BBE - Crusher

culturejam · Post by **culturejam** » 19 Jul 2009, 17:55

I got this in a recent trade, just out of curiosity. It kinda sucks, but I thought I'd post the guts anyway in case someone was interested.

culturejam · Post by **culturejam** » 19 Jul 2009, 18:45

Forgot to mention:

The op amp is TL072.

CHEEZOR · Post by **CHEEZOR** » 22 Jul 2009, 02:12

culturejam wrote:It kinda sucks

I feel the same way! But some people like them.

With some mods it might sound good. I never tried. It sounded really "Blah" to me...

Thanks for the pics though!

B_Y_O_Bass · Post by **B_Y_O_Bass** » 12 Sep 2009, 15:02

First Post on this Blog, so bear with me...(registered just because this is the only blog on google discussing this pedal)

The BBE Crusher is an interesting pedal, Passive EQ is what sold me on it before I even listened to it.

This pedal is super-mod friendly. Passive EQ means that the user can "Tweek the Freq" of each bandwidth to suit.

Single OpAmp (TL 072 means you can sub almost any imaginable DIP-8) is used for in and output gain, no clipping stage.

Clipping stage is courtesy of two low voltage (red) LEDs, which sound terribly fuzzy IMHO.

I replaced the DIP-8 Opamp with a socket to make swapping quick and dirty.
And I replaced the clipping LEDs with 4 inline sockets (cut into singles to fit) so that I can swap with Germ Diodes or Silly-con diodes to taste.

Real interesting is that you can replace the clipping stage entirely with Polarized Caps of similar capacitance of the diodes (still working on that exact measurememnt, more to come) and have a clean boost with a passive EQ, which is something that is completely vacant from the market today.

Below are some pics of the PCB before I started the wild modding.
Note that this PCB is Double Sided, and I have posted a pic of the trace side with the Pots removed, for anyone that wants a DIY home brew of this pedal (probably going to come in handy since BBE liked to discontinue products at the height of their popularity, just like everyone)

KEEP THIS POST ROLLING....SUBMIT ANY IDEAS or OPINIONS ABOUT THE bbe CRUSHER .......peace

CHEEZOR · Post by **CHEEZOR** » 12 Sep 2009, 16:09

Cool idea with the mod to turn it into a clean boost with an eq.

Would love to hear how it turns out.

chicago_mike · Post by **chicago_mike** » 12 Sep 2009, 19:02

My guess is a fender tonestack style preamp, so theres LOTS of room for mods.

analogguru · Post by **analogguru** » 12 Sep 2009, 19:04

I don´t know why there have to be so many similarities with the .....: Marshall Guv´nor....

analogguru

chicago_mike · Post by **chicago_mike** » 12 Sep 2009, 19:40

bass players like that guvnor pedal. those in rage against the machine cover bands anyhoo

analogguru · Post by **analogguru** » 12 Sep 2009, 20:09

Ah I understand:
"If you like the Marshall Guv´nor, you will love the BBE Crusher - just remove the LED´s and double the input cap C4."

[...and you´ve nearly got a Guv´nor (without the clipping diodes).]

analogguru

B_Y_O_Bass · Post by **B_Y_O_Bass** » 12 Sep 2009, 20:16

I don't think that you can just strap over the clipping diodes.
True, it would eliminate the clipping stage, but every diode has a capacitance value, so to keep the circuit truer to spec,
you should replace it with a polarized cap of similar value.

And doubling the input cap would just change the load of the input signal, similar to a tone stack, but without the control a tonestack provides.YMMV

Do we have a Guv-nor schem that we can post for further compare and discussion,
or should we just bring this to the Guv-nor thread?

