calling 4049 and 4069 distortion users/experts

[swt]

HI Guys!!. i've just traced two snarling dogs pedals. The blue doo, and the tweedy dog. To my surprise, the circuits where identical, with only a couple of caps different. They sound radically different. The ics numbers are erased. The question is...appart from the caps...could they be using different ics, for example 4069, and 4049??. I don't think the caps are the only difference, as the one with larger caps, sounds less bassy ( tweedy dog). What do you think?.

[puretube]

free information sucks...

[brad]

are they like a Tube Sound Fuzz?

[Mark Hammer]

One of them, and I forget which one, is actually a note for note clone of the old E-H Hot Tubes.  I have the schem somewhere, but can't find it at the moment.

[B Tremblay]

...the old E-H Hot Tubes.

Don't you mean the MXR Hot Tubes?  :wink:

I owned a Black Dog (which is the clone circuit Mark is referring to) and it used a 4049, so it's a safe bet that yours do as well.

[swt]

could it be so drastic the sound change, just with a couple of different caps in there?. Both were 16 pin ics, so ...maybe a 4009 as you stated?.

[Mark Hammer]

...the old E-H Hot Tubes.

Don't you mean the MXR Hot Tubes?  :wink:

I owned a Black Dog (which is the clone circuit Mark is referring to) and it used a 4049, so it's a safe bet that yours do as well.

Heh, heh.....

The reference is to a self-perpetuating error.  MXR *never* made any pedals named a Hot Tubes. That hasn't stopped an error in titling from being duplicated at simple-minded duplications of Jamie Heilman's Leper's archive all over the world for almost a decade now.

I did manage to find the schematic I have, and it is the Black Dog and Tweedy Dog that are essentially copies of the original Hot Tubes.  These use a CD4049UBE (unbuffered).

There have been a number of 4049-based overdrive units posted over the years.  Tinkering with feedback caps and drive-determining resistors, without having to radically change the PCB layout, can change the character in interesting ways.  Whether it sounds "tube-ish" depends on your mental template of what tube overdrive sounds like.