Search found 212 matches

by Frank_NH
11 Oct 2023, 17:11
Forum: Modern Stompbox Effects (1975 - ...)
Topic: PAL Fx JCM 800 Emulator [schematic]
Replies: 73
Views: 66024

Re: PAL Fx JCM 800 Emulator [schematic]

I did a simulation of the PAL-800 circuit schematic in LTSpice and it looks like it should work OK. However, I noticed that the source resistor for Q2 was 10K - is this correct? It seems like it should be closer to 1K. Also, you could probably replace Q4 with another JFET with a higher IDSS (like 2N...
by Frank_NH
18 Sep 2023, 12:47
Forum: Boutique Stompboxes dissected...
Topic: JHS - Bender [traced]
Replies: 13
Views: 4070

Re: JHS - Bender [traced]

287m wrote: 18 Sep 2023, 11:59 Just Hot Silicon Bender?
Yes.

viewtopic.php?t=7767&hilit=hot+silicon+bender

Image
by Frank_NH
02 Aug 2023, 14:50
Forum: DIY Projects
Topic: Mesa Clean channel emulator
Replies: 7
Views: 1095

Re: Mesa Clean channel emulator

Here's an idea. Take the Dr. Boogie schematic and mod it to add 47K resistors in series with the JFET source bypass caps (reducing gain), to mimic the clean channel setting in the DR (based on the DR tube amp schematic). Maybe someone's done that already.
by Frank_NH
31 Jul 2023, 20:46
Forum: Pedal Debugging & Troubleshooting Support
Topic: Morning Glory problem with 2N5457
Replies: 19
Views: 1916

Re: Morning Glory problem with 2N5457

I had a go at this in LTSpice (using a 2N5457 JFET model) and as Manfred confirmed the JFET stage is biased at a very low drain current (due to the large source resistor). The effect of this with the 22K drain resistor is that you get an AC gain of about 3 (9.5 dB) for lower amplitude signals (e.g. ...
by Frank_NH
07 Jul 2023, 20:41
Forum: Boutique Stompboxes dissected...
Topic: Creepy Fingers Lonely Heart Fuzz
Replies: 12
Views: 2692

Re: Creepy Fingers Lonely Heart Fuzz

Thanks for the schematic. After I initially responded to this post, I went to my breadboard and recreated the original Vox 7120 preamp, including the gain stage and bass/treble control circuit after the volume control. Using a charge pump, I ran the source voltage to about 25V, with resistors to dro...
by Frank_NH
02 Jun 2023, 14:31
Forum: Parts & Tools Sourcing & Trading
Topic: Transistor Sockets?
Replies: 10
Views: 1799

Re: Transistor Sockets?

Are there sockets which permit you to solder the transistor in place once you’ve chosen the proper part? You can do it with the plastic ones but it usually melts the plastic a bit.
by Frank_NH
26 May 2023, 13:47
Forum: Amplifiers
Topic: TDA2050 (single & dual PS, mono & bridge)
Replies: 9
Views: 1821

Re: TDA2050 (single & dual PS, mono & bridge)

I have several of these cheap power amp modules that I bought to play around with. I find it's much easier just buying a single +voltage power supply to use with these amps versus a bipolar supply (stand-alone off-the-shelf bipolar power supplies seem to be few and far between). The disadvantage is ...
by Frank_NH
17 May 2023, 18:00
Forum: Parts & Tools Sourcing & Trading
Topic: Transistor Sockets?
Replies: 10
Views: 1799

Re: Transistor Sockets?

As for "solderless", I think you'll have to solder the socket to the board, try out your transistors, then desolder the socket and install your chosen parts. Personally, I prefer not using sockets for transistors as they don't seem to hold the legs very well for long term use. For ICs, on ...
by Frank_NH
01 May 2023, 12:27
Forum: Boutique Stompboxes dissected...
Topic: Creepy Fingers Lonely Heart Fuzz
Replies: 12
Views: 2692

Re: Creepy Fingers Lonely Heart Fuzz

That’s a mistake on the schematic. It should be 47K and not 3.3K. By the way, if you want to know what these amps sound like, here’s an example from YouTube........ That makes much more sense, thanks. My current guess is that the gate trim is the Q1 emitter resistor. I will have a play around today...
by Frank_NH
30 Apr 2023, 01:55
Forum: Boutique Stompboxes dissected...
Topic: Creepy Fingers Lonely Heart Fuzz
Replies: 12
Views: 2692

