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Last post

Memphis Tremolo Modulator reverse engineered

Last post by george giblet « Today, 03:46
Posted in Vintage Stompbox Corner ( ... - 1975)
Replies: 8
by bamboone » 01 Mar 2023, 04:24 » in Vintage Stompbox Corner ( ... - 1975)

Hi, gang! Here are some gut shots of my Memphis Tremolo modulator, and also an x-ray component side shot of the PCB showing parts & placement. I have seen gut shots of many other Memphis pedals online that use the exact same PCB! VERY clever engineering! I had originally intended to draw up a schematic also, but I'm too lazy to do that by hand anymore. Perhaps a group member might suggest an intuitive (like: drag and drop schematic symbols from a list) program for drawing schematics?

8 Replies

687 Views

Last post by george giblet
Today, 03:46
Zvex - '59 Sound [traced]

Last post by KirkD777 « Yesterday, 20:32
Posted in Boutique Stompboxes dissected...
Replies: 10
by Nocentelli » 23 Feb 2018, 14:04 » in Boutique Stompboxes dissected...

Yet another one bugg has posted on his site:

Box of Rock variant, with minor changes to cap values Q2/3 source resistors and D-G bias resistor of Q3 so would be quite possible to do a BoR/'59 Sound mode switch with a 4P3T rotary.

I like this more than i remember liking the BoR when i made one years ago, but i just don't like having a single BMP style tilt tone pot and am considering putting a Bassman tonestack on the end instead - If anyone has any advice/suggestions/experience of doing...

10 Replies

4853 Views

Last post by KirkD777
Yesterday, 20:32
How to boost bass on input DS-1?

Last post by Cluckhold « Yesterday, 19:22
Posted in Pimp-My-Cheap-Pedal
Replies: 13
by Cluckhold » 11 Mar 2023, 23:15 » in Pimp-My-Cheap-Pedal

Good afternoon,

I was modding an unrelated Bad Monkey overdrive and one of the mods adjusted the intensity of the bass knob. I reverted it because it was too much for my liking, but it worked really well into my DS-1.

My question is, are there any ways to add a pre-distortion bass boost on the pedal? Hopefully one that wouldn't require I add my own little circuit board into the pedal?

13 Replies

453 Views

Last post by Cluckhold
Yesterday, 19:22
Darkglass - Duality Fuzz Engine [traced]

Last post by aionios « Yesterday, 14:39
Posted in Boutique Stompboxes dissected...
Replies: 27
by tommymariotti » 19 Jul 2021, 10:28 » in Boutique Stompboxes dissected...
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Hi Guys,
yesterday a frind of mine give me a Darkglass Duality to try.
I just opened it and shoot some pictures.
It is based on 4049UBE CMOS.
All Pots are 100kB except for the Level Pot which is 100kA.

unfortunately I cannot hold the pedal so I will start tracing the pedal from the photos. In the next few months I will have the opportunity to have the pedal back in my hands and check all the connections. If someone has the pedal and wants to help me, you can write to me in PM.
27 Replies

7681 Views

Last post by aionios
Yesterday, 14:39
Mosky Ch-Vibe - does not sound like a Univibe [Solved]

Last post by howmuch « Yesterday, 14:13
Posted in Pedal Debugging & Troubleshooting Support

by howmuch » Yesterday, 14:13 » in Pedal Debugging & Troubleshooting Support

Thought I'd pick up one of these to see what it's like.
I was hoping I'd be lucky and it would be a take on the Moen Shaky Jimi/Jimi Nova, which are based on the EasyVibe.
Here's links to the Moen Shaky Jimi and Moen Jimi Nova threads.
And I'd like to thank John Hollis for his lovely EasyVibe circuit. :thumbsup

What's inside then? The highlights:
1 x ST 064C
3 x TI TL062C
4 x LED/LDR pairs

It does indeed look to be generally based on the Moen/EasyVibe circuit although I haven't checked the...

0 Replies

34 Views

Last post by howmuch
Yesterday, 14:13
Bearfoot - Model H [traced]

Last post by sopapo1 « Yesterday, 12:32
Posted in Boutique Stompboxes dissected...
Replies: 53
by WhiteKeyHole » 23 Jun 2011, 01:33 » in Boutique Stompboxes dissected...
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Can I get the Dale resistor values? Thanks!
53 Replies

14287 Views

Last post by sopapo1
Yesterday, 12:32
Boss DD-6 service notes

Last post by ryanuk « Yesterday, 12:18
Posted in Modern Stompbox Effects (1975 - ...)
Replies: 3
by ryanuk » 15 Oct 2022, 16:33 » in Modern Stompbox Effects (1975 - ...)

