WEM, Watkins, Rush - Pepbox, Rush Pep Box  [schematic]

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
User avatar
bloom
Information
Posts: 4
Joined: 09 Aug 2019, 21:19
Been thanked: 3 times

Post by bloom »

^ Apologies for the double post but can't find an edit button - should have specified I'm working with the Si layout without tone control!

User avatar
bloom
Information
Posts: 4
Joined: 09 Aug 2019, 21:19
Been thanked: 3 times

Post by bloom »

Swapping the 500k trim for a 1M seems to have solved the problem! Thought that might be of use for anyone who builds this and can't get it to bias... :D

User avatar
Frank Triggs
Information
Posts: 22
Joined: 16 May 2021, 11:03
my favorite amplifier: Marshall JCM800 2204
Location: UK
Has thanked: 7 times
Been thanked: 11 times
Contact:

Post by Frank Triggs »

Josh over at JHS pedals just uploaded an interview with Pepe Rush's daughter, who now builds the original MK1. Great interview, and Josh demo's it, sounds killer.
Original used ACY41 germanium.



The authentic units made by Lucy Rush with exact specs, components etc., are available here: https://reverb.com/item/41134454-the-rush-pepbox
Music is a sculpture in time and space...

User avatar
Electric Warrior
Diode Debunker
Information
Posts: 737
Joined: 23 Feb 2009, 03:37
Has thanked: 23 times
Been thanked: 104 times

Post by Electric Warrior »

More reliable information and nice photos can be found here: https://fuzzboxes.org/pepbox

User avatar
fuzzbunny
Information
Posts: 46
Joined: 09 Jan 2012, 18:12
Has thanked: 59 times
Been thanked: 14 times

Post by fuzzbunny »

Electric Warrior wrote: 20 Jun 2021, 08:40 More reliable information and nice photos can be found here: https://fuzzboxes.org/pepbox
Thanks for the link.

I checked out the other fuzzbox info on the site. Great info, quality photos, fantastic job.

Kudos to the person(s) who helped put this together.

User avatar
modman
a d m i n
Information
Posts: 4890
Joined: 19 Jun 2007, 16:57
Has thanked: 4394 times
Been thanked: 2131 times

Post by modman »

This link is missing from this thread: 2015 interview with Pepe Rush
http://musical-den.blogspot.com/2015/02 ... -rush.html
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

User avatar
MarkL
Information
Posts: 25
Joined: 12 Jan 2013, 17:07

Post by MarkL »

I've read this thread with great interest and want to thank everybody for helping to clarify a lot about this circuit. I'm going to try building up my own..but I do have a few questions to see where it might be worth tinkering with the values.

1. Someone mentioned above that the circuit relates to a Tonebender MK I insofar as it has a lot in common with the FZ-1. Does this mean that the 16K to GND on the base of Q1 sets the bias for that transistor the way the resistors/50K pot on the MK I do?

2. I'd like to better understand what the 820K is doing -- will lowering or raising that have an effect on volume? I like the mod on the MK I bringing the 2M2 down to 1M for a volume boost, but it doesn't look to me like that 820K is situated in a similar place in the circuit's topography, so I'm wondering if it functions a bit more like the 470R on the power rail between Q1/Q2 on a fuzz face.

3. I'm assuming that the 10K on the collector of Q2 functions similarly to the 15K on the Q3 collector of the MK I...so I would imaging that increasing that slightly (to, say, 12K) might introduce a bit of gating...am I correct about that?

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 »

peps1 wrote: 25 Nov 2010, 23:43 Looking at the schematic posted be EW......looks like this is about right, but please let me know of you spot a mistake!
TESTPROOF.png
OVERLAY.png
Hello everything is fine?
Can you give me the dimensions of your PCB? thanks
Attachments
WEM-Rush-Pep-Box-silicon-transistors-19-1024x682.jpg

Post Reply