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Pigtronix - Keymaster
Posted: 10 Mar 2014, 11:20
by apollomusicservice
Here's one interesting
schematic for those who like to connect the pedals in serial or parallel connections.
In my opinion, routing signals in a serial mode has a disadvantage because the signal after the loop A is
divided into two way, loop B and crossfade pot, means not purely routing Loop A and Loop B
(potentiometer crossfade is in parallel with the loop B).
Re: Pigtronix KEYMASTER schematic, guts
Posted: 12 Mar 2014, 20:12
by marshmellow
R11 should probably connect from pin 1 to pin 2 of the opamp.
Re: Pigtronix KEYMASTER schematic, guts [schematic]
Posted: 13 Mar 2014, 07:54
by apollomusicservice
Thanks to "marshmellow" I've made small corrections in schematic.
Re: Pigtronix KEYMASTER schematic, guts
Posted: 05 Apr 2014, 15:06
by DWBH
Anyone built this?
Maybe I'll try it, I want to use some guitar pedals with vocals. Though I think the boost function would make more sense in the Send/Return loop rather than in the input/output sections.
Re: Pigtronix KEYMASTER schematic, guts
Posted: 07 Apr 2014, 20:16
by DWBH
On Pigtronix specs it says the in/out boosts are to/from the loops. That is true, but even with both loops off they are still boosting the signal, right?
I thought they were there to boost send/return levels for pedals with volume drops/etc, but apparently they also boost the 'uneffected' signal.
Right, or I am I seeing this wrong?

Re: Pigtronix KEYMASTER schematic, guts
Posted: 01 May 2014, 06:42
by Bernardduur
I have a Bass Station in that uses the Keymaster PCB for the (1) FX loop and the boost. All other features are not added
What bothers me is that the FX loop pops really loud when engaged or disengaged. I've contacted em to see if they forgot something??
Re: Pigtronix KEYMASTER schematic, guts
Posted: 08 Aug 2014, 01:36
by peanutismint
I'd love to try and make a simplified version of this. Am I right in thinking the reamp part is basically 2 x DI boxes but one wired in reverse??
Re: Pigtronix KEYMASTER schematic, guts
Posted: 04 Jan 2015, 17:25
by bjlotus
Hi all,
just wondering, has anyone built one of these? there's no much info online, so I ended up here.
I've bought a unit a few months ago, and thou it works nice, there's a small amount of bleed when I turn the crossfade knob. i.e: when I go from loop B to 100% loop A, I still can hear a bit of loop B... I'm kinda dissapointed with this, since the blending function was the main reason why I bought it.
I've sent a couple mails to pigtronix and they gave me 2 options: 1) They said they could repair it (but I'm living overseas, so that make things complicated) OR 2) They said I could mod it myself, by just replacing the crossfade potentiometer for a B1Meg pot.
So I was thinking about option 2. I'm not very handy with electronics, but a friend could do it... What do you think? Can you confirm if this would work? is it just a desolder > replace > solder thing?
I guess it's a 'common issue' since they're telling me WHAT to mod based on my description of the problem.
Any input will be greatly appreciated.
Cheers!
Re: Pigtronix KEYMASTER schematic, guts
Posted: 04 Jan 2015, 18:59
by apollomusicservice
At the beginning of my post I have noticed that problem, B1M pot will slightly compensate this disadvantage but the problem is in the concept of that pedal.
Re: Pigtronix KEYMASTER schematic, guts
Posted: 05 Jan 2015, 23:48
by bjlotus
apollomusicservice wrote:At the beginning of my post I have noticed that problem, B1M pot will slightly compensate this disadvantage but the problem is in the concept of that pedal.
Hi apollomusicservice, thanks for replying.
I see... I thought that the 'disadvantage' you mention at the beginning was about running the loops in serial mode (I'm using them in parallel). Basically, what fails is the "mix" between the two with the crossfade knob or exp. pedal.
Do you think that replacing the pot. worth a try?
Thanks again for your time.
Jon
Re: Pigtronix KEYMASTER schematic, guts
Posted: 06 Jan 2015, 08:23
by apollomusicservice
Yes, give it a try. You have to order from Pigtronix pot, remove three knobs,
unscrew three nuts from pots and one from switch. Remove all connectors from rear side and pcb is out. After that replacing pot is easy.