Danelectro - DD-1 Fab Tone Distortion

briggs · Post by **briggs** » 08 Dec 2007, 12:00

Clay - on another point, do you have the scheme for the tone section of the danelectro fab red distortion (the one with the active mids section), I've been interested in that section of the pedal for a while now but I've, as yet, been unable to locate a single scheme for it!

EDIT: schematic found, threads merged!

Uma Floresta · Post by **Uma Floresta** » 08 Dec 2007, 15:18

You mean this one?

Clay drew this out a while ago. No values, though. The SMD resistors have the values printed on them, but the SMD cap values, where printed, are a mystery to me - sames goes for the SMD trannies.

briggs · Post by **briggs** » 10 Dec 2007, 18:54

Hmm, I wish I had some values. I'd love to do some work and have a look at what frequency bands that tone section is working at!

Anyone got values?

Uma Floresta · Post by **Uma Floresta** » 10 Dec 2007, 19:24

briggs wrote:Hmm, I wish I had some values. I'd love to do some work and have a look at what frequency bands that tone section is working at!

Anyone got values?

I could maybe try to fill in some of the blanks - I'm in the middle of studying for the GMAT, but if I can find some time I'll see about getting some of the R values, at least.

briggs · Post by **briggs** » 10 Dec 2007, 22:00

cheers!

Uma Floresta · Post by **Uma Floresta** » 10 Dec 2007, 22:20

Actually, I might be able to get cap values too - some of them are regular size film caps - we'll see!

jakerandall · Post by **jakerandall** » 18 Dec 2007, 00:53

Is that the full schematic for the daneletro red fab distortion?

Anyone have any values yet?

Uma Floresta · Post by **Uma Floresta** » 18 Dec 2007, 04:06

Shoot, I'll see if I can post some tomorrow - I've been so busy.

Uma Floresta · Post by **Uma Floresta** » 18 Dec 2007, 22:25

Okay, here is what I was able to do today:

Opamp is a tiny LM833. I'm sure I got some resistor values wrong - some of them were very hard to read. The values are in small print, and some of them weren't printed very well. I will compare to my other Fab Distortion to see if I those particular resistors are printed better.

The caps that I marked "? pF" are completely blank. They look much like the SMD resistors, but have no numbers, and are kind of foggy in the middle. I assume they are low value. The other two mystery caps I filled in here had clear markings, but I have no idea what value they might be, and my multimeter doesn't measure capacitance. I have no idea what the transistor is, either.

Eventually I'll see if I can flesh out the whole thing, or as much as possible, after the new year.

Uma Floresta · Post by **Uma Floresta** » 18 Dec 2007, 23:08

Okay, I actually was able to finish getting values for everything - but I am sure there are errors in some places. After new year's I'll sit down with a magnifying glass and really look closely. My eyes hurt after this exercise.

briggs · Post by **briggs** » 19 Dec 2007, 00:07

Many thanks Uma. I've been after investigating this one for a long while now!

Uma Floresta · Post by **Uma Floresta** » 19 Dec 2007, 00:42

briggs wrote:Many thanks Uma. I've been after investigating this one for a long while now!

No problem!

Uma Floresta · Post by **Uma Floresta** » 19 Dec 2007, 15:24

I wasn't planning on doing any more, but I had the nagging feeling I'd got something wrong, and so I did.

I think I've figured out the values on the marked SMD caps - AA7 is 10uF according to a data sheet I found, and E105L is so obvious I missed it - 1uF. The letters threw me off the otherwise normal capacitor code convention.

I still don't know what the transistors are. The diodes are marked as being 1.9v.

I'll put this on my list of things to build. This really is a great little pedal, and using some quality parts and perhaps tweaking it a bit might make it even better.

Uma Floresta · Post by **Uma Floresta** » 19 Dec 2007, 15:28

Clay, if you're around and you see I've made any more errors, please point them out!

Uma Floresta · Post by **Uma Floresta** » 19 Dec 2007, 15:44

According to this site:
http://www.digchip.com/datasheets/parts ... s_ks08.php

L7 could be an NPN Epitaxial Silicon Transistor: 40v, 100ma.

If that's the case, perhaps the following transistors could be used in a non-SMD build:

2N3903
2N3904 - available at Small Bear
MPS3904

I don't know a lot about transistors, someone tell me if I'm off. All of these are supposed to be NPN, 40v, 100ma

JHS · Post by **JHS** » 19 Dec 2007, 16:15

For L7 you can use any high gain trannie, like 2N5088 or BC549C.
Take a look on Boss or DOD schems for HM-pedals. Those pedals have similar gyrators and the trannie specs are on the schems too.

You can even subs the trannies with a LM833 or other dual opamp, IBZ pedals often have IC-driven gyros.

JHS

swt · Post by **swt** » 19 Dec 2007, 16:22

that looks similar to the nobels od1r, although i guess the nobels sounds better, clearer and od focused...

Uma Floresta · Post by **Uma Floresta** » 19 Dec 2007, 22:30

swt wrote:that looks similar to the nobels od1r, although i guess the nobels sounds better, clearer and od focused...

Yeah, it does look similar. Good eye!

briggs · Post by **briggs** » 19 Dec 2007, 22:31

I noticed that - nobels is a bit more complicated circuit wise. More stuff going on!

jakerandall · Post by **jakerandall** » 19 Dec 2007, 23:18

Briggs lets see your build.

I am playing with this. I am thinking it might need the buffers. There are still some missing values. I wonder if there is a different chip that could be used as well.

Danelectro - DD-1 Fab Tone Distortion [schematic]