Catalinbread - Dirty Little Secret  [traced]

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

Re: Catalinbread - Dirty Little Secret

Postby dap9 » 01 Jan 2014, 23:24

Dr. Satan wrote:
dap9 wrote:Overall I'm pretty pleased. When compared to my original DLS MkIII, it sounds pretty close. I only need to do two things in order to get my build 100% to my liking:

1. Decrease the overall gain - mine has a little too much at the minimum setting
2. Decrease the Bass - the original pedal is pretty bassy, and I think my build is similar, but I'd like it to be a little more useable.

Any tips are greatly appreciated :thumbsup


1. Decrease the limiting resistor on the gain control (47K to ground) to 33K or maybe lower, and it should bleed more signal to ground and give less gain/volume. Or you can take it out completely, it's basically a volume control of the first gain stage being fed to the second. If you turn it all the way down, it's the same as turning the output volume control all the way down- it sends all the signal to ground.

2. Decrease the value of coupling caps, the 220n on the input and output could be halved(100n~120n) and that will kill some bass. It is usually more noticeable on the input.


That's what I was thinking - thanks for the confirmation! :thumbsup
User avatar
dap9
Solder Soldier
 
Posts: 203
Joined: 21 Dec 2007, 03:56
Has thanked: 9 times
Have thanks: 0 time

Re: Catalinbread - Dirty Little Secret

Postby armdnrdy1 » 12 Oct 2014, 20:53

There did not seem to be an updated schematic of the DLS MK3 with the corrected values of R3 (1K) and R9 (680R) so...here it is.

Question...does anyone know which position the switching depicts? With all of the switches on the lug 1 side...is this "super lead" or Super bass"?
You do not have the required permissions to view the files attached to this post.

For this message the author armdnrdy1 has received thanks: 5
Blitz Krieg (15 Oct 2014, 11:08), floris (05 Jan 2017, 18:52), modman (19 Oct 2014, 18:12), Nocentelli (13 Oct 2014, 05:27), ThiagoFaraday (31 Dec 2016, 05:47)
armdnrdy1
Breadboard Brother
 
Posts: 105
Joined: 07 Oct 2012, 01:11
Has thanked: 14 times
Have thanks: 66 times

Re: Catalinbread - Dirty Little Secret

Postby armdnrdy1 » 13 Oct 2014, 01:13

In case anyone else wants to know..I looked up Marshall Lead and Bass schematics and looked at the tone stacks.

The switching (super lead/super bass) shown in the schematic is depicted in the Super Bass position.

The combo of R13 (56K) and C22 (270pf) is Super Bass. The combo of R21 (33K) and C12 (470pf) is Super Lead.

For this message the author armdnrdy1 has received thanks:
Nocentelli (13 Oct 2014, 05:28)
armdnrdy1
Breadboard Brother
 
Posts: 105
Joined: 07 Oct 2012, 01:11
Has thanked: 14 times
Have thanks: 66 times

Re: Catalinbread - Dirty Little Secret

Postby J0K3RX » 14 Oct 2014, 04:41

armdnrdy1 wrote:In case anyone else wants to know..I looked up Marshall Lead and Bass schematics and looked at the tone stacks.

The switching (super lead/super bass) shown in the schematic is depicted in the Super Bass position.

The combo of R13 (56K) and C22 (270pf) is Super Bass. The combo of R21 (33K) and C12 (470pf) is Super Lead.



You could try a 50k pot in series with a 33k resistor instead of just two fixed positions, then you could get a wide variation sweep...
User avatar
J0K3RX
Degoop Doctor
 
Posts: 973
Joined: 29 Jun 2011, 02:25
Location: US Florida
Has thanked: 293 times
Have thanks: 464 times

Re: Catalinbread - Dirty Little Secret

Postby armdnrdy1 » 15 Oct 2014, 07:26

Thanks for the heads up on that J0K3RX.

I actually finished the board layout already. Six controls on the top of a 125C enclosure.
I was planning to use the presence trimmer as an off board control but couldn't find a good place for the 4PDT toggle switch. They're kind of large. So I made the Presence control a trimmer again and fit the S Lead/S Bass switch in it's place.

I think I'd rather stick with a switch so that I can switch in between the two original Marshall tone stacks. After all...there is a lot of variation already with the full range of tone controls.

The user manual states that you can "mess" with the presence trimmer but...the factory setting is about 50%.
I'm sure that this is a "sweet spot" for this circuit. It's probably not something I would mess with much.

