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previous: Kremator Hello,i'm not too sure, but... -- 5/18/2000 9:41 AM

Re: Switching between two seperate preamps

5/18/2000 10:21 AM
Steve A.	Re: Switching between two seperate preamps K: I agree. I think that most people will put a single 1M grid load resistor right on the input jack, while putting the 33k (or whatever) grid stopper right on the tube socket. For the second channel, I've seen it wired up two different ways. In one scheme, a single 33k resistor in mounted on the V1 socket and a jumper wire is run to the other stage (which doesn't use a separate grid stopper). In the other scheme, two separate lengths of shielded cable are run from the input jack to each grid pin, which has its own grid stopper. The input impedance of a preamp tube is very high and sending a signal to two stages instead of one does not seem to load down the guitar at all. So I see no need to switch the inputs with relays; switching the signal at the output seems to work just fine. BTW be sure to mute the unused channel, especially if it has a lot of gain. (Sometimes you can skip muting a low gain channel but if the contacts are available I'd do it anyway.) --Just my 2 cents worth. Steve Ahola

5/18/2000 10:21 AM

Steve A.

Re: Switching between two seperate preamps

K:

    I agree. I think that most people will put a single 1M grid load resistor right on the input jack, while putting the 33k (or whatever) grid stopper right on the tube socket.

    For the second channel, I've seen it wired up two different ways. In one scheme, a single 33k resistor in mounted on the V1 socket and a jumper wire is run to the other stage (which doesn't use a separate grid stopper). In the other scheme, two separate lengths of shielded cable are run from the input jack to each grid pin, which has its own grid stopper.

    The input impedance of a preamp tube is very high and sending a signal to two stages instead of one does not seem to load down the guitar at all. So I see no need to switch the inputs with relays; switching the signal at the output seems to work just fine.

    BTW be sure to mute the unused channel, especially if it has a lot of gain. (Sometimes you can skip muting a low gain channel but if the contacts are available I'd do it anyway.)

--Just my 2 cents worth.

Steve Ahola

Replies