Dirk_Hendrik · Post by **Dirk_Hendrik** » 12 Sep 2009, 20:31

B_Y_O_Bass wrote:, but every diode has a capacitance value, so to keep the circuit truer to spec,
you should replace it with a polarized cap of similar value.

analogguru · Post by **analogguru** » 12 Sep 2009, 20:49

Guvnor.. - Crusher - Value

R16 (2M2) = R.6 = 10M
C5 (10n) = C4 = 4n7
R3 (1M) = R4 = 1M
R1 (2k2) = R7 = 2k2
C1 (100n) = C6 = 220n
C2 (120p) = C5 = 120p
VR1 (100kB) = VR4 = 100kB
C3 (220n) = C7 = 220n
R2 (10k) = R8 = 10k
C4 (100n) =... = shorted
R6 (680k) = R9 = 680k
C8 (220p) = C8 = 250p
C9 (220n) = C9 = 470n
R7 (1k) = ... = shorted
LED´s are in parallel to R6 in the BBE Crusher
C13 (4n7) = C10 = 4n7
C12 (10n) = .... = ommitted
R11 (100) = .... = ommitted
R9 (1k5) = R10 = 1k5
VR4 (10kA) = VR1 = 10kA
VR3 (10kA) = VR3 = 10kA
C11 (220n) = C13 = 220n
C6 (68n) = C13 = 68n
VR2 (10kA) = VR5 = 10kA
R10 (680) = R11 = 1k
R8 (680) = R12 = 1k
C10 (100n) = C11 = (100n)
VR5 (100kB) = VR2 = 100kA
R12 (22k) = R13 = ???
C14 (470p)= .... = ommitted

analogguru

culturejam · Post by **culturejam** » 12 Sep 2009, 21:06

B_Y_O_Bass wrote:Single OpAmp (TL 072 means you can sub almost any imaginable DIP-8) is used for in and output gain, no clipping stage.

The TL072 is a dual op amp. So any DIP-8 isn't going to work. But any dual op amp in a DIP-8 package will work. Also, TL072 is JFET input, so using BJT input op amps (like a JRC4558) might result in some tonal variation.

B_Y_O_Bass wrote:I don't think that you can just strap over the clipping diodes.
True, it would eliminate the clipping stage, but every diode has a capacitance value, so to keep the circuit truer to spec,
you should replace it with a polarized cap of similar value.

Most of the diodes used in effects circuits have VERY low capacitance, as far as I know. For example, 1n4148 data sheet lists 4 pf as the MAX capacitance at the junction. So I really don't think it's necessary to replace that. And I doubt you can find a polarized cap with a value that small. But I could be wrong.

B_Y_O_Bass · Post by **B_Y_O_Bass** » 12 Sep 2009, 21:50

culturejam wrote:The TL072 is a dual op amp. So any DIP-8 isn't going to work. But any dual op amp in a DIP-8 package will work. Also, TL072 is JFET input, so using BJT input op amps (like a JRC4558) might result in some tonal variation.
trunc------------------------------------------------------------------------------------------------ated
Most of the diodes used in effects circuits have VERY low capacitance, as far as I know. For example, 1n4148 data sheet lists 4 pf as the MAX capacitance at the junction. So I really don't think it's necessary to replace that. And I doubt you can find a polarized cap with a value that small. But I could be wrong.

I totally agree with Culturejam about the OpAmp needing to be DUAL (glazed over that necessity in my first post, apologies), and a good point about the JFET inputs vs. the BJT. If you are the kind of tweeker that stocks a bunch of kinds, try them all until you find one you like.
My favorite so far is still the NE5532 for clear, full-range frequency response. But I'm a bassman, that's what I look for in an OpAmp.

And thank you also to Analogguru for posting the schems for the Guv-nor, and for the detailed comparison of parts.

According to the schems, you could pull the clipping diodes completely and not need any polarized caps, and still have a fully functioning circuit for line or instrument level applications.
BTW, the increase in value of the input cap in the Guv-nor would account for its use with an instrument level signal, and may also account for the Crusher's less than stellar response to a direct instrument signal.
I always had more fun running it after a pedal with a line level output, such as my BB OPA equipped GE-7 eq box.

