Parallel, switchable - volumes/Gain

[Chris_P]

Hi all,

Ive been planning my new amp build for a week or so now, ive come across this schematic.

http://i45.tinypic.com/28cd7hh.png" onclick="window.open(this.href);return false;

I know its all been seen before, the part that I want to use is the switchable gain & master volumes to create the 2 seperate channels. Atm I see there are 2 gain pots in parallel, the relay will switch between the wipers of each (one channel skips a few gainstages).. at the other end, at the same time, same thing happens with the 2 master volumes in parallel.. allowing for seperate gain/master for each channel.

Im just wondering, as the pots are in parallel, wouldnt the ground(s) need to be lifted on whatever pot comination isnt selected? The way I see it atm, though your switching between what should be 2 channels.. the redundant gain/master would be attenuating the signal depending on their setting. Would this cause a problem? Im very much a learner, so I could well be wrong about this

Cheers, Chris.

[neikeel]

re:
http://i45.tinypic.com/28cd7hh.png" onclick="window.open(this.href);return false;


as the pots are in parallel, wouldnt the ground(s) need to be lifted on whatever pot comination isnt selected? The way I see it atm, though your switching between what should be 2 channels.. the redundant gain/master would be attenuating the signal depending on their setting.Would this cause a problem?

Working through it I have to agree!

Im very much a learner, so I could well be wrong about this

Cheers, Chris.

I hope we are all learning! Whose schematic is it?

[Chris_P]

Tbh I dont know who's schematic it is, but its no secret, a quick google search throws it up. Ive seen it on these forums before as well as others, its ment to be a bogner extacy.. not too bothered about recreating the whole thing myself.

Hmm, I guess it would only take one extra relay to lift the ground(s).. if need be. Just need to figure out how many relays I can run at once, the relays are 5v and the power constumption is rated at 150Mw. Is that (0.15/5)x1000=30ma current per relay?


Chris.

[neikeel]

Tbh I dont know who's schematic it is, but its no secret, a quick google search throws it up. Ive seen it on these forums before as well as others, its ment to be a bogner extacy.. not too bothered about recreating the whole thing myself.

Hmm, I guess it would only take one extra relay to lift the ground(s).. if need be. Just need to figure out how many relays I can run at once, the relays are 5v and the power constumption is rated at 150Mw. Is that (0.15/5)x1000=30ma current per relay?


Chris.

Don't forget to shunt to ground with some 1megs to stop the popping etc.

[Chris_P]

Tbh I dont know who's schematic it is, but its no secret, a quick google search throws it up. Ive seen it on these forums before as well as others, its ment to be a bogner extacy.. not too bothered about recreating the whole thing myself.

Hmm, I guess it would only take one extra relay to lift the ground(s).. if need be. Just need to figure out how many relays I can run at once, the relays are 5v and the power constumption is rated at 150Mw. Is that (0.15/5)x1000=30ma current per relay?


Chris.

Don't forget to shunt to ground with some 1megs to stop the popping etc.

Cool.. this is something im unfamiliar with, herd it mentioned but dont really know what it really implies. Care to explain?

EDIT: Think I might get it now after a bit of reading. So, whenever a signal wire is being switched a 1meg will be added from that relay terminal to ground. Does that sound right?

Cheers, Chris.

[sfb]

That schematic seems to be Bogner XTC with few errors.