Would anyone have a schematic or service notes for the Boss DD-6.
I bought one over the weekend. Totally dead as described.
No light or sound at all.

Hoping it's just a power problem. Found a post on another forum that suggests it could be the IC6 5v regulator. Will check that first. As well as checking all the power rails are correct.

There are some similarities to the dd7 but feel like im flying on the dark without a schematic.
Can find the dd3, 5 and 7 but not 6.
Does anyone have it?

3 Replies

349 Views

Last post by ryanuk
Yesterday, 12:18
Behringer - GI100 Ultra-G Cabinet Simulator [schematic]

Last post by Lani « Yesterday, 10:15
Posted in Modern Stompbox Effects (1975 - ...)
Replies: 9
by george giblet » 18 Feb 2021, 12:59 » in Modern Stompbox Effects (1975 - ...)

I found a video with a few pics of the PCB and managed to trace cabinet sim section.

When I compare the frequency response of the circuit as drawn it doesn't seem to match up with the response plots of the GI100 I've seen. It's not bad but it looks a little bottom heavy and the mid dip frequency looks a little high. Having said that the impulse responses I've seen all seem to disagree in the low end. I don't know what to believe.

I'm sure the part values that matter are correct on the...

9 Replies

2829 Views

Last post by Lani
Yesterday, 10:15
Source low beta russian germaniums

Last post by Germanium1 « Yesterday, 08:01
Posted in Parts & Tools Sourcing & Trading

by Germanium1 » Yesterday, 08:01 » in Parts & Tools Sourcing & Trading

Hello
Since high beta germaniums become so expensive Im searching for germanium transistors with low hfe and leakage. Do any of you know what russian models to search for??

Like like 1-10 hfe maybe at most 20
And 1-30ua leakage, the lower the better

Its for distortion pedals and the low leakage is the most critical since i use them in darlington configuration

I”’ve hade excellent results with af239 and a few other low leakage AFs with zero to 20ua leakage.

Sorry for my bad english

0 Replies

53 Views

Last post by Germanium1
Yesterday, 08:01
Orange Kongpressor Gut Shots

Last post by Tassieviking « Yesterday, 02:58
Posted in Modern Stompbox Effects (1975 - ...)
Replies: 19
by Antigua » 05 Aug 2020, 07:10 » in Modern Stompbox Effects (1975 - ...)

I don't have an circuit analysis to offer at this juncture, but I've not seen any gut shots of the Kongpressor on the Internet, so I thought I'd supply some. It looks like it might have originally been named Squash Comp in the design phase.

The clustered strips of resistors is unusual looking, to my eye, I haven't seen anything quite like it in the few dozen pedals I've opened up.

19 Replies

2047 Views

Last post by Tassieviking
Yesterday, 02:58
Earthquaker Devices Zap Machine V2

Last post by graybench « 26 Mar 2023, 16:16
Posted in Boutique Stompboxes dissected...

by graybench » 26 Mar 2023, 16:16 » in Boutique Stompboxes dissected...

I've been hunting down this pedal for a while after EQD featured it on their youtube channel.
This is second version, 350 made for prymaxe. There is a V1 of which only ~20 were made.

zapmachinev2.jpg

PCBtoptraces.jpg

PCBbottraces.jpg

Here is my guess for V1 based on the screenshot below from that youtube video. THIS IS AN APPROXIMATION, USE WITH CAUTION.
Specifically, I'm not sure about the emitter connection for Q2, either the 1K or 470R might be an emitter resistor....

0 Replies

212 Views

Last post by graybench
26 Mar 2023, 16:16
Speaker Line Out Isolation Transformer question

Last post by Soulchief « 26 Mar 2023, 15:50
Posted in Amplifiers

by Soulchief » 26 Mar 2023, 15:50 » in Amplifiers

Speaker Line Out Isolation Transformer question:

Does anybody know what Type/Spec ‘Isolation Transformer’ Suhr or Bradshaw uses for their Speaker Line Out Boxes? Correct resistances?

Want to attempt to make one.

I see these resistance specs options but don’t know what is needed:
— 600:600
— 10k:10k
— 10k:600 ?