It is clear from this forum's posts that users of the Marshall Guv-nor, and its clones, have a love for its performance, and unfortunately, I have never been lucky enough to plug one in (fault my age bracket, and the plethora of DOD pedals on the market when I began my pedal quest).

You guys & gals offer terrific and valid points, makes me glad that I joined this community!
Keep up the awesome discussions!

TWANG · Post by **TWANG** » 01 May 2010, 05:40

This is my first post in here. I just joined today.
I was searching for info on the BBE crusher, got one in trade.
I don't like the fizzy gain at all.
I do like the passive EQ.

I don't have ANY experience with pedals.
I have built about ten or fifteen epiphone valve juniors, both modifying stock boards and building eyelet and or turret
boards.

If I could either dump that fizzy gain.. or turn this into more of a clean boost, I'd be very happy.

Anyone want to boss me around?

Thanks!

TWANG

DiscoFreq · Post by **DiscoFreq** » 01 May 2010, 16:45

I think I have a prototype of this one:

TWANG · Post by **TWANG** » 02 May 2010, 06:04

I tried the ds 1 huevos grande mods posted here and I was pretty surprised at how well they made that mediocre pedal sound.
I actually use it now.
but I need a handle on what will cure the tin fizz in this crusher..
right now I keep the gain off completely.

If I could just get a boost out of it, it would be really nice in front of my modded epi vj.
but with gain off. it's pretty much just a passive device for eq. a little more power to the thing, clean, would be excellent.
Actual decent distortion sound would be like xmas.

TWANG · Post by **TWANG** » 02 May 2010, 06:19

quote
This pedal is super-mod friendly. Passive EQ means that the user can "Tweek the Freq" of each bandwidth to suit.
unquote

so.. the cap and resistor over each pot on the pcb form the rolloff for bass mid and treble. so I could change either or both
to taste and adjust the rolloff point?

quote
Clipping stage is courtesy of two low voltage (red) LEDs, which sound terribly fuzzy IMHO.
unquote

So.. I could just clip the leds out.., and that would dump the fuzz.. and leave the gain pot more or less a boost?

quote
Real interesting is that you can replace the clipping stage entirely with Polarized Caps of similar capacitance of the diodes (still working on that exact measurememnt, more to come) and have a clean boost with a passive EQ, which is something that is completely vacant from the market today.
unquote

that would be ideal for me. My amp is already tweaked for the overdrive I like.. made for my guitar and pickups and speaker cabinet.. so if I understand this correctly, I'd clip out the diodes and put in polarized caps. probably 16v?
with uF of same value as diodes and she'd boost clean.
I need to know the values then..

I only see one diode on the pcb. up by the power supply input.
are there more?

anyway, I'm a little confused.. the clipping stage is the leds.. but I can replace them with caps?
or replace the diode(s) with caps?

TWANG · Post by **TWANG** » 02 May 2010, 17:39

I desoldered one red led and clipped the other.
jumpered both.

now I get no sound at all when it's on.

perhaps I did it wrongly.
for instance, did I need to jumper? seems like I did

also, I just soldered to the side the leds were on.. didn't pierce the holes..
so maybe I just don't have a connection BUT I tested to the cap nearby. that ceramic, I forget the name/designation.
and I got the meter to confirm.

TWANG · Post by **TWANG** » 02 May 2010, 19:50

I tried a bunch of things.
pulled out the two red leds.
jumper. no sound at all.

200pf silver mica was the best
tried 47pf and 300 pf and 500 pf

but in the end this has the butt ugliest distortion you could ever imagine.
I don't see how any company could have produced this thing.

all it crushes is your tone.

with two 200pF silver micas I can get to about one on the gain before it breaks up.. but it's not enough of a boost to make the pedal worth having.

has anyone done anything decent with this thing?

BBE - Crusher [schematic]