apr 2014, 13:25 I went back and looked into the Tim Pierce OD a bit, and even found a gut shot of it...
For continuity, there's a subsequent trace and discussion of the Tim Pierce OD at viewtopic.php?p=294618
by mauman
21 Oct 2024, 13:21
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Goodrich - Model 7A Super Sustain Match Box [schematic]
Replies: 6
Views: 18197

Re: Goodrich Model 7A Super Sustain Match Box [schematic] [schematic]

I'm repairing yet another one of these, and this one has a Motorola MC33171P op amp. It's similar to the MC34181, with slightly worse specs, but still plenty good enough for this device. This op amp has a noisy output, but both the 33171 and 34181 are obsolete in PDIP, I will probably get a used ...
by mauman
20 Oct 2024, 02:45
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Harmony - H66 Vibrajet Tremolo effect
Replies: 3
Views: 672

Re: Harmony - H66 Vibrajet Tremolo effect

Thanks! What's the function of the RCA jack?
by mauman
08 Oct 2024, 16:54
Forum: Pedal Debugging & Troubleshooting Support
Topic: tc scf debugging -- dc offset
Replies: 1
Views: 370

Re: tc scf debugging -- dc offset

I think there is a thread which contains relevant schematics and discussion of this pedal: viewtopic.php?t=18002 If it's the correct version, maybe it will assist in troubleshooting.
by mauman
07 Oct 2024, 18:41
Forum: DIY Projects
Topic: Demo amp
Replies: 4
Views: 637

Re: Demo amp

Alpha 4-inch speaker response Strange, I thought guitar speakers cut frequencies after 4-6 kHz. Depends on the speaker, you're using a 4 inch speaker rather than the more typical 8, 12 or 15 inch in guitar cabinets so I pulled a 4-inch frequency response. You can compare a lot of different (Jensen ...
by mauman
07 Oct 2024, 14:19
Forum: DIY Projects
Topic: Demo amp
Replies: 4
Views: 637

Re: Demo amp

IMHO, adding a low-pass filter isn't necessary. The Ruby has a pretty flat frequency response on the high end, but your 4-inch speaker will probably have a steep roll-off above 10-12 kHz or so. Here's the Electrosmash Ruby frequency response analysis, and the response of an Eminence Alpha 4-inch ...
by mauman
23 Sep 2024, 01:42
Forum: Stuff Seen for Sale
Topic: Please tell me, sites where you can sell your pedals
Replies: 5
Views: 2537

Re: Please tell me, sites where you can sell your pedals

The way Reverb shows list pricing but never the actual selling price caused general prices for gear to go up like crazy as for many those list prices were interpreted as "that's what they're worth". There's a trick to seeing actual prices rather than wish-upon-a-star prices. 1. Search for your ...
by mauman
20 Sep 2024, 21:42
Forum: Stuff Seen for Sale
Topic: Please tell me, sites where you can sell your pedals
Replies: 5
Views: 2537

Re: Please tell me, sites where you can sell your pedals

Unfortunately, Reverb is no longer a good marketplace for small pedal-makers. I sold hundreds of custom pedals there, but abandoned it a couple of years ago. Reverb was bought by Etsy, and the rules and processes changed to favor the large commercial vendors, and it became impossible to get noticed ...
by mauman
20 Sep 2024, 02:09
Forum: Modern Stompbox Effects (1975 - ...)
Topic: CORLAND K25 - 1979 Amplifier
Replies: 10
Views: 1486

Re: CORLAND K25 - 1979 Amplifier

Red-Violet-Orange is 27k in the 4-band color code.
by mauman
15 Sep 2024, 21:46
Forum: Modern Stompbox Effects (1975 - ...)
Topic: CORLAND K25 - 1979 Amplifier
Replies: 10
Views: 1486

Re: CORLAND K25 - 1979 Amplifier

FaustoM wrote: 15 Sep 2024, 14:09 For this application what is a good replacement for the BC238 ?
Most any silicon NPN with beta around 300 or 400 that's rated for 100 mA of collector current. 2N5088 or 2N5089 should work, and they have an E-B-C pinout that's a mirror of the BC238's C-B-E, so just flip them 180 degrees.
by mauman
14 Sep 2024, 22:39
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Germanium in my attic
Replies: 19
Views: 3255

Re: Germanium in my attic

When the transistors were made, they tested each one for beta (hFE), then tossed them into a bin based on the beta range. The transistors in each bin got a different color dot, so different color dots meant different beta ranges. Another way manufacturers indicated the bins was with letter suffixes ...
by mauman
14 Sep 2024, 22:26
Forum: Modern Stompbox Effects (1975 - ...)
Topic: CORLAND K25 - 1979 Amplifier
Replies: 10
Views: 1486

Re: CORLAND K25 - 1979 Amplifier

If you connect a 100k resistor across lugs 1 and 3 of your 100k pot, the new pot value will be around 50k. The taper will change a little, but it will be close.
Reduce 100k pot to 50k
Reduce 100k pot to 50k
by mauman
09 Sep 2024, 22:32
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Mutron filter in Ken Smith bass
Replies: 6
Views: 872

Re: Mutron filter in Ken Smith bass

This is an excellent argument for SMD. Did it come with a pry bar for insertion and removal?
by mauman
09 Sep 2024, 20:16
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Thurlby Harmonic Multiplier (octave-up and ring mod)
Replies: 12
Views: 2799

Thurlby Harmonic Multiplier (octave-up and ring mod)

This vintage octave-up/ring modulator showed up on Reverb for just a few days. Here are the seller's pics if anyone wants to trace it. The only adjustments are two trim pots. The instructions are posted on Effects Database and are included here for continuity. Apparently Thurlby is still in business ...
by mauman
02 Sep 2024, 14:35
Forum: Boutique Stompboxes dissected...
Topic: Prescription Electronics - COB ( Clean Octave Blend ) [traced]
Replies: 40
Views: 27682

Re: Prescription Electronics - COB ( Clean Octave Blend ) [traced]

Just adding a note to this old thread. Having built a lot of these, I've gotten the most consistent octave using the following. The part numbers refer to the rousejeremy vero layout and BOM above. Q1, Q2, Q4 = 2N5088 with beta around 425-435 Q3 = BC547B or BC550 with beta around 325-350 D1, D2 ...