BBE - 427 Distortion  [schematic]

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nashsnazzy
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Post by nashsnazzy »

I actually have one of these and just thought I would add some photos that I took for anyone's consideration. Its an interesting pedal, has a crunchy bright top end that gets brighter with more gain. As a result you'll fiddle with the tone knob as you fiddle with the gain most likely. They mention the muff as an inspiration but it doesn't look anything like a muff to me unless its part of the op amp version.

http://imgur.com/WCx6dCa
http://imgur.com/VAYSJ87
http://imgur.com/182jpO9
Attachments
BBE 427 Distortion guts 3
BBE 427 Distortion guts 3
BBE 427 Distortion guts 1
BBE 427 Distortion guts 1
BBE 427 Distortion guts 2
BBE 427 Distortion guts 2

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BAARON
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Post by BAARON »

Actually, they just say that the tone control is inspired from a '70s BMP, not the entire circuit.
http://www.bbesound.com/products/stomp- ... -427P.aspx

If you gave us a few more photos so we could see what's behind some of the bigger components, it probably wouldn't be hard to trace this thing.

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Duckman
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Post by Duckman »

Rat inspired... just a guess :P

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nashsnazzy
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Post by nashsnazzy »

I didn't catch that tone control big muff thing. I bet it is based on a rat although I think the rat is easier to dial in. I'll see what I can do on the pics. Getting the pedal back together is a little trick because the LED doesn't want to line up without a lot of fiddling through the AC jack hole.

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BAARON
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Post by BAARON »

I'll probably tackle tracing it next week when I have some spare time, so a few more good photos of the top side of the board would be handy.

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BAARON
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Post by BAARON »

Got an initial trace of the circuit done. I think I've got the overall architecture figured out, but there were a lot of component values that I couldn't see due to camera angles. I'll have to get nashsnazzy to confirm/check some component values once I draw up a schematic.
Duckman wrote:Rat inspired... just a guess :P
Nope. It's [a modified] BBE Crusher/Marshall Guv'nor circuit with a BMP tone control. I'll post the schematic once I have some time to sit down with AutoCAD later in the week.

Paul Gagon's bio says that he "designed" the Crusher in the mid-late '80s and built about a dozen of them for some of the the guitarists who visited the Jackson guitar plant (where he worked at the time), but that the Crusher didn't enter commercial production until about 20 years later at BBE. This would suggest that the design of the Crusher predates Marshall's production of the Guv'nor (early '90s, I think?) by a couple years, but I don't have any evidence as to which circuit actually came first and which one was the copy. BBE's product literature pretty firmly states that Gagon designed the Crusher and the 427 himself, but they never make reference to the Guv'nor (either as a derivative of it, or an inspiration for it), and we all know how honest companies tend to be when claiming ownership of pedal circuits...

Anybody know anything about the origin of the Guv'nor to confirm or dispute Gagon's claim to the invention of the design?

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Whalestone
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Post by Whalestone »

BAARON wrote:Marshall's production of the Guv'nor (early '90s, I think?)
According to this post, Marshall states that the Guv'nor was first issued in '89:
http://vintageamps.com/plexiboard/viewt ... 15#p898489
H. Wahlsten
Founder of Whalestone

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Duckman
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Post by Duckman »

BAARON wrote:
Duckman wrote:Rat inspired... just a guess :P
Nope. It's [a modified] BBE Crusher/Marshall Guv'nor circuit with a BMP tone control.
So, I guess my guess was wrong :lol:
The TL072 have more sense now you mention it
Thanks for your work

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BAARON
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Post by BAARON »

Here's the schematic. Had some spare time tonight to sit down with AutoCAD and draw this sucker up. Could somebody move this thread to the Modern Effects forum?

There are a few values that I couldn't make out in the photos (either due to focus or camera angle). Nashsnazzy, if you look them up on your board and post them, I will add them to the schematic. Here is a list of what's missing:

Ra: need part number. Beside R3 on board.
Rb: need part number and confirm if 10k. Beside R10 under gain pot.
Rc: need part number. Under tone pot, beside edge of board and Cc.
Rd: need part number and value. Between R9 and Cc on board.
R3: confirm if 1K.
R10: need value.

Ca: need part number and value. Ceramic cap beside C5 on board.
Cb: need part number and value. Green cap under gain pot.
Cc: need part number and value. Green cap under tone pot, oriented parallel with resistors.
C1: need value.
C4: need value.
C5: need value.
C6: need value.
C10: confirm if 1000uF. (BBE uses this in most of their pedals.)
C11: need value.

D1: need diode type if you want to get really detailed.

Tone pot: need value.

LEDs are 5mm red. Not sure of forward voltage, but probably about 1.6-1.8v.
Attachments
Schematic is missing values/labels that were not visible in nashsnazzy's photos.
Schematic is missing values/labels that were not visible in nashsnazzy's photos.
BBE 427 incomplete.PNG (10.27 KiB) Viewed 5829 times

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Manfred
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Post by Manfred »

In comparison with the BBE-Crusher and the BBE-Screamer Schematics I added
some part values which are excerpted from similar circuit sections.

