Crowther Audio - Prunes & Custard

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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Bernardduur
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Post by Bernardduur »

Well, my main focus is the bass; guitar is just for side projects

I must say that it is quite standing on both guitar, bass as organ; and yes, it can withstand the bass a bit more. On bass, through my Ampeg with some minor OD, it refects good on the way I play, power, intensity, etc; on guitar (Tele / SG through Dumble) is is less dynamic and less open sounding.......

BUT

On bass I can't stand the notes it produces.... it sounds too..... artificial.... to high endish..... too much. Like someone over at Talkbass said, like a duck having sex with a fuzz box. And although I am known for my use of OD, fuzz and synths (I have two on my board) I can't really use the sound of this unit.....

On guitar I can use it quite nicely over an already overdriven amp to make my single notes stand out more; I knew before I played this unit that Wilco used this unit quite intensive on their last album and now by playing it I can see where the sounds get from. Still, I can't really be using this pedal any time soon.......


Last note; I have an original here from a friend. It sounds identical. Great job!
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Post by bajaman »

Hi and thanks for the comments Bernardduur - I must check that Wilco album out - Hmmmmm - a duck having sex with a fuzz box :lol: :lol:
bajaman

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Post by theblackman »

I like it for bass with the mix and drive about half way for a nice overdrive sound, other than that it sounds like what your stomach would make if you ate a whole lot of "prunes and custard"..

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Post by modman »

Such great team work! incredible guys, almost cannot believe it. Can hardly follow all threads now, there's just too much.

I will add some definite links in the first post for reference. This could even move into the DIY Projects folder if there are no objections to that. Let me know.

mm
---
EDIT

Added to the White List as

Crowther Prunes and Custard part-numbered gutshot - pcb transfer & parts layout - schematic
Last edited by modman on 19 Feb 2008, 13:18, edited 2 times in total.
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Post by sonicvi »

I have a quick question about this project. In the photos of the pedal it appears as though the bands on the diodes are facing inward but on the Ham and Mustard layout they're facing outward. Does it not matter which way they're facing as long as they're all the same on each side?

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Post by Rodgre »

bajaman wrote:Judging by the physical colour, and on past Paul Crowther pedals, it is a zener - for over voltage protection or more probably for regulation to avoid uneccessary hum,when used with an unregulated 9v dc power supply (usually put out at least 12v dc).
cheers
bajaman
I just built one up on perfboard and I didn't bother with this diode because I didn't have one (although I do have some 4739 9.1v zeners??) I also tried a few different op-amps because I didn't have an TL072s (tried TL082, 4558, 1458, ne5532, LF353, etc). I also didn't have a reverse log pot for the gain, so I just wired up a 50k audio pot. Anyway, it works great as a thick sounding fuzz, but it doesn't seem to get all that weedy sweepy decay sound that the original has. Is there anything crucial to the circuit to make that happen that I might have missed?

Roger

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Post by sonicvi »

Rodgre wrote:
bajaman wrote:Judging by the physical colour, and on past Paul Crowther pedals, it is a zener - for over voltage protection or more probably for regulation to avoid uneccessary hum,when used with an unregulated 9v dc power supply (usually put out at least 12v dc).
cheers
bajaman
I just built one up on perfboard and I didn't bother with this diode because I didn't have one (although I do have some 4739 9.1v zeners??) I also tried a few different op-amps because I didn't have an TL072s (tried TL082, 4558, 1458, ne5532, LF353, etc). I also didn't have a reverse log pot for the gain, so I just wired up a 50k audio pot. Anyway, it works great as a thick sounding fuzz, but it doesn't seem to get all that weedy sweepy decay sound that the original has. Is there anything crucial to the circuit to make that happen that I might have missed?

Roger
I built on with the layout posted in this thread and it works great.

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Post by sonicvi »

I will post pics and a clip after I get 5 posts

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Post by modman »

I built this one, and must say I'm almost a Crowther fan now. Did have the chance to play an original and it was exactly as I remember it soundwise. I used a 100KB with a 100K resistor across to make up a 50K C pot.

Thanks everybody, theblackman for the degooping, baja for the layout, kromagnon for the schemo and everybody who helped this along. A truly collaborative effort, great.
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Post by 9 volt »

Hey there, I've just put one of these together (used the pcb) and am not having too much luck. I've used an audio probe and the signal stops at the IC. (after the 2.7k resistor). Just wondering if anyone has some advice (I could post voltages). Rechecked traces and they seem ok. Off wiring- ground of both sockets connected to the neg battery wire then going into the E hole on the pcb. Thanks

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Post by 9 volt »

Well I found one problem, neg rail connected to the input rail....fixed this and have sound. Though still not working properly, tried two wirings.
1) ground socket to socket, battery direct to board- lots of feedback.
2) ground sockets and battery to board- weak signal with no distortion.
Audio probed the IC- stage one doesn't seem to boost signal......maybe someone has an insight, Thanks

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Post by krome_magnon »

Here's a quick and dirty suggestion for off board wiring...

Image

Is it any help? he power hook up would obviously be a little different if a DC socket rather than just a batter was used.
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LMJS
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Post by LMJS »

That duck fuzz sounds like a hella idea.

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Post by 9 volt »

Thanks, I'll try it out again today. I tried this wiring (without led), so I figure I've got another problem in the circuit. Lacks drive. I'll keep you posted. Thanks for the help.

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Post by 9 volt »

Got it working (trace problems) Thanks for the help though. One thing- I cut the trace and changed the wiring for the bass switch. It didn't do much the way it was with the joined trace between the first two wires. I cut it and swapped the wires eg centre on the left, there is now a definite difference in the two settings for guitar and bass (may be wrong but gives variety).

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Post by flood »

this forum rocks my socks off! great work guys.
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Post by jazzercountry »

Troubleshooting time!

Ok, I fired this up and I've got signal when bypassed, and the LED lights up no problem. I've got no output when effect is engaged and I'm trying to figure out why. I busted out the audio probe and audio stops at pin 3 of the IC, and it also doesn't make it across the 1M resistor just past that. I marked up this picture to show where exactly it stops. I'm getting audio all the way from the input up to the spots marked in red. I tried swapping out the 1M resistor, but that didn't do anything (I'm not sure why I even bothered with that).
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Post by bajaman »

is the op amp in the correct way around???
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Post by jazzercountry »

It's in the right way (dot in the upper left). Should I try flipping it? It's socketed, so it shouldn't be DOA from heat damage or anything like that.

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Post by bajaman »

Should I try flipping it?
No!!!!!
It is correct.
Check the voltages on the op amp pins and list them here please.
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