Crowther Audio - Prunes & Custard

bajaman · Post by **bajaman** » 10 Sep 2007, 00:52

Hi Richard - sorry for the confusion - i was not sure if they were verified values on your earlier pic with values added

Did you measure the resistor immediately to the left (looks like 390k)

cheers
bajaman

theblackman · Post by **theblackman** » 10 Sep 2007, 00:56

no, i didn't measure that one, (you are talking about the vertical one right?)

bajaman · Post by **bajaman** » 10 Sep 2007, 01:04

bajaman · Post by **bajaman** » 10 Sep 2007, 01:08

I have adjusted the resistor values on my PCB and layout for the Ham and Mustard - The values shown on Krome Magnon's last schematic appear to be correct - many thanks to Richard ( the blackman ), for measuring and confirming values etc.
Don't forget to hit F5 to refresh your browser if viewing the new photobucket file.
cheers
bajaman

goaltoday · Post by **goaltoday** » 10 Sep 2007, 01:54

Thanks to all of you!!

bajaman · Post by **bajaman** » 10 Sep 2007, 12:35

I have made some further corrections to the PCB layout , so that the switches and pots are more evenly symmetrically spaced. Please download the amended version from the earlier photobucket link - sorry for the inconvenience
bajaman

lohstah · Post by **lohstah** » 10 Sep 2007, 13:33

very cool

thanks for the layout !

cheers,
lohstah

krome_magnon · Post by **krome_magnon** » 10 Sep 2007, 21:42

theblackman wrote:hi guys, when I dismantled the P&C there were a number of components under the goop which had been damaged by my scraping, fortunately only the diodes were broken and easily replaced.

So the 2 diodes and resistor I have marked up as "possibly not fitted" were never there in the first place, though the holes exist for them? If so I'll remove them fron the next version of the schem.

theblackman wrote:The resistors that you are asking about had some of the markings partially scraped off so I desoldered and measured with a DMM and made sure what was left of the markings agreed with the DMM reading.

Thanks for doing that, and the values on my last schem are pretty much as per your earlier image and what we have bashed out in this thread?

I'll do a final version crediting the board for figuring it all out but if anyone want's to do a better schem please jump in, I only had a whack at it because this thread seemed to have stalled.

bajaman · Post by **bajaman** » 10 Sep 2007, 21:46

Thanks Krome for your schem

bajaman

celadine · Post by **celadine** » 11 Sep 2007, 01:10

+1 Thanks!

Bernardduur · Post by **Bernardduur** » 11 Sep 2007, 15:19

Bajaman, your layout has a slight error

On the bottom, the mix pot connections are wrong. The line of the drive potmeter should go to the most right leg of the mix potmeter

Now it won't mix a lot

bajaman · Post by **bajaman** » 11 Sep 2007, 20:50

OOOOOPs

sorry - thanks for recognizing the error Bernarduur

- I have amended it - don't forget to press F5 to refresh your browser for the new image.
Cheers
bajaman

krome_magnon · Post by **krome_magnon** » 12 Sep 2007, 19:20

Before I edit the schem to be the final version, was the CP10H correct or was it a CP104?

Was it the 10 Volt zener or the rectifier diode?

bajaman · Post by **bajaman** » 12 Sep 2007, 19:34

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

Jim777 · Post by **Jim777** » 13 Sep 2007, 02:23

It used to be quite common for some jap pedals to have an 11volt zener at psu input to protect from over voltage.

krome_magnon · Post by **krome_magnon** » 13 Sep 2007, 18:22

Ok, here's the latest (final?) version of my attempt at tracing the schem. Thanks to theblackman for the intial de-goop and all measurements and everyone else who chipped in.

theblackman · Post by **theblackman** » 14 Sep 2007, 05:02

krome_magnon wrote:So the 2 diodes and resistor I have marked up as "possibly not fitted" were never there in the first place, though the holes exist for them?

Correct.

krome_magnon wrote:Thanks for doing that, and the values on my last schem are pretty much as per your earlier image and what we have bashed out in this thread?

Yep, that's right.

Bernardduur · Post by **Bernardduur** » 14 Sep 2007, 10:01

Hey Bajaman!

Two more mistakes!
- The switch names are reversed
- You miss a trace between pin 1 and the line connecting the 2k / 10 uF

Jim777 · Post by **Jim777** » 14 Sep 2007, 10:22

Maybe there's an earlier version with 2 extra diodes and resistor?

bajaman · Post by **bajaman** » 14 Sep 2007, 22:27

Amended earlier photobucket link to PCB and Layout - many thanks to Bernardduur for spotting my mistakes, and sorry for any inconvenience.
How does it sound Bernadduur - apparently it is more suited to bass guitar.
cheers
bajaman

ps: don't forget to press F5 to refresh your browser image.