Search found 389 matches

by george giblet
21 Feb 2024, 23:18
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Schaller - Fuzz (Germanium) [schematic]
Replies: 54
Views: 26855

Re: Schaller - Fuzz (Germanium) [schematic]

@by karsten_h
Perhaps a silicon version?
With stretch those transistors look like BC108B (maybe BC109B).

The tonehome pages have a pic showing BC239B, so from that I'd guess it's BC109B,
https://www.tonehome.de/schaller-electronic/fuzz/
by george giblet
17 Feb 2024, 00:14
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Boss - SD-1w Super OverDrive (Waza Craft)
Replies: 11
Views: 7256

Re: Boss - SD-1w Super OverDrive (Waza Craft)

I reported tracing SD-1W on X(Twitter). Here is the schematic. Blog link (Japanese) https://drugscore.blog.fc2.com/blog-entry-334.html Your schematic looks good. I traced this back in Aug 2019 and forgot all about it. I couldn't work out some of the values of the smaller compensation caps from the ...
by george giblet
05 Feb 2024, 18:51
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Boss OD-2R 1994 Corrected Schematic
Replies: 1
Views: 488

Re: Boss OD-2R 1994 Corrected Schematic

Humble apologies, I missed fixing the 9V on Q17/Q18.
Schematic updated to V1.1.

If you see anything please let me know.
by george giblet
05 Feb 2024, 01:35
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Boss OD-2R 1994 Corrected Schematic
Replies: 1
Views: 488

Boss OD-2R 1994 Corrected Schematic

It seems the discrete op amp for Turbo mode on the Boss OD-2R is powered from a 5.6V supply not a 8V supply. A similar kind of issue occurred on J.Luja's 2002 OD-3 schematic. The main correction in the case of the OD-2R is the zener voltage. I've updated muzh's OD-2R schematic and corrected a few ot...
by george giblet
03 Feb 2024, 20:27
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Boss - BD-2 Blues Driver 1995 [schematic]
Replies: 181
Views: 217533

Re: Boss - BD-2 Blues Driver 1995 [schematic]

I did a clean-up/rebuild of the original Boss BD-2 schematic with correct part designators and part values.
Took more effort than you think!
boss bd2 schematic - cleaned up V10 GG2024_02_03.png
by george giblet
03 Feb 2024, 03:47
Forum: Boutique Stompboxes dissected...
Topic: Monolith Orchid Fuzz
Replies: 9
Views: 1312

Re: Monolith Orchid Fuzz

Well, just to put a line in the sand I've updated the schematic to show the best guess values.
Monolith - Silicon Orchid Fuzz V12.png
by george giblet
02 Feb 2024, 12:23
Forum: Boutique Stompboxes dissected...
Topic: Monolith Orchid Fuzz
Replies: 9
Views: 1312

Re: Monolith Orchid Fuzz

Bit of a long shot here: I had a look at some other Monolith pedals. The "Bug Silicon Sustain" and "Bug JR Sustain" have similar green ceramic caps. The "Bug Silicon Sustain" has a 560pF orange ceramic cap and a 470pF green ceramic cap, the same type of caps used on the...
by george giblet
02 Feb 2024, 03:50
Forum: Boutique Stompboxes dissected...
Topic: Monolith Orchid Fuzz
Replies: 9
Views: 1312

Re: Monolith Orchid Fuzz

I found one more picture. It doesn’t really show much else unfortunately. I really can’t make anything out on the last cap though. Edit: I was playing with some filters on the photo, it looks like 71… maybe 471, 470pf? Oh man so close! It's a tough one. After playing with the image I'm guessing _71...
by george giblet
01 Feb 2024, 21:31
Forum: Boutique Stompboxes dissected...
Topic: Monolith Orchid Fuzz
Replies: 9
Views: 1312

Re: Monolith Orchid Fuzz

Minor update while it's fresh in my mind.
Unfortunately couldn't resolve the main unknowns.
Monolith - Silicon Orchid Fuzz V11.png
by george giblet
31 Jan 2024, 03:55
Forum: Boutique Stompboxes dissected...
Topic: Monolith Orchid Fuzz
Replies: 9
Views: 1312

Re: Monolith Orchid Fuzz

It's definitely a Fuzz Face type circuit, in fact the Monolith web site calls it a Tone Bender V1.5 variant. The schematic has some parts missing but captures the general idea. It would be nice to get the correct value for C2 (the green ceramic cap) No idea what's happening with D2/C6. Units approx ...
by george giblet
28 Jan 2024, 11:09
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Ibanez - Overdrive II OD-855
Replies: 12
Views: 1464

