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Keeley - 30ms Double Tracker

PostPosted: 06 Mar 2018, 19:41
by floris
Keeley 30ms Double Tracker gutshots.

Spin Semiconductor FV-1 for audio delay / detune / reverb: http://www.spinsemi.com/products.html
24LC32A 8pin DIP EEPROM that holds the program for the FV-1 chip.
TL074 for the audio path, probably buffers and such to interface with the FV-1 chip.
TQ2-9V "single side stable" DPDT relay that is used for true bypass next to a 3PDT foot-switch.
4x 10kB pots for controlling the parameters of the program running on the FV-1 chip.

2018-03-06 17.11.09.jpg

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Re: Keeley - 30ms Double Tracker

PostPosted: 07 Mar 2018, 16:01
by caspercody
Check out Pedalpcb.com Unison Double tracker. Might help with the schematic.

http://www.pedalpcb.com/product/unison/

Re: Keeley - 30ms Double Tracker

PostPosted: 07 Mar 2018, 22:51
by Boba7
A relay AND a 3pdt?

Re: Keeley - 30ms Double Tracker

PostPosted: 08 Mar 2018, 00:06
by floris
Boba7 wrote:A relay AND a 3pdt?

Yes I also found that interesting. Seems overkill.

Also the PCB mentions a "trails" function next to the 2 DIP switches and at the bottom of the PCB.
But this is not implemented as far as I can see.

Re: Keeley - 30ms Double Tracker

PostPosted: 08 Mar 2018, 09:23
by Boba7
floris wrote:
Boba7 wrote:A relay AND a 3pdt?

Yes I also found that interesting. Seems overkill.


Is the 3pdt latching or momentary?

Re: Keeley - 30ms Double Tracker

PostPosted: 09 Mar 2018, 14:41
by floris
Boba7 wrote:Is the 3pdt latching or momentary?

It is a latching switch.

Re: Keeley - 30ms Double Tracker

PostPosted: 14 Mar 2018, 19:06
by floris
Some picts with IC1 TL074 quad opamp removed:

2018-03-14 16.34.24 - Copy.jpg


2018-03-14 16.34.39.jpg


Opamp B has minus input and output connected together so it is a buffer.
Opamp C has a resistor between input and output and works as an amplifier or mixer.
Opamp D is not used.

In my pedal, the signal was very soft.
Measurements on the IC1 TL074 pins showed that the opamps were not working properly: Output pins were not at V-bias of 4,5V DC.
I replaced IC1 with a new TL074, and all is working again. :thumbsup