Re: Creepy Fingers Lonely Heart Fuzz

So I'm just going to breadboard the circuit above (i.e. Q1+2 up to the mds control) but the base-to-ground resistor on Q2 looks odd - I've never seen it be the same value as the emitter resistor, usually much higher - Is this maybe where the. gate trimmer visible on bugg's PCB is situated? That’s a...
by Frank_NH
22 Apr 2023, 21:38
Forum: Pedal Debugging & Troubleshooting Support
Topic: Lizard Queef help
Replies: 2
Views: 318

Re: Lizard Queef help

Check the orientation of your transistors. Q1 at least should be flipped around based on your voltages.
by Frank_NH
21 Apr 2023, 16:17
Forum: Modern Stompbox Effects (1975 - ...)
Topic: JHS/EHX Lizard Queen
Replies: 111
Views: 23966

Re: JHS/EHX Lizard Queen

Apparently they dont have to provide credit to the books from the 60's either, because Hemmo and Escobedo did the same thing... Would love to see a scan of the pages of those elusive "books from the 60's". On the other hand I guess its fair game after all because look at Way Huge and Love...
by Frank_NH
20 Apr 2023, 12:24
Forum: Modern Stompbox Effects (1975 - ...)
Topic: JHS/EHX Lizard Queen
Replies: 111
Views: 23966

Re: JHS/EHX Lizard Queen

He doesn't design original circuits! I'm not sure he can. All his pedals are copies of something else. This is no different. Yeah that's pretty well known. It just disappoints me. I don't mind things being based on other things, or addressing problems the original circuit has, that's a clear improv...
by Frank_NH
16 Apr 2023, 12:37
Forum: Modern Stompbox Effects (1975 - ...)
Topic: JHS/EHX Lizard Queen
Replies: 111
Views: 23966

Re: JHS/EHX Lizard Queen

And here is another example of proper attribution, this time by Benson Amps. Note how they give credit to Jack Orman for the pickup simulator idea. And by the way, their germanium fuzz is really novel and what I would consider an "original" design... https://www.bensonamps.com/guitarpedals...
by Frank_NH
16 Apr 2023, 12:24
Forum: Modern Stompbox Effects (1975 - ...)
Topic: JHS/EHX Lizard Queen
Replies: 111
Views: 23966

Re: JHS/EHX Lizard Queen

IMG_8899.jpeg The main problem with this argument is that while you may not have to credit someone if you provide instructions on how to make a grilled cheese sandwich, likewise you would not claim that the grill cheese sandwich was your "original" recipe. :slap: Here is the proper way to...
by Frank_NH
13 Apr 2023, 10:50
Forum: Modern Stompbox Effects (1975 - ...)
Topic: JHS/EHX Lizard Queen
Replies: 111
Views: 23966

Re: JHS/EHX Lizard Queen

Funny that's my modded schematic of Tim's from my site. Also curious I sent a request to the JHS site to do an episode on Tim Escobedos work. I really wish Josh would just acknowledge Tim and the other diy roots. Seems a stretch to call it original. http://aaronlumguitar.blogspot.com/2015/01/new-di...
by Frank_NH
12 Apr 2023, 21:27
Forum: Modern Stompbox Effects (1975 - ...)
Topic: JHS/EHX Lizard Queen
Replies: 111
Views: 23966

Re: JHS/EHX Lizard Queen

I wasn't talking about the $99 one, I was talking about the big box one. One of the selling points of it was "just like it was the 70s". The crap switch is fine for the $99 unit, and it will fail, soft click or not. But If I paid $350 for the big box one, I would not want some crap switch...
by Frank_NH
12 Apr 2023, 18:46
Forum: Modern Stompbox Effects (1975 - ...)
Topic: JHS/EHX Lizard Queen
Replies: 111
Views: 23966

Re: JHS/EHX Lizard Queen

I have to wonder, no LED... then why use a crappy 3PDT footswitch instead of a Carling DPDT that lasts 50x longer? I mean for $350 you could at least use top shelf parts that were available back then. Not surprised it's one of Tim's circuits at all. I believe these Lizard Queens are $99 (for the na...
by Frank_NH
23 Mar 2023, 23:37
Forum: Boutique Stompboxes dissected...
Topic: Bearfoot - Model H [traced]
Replies: 53
Views: 17829

Re: Bearfoot - Model H [traced]

I didn’t bias either jfet but you could install trimmers (temporarily) and see what drain resistance sounds best.

I’m currently rebuilding my vero and can report my voltages when I get the opportunity.
by Frank_NH
10 Feb 2023, 04:00
Forum: DIY Projects
Topic: Clown Centurion (reworked Klon) [documentation]
Replies: 34
Views: 10654

Re: Clown Centurion (reworked Klon) [documentation]

Nice video. FSB will be getting lots of visitors now. :D