Re: Ibanez - Overdrive II OD-855

Took me a while to find an example. In 04 above the DC jack has no labels and the lines on the side of the box run over the jacks. That one is a bit of a odd-ball. It seems like a real build so maybe they used up old enclosures. Here's what is more normal for the early DC jack. I found an example fo...
by george giblet
28 Jan 2024, 01:19
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Ibanez - Overdrive II OD-855
Replies: 12
Views: 1464

Re: Ibanez - Overdrive II OD-855

Here's what I compiled Ibanez OD-855 Overdrive II G.Giblet, V1.0,2024/01/28 * Constant features Script logo: flying fingers (FF) on side, no LED, no DC Jack, DBT controls Modern logo: LED, germanium diodes, PCB Rev A * PCB's First PCB: MP-DO701 REV A PCB: MP-DO701A ; incorporates 100R output resisto...
by george giblet
27 Jan 2024, 21:24
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Ibanez - Overdrive II OD-855
Replies: 12
Views: 1464

Re: Ibanez - Overdrive II OD-855

I ran my eyes over the 1978 PCB and found another difference: The Tone Control resistor is 200 ohm (R8 220R ohm factory schematic). That matches up with the value on Patrik Eriksson's schematic, which is for a later version with the LED and the DC jack. It seems safe to conclude the 1978 changes hel...
by george giblet
27 Jan 2024, 01:15
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Ibanez - Overdrive II OD-855
Replies: 12
Views: 1464

Re: Ibanez - Overdrive II OD-855

Wow, check it out. Did a search for some new blood on the subject. https://soundgas.com/product/ibanez-od-855-overdrive-ii/ 1978 unit, script logo, no LED germaniums! (That's after version 1 and before version 2, based on above list.) So it looks like the change to germaniums occured in 1978. That m...
by george giblet
27 Jan 2024, 01:08
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Ibanez - Overdrive II OD-855
Replies: 12
Views: 1464

Re: Ibanez - Overdrive II OD-855

I did; I measured them and they were silicon. They also look a lot like the diodes in the vintage TS808 I had Thanks for clearing that up. I'm not sure I have enough data to clear-up when the change to germaniums occurred. I'm quite certain version 5 does have germaniums. It will take a while decip...
by george giblet
26 Jan 2024, 07:29
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Ibanez - Overdrive II OD-855
Replies: 12
Views: 1464

Re: Ibanez - Overdrive II OD-855

Did you confirm the diodes were silicon? 1) I traced a unit some years back from photos and that was the main hanging point. The diodes looked like silicons. OD855_Narrow_NoLED.png 2) I had the factory schematic for a later narrow box version with the LED but no DC jack and it showed germaniums. Iba...
by george giblet
12 Nov 2023, 21:20
Forum: Electric Guitar/Bass Wiring
Topic: 9V Low Battery Indicator (Layout)
Replies: 15
Views: 4220

Re: 9V Low Battery Indicator (Layout)

Just found this out in the garage, don't know what volts it is set for. 2n2222 transistors, so mostly the same as the original post? The original uses the transistor VBE voltage as the reference voltage and tries to keep the currents low. Your circuit is something like this one: LED Voltmeter - sch...
by george giblet
12 Nov 2023, 04:17
Forum: Amplifiers
Topic: Fender H.O.T. practice amp hum (50hz) noise even the guitar is un plugged.
Replies: 20
Views: 2910

Re: Fender H.O.T. practice amp hum (50hz) noise even the guitar is un plugged.

These problems often occur because of the multiple ground connections at the panel mounted 6.5mm jacks. Depending on the type of jacks used and if they are PCB mounted, a solution is often to replace the 6.5mm speaker jack with an isolated jack.
by george giblet
11 Nov 2023, 06:27
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Earth Sound Research - Graphic Fuzz [schematic]
Replies: 106
Views: 148910

Re: Earth Sound Research - Graphic Fuzz [schematic]

The schematic and an oscillation fix for for this unit was posted on DIYSB some years back.
Earth Sound Research Graphic Fuzz - oscillation fix mod.png
by george giblet
10 Nov 2023, 22:36
Forum: DIY Projects
Topic: Re-amp box transformer quest and 0 Ohm resistor
Replies: 18
Views: 565

Re: Re-amp box transformer quest and 0 Ohm resistor

If you are measuring in-circuit you will get the same impedance across the 1k pot as the transformer secondary (tx pins 1 and 3) because they are connected in parallel - that would be your 836 ohm measurement. Is that how you measured it? If the pot had a marking we could work out what resistance wa...