Dual Channel overdrives like Barber Half Gainer

[Matybigfro]

I really love the functionality of the Barber Half Gainer it's a dual channel pedal in it's simplest sense so more usable and sensible than the Fulldrive so called boost switch but simpler than simply two pedals in box ala visual sound/KoT. I always like having alot of options of how much gain I have but am not often looking for significant tone differences so its a real no brainer for more like why have one gain setting on a pedal when you can have two but actually match or atleast control level for them too.

If you're not familiar with the Barber Half Gainber you basically have a shared EQ section and then two volume and two gain knobs (Channel 1/2) a on/off footswitch and a another footswitch that changes from channel one two channel two.

I have unfortunately sold on my half gainer so can't have a proper look now as to how it's done and can't find any schematics for it.


I'm thinking of building myself a new OD pedal from vero and wanted to add this functionality on as it seems like such straightforward and great way to get two different sounds out of a pedal.

My assumption is that it's similar to the Fulldrive but rather than simply switching in or out an extra potentiometer its switching between the two potentiometer. Would adding it into any other circuits be that simple or is there something that I'm missing or need to consider for seemless switching without popping noises or other.

[iainpunk]

if you want to change the gain on the go, you could also do a normal overdrive with expression pedal controlled gain, or just throw a volume pedal before the overdrive to tame the gain. your guitar's volume control is also a good gain control for a lot of overdrives or distortions.

if i were to build such a dual channel overdrive i'd have one main drive (probably a DOD250) and a simple boost (like the LPB-1) in front of it, and have the bypass for the boost in the loop of the master bypass.

cheers

[Matybigfro]

I can see the value for the boost style or expression pedal control of gain (a more advance version of the boost in the fulldrive) But neither achieve what I'm after as neither give you the ability to set level at unity and have different amounts of overdrive which is what I'm really after.

I've found the solution here https://www.freestompboxes.org/viewtopic.php?p=225536#p225536

[idy]

It appears the link to your solution is butchered...

I did this in one of the first pedals I monkeyed a lot with, a tube screamer thing. Footswitch gives you two different sets of gain volume. Also switched out diodes (low gain was assymetric clipping) and padded out the louder (assymetric) side so they would work in the same range (ie mid level volume very similar for both sides) and changed the color of the indicator LED.

So that used optos: a board with LEDs shining on two several different sets of LDRs. There are issues with switching between the wipers of seperate volume and gain, better to disconnect two legs instead of just one..., So with that you can have as many poles on your footswitch as you want! 
I don't know why, but the bicolor LED flashes the other color in one setting, on signal peaks. Some unsanitary but harmless(?) stupidity in the switching...

These issues (balancing two sides, avoiding interaction between the two sets of knobs) are not huge, you may not mind, etc. But the dream, that the two sides act like you want them to, is an invitation to tweak.

[idy]

...and the opto thing does away with popping from interrupting her signal path at two points in the circuit at once. Like a cross fade. Fun.

[duck_arse]

I've found the solution here https://www.....org/viewtopic.php?p=225536#p225536

It appears the link to your solution is butchered...

not butchered, edited. it is site policy to deny any links to the other place. interesting reading can be had by searching why is the other place banned. all members are required to read this stuff - you will be tested on the content.