Dunlop - 105Q Bass Wah

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
User avatar
mrslunk
Information
Posts: 3
Joined: 22 Sep 2009, 04:13
Completed builds: Bigmuffpi, Dod 440.
Been thanked: 1 time

Post by mrslunk »

let me know which section you want more pics of and i'll get on it

User avatar
chicago_mike
Tube Twister
Information
Posts: 1754
Joined: 03 Jul 2008, 04:38
Has thanked: 22 times
Been thanked: 316 times

Post by chicago_mike »

Well, pretty much anything and everything. As fina and clear a detail as you can get I guess.

Its far beyond me to trace, but theres some real nut-balls here who will do it. Of course I mean that in the nicest way possible. :mrgreen: :oops:
Skyline FX 2013

User avatar
himister
Resistor Ronker
Information
Posts: 425
Joined: 07 May 2009, 00:48
Has thanked: 21 times
Been thanked: 30 times

Post by himister »

Guess I'm a bit sarcastic today, but I really wonder how we could measure precisely those caps without desoldering them? :hmmm:
Don't get me wrong I would really like to see this white fellow REd. I'll help much as I can.
:wink:

User avatar
chicago_mike
Tube Twister
Information
Posts: 1754
Joined: 03 Jul 2008, 04:38
Has thanked: 22 times
Been thanked: 316 times

Post by chicago_mike »

no clue.. :hmmm:
Skyline FX 2013

User avatar
matt239
Solder Soldier
Information
Posts: 228
Joined: 11 Sep 2010, 18:54
Has thanked: 60 times
Been thanked: 5 times

Post by matt239 »

+1 I'd love to see a schematic for this.

User avatar
Bernardduur
Transistor Tuner
Information
Posts: 1218
Joined: 24 Aug 2007, 07:36
my favorite amplifier: Welagen - ODR
Location: Losser.........
Has thanked: 94 times
Been thanked: 732 times

Post by Bernardduur »

So here are some units I have traced;

First my own; old through hole version (approx around 1998):
Dunlop - 105Q.JPG
And one I fixed, a Rev E
Dunlop - 105Q rev E.JPG
'No more....... loud music.......'
Follow my love for pedals and amps on https://bernardduur.blogspot.com and https://www.instagram.com/bernardduur1

User avatar
akmeddie
Information
Posts: 1
Joined: 11 Dec 2018, 09:18
Has thanked: 1 time

Post by akmeddie »

Bernardduur, thank you so much!
This is really interesting. I always thought, the 105q was really the MXR envelope filter (using the CMOS inverters) with some buffers and without the envelope detector.
Turns out, that the filter itself is a similar construction (switched capacitor filter is what they call it?), but with op amps.

Does anyone know if those MC33174s are replaceable with TL074s?

Thanks!

User avatar
Manfred
Tube Twister
Information
Posts: 1937
Joined: 04 Apr 2009, 23:42
Has thanked: 1671 times
Been thanked: 1344 times

Post by Manfred »


User avatar
TWSpedals
Breadboard Brother
Information
Posts: 53
Joined: 30 Dec 2020, 23:48
Has thanked: 18 times
Been thanked: 51 times

Post by TWSpedals »

Looks to be a state variable filter like what you see in a Mutron 3 but with the LDRs swapped out for a 4016
Have a nice day!

Post Reply