I'll post build docs after I'm finished with my build. I ordered 4393s from a trusted seller on Ebay, but don't expect them for a few weeks.
armdnrdy1
Breadboard Brother
 
Posts: 105
Joined: 07 Oct 2012, 01:11
Has thanked: 14 times
Have thanks: 66 times

Re: Catalinbread - Dirty Little Secret

Postby roseblood11 » 15 Oct 2014, 08:10

use two 2pdt switches instead of the 4pdt. they are cheaper, more reliable and you get four useful sounds instead of two.
roseblood11
Opamp Operator
 
Posts: 1693
Joined: 23 Aug 2008, 15:21
Has thanked: 322 times
Have thanks: 301 times

Re: Catalinbread - Dirty Little Secret

Postby armdnrdy1 » 15 Oct 2014, 15:00

Maybe I'll bread board the circuit after the JFETs arrive and check out the tonal difference with the different switching options.

I also went through the pictures of the MK3 that were uploaded earlier in this thread. I compared them to the schematic and found a few mistakes with the pot wiring.

The Treble, Mid, and Master are wrong on the schematic marked V1.1.
I'll upload a corrected schematic after my build is verified.
armdnrdy1
Breadboard Brother
 
Posts: 105
Joined: 07 Oct 2012, 01:11
Has thanked: 14 times
Have thanks: 66 times

Re: Catalinbread - Dirty Little Secret

Postby armdnrdy1 » 19 Oct 2014, 15:50

roseblood11 wrote:use two 2pdt switches instead of the 4pdt. they are cheaper, more reliable and you get four useful sounds instead of two.


I don't know if you deal with BLMS but...Lawrence has good prices and a good variety of switches.
The 4PDT are a reasonable $2.99 US.

http://www.bitcheslovemyswitches.com/#! ... ry=8583650

As far as two 2PDT switches being "more reliable" than a 4PDT.....I would have to question why you would come up with that conclusion.
armdnrdy1
Breadboard Brother
 
Posts: 105
Joined: 07 Oct 2012, 01:11
Has thanked: 14 times
Have thanks: 66 times

Re: Catalinbread - Dirty Little Secret

Postby modman » 19 Oct 2014, 18:13

armdnrdy1 wrote:There did not seem to be an updated schematic of the DLS MK3 with the corrected values of R3 (1K) and R9 (680R) so...here it is.
Question...does anyone know which position the switching depicts? With all of the switches on the lug 1 side...is this "super lead" or Super bass"?

Thanks so much if you put work into that.
But it's always good to somehow not the version information, a date, or something to distinguish it.

But great work


In general, threads like these need cleaning up, it's becoming an unreadable mess...
"The whole point of diy is diy. It's not dsoiyathodtr - do some of it yourself and then have others do the rest" (paulc)
User avatar
modman
a d m i n
 
Posts: 4247
Joined: 19 Jun 2007, 17:57
Has thanked: 2889 times
Have thanks: 498 times

Re: Catalinbread - Dirty Little Secret

Postby rezzonics » 25 Sep 2016, 17:21

Can a JFET based overdrive circuit be powered at 3.3V?
I took the Catalinbread Dirty Little Secret overdrive pedal that emulates a Marshall super-lead / super bass amp and tried to see if I could clone it using 3.3V instead of 9V.
I have to say that it's a bit of a challenge, JFETs in general don't work very well at low voltages, it's difficult to bias them and it's difficult to make them work in the active region.
But I think I found the "dirty little secret" to make them work.
The answer can be found on this blog post I published:
Dirty Little Secret 3v3 clone: LTSpice analysis
Spoiler: Pinch-off voltage
User avatar
rezzonics
 
Posts: 28
Joined: 22 Sep 2011, 20:30
Location: Paris, France
Has thanked: 2 times
Have thanks: 9 times

Re: Catalinbread - Dirty Little Secret

Postby bmxguitarsbmx » 25 Sep 2016, 18:01

Yeah! They work great at 33V ;)

I have quite a few j201's that I have sorted out with Vgs <=0.18V . PM me your address, I'll send you a care package. Then you can tell us :thumbsup
bmxguitarsbmx
Breadboard Brother
 
Posts: 116
Joined: 25 Mar 2010, 22:15
Has thanked: 176 times
Have thanks: 61 times

Re: Catalinbread - Dirty Little Secret

Postby rezzonics » 25 Sep 2016, 20:10

bmxguitarsbmx wrote:Yeah! They work great at 33V ;)

I have quite a few j201's that I have sorted out with Vgs <=0.18V . PM me your address, I'll send you a care package. Then you can tell us :thumbsup

They should work up to 40V, but I meant 3.3V not 33V. I am a low voltage guy.
User avatar
rezzonics
 
Posts: 28
Joined: 22 Sep 2011, 20:30
Location: Paris, France
Has thanked: 2 times
Have thanks: 9 times

Re: Catalinbread - Dirty Little Secret

Postby bmxguitarsbmx » 25 Sep 2016, 21:26

I know. That's what the wink is for.

