E.W.S. Trilogic

[Alex]

This is E.W.S. Trilogic version of Frabbio at FSB.

!!!New layout!!!

Previous layout had a couple of mistakes.
New layout corrected by "John Kallas" (Check below for corrections explanation and his versions of the pedal)
Not verified yet.

[IvIark]

Nice job, thanks for sharing this and the Super OCD

[Mark SL]

What type of transistor is used?

[Alex]

It's a BS170.
I've updated the layout.

[Mark SL]

I built it with a 7660 instead of a 1044 and Im getting a high pitch whine. This has happened in other circuits so I ordered a few 1044s to see if that helps.  One other thing to note is the bass pot drops the volume significantly when you turn it up.  The Q pot does not have a value and the transistor does not have a type posted.  If you could post the schematic I'd be happy to look it over.  It seems like its almost there but needs a second set of eyes.  

[Mark SL]

Also is that really a 2.2uF film cap on the left hand side or is it a 2.2nF?

[Alex]

You can find the schematics here:
http://www.freestompboxes.org/download/file.php?id=20955&mode=view

The pot is 10K (Mid and Q may have been trimmers) and the cap is 2.2uF in the schematics.

[johnk]

first,i want to thank Alex for posting his layout. IMO, I think the parametric mids Q and Freq controls were meant to be external pots (which makes it way more flexible).


NEW LAYOUT FOR THE PARAMETRIC WITH CORRECTIONS IN NEW POST BELOW

I also drew up the simpler, 'stock' version without a charge pump and with selectable mids for those that don't want the parametric# if you want to run it on 18V from a 9V supply, just build and add a tiny daughter board for a charge pump# I haven't built and verified it yet, but I've gone over it a zillion times so I believe that it is correct# this one will fit in a 1590B even with the charge pump:

[Silver Blues]

Mark SL wrote

I built it with a 7660 instead of a 1044 and Im getting a high pitch whine.

Is it a 7660S? The 'S' designation is crucial in avoiding whine in audio circuits.

[johnk]

also, I found two errors in Alex's Tri-logic parametric layout and have since corrected my layout.
bass 1 lug is supposed to connect to the 47n cap, and that 47n's other side connects to negative side of the 10u cap (on column 11) instead of parallel with it. and the treble lug 3 is supposed to connect to the 2K2 resistor and, the other side of the 2K2 connects to the same negative side of the 10u cap.

[johnk]

so if you've already built his layout, you need to add a cut at i23 and relocate a few components to look like this:

[Alex]

Hi John.
Thanks for fixing my layout.
I hope it works as it should.

[johnk]

well, both yours and mine layoust now match the FSB schematic exactly (I've been over them a zillion times!), so as long as the schematic works, the circuit will too. I plan to build both of them up in the next couple of days so I can verify both of them.

[johnk]

the FSB schematic with the parametric mids had quite a few errors so I corrected them (mostly in the treble and bass controls). it was also missing a 1n cap. I used Alex80's layout and made the corrections so it's now verified.

I finally got around to building it and it sounds great.

[johnk]

BTW, here's the corrected schematic for the parametric version:

[johnk]

just an FYI.........after building both the stock and parametric versions, (and both are working properly), I actually prefer the stock one, however I did slightly mod mine for more output.

[glasspak73]

Hello johnk,can you explain why you prefer the stock circuit better? I want to build the parametric,does it have alot of background noise to it? Thank you for all the info and thanks to Alex80 also.

[j-pee]

C14 and C15 could be just one cap, right?
only because of the desired value are there 2 caps connected in series, right?
(just curious :))

[BetterOffShred]

It's like an active James tone stack baxandall-tone-circuit.gif
Or baxandall
C14 and c15 are not really in series there

[j-pee]

should have understood without asking :)
thank you!