Search found 40 matches

by jg
12 Jan 2016, 00:31
Forum: Modern Stompbox Effects (1975 - ...)
Topic: EHX - Crayon
Replies: 4
Views: 8047

Re: EHX Crayon

Just traced a Crayon, it is almost an exact copy of the BB Preamp. The EQ caps are slightly different and all the electrolytics are 10uF, even the NP ones. But that's the only difference. Treble caps are 36nF and the base caps are 5.1nF.
by jg
28 Sep 2011, 20:40
Forum: Boutique Stompboxes dissected...
Topic: Devi Ever/Effector 13: Truly Beautiful Disaster
Replies: 58
Views: 17898

Re: Devi Ever/Effector 13: Truly Beautiful Disaster

I've seen that configuration used in some analog synth circuits as part of the noise generator, it usually gets passed onto two filters that produce white and pink noise.... :hmmm: what`s pink noise? like when i hear my neighbors fucking through the wall? Technically colours are used to describe di...
by jg
18 Sep 2010, 17:57
Forum: Boutique Stompboxes dissected...
Topic: Fulltone - OCD [traced]
Replies: 622
Views: 281045

Re: Fulltone - OCD [traced]

I'm very familiar with version 4 boards. More than you know. Since you sold the pedal and therefore cannot illustrate your point with pictures, I guess the point is moot.
by jg
17 Sep 2010, 16:33
Forum: Boutique Stompboxes dissected...
Topic: Fulltone - OCD [traced]
Replies: 622
Views: 281045

Re: Fulltone - OCD [traced]

I kind of like the TL082. With its jfet inputs and bipolar output it sounds good in a lot of circuits. The 2262 being all MOSFETs can sound good on their own being overdriven as they clip nicely, but as a buffer they always sound 'flat' to me. Plus there's the max 16V supply issue. I've reworked 100...
by jg
14 Aug 2010, 15:28
Forum: Boutique Stompboxes dissected...
Topic: Fulltone - GT 500
Replies: 107
Views: 43752

Re: Fulltone - GT 500

sevinisthenumber wrote:Is the boost side of this simply a Fat Bastard?!
No, for one, the Fat Bastard is inverting, the boost side of the GT500 is not.
by jg
04 Apr 2008, 17:35
Forum: Boutique Stompboxes dissected...
Topic: Fulltone - GT 500
Replies: 107
Views: 43752

Re: Fulltone - GT-500

Gyrators have very limited dynamic range But seemingly enough for about any commercial graphic EQ on the market. True, because they are typically used on the inverting input to an opamp where the signal swing is minimal. If you want to use it in any other configuration such that it acts on the full...
by jg
04 Apr 2008, 14:40
Forum: Boutique Stompboxes dissected...
Topic: Fulltone - GT 500
Replies: 107
Views: 43752

Re: Fulltone - GT-500

There was some rumor that the boost section was very similar to the Fat boosted that you can find on General guitar gadgets (the AMZ minibooster / fat booster story again?). For the distortion side you could look at any number of fet overdrives, look on Run Off Groove (Eighteen, English Channel, Ma...
by jg
24 Mar 2008, 21:15
Forum: Printed/Published Online Designs
Topic: Jack Orman - Fet Muff
Replies: 15
Views: 5980

Re: fet muff

I might be missing some theory, but I still have a question : Why is there only one diode in the feedback path on the FETs instead of two in the original big muff ? This diode thing bugs me also. Since the capacitor is charged in one direction by the diode, it has no discharge path, except for the ...
by jg
18 Feb 2008, 20:11
Forum: Boutique Stompboxes dissected...
Topic: Bad Cat - X-treme Tone [traced]
Replies: 28
Views: 8386

soulsonic wrote:
chris_d wrote:In the schematic, off of the filament bridge, what is that OR92/2W? Is that a just a 2 watt, 92 ohm resistor?

-chris
Nope, it's 2 watt 0.92 ohm.
I doubt that. Maybe .82 ohms. .92 isn't a standard value.
by jg
11 Feb 2008, 21:58
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Colorsound - Power Boost / Overdriver
Replies: 188
Views: 149874

I think that I noticed one more thing. I counted 15 resistors on PCB. Schematic have only 14. To make things more complicated I found another picture of the PCB which has... 16 resistors! I circled this additional one :) https://img212.imageshack.us/img212/3082/colorsoundpowerboosttg7.th.jpg Looks ...
by jg
02 Feb 2008, 17:58
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Interfax - Harmonic Percolator [schematic]
Replies: 371
Views: 228396

Here you can find the guts of a real (original) one: http://acapella.harmony-central.com/forums/showthread.php?t=1008997&highlight=interfax analogguru That appears to be the same one that DiscoFreq has on his site. That one also matches the Barge schematic that has two NPN transistors. Chuck Co...
by jg
25 Jan 2008, 17:08
Forum: Capacitors
Topic: Determining capacitor type from schematic?
Replies: 4
Views: 3264

So there is no functional difference between different types of unpolarized or between polarized? How about between unpolarized and polarized? Can I substitute a polarized for an unpolarized and vice-versa, or are they strictly not interchangeable? You can substitute polarized for unpolarized if th...
by jg
25 Jan 2008, 16:42
Forum: Capacitors
Topic: Determining capacitor type from schematic?
Replies: 4
Views: 3264

Re: Determining capacitor type from schematic?

When I look at a schematic and see various unpolarized capacitor circuit symbols, how do I decide what type (i.e., polyester film, electrolytic, maybe others I haven't learned about yet) I should use in a build? You try as many as you can in all the locations of your circuit. You compile a list of ...
by jg
15 Jan 2008, 16:38
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Arion - SCH1 and SCH-Z
Replies: 12
Views: 8624

by jg
04 Jan 2008, 18:16
Forum: Parts & Tools Sourcing & Trading
Topic: Dual LDR source
Replies: 7
Views: 5405

I found the data info. Thanks for the pic!
by jg
04 Jan 2008, 16:26
Forum: Parts & Tools Sourcing & Trading
Topic: Dual LDR source
Replies: 7
Views: 5405

Meanderthal wrote:Could you possibly rig up a VTL5C4/2? Or is this for a Mutron(won't work, tried it)... ?
It's not a Mutron but the situation is the same in that the two LDR sections are in separate parts of the circuit and therefore need to be isolated.
by jg
04 Jan 2008, 15:50
Forum: Parts & Tools Sourcing & Trading
Topic: Dual LDR source
Replies: 7
Views: 5405

analogguru wrote:Aren´t these Hamamatsu (HTV) P873-13 which are OOP ?

analogguru
I don't know, but I see Smallbear has the P873-13 available but no picture or datasheet......
by jg
04 Jan 2008, 15:31
Forum: Parts & Tools Sourcing & Trading
Topic: Dual LDR source
Replies: 7
Views: 5405

Dual LDR source

Anyone run across a source for these? And yes, I know I could 'roll my own' but the forum is Part Sourcing.

Image
by jg
19 Dec 2007, 02:40
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Ibanez - PT-707 Phasetone II [schematic]
Replies: 7
Views: 8371

Re: Ibanez Phasetone II / PT707 Schematic (inside) [schematic]

Pretty close to an MXR Phase 100 as I expected but slightly different. All component numbering is the same as it is on the board. Enjoy! http://www.dirk-hendrik.com/temp/ibanez_pt707.pdf Any luck finding dual LDRs like that? Roll your own :wink: Thank you captain obvious. That's what I'm having to ...