— Xicon, Jenson, Edcor ?

Anybody have any ideas or knowledge on this?

Thanks for any help

0 Replies

77 Views

Last post by Soulchief
26 Mar 2023, 15:50
Bonson Praemp [documentation]

Last post by dylan159 « 26 Mar 2023, 14:50
Posted in DIY Projects
Replies: 7
by dylan159 » 23 Mar 2021, 10:38 » in DIY Projects

bonson.PNG

Hello, this is a circuit based on the Benson Preamp, called the Bonson praemp, because I'm refusing to call it a preamplifier. This is part of a streak of me going through circuits I see and even like, to conform them more to my standards while trying to keep the same timbre and character. A more thorough explanation is give at the beginning of the Clown thread .

Up for some circuit analysis? The Bonchild (name changes every time, it's a rule) consists of the same building block...

7 Replies

3479 Views

Last post by dylan159
26 Mar 2023, 14:50
NTE references

Last post by theehman « 26 Mar 2023, 14:28
Posted in Parts & Tools Sourcing & Trading
Replies: 1
by blaise » 26 Mar 2023, 13:52 » in Parts & Tools Sourcing & Trading

Hi,

My local electronics shop goes by NTE references. While shopping there, I noticed that many common components have the same reference (e.g. both 1N914 and 1N4148 are NTE 519).
Am I shooting myself in the foot because NTE assimilate otherwise different components or are 1N914 and 1N4148, or 2N5088 and 2N3903 different names for the same chips?

See for NTE references lookup.

1 Replies

63 Views

Last post by theehman
26 Mar 2023, 14:28
Noise Terminator (Decimator 2 Gstring) jn Effects loop problem

Last post by es335 « 26 Mar 2023, 14:27
Posted in PCB Guitar Mania - pedal builders group and debug
Replies: 5
by es335 » 25 Mar 2023, 15:39 » in PCB Guitar Mania - pedal builders group and debug

Hi,

I build this pedal from PCB Guitar Mania and if I use it with a dirt pedal in the loop of the Terminator itself all works well.
However, when I try to use it in the Serial Effects send / return of my Amp the signal of the guitar is sent straight to the effects return, instead of the guitar out of the Noise Terminator.

Anyone experienced this problem?

Thanks, Ron

5 Replies

129 Views

Last post by es335
26 Mar 2023, 14:27
Older Biyang Baby Boom Max Distortion Guts

Last post by soulsonic « 26 Mar 2023, 14:21
Posted in Modern Stompbox Effects (1975 - ...)
Replies: 1
by dmc777 » 20 Mar 2023, 04:10 » in Modern Stompbox Effects (1975 - ...)

Doesn’t sound like a rat too me. Has more mids.

1 Replies

195 Views

Last post by soulsonic
26 Mar 2023, 14:21
ProCo Turbo Rat w/Electronic Bypass (anyone seen one?)

Last post by soulsonic « 26 Mar 2023, 12:59
Posted in Modern Stompbox Effects (1975 - ...)

by soulsonic » 26 Mar 2023, 12:59 » in Modern Stompbox Effects (1975 - ...)

When I was in highschool in the mid-1990's, one of my bandmates got a brand new Turbo Rat. I was surprised to see that it didn't have the same kind of footswitch as my Rat 2 (also bought new around the same period, probably 1994). His Turbo Rat had a plastic soft touch footswitch like this:

I later saw this same style footswitch on my Roadkill. We now all know that the Brat/Roadkill used electronic FET switching like a Boss/DOD pedal. Now I'm very curious if there was a short-lived version of...

0 Replies

61 Views

Last post by soulsonic
26 Mar 2023, 12:59
Nocentelli's JFET boost with Baxandall [documentation]

Last post by brobri « 26 Mar 2023, 03:41
Posted in DIY Projects
Replies: 10
by Nocentelli » 08 Oct 2017, 19:17 » in DIY Projects

A simple boost/preamp circuit I put together recently. The JFET starts to clip in a pleasingly smooth manner if you really dig in so the gain control allows you to set how hard you need to play to make this happen. The simple active two band EQ gives a nice range of tones for not many parts.