The tone control circuit looks like the circuit applied at Proel Blues Distortion
download/file.php?id=13223&mode=view
BBE427_2.jpg

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Post by BAARON »

Unless my eyes deceive me, the capacitor you added to the tone control in my drawing does not exist on the board. It is not visible from the top side of the board, nor is there a spot for it when the board is considered from the back side. (No leads. Every component is already accounted for in my drawing, as far as I can tell, aside from the switching and the wire routing and boring details like that.)

Besides, it already matches the Boss DS-1 version of the BMP tone control (without the extra cap that you added). It even has the matching 6k8 resistors. I wonder if the caps and the third resistor will match the DS-1 as well? We need nashsnazzy to chime in here and check the missing values in his pedal.

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Post by Manfred »

BAARON wrote:Unless my eyes deceive me, the capacitor you added to the tone control in my drawing does not exist on the board. It is not visible from the top side of the board, nor is there a spot for it when the board is considered from the back side. (No leads. Every component is already accounted for in my drawing, as far as I can tell, aside from the switching and the wire routing and boring details like that.)

Besides, it already matches the Boss DS-1 version of the BMP tone control (without the extra cap that you added). It even has the matching 6k8 resistors. I wonder if the caps and the third resistor will match the DS-1 as well? We need nashsnazzy to chime in here and check the missing values in his pedal.
You are right.
I suppose, both BBE and Proel applied the Boss circuit.
I bought a defective Proel DS-10 at Ebay yesterday, so I can check out how affects the extra cap the tone after mending.
I intend to buy the BBE 427 over the course of the current year.
DS1_toneControl.jpg
DS1_toneControl.jpg (13.93 KiB) Viewed 5765 times

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Post by Manfred »

I had traced de FD427 and redraw the layout and excerpted the schematic.
Part list:
C1 1uf 50 Volts
C2 100nf Foil
C3 330pf Ceramic
C4 22nf Foil
C5 47nF Foil
C6 100pf Ceramic
C7 470pf Ceramic
C8 220nf Foil
C9 220nf Foil
C10 1000uf 16 Volts
C11 10uf 25 Volts
D1 1N4001
LED1 3MM red
LED2 3MM red
LED3 3MM BLUE
R1 6k8
R2 680k
R3 1K
R4 1k
R5 10k
R6 2k15
R7 10M
R8 1M
R9 6k8
R10 2k15
R11 6k8
R12 10k
R13 10k
U1A TL072CN
VR1 B10k
VR2 A100k
VR3 B100k
BBE_FD427_Schematic.JPG
BBE_FD427_ConnectionPlug.JPG
BBE_FD427_PCB_PARTS.JPG
BBE_FD427_PCB_PARTS_1.jpg
BBE_FD427_PCB_PARTS_2.jpg
Layouts not verified
FD427_Layout.jpg
FD427_Layout.jpg (67.09 KiB) Viewed 5688 times
BBE_FD427_PCB_Bottom.JPG
BBE_FD427_PCB_Top.JPG

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BAARON
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Post by BAARON »

Thanks for finishing that off! Looks good.

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Post by Manfred »

Here the corrected schematic, the pin numbers 2 and 3 of the OpAmp were interchanged.
BBE_FD427_Schematic_V2.JPG

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Post by modman »

At last moved to Modern Stompboxes - 5 years too late.
Great work though
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

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Post by Manfred »

I found a drawing error in the PSU part when I created the Vero layout.
Here is the corrected schematic:
BBE_FD427_corrected_Schematic.JPG
BBE_FD427_Layout_Top.jpg
BBE_FD427_Layout_Bottom.jpg
Ready to print PDF-files:
BBE_FD427_Vero_Components.pdf
(166.28 KiB) Downloaded 125 times
BBE_FD427_Vero_Components_color.pdf
(196.77 KiB) Downloaded 101 times
BBE_FD427_Vero_SolderSide.pdf
(63.21 KiB) Downloaded 112 times
BBE_FD427_Vero_SolderSide_color.pdf
(63.28 KiB) Downloaded 114 times
Lochmaster 4.0 - file:
FD427.zip
(114.63 KiB) Downloaded 127 times

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Post by roseblood11 »

This one has the polarity protection diode in series:
http://dirtboxlayouts.blogspot.com/2019 ... rtion.html

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Post by Manfred »

Thanks for the hint you are right, in the original PCB above the diode for the reverse polarity protection is connected in series.
BBE itself uses both variants of the diode once in parallel and then again in series to the power supply input.
I will adapt the schematic and the layout soon.

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Post by Manfred »

The reverse polarity protection diode is now connected in series to the circuit.
BBE_FD427_Schematic.JPG
FD247_Vero2_Top.jpg
FD247_Vero2_Rear.jpg
Ready to print PDF-files
FD247_Vero2_TopColored.pdf
(142.33 KiB) Downloaded 112 times
FD247_Vero2_Top.pdf
(140.02 KiB) Downloaded 99 times
FD247_Vero2_RearColored.pdf
(63.28 KiB) Downloaded 102 times
FD247_Vero2_Rear.pdf
(63.21 KiB) Downloaded 104 times
Lochmaster 4.0 file:
FD427.zip
(114.64 KiB) Downloaded 110 times

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