Search found 20 matches

by vtguedes
09 Jun 2020, 22:00
Forum: Pedal Debugging & Troubleshooting Support
Topic: DIY Dumbloid acting as an oscillator [SOLVED]
Replies: 4
Views: 184

Re: DIY Dumbloid acting as an oscillator [SOLVED]

Hello, Michael. The schematic used for that layout woud help a lot. The photos attached aren't crisp enough to look for shorted nodes on the circuit, or cold solder joints, but I would start from there. Basically: 1. Check with the digital meter for continuity between traces so you can be sure that ...
by vtguedes
30 Jul 2019, 14:00
Forum: Boutique Stompboxes dissected...
Topic: Benson Preamp [traced]
Replies: 89
Views: 22548

Re: Benson Preamp [traced]

Great to see you getting close to the real thing. I couldn't do any breadboarding last week but I'm glad the SMD fets made a difference.
by vtguedes
29 Jul 2019, 20:31
Forum: Boutique Stompboxes dissected...
Topic: Benson Preamp [traced]
Replies: 89
Views: 22548

Re: Benson Preamp [traced]

I just realized you are using through-hole J201 fets, did you buy these a long time ago? It's been a while since these have been discontinued, and there are several chinese fakes with the Fairchild logo that just aren't as gainy as the real deal, I have a JCM800 preamp with these fake chinese fets t...
by vtguedes
26 Jul 2019, 14:18
Forum: Boutique Stompboxes dissected...
Topic: Benson Preamp [traced]
Replies: 89
Views: 22548

Re: Benson Preamp [traced]

Maybe you could try comparing capacitance readings between the original board and your breadboarded circuit?
by vtguedes
25 Jul 2019, 14:59
Forum: Boutique Stompboxes dissected...
Topic: Benson Preamp [traced]
Replies: 89
Views: 22548

Re: Benson Preamp [traced]

Still on the tone stack theme, RoG (again) Supreaux Deux bottom switch mod also looks a lot like the bass tone control. My guess is that the first capacitor on the bass control don't let much bass through it and then the bass potentiometer acts like a bypass to the capacitor. The second capacitor on...
by vtguedes
25 Jul 2019, 13:47
Forum: Boutique Stompboxes dissected...
Topic: Benson Preamp [traced]
Replies: 89
Views: 22548

Re: Benson Preamp [traced]

Thanks for the tracing! To my eyes it looks like the tone stack has something in common with the James tonestack from the Tone Stack Calculator website: James Tonestack.JPG That would give us the idea of the value of a couple of capacitors. The capacitor in paralel with the 1k resistor I'd test 680n...
by vtguedes
25 Jun 2019, 17:44
Forum: Boutique Stompboxes dissected...
Topic: Greer Lightspeed
Replies: 26
Views: 11386

Re: Greer Lightspeed

I made my vero layout using the same schematic and didn't have any noise problems with neither TL072 or 4558.
by vtguedes
19 Jun 2019, 15:13
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Imagining the Keeley Fuzz Bender schematic
Replies: 15
Views: 3450

Re: Imagining the Keeley Fuzz Bender schematic

I'm not sure how presence works in the frequency spectrum, but it is related to the "sizzle" in the output signal, specially when an amplifier is distorting. Also, it is a control implemented in the negative feedback network of the power amplifier, so it is not a filter in the pre or post gain stage...
by vtguedes
17 Jun 2019, 19:11
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Imagining the Keeley Fuzz Bender schematic
Replies: 15
Views: 3450

Re: Imagining the Keeley Fuzz Bender schematic

No problem with a boost that high. You'll won't hear anything beyond 20kHz, and you could allways use a simple low pass filter to cut anything above 10kHz (the harmonic content of a guitar won't go higher than 6kHz).
by vtguedes
11 Jun 2019, 20:00
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Imagining the Keeley Fuzz Bender schematic
Replies: 15
Views: 3450

Re: Imagining the Keeley Fuzz Bender schematic

This is a link for a parametric 3 band eq using gyrators. Maybe start from this and tweak?

http://sound.whsites.net/project28.htm
by vtguedes
30 May 2019, 14:14
Forum: DIY Stompbox designs
Topic: DIY Loadbox (and/or DI) questions
Replies: 15
Views: 3815

Re: DIY Loadbox (and/or DI) questions

The photos from the thing got lost with some old computer aprox 15 years ago.

