Jext Telez - White Pedal  [traced]

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

Re: Jext Telez - White Pedal

Postby Frank_NH » 04 Feb 2018, 04:35

Here's quickie demo for the Yer Blues Fuzz on Vimeo. Notice all the wires around my breadboard (yikes!). :D :shock: :lol:

https://vimeo.com/254156214

For this message the author Frank_NH has received thanks:
Motter (04 Feb 2018, 20:06)
Frank_NH
Breadboard Brother
 
Posts: 96
Joined: 12 Jun 2013, 15:18
Has thanked: 13 times
Have thanks: 41 times

Re: Jext Telez - White Pedal

Postby Motter » 04 Feb 2018, 09:34

Great job, and nice tones Frank! You're right, the MRB and cocked wah sounds really make this circuit what it is. Can your circuit run at 9V? I'm not enthusiastic about charge-pumping everything out there the way some builders seem to be.
Motter
Breadboard Brother
 
Posts: 134
Joined: 24 Aug 2012, 19:02
Location: New Orleans
Has thanked: 26 times
Have thanks: 87 times

Re: Jext Telez - White Pedal

Postby albru80 » 04 Feb 2018, 14:42

Great job, Frank!
I've drawn a layout that should fit in a 125B box:
You do not have the required permissions to view the files attached to this post.

For this message the author albru80 has received thanks: 2
FeVeR2112 (05 Feb 2018, 10:03), Motter (04 Feb 2018, 20:06)
albru80
 
Posts: 45
Joined: 10 May 2010, 19:33
Has thanked: 1 time
Have thanks: 48 times

Re: Jext Telez - White Pedal

Postby Frank_NH » 04 Feb 2018, 21:03

Motter wrote:Great job, and nice tones Frank! You're right, the MRB and cocked wah sounds really make this circuit what it is. Can your circuit run at 9V? I'm not enthusiastic about charge-pumping everything out there the way some builders seem to be.


OK - here's a stripped-down 9V version! :D

After some LTSpice redesign and a go on the breadboard, it turns out that the gain stages can run comfortably at 9V, but in addition you can simplify the clipping and just make it straight to ground (unlike my 18V version, where I tried to stay truer to the original preamp voltages). I've shown this with some 1N34A clipping diodes but you can retain the original two PNP transistor clipping and experiment with germanium transistors. I think, overall, it retains the spirit of the Conqueror preamp. By the way, the original preamp had a second transistor gain/mixer stage after the tone stack and before going to the power amp, so that could be added if you wanted more output (this gets enough output for a pedal).

Have fun!
You do not have the required permissions to view the files attached to this post.

For this message the author Frank_NH has received thanks: 2
FeVeR2112 (05 Feb 2018, 10:03), Motter (05 Feb 2018, 06:57)
Frank_NH
Breadboard Brother
 
Posts: 96
Joined: 12 Jun 2013, 15:18
Has thanked: 13 times
Have thanks: 41 times

Re: Jext Telez - White Pedal

Postby Frank_NH » 04 Feb 2018, 21:13

albru80 wrote:Great job, Frank!
I've drawn a layout that should fit in a 125B box:


Thanks Alex! Check out the 9V version. :D
Frank_NH
Breadboard Brother
 
Posts: 96
Joined: 12 Jun 2013, 15:18
Has thanked: 13 times
Have thanks: 41 times

Re: Jext Telez - White Pedal

Postby albru80 » 05 Feb 2018, 15:38

Cool! This is the 9V version (with clipping transistors):
You do not have the required permissions to view the files attached to this post.
albru80
 
Posts: 45
Joined: 10 May 2010, 19:33
Has thanked: 1 time
Have thanks: 48 times

Re: Jext Telez - White Pedal

Postby Frank_NH » 05 Feb 2018, 16:01

albru80 wrote:Cool! This is the 9V version (with clipping transistors):


Thanks again! I'll see if I can get this one built this week. You definitely want to socket the clipping transistors and try out your favorite PNPs. Silicon PNPs will work but perhaps not have the mojo of germanium. I unfortunately don't have very many germanium transistors in my parts stash so I'll to order some from Small Bear.
Frank_NH
Breadboard Brother
 
Posts: 96
Joined: 12 Jun 2013, 15:18
Has thanked: 13 times
Have thanks: 41 times

Re: Jext Telez - White Pedal

Postby Motter » 05 Feb 2018, 16:04

Frank, I've got dozens of germanium transistors and diodes, and I'll never use all of them. Send me your mailing address
Motter
Breadboard Brother
 
Posts: 134
Joined: 24 Aug 2012, 19:02
Location: New Orleans
Has thanked: 26 times
Have thanks: 87 times

Re: Jext Telez - White Pedal

Postby Frank_NH » 05 Feb 2018, 16:38

Motter wrote:Frank, I've got dozens of germanium transistors and diodes, and I'll never use all of them. Send me your mailing address


Thanks for the offer. Let me get this built first and I'll let you know. The original used the ACY22 PNP germanium transistors, with an hfe minimum of 30. Not sure what the equivalent would be but one could try any of the usual suspects (e.g. AC128...). Also not sure what the effective forward voltage is when wired as a diode, but that would be useful information.

https://www.digchip.com/datasheets/part ... 22-pdf.php
Frank_NH
Breadboard Brother
 
Posts: 96
Joined: 12 Jun 2013, 15:18
Has thanked: 13 times
Have thanks: 41 times

Previous

Return to Boutique Stompboxes dissected...

Who is online

Users browsing this forum: wayshot and 9 guests