FETBoost_schem_nocentelli.bmp

10 Replies

3481 Views

Last post by brobri
26 Mar 2023, 03:41
SD1 - try getting a real transparent overdrive - I'm not able

Last post by Klay1975 « 26 Mar 2023, 03:34
Posted in Pedal Debugging & Troubleshooting Support
Replies: 3
by nooneknows » 06 Nov 2020, 18:34 » in Pedal Debugging & Troubleshooting Support

Hi,

since we are again in lockdown and I had to occupy my time, I thought What about taking out one of my old SD1 out the drawer and mod it to get the most transparent overdrive I can get ,like my Timmy for example? I love the Timmy transparency, that pleasant grit on the highs, the crunchy round bass.
My idea was to get rid of all the component that trim the bass and cut the high, flatting the mid hump, It turned out it's not that easy as I thought.

so (referring to Boss schematics):

- I...

3 Replies

911 Views

Last post by Klay1975
26 Mar 2023, 03:34
Kauffman Audio Appliances - Aurora Overdrive

Last post by culturejam « 26 Mar 2023, 01:22
Posted in Boutique Stompboxes dissected...
Replies: 5
by soulsonic » 24 Mar 2023, 13:59 » in Boutique Stompboxes dissected...

Getting this thread started. Will come back to it later this evening and update with schematic and pics. I have the neat CAD drawing almost complete, so please be patient for a couple hours, will upload after I'm home from work.
A Kauffman Audio Appliances Aurora overdrive just landed on my bench. I've finished the trace and it's a Timmy with a few parts changed - mostly to the detriment of what makes the Timmy sound great, IMO.
Quick rundown of core differences:
JRC4558 opamp instead of 4559...

5 Replies

292 Views

Last post by culturejam
26 Mar 2023, 01:22
Retro Channel - The Fuzz [traced]

Last post by soggybag « 25 Mar 2023, 17:04
Posted in Boutique Stompboxes dissected...
Replies: 95
by KHELSTROM » 06 May 2011, 00:02 » in Boutique Stompboxes dissected...
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Just stumbled across this on the web. It appears to stabilize the effect of temperature on the transistors via a proprietary circuit . Any guesses as to what's going on here?
95 Replies

36038 Views

Last post by soggybag
25 Mar 2023, 17:04
Digitech - Bad Monkey [schematic]

Last post by cspar « 25 Mar 2023, 16:11
Posted in Modern Stompbox Effects (1975 - ...)
Replies: 29
by Bernardduur » 01 Nov 2012, 16:23 » in Modern Stompbox Effects (1975 - ...)
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So, got one in and traced it.

Speaker sim out is similar to the Screamon Blues pedal
Digitech - Bad Monkey.JPG
29 Replies

22344 Views

Last post by cspar
25 Mar 2023, 16:11
Little treat for you [documentation]

Last post by stomper « 25 Mar 2023, 14:38
Posted in DIY Projects
Replies: 5
by ansil » 09 Mar 2023, 05:10 » in DIY Projects

Good morning or evening friends depending on how the case may be.
I have not been able to play for a while but I was digging up some of my old stuff while I was going through chemotherapy.

I've forgotten about this wonderful little practice amp that I built on a piece of purfboard.
I have a problem with my hands so please cut me some slack on the drawing.
It was the easiest way for me to do it and also hopefully it shows a little bit easier for people who are newer.
Before I get into the...

5 Replies

435 Views

Last post by stomper
25 Mar 2023, 14:38
BAJA Ampeg SVT bass amplifier pedal 9v 010418 [documentation]

Last post by mcrowe « 25 Mar 2023, 13:06
Posted in DIY Projects
Replies: 67
by bajaman » 01 Apr 2018, 08:40 » in DIY Projects
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Here is the second installment of my bass amplifier series - the Ampeg SVT in 9v pedal friendly format.
Plug this pedal into any high wattage power amplifier and experience the Super Valve Technology sound without tubes :wink:
This design is based on the original Ampeg SVT but with the 5 frequency bands mid boost / cut rotary switch used in the later SLM MkII model.
I left the bass cut option in the ultra bass switch control out as well just as they did in the MkII :wink: However I modeled the...
67 Replies

23057 Views

Last post by mcrowe
25 Mar 2023, 13:06
WMD Geiger Counter - [gut shots]

Last post by karul « 24 Mar 2023, 17:13
Posted in Boutique Stompboxes dissected...
Replies: 141
by rousejeremy » 01 Aug 2009, 04:46 » in Boutique Stompboxes dissected...
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Any idea what's going on inside this device?
141 Replies

42398 Views

Last post by karul
24 Mar 2023, 17:13

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