The box is on my parent's house but they don't live far from me, when I get the chance I'll take a new one or might make a new load box since I have a spare 6,5" speaker from an old practice amp.
by vtguedes
29 May 2019, 22:44
Forum: DIY Stompbox designs
Topic: DIY Loadbox (and/or DI) questions
Replies: 15
Views: 3815

Re: DIY Loadbox (and/or DI) questions

Hi Manfred,

Sorry I didn't really explain what I did to the speaker to use it as a passive load.

I removed just the cone and secured everyhing else with a bunch of zip ties to "simulate" the cone tension/resistance and keep everything in place.
by vtguedes
29 May 2019, 19:43
Forum: Boutique Stompboxes dissected...
Topic: R3FX Resistafier
Replies: 7
Views: 1764

Re: R3FX Resistafier

Not trying to justify anything about the guts of that pedal, but I have built pedals with far better gutshots that have failed me and also had far worse builds that never had any problem and have been abused for years. I wouldn't sell a pedal that look like that, but that's just me. Besides that, ye...
by vtguedes
29 May 2019, 19:33
Forum: DIY Stompbox designs
Topic: DIY Loadbox (and/or DI) questions
Replies: 15
Views: 3815

Re: DIY Loadbox (and/or DI) questions

My passive reactive loadbox is an 8 ohm 8 inch 30W speaker with its cone removed. A speaker with a removed cone is not really a reactive load, it is only an inductance. The coil shows not the desired impedance response of the complete speaker respectively of the box in which it is installed. This i...
by vtguedes
29 May 2019, 13:44
Forum: Boutique Stompboxes dissected...
Topic: Greer Lightspeed
Replies: 26
Views: 11386

Re: Greer Lightspeed

I built it but have a squeal happening when drive and loudness reach a certain point in relation to each other - i.e.: when the drive is full up, the loudness will cause squeal when about half way. the same happens when the drive is lower but the loudness is higher. Anyone else encounter this? Did ...
by vtguedes
28 May 2019, 17:44
Forum: Boutique Stompboxes dissected...
Topic: Greer Lightspeed
Replies: 26
Views: 11386

Re: Greer Lightspeed

Be aware that, besides the clipping options, the Lightspeed is a Timmy with fixed bass and treble controls AND a treble roll-off after the 2nd op amp. That might make some of the difference between single coils and humbuckers you said. Anyway, you could make a regular lightspeed and put a spdt on-on...
by vtguedes
24 May 2019, 19:33
Forum: DIY Stompbox designs
Topic: DIY Loadbox (and/or DI) questions
Replies: 15
Views: 3815

Re: DIY Loadbox (and/or DI) questions

Hi, My passive reactive loadbox is an 8 ohm 8 inch 30W speaker with its cone removed. I use it to record silently using a Fender Champ clone (6 watts-ish). To plug into the audio interface (i use an UMC202 just like you), I have used it with a 10k resistor and a 5k potentiometer associated in series...
by vtguedes
21 May 2019, 15:33
Forum: Boutique Stompboxes dissected...
Topic: Greer Lightspeed
Replies: 26
Views: 11386

Re: Greer Lightspeed

Oh, I've tested my build with 4558, TL072, TL082 and the OPA. All sounded the same to my ears, I just wrote in the layout the same part that was in the schematic.
by vtguedes
21 May 2019, 15:16
Forum: Boutique Stompboxes dissected...
Topic: Greer Lightspeed
Replies: 26
Views: 11386

Re: Greer Lightspeed

Pedal PCB has it traced. It is a timmy with fixed eq controls, assymetrical clipping with 5 diodes (3+2) back to back and a simple treble roll-off for tone control at the end. Build docs here: https://www.pedalpcb.com/product/mach1od/ I have done a vero layout from PedalPCB's schematic, it is verifi...
by vtguedes
06 May 2019, 16:20
Forum: Boutique Stompboxes dissected...
Topic: LCA Guitars overdrive/distortion
Replies: 6
Views: 1029

Re: LCA Guitars overdrive/distortion

I would bet that something is touching the enclosure and shorting signal to ground. Happened to me in my first builds.