Deep Trip BOG Silicon Fuzz  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
Post Reply
User avatar
Pyr0
Information
Posts: 30
Joined: 08 Jan 2012, 15:01
Has thanked: 22 times
Been thanked: 19 times

Post by Pyr0 »

Hi everyone,

anyone interested in the Deep Trip Silicon BOG fuzz ?
I have a loan of an early one and I could post pics of both sides of the PCB, I could take note of capacitor and resistor values too if that would help in tracing this pedal.

so any interest ? 8)

User avatar
telecaster
Resistor Ronker
Information
Posts: 444
Joined: 17 Jan 2009, 00:57
Has thanked: 162 times
Been thanked: 12 times

Post by telecaster »

Yes, go ahead. :shock:
KindaFuzzy - Looks like a blue nail polish and nutella sandwich.
Freekish - "Our originality is in the basement. Our business is in the toilet"
Guitarlcarl - I did take offence at being called an idiot by a moron.

User avatar
Pyr0
Information
Posts: 30
Joined: 08 Jan 2012, 15:01
Has thanked: 22 times
Been thanked: 19 times

Post by Pyr0 »

Here's a couple of pics to start with, just taken with a phone, I'll have to take some with a better camera, maybe tomorrow.

Image

Image

User avatar
Pyr0
Information
Posts: 30
Joined: 08 Jan 2012, 15:01
Has thanked: 22 times
Been thanked: 19 times

Post by Pyr0 »

ok I've had a quick go at tracing this, I will need to draw it up later. All transistors are BC239B
It looks like it's a pretty standard silicon fuzz face, with a bypassable common collector input buffer, this is switched in and out via the "Mode" switch.
The "Voice" switch is a 3 position single pole, which switches between different input capacitors in parallel - 4n7, 4n7||33n, and 4n7||10uF.
then a regular fuzz face, with 50k internal trimmer on the collector of Q1, the "Mood" pot is a 10k Q2 collector bias control, "Fuzz" pot is a 1kC.
There's a 220pF cap between B and C of Q1, and a 150pF between C and B of Q2.
100k Vol control then into another common collector buffer stage.
Almost all caps are seramic, or multilayer ceramic, only exception is the 22uF fuzz cap (with a 120R in series with it to the wiper), and there's 2 x 330uF elecs in the power supply section.

This is my first time tracing any pedal, so hopefully I can get it right.
I'll post up a schematic later or tomorrow.
8)

User avatar
Pyr0
Information
Posts: 30
Joined: 08 Jan 2012, 15:01
Has thanked: 22 times
Been thanked: 19 times

Post by Pyr0 »

Ok, I think this is correct.

Image

User avatar
Pyr0
Information
Posts: 30
Joined: 08 Jan 2012, 15:01
Has thanked: 22 times
Been thanked: 19 times

Post by Pyr0 »

I forgot to write down the trimmer value in above image, it's a 50k trimmer.

User avatar
Nocentelli
Tube Twister
Information
Posts: 2222
Joined: 09 Apr 2009, 07:06
Location: Leeds, UK
Has thanked: 1152 times
Been thanked: 954 times

Post by Nocentelli »

I think the 100k from the emitter of the second transistor in the fuzzface sectionj needs to connect to the base of the first transistor: At least, that's how it is in every fuzzface variant I've seen.

Thanks for this btw - I know it's Yet Another FuzzFace, but it's always interesting to see and maybe try out tweaks that others have done to wring more out of this classic circuit.
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

User avatar
Pyr0
Information
Posts: 30
Joined: 08 Jan 2012, 15:01
Has thanked: 22 times
Been thanked: 19 times

Post by Pyr0 »

Yes you are right, just had another look at it. I just put it in the wrong place when drawing the schematic. Thanks, I will do up a revised schematic later.
Also, what software do people here use for drawing schematics ?

User avatar
Pyr0
Information
Posts: 30
Joined: 08 Jan 2012, 15:01
Has thanked: 22 times
Been thanked: 19 times

Post by Pyr0 »

I measured the gains of the two transistors in the fuzz section, they are 323 and 350 on my DMM.

User avatar
Nocentelli
Tube Twister
Information
Posts: 2222
Joined: 09 Apr 2009, 07:06
Location: Leeds, UK
Has thanked: 1152 times
Been thanked: 954 times

Post by Nocentelli »

I use easypcb/easyschem which is a free download. It's not the best, doesn't look great and is not quick but it is simple and intuitive to install and use and it's free. I'd be tempted to get into Eagle, as it will do layouts and produce files that can be sent direct if you want pcbs fabbed in the future.
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

User avatar
Menegozzo
Information
Posts: 2
Joined: 07 Oct 2016, 21:27
Been thanked: 12 times

Post by Menegozzo »

Hello, guys! My name is Du Menegozzo and I'm the main man here at Deep Trip. I'm flattered to see the interested in my pedals! :D The BOG is indeed a modded Fuzz Face with added buffers and controls, BTW I've always made that pretty clear in our website, instructions manuals etc., I like the idea of buyers knowing exactly what they're getting instead of having a website full of adjectives trying to sell the pedal as if it was something else.

The unit in this post is from our first generation of pedals (2007-2010), those are very different from the ones we've been making since 2012, that you can see in our website now: http://www.deeptripland.com

The v1 had switchable input buffer (MODE switch up turns the buffer off) and switchable input caps (three position MODE switch). Basic schematic is correct, but it has multiple errors in values and connections. There are 4k7 resistors labeled as 47k in the schematic, for example, and 4M7 as 470k. Resistor at the "Fuzz" pot is 12r, not 120r (just limiting max fuzz to avoid oscillation). 47nF at the base of the second transistor of the fuzz section should be parallel to the 1k2 resistor. And the 100k resistor from the emitter of that second transistor should go at the base of the first one, just like in the original Fuzz Face schematic.

The v2 models don't have the switches, they have fixed input and output buffers, a "Lows" pot instead of the VOICE switch and a "Highs" pot instead of the MODE switch. And, of course, much better PCBs and assembly, it's been a long way since then... :)

Breadboard it, experiment and have fun! :horsey:

User avatar
Felipe Ballarin
Information
Posts: 1
Joined: 26 Aug 2016, 15:52
Has thanked: 4 times

Post by Felipe Ballarin »

Hello Menegozzo,

One more question, so in the V2, just after the bufer do you still have the 4m7 and 120pf in parallel to ground?
Or it gonna be redundant, since you have the 120pf before the buffer, and the high impedance in the input due the buffer. :scratch:
Im trying to understand the mods you did here, cause its sounds killer! 8)
Im on the right track here or just talking shit? ahahah
Cheers from Brasília!!

User avatar
Menegozzo
Information
Posts: 2
Joined: 07 Oct 2016, 21:27
Been thanked: 12 times

Post by Menegozzo »

Felipe Ballarin wrote:Hello Menegozzo,
Hello, Felipe! Sorry I didn't see your message before... :slap:
One more question, so in the V2, just after the bufer do you still have the 4m7 and 120pf in parallel to ground?
Or it gonna be redundant, since you have the 120pf before the buffer, and the high impedance in the input due the buffer. :scratch:
Im trying to understand the mods you did here, cause its sounds killer! 8)
Im on the right track here or just talking shit? ahahah
Cheers from Brasília!!
On the current models there's no need for the 4M7 just after the buffer because there's no switching, the buffer is always on. That resistor was meant to "pull down" the small voltage that builds up on the pin of the capacitor when it's not connected to anything (like the 1M resistor you see in virtually all input and output sections of pedals, except when there's another resistance to ground there, like the volume potentiometer on a Fuzz Face, for example). On the v2 models, the buffers are quite different from the v1 units in many other details, anyway.

The small 120pF is there to tame a small amount of high end, I usually try different values at different points of the circuit because you can get very different results. Don't forget you have different impedances and the interaction among the potentiometers, the guitar and the amplifier (or the other pedal after yours). Considering a stock Fuzz Face circuit, for example, if you put a capacitor to ground at the base of Q1, your guitar volume control will interact directly with that capacitor's frequency cut, changing it while you turn the guitar's knob. If you place it after Q1, that interaction will probably be close to zero. That's the kind of thing I mean...

Let me know when you come to São Paulo, come have a coffee and talk guitar electronics "shit" with us here at Deep Trip! :lol:

User avatar
andregarcia57
Cap Cooler
Information
Posts: 572
Joined: 16 Nov 2008, 15:42
Has thanked: 73 times
Been thanked: 109 times

Post by andregarcia57 »

great pedal, passed here in my hands.
Attachments
bog.png
20210401_204046.jpg

Post Reply