Byrdhouse compressor help (Trimmer)

[mandolintom88]

Hello, I've got all the on board components soldered in and the pedal is working fine. Im just curious as what the trimmer does? Sorry I'm a noob at schematics. I can read one enough to troubleshoot but that's about the extent of my knowledge so far.

Thanks in advance!

 

[Feral Feline]

I don't have the Byrdhouse PCB (because it's a Dyna-Ross derivative that kills bass), but since no one else is chipping in I'll try.

According to the good ol' Electrosmash site (yay! it's back online!)...

ElectroSmash - MXR Dyna Comp Analysis

MXR Dyna Comp guitar pedal analysis by ElectroSmash.

www.electrosmash.com

... "The 2K trimmer resistor adjusts the bias currents of the OTA differential inputs, trying to make a perfectly balanced OTA. Imbalances in the + and - input pins can make the OTA noisy as the signal change levels. In practice, this trimmer is adjusted to the middle position and in very very very rare occasions it is adjusted to any other value."



Check out the analysis at Electrosmash, which may help clarify things for you.

At any rate, mark the trimmer where it's at, mess around with the trimmer and see what effect it has on the circuit and then set it back where it was (or to whatever sounded best to you).

 

[mandolintom88]

I don't have the Byrdhouse PCB (because it's a Dyna-Ross derivative that kills bass), but since no one else is chipping in I'll try.

According to the good ol' Electrosmash site (yay! it's back online!)...

ElectroSmash - MXR Dyna Comp Analysis

MXR Dyna Comp guitar pedal analysis by ElectroSmash.

www.electrosmash.com

... "The 2K trimmer resistor adjusts the bias currents of the OTA differential inputs, trying to make a perfectly balanced OTA. Imbalances in the + and - input pins can make the OTA noisy as the signal change levels. In practice, this trimmer is adjusted to the middle position and in very very very rare occasions it is adjusted to any other value."



Check out the analysis at Electrosmash, which may help clarify things for you.

At any rate, mark the trimmer where it's at, mess around with the trimmer and see what effect it has on the circuit and then set it back where it was (or to whatever sounded best to you).

Thank you! That makes sense, ill give the Electrosmash article a read as well.

Thanks again!

 

[Coda]

I don't have the Byrdhouse PCB (because it's a Dyna-Ross derivative that kills bass), but since no one else is chipping in I'll try.

According to the good ol' Electrosmash site (yay! it's back online!)...

ElectroSmash - MXR Dyna Comp Analysis

MXR Dyna Comp guitar pedal analysis by ElectroSmash.

www.electrosmash.com

... "The 2K trimmer resistor adjusts the bias currents of the OTA differential inputs, trying to make a perfectly balanced OTA. Imbalances in the + and - input pins can make the OTA noisy as the signal change levels. In practice, this trimmer is adjusted to the middle position and in very very very rare occasions it is adjusted to any other value."



Check out the analysis at Electrosmash, which may help clarify things for you.

At any rate, mark the trimmer where it's at, mess around with the trimmer and see what effect it has on the circuit and then set it back where it was (or to whatever sounded best to you).

The Byrdhouse has a low position on the toggle that works pretty well on bass…

 

[Feral Feline]

The Byrdhouse has a low position on the toggle that works pretty well on bass…

I'll give it a go, but so far I've not liked what I heard from Dyna-Ross comps on my bass (not that I've tried a lot, just a few friends' pedals);
I can always give the Byrdhouse to one of those friends.