Some jfet's won't work because Vgs will be close to 3.3V, and for the dirty little secret, the top Jfet's source will be at ~ (0.5*3.3V)+Vgs. As you can see, Vgs actually must be lower than1.15V. That's why I offered you some very low Vgs jfets.
bmxguitarsbmx
Breadboard Brother
 
Posts: 116
Joined: 25 Mar 2010, 22:15
Has thanked: 176 times
Have thanks: 61 times

Re: Catalinbread - Dirty Little Secret

Postby rezzonics » 25 Sep 2016, 22:39

bmxguitarsbmx wrote:I know. That's what the wink is for.

Some jfet's won't work because Vgs will be close to 3.3V, and for the dirty little secret, the top Jfet's source will be at ~ (0.5*3.3V)+Vgs. As you can see, Vgs actually must be lower than1.15V. That's why I offered you some very low Vgs jfets.

Ah OK, sorry I got confused.
Yes, J201 Vgs(th) can be as low as -0.3V and as high as -1.5V
User avatar
rezzonics
 
Posts: 28
Joined: 22 Sep 2011, 20:30
Location: Paris, France
Has thanked: 2 times
Have thanks: 9 times

Re: Catalinbread - Dirty Little Secret

Postby rezzonics » 28 Sep 2016, 18:12

Spice simulations of a version of Dirty Little Secret with MOSFETs instead of JFETs and at 3.3V
Dirty Little Secret MOSFET 3.3V version: LTSpice analysis.

Schematics:
Image

I think it's not a DLS anymore but does it sound similar?

Here are some guitar samples sound tests made with the simulations output form the original effect circuit, the JFET 3.3V version and the 3.3V MOSFET version:

Dirty Little Secret LTSpice simulations sound test
User avatar
rezzonics
 
Posts: 28
Joined: 22 Sep 2011, 20:30
Location: Paris, France
Has thanked: 2 times
Have thanks: 9 times

Re: Catalinbread - Dirty Little Secret

Postby rezzonics » 28 Sep 2016, 18:15

These are the schematics of the JFET 3.3V version I came up with:
Image
User avatar
rezzonics
 
Posts: 28
Joined: 22 Sep 2011, 20:30
Location: Paris, France
Has thanked: 2 times
Have thanks: 9 times

Re: Catalinbread - Dirty Little Secret

Postby try20 » 14 Feb 2017, 17:34

Hello!
Presence pot characteristics A or B? The manufacturer says that the Presence initially stands in the middle. In the middle - a 5 K or not, if the characteristic of A?
try20
 
Posts: 1
Joined: 09 Feb 2017, 14:14
Has thanked: 1 time
Have thanks: 0 time

Re: Catalinbread - Dirty Little Secret

Postby armdnrdy1 » 14 Feb 2017, 22:03

If you are referring to taper for the Presence pot....I used a linear or 'B', taper....works fine!

For this message the author armdnrdy1 has received thanks:
try20 (15 Feb 2017, 11:29)
armdnrdy1
Breadboard Brother
 
Posts: 105
Joined: 07 Oct 2012, 01:11
Has thanked: 14 times
Have thanks: 66 times

Re: Catalinbread - Dirty Little Secret

Postby fernsak » 02 Jun 2017, 21:38

mganzer wrote:After some ajustments (of spacement) here it go. Working and verified.


I really dig your layout and it fits a 1590B! Would it be possible to add spaces for the 1M in series with the 2n2 cap needed for the Super Bass mode? That way both versions could be built on the same board. I'm not looking for features like mode switching or voltage doubling, just the ability to build it in SB mode without "offboard wiring" lol. Thanks!
fernsak
 
Posts: 2
Joined: 01 Dec 2016, 21:48
Has thanked: 1 time
Have thanks: 0 time

Re: Catalinbread - Dirty Little Secret

Postby roseblood11 » 06 Jul 2017, 17:47

Does anybody have a pcb for the DLS Mk1 for sale? Maybe the Grapevine V2 from madbean?
roseblood11
Opamp Operator
 
Posts: 1693
Joined: 23 Aug 2008, 15:21
Has thanked: 322 times
Have thanks: 301 times

Previous

Return to Boutique Stompboxes dissected...

Who is online

Users browsing this forum: BlueMeany, Google [Bot], HEAD, sado353, vai0306 and 4 guests