Search found 292 matches

by POTL
18 Oct 2023, 23:56
Forum: Boutique Stompboxes dissected...
Topic: Red Witch - Empress Chorus Vibrato
Replies: 6
Views: 4713

Re: Red Witch - Empress Chorus Vibrato

I think take based on zombie chorus
by POTL
13 Oct 2023, 04:57
Forum: Modern Stompbox Effects (1975 - ...)
Topic: PAL Fx JCM 800 Emulator [schematic]
Replies: 73
Views: 66038

Re: PAL Fx JCM 800 Emulator [schematic]

Hello. The source resistor for Q2 is 10K, and it's correct following the PAL800 schematic and the other JFET emulator, beacuse both come from the original JCM800 schematic. I guess I heard about replace Q4 with a 2N5458, but I think that's not a big issue. I know Dr. Boogie has a scaled tonestack, ...
by POTL
13 Oct 2023, 04:47
Forum: Modern Stompbox Effects (1975 - ...)
Topic: PAL Fx JCM 800 Emulator [schematic]
Replies: 73
Views: 66038

Re: PAL Fx JCM 800 Emulator [schematic]

I'm sure that should work, but I checked a lot of time, every single part, replaced suspect ones, resoldered, measured, continuity... Thanks for the tip about the biasing, but, until the Mid mess up the voltage I can't do anything. Why you say "the problem is in the transistor"? Do you th...
by POTL
10 Oct 2023, 20:53
Forum: Modern Stompbox Effects (1975 - ...)
Topic: PAL Fx JCM 800 Emulator [schematic]
Replies: 73
Views: 66038

Re: PAL Fx JCM 800 Emulator [schematic]

the problem is in the transistor. a few years ago I was inspired to emulate tube preamps using jfet, I collected all the circuits of known devices both with a buffer in front of the tone stack (Marshall, Vox, Laney, etc) and without a buffer (Orange, Peavey, Splawn, Mesa Mark etc). They all worked f...
by POTL
30 Jul 2023, 00:59
Forum: Pedal Debugging & Troubleshooting Support
Topic: Morning Glory problem with 2N5457
Replies: 19
Views: 1916

Re: Morning Glory problem with 2N5457

CheapPedalCollector wrote: 27 Jul 2023, 19:45 I don't think R18 is correct either, it doesn't make any sense.

Josh himself has said that this circuit hasn't been accurately traced. Hopefully someone with a V3 can trace it correctly.
R18 reduces the gain of the jfet stage.
by POTL
30 Jul 2023, 00:57
Forum: Pedal Debugging & Troubleshooting Support
Topic: Morning Glory problem with 2N5457
Replies: 19
Views: 1916

Re: Morning Glory problem with 2N5457

Replace 22k resistor to 100k trimpot and biasing jfet.
by POTL
28 Jul 2023, 23:33
Forum: DIY Projects
Topic: Introducing the Alternate Dimension: Flexible Dimension/Dual Chorus
Replies: 15
Views: 2968

Re: Introducing the Alternate Dimension: Flexible Dimension/Dual Chorus

There's a good analysis of this pedal in the Aion clone PCB build document at https://aionfx.com/app/files/docs/blueshift_documentation.pdf. I don't see a lot of opportunity for mods, everything is pretty tightly linked together and it requires some calibration to work well. the only useful mod (at...
by POTL
18 Feb 2023, 20:24
Forum: DIY Projects
Topic: PUP: a host of Perfectly Usable Phasers [documentation]
Replies: 54
Views: 6849

Re: PUP: a host of Perfectly Usable Phasers [documentation]

The scheme is good because it does not require identical jfets. But, as far as I know, it can have clipping problems, just like jfets. It seems to me that it is more reasonable to replace CMOS and Jfets with a photoresistor + LED. You could try using OTA, but not like in the EHX Small Stone circuit...
by POTL
12 Feb 2023, 12:55
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Boss smd question
Replies: 1
Views: 336

Re: Boss smd question

No
by POTL
11 Feb 2023, 20:16
Forum: DIY Projects
Topic: PUP: a host of Perfectly Usable Phasers [documentation]
Replies: 54
Views: 6849

Re: PUP: a host of Perfectly Usable Phasers [documentation]

The scheme is good because it does not require identical jfets. But, as far as I know, it can have clipping problems, just like jfets. It seems to me that it is more reasonable to replace CMOS and Jfets with a photoresistor + LED. You could try using OTA, but not like in the EHX Small Stone circuit ...
by POTL
08 Apr 2021, 09:22
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Ecstasy Red
Replies: 69
Views: 45492

Re: Bogner - Ecstasy Red

It’s really bs170?
Where j201 from picture?
by POTL
03 Feb 2021, 18:35
Forum: Pedal Debugging & Troubleshooting Support
Topic: U1226 Pedal Preamp Hiss
Replies: 1
Views: 592

Re: U1226 Pedal Preamp Hiss

1) I would start by replacing R12, R13, R14 with trimpots, try the standard 100K 2) the noise of the first channel is more noticeable, since the first channel is structurally brighter. 3) Between the gate and the ground, it is worth installing a small capacitor of 220p (imitation of the internal cap...
by POTL
14 Jan 2021, 20:48
Forum: Modern Stompbox Effects (1975 - ...)
Topic: MXR M288 Bass Octave Deluxe [gut shots, tracing]
Replies: 20
Views: 8182

Re: MXR M288 Bass Octave Deluxe [gut shots, tracing]

What do you think is the point in doubling the tension? Will this have a positive effect on octave performance or tracking?
Or is it just to increase the dynamic range?
by POTL
25 Oct 2020, 14:14
Forum: Pimp-My-Cheap-Pedal
Topic: Joyo Vintage Phase Gutshots
Replies: 3
Views: 1557

Re: Joyo Vintage Phase Gutshots

Thanks
by POTL
24 Oct 2020, 16:56
Forum: Pimp-My-Cheap-Pedal
Topic: Joyo Vintage Phase Gutshots
Replies: 3
Views: 1557

Re: Joyo Vintage Phase Gushots

what transistors are used here?
by POTL
04 Sep 2020, 15:00
Forum: Pimp-My-Cheap-Pedal
Topic: Behringer VM1 Vintage Time Machine
Replies: 109
Views: 85975

Re: Behringer VM1 Vintage Time Machine

Hello. This circuit looks like an attempt to take the best of both worlds (I think Chase Bliss Tonal Recall was able to achieve this). We all know that DMM has excellent replay quality and built-in modulation. But reps can get overwhelmed. The boss has a high input impedance, which allows him to wor...
by POTL
23 Aug 2020, 10:42
Forum: Pedal Debugging & Troubleshooting Support
Topic: 3 Band Baxandall Calculator
Replies: 2
Views: 2310

Re: 3 Band Baxandall Calculator

I built it several times and simulated it several times.
3 bands are too many for this equalizer, the controls become dependent on each other (not very much, but noticeably).
I would consider other schemes.
by POTL
06 Aug 2020, 10:38
Forum: Printed/Published Online Designs
Topic: Tap Tempo for BBD
Replies: 2
Views: 2517

Re: Tap Tempo for BBD

Another addition. I tested the LFOs of most flangers and noticed that they have a wider range than other effects. At least those that don't use the original watch. Interestingly, there are some interesting exceptions among deep-sounding flangers. 1) The Electric Mistress uses a non-inverting amplifi...
by POTL
06 Aug 2020, 08:37
Forum: Printed/Published Online Designs
Topic: Tap Tempo for BBD
Replies: 2
Views: 2517

Re: Tap Tempo for BBD

OK I modulated the standard LFOs Most circuits have a range of no more than 4V between maximum and minimum values, which means that we can simulate normal LFOs well. The only exceptions are Flangers, which work without original watches. Perhaps this is the reason for the lack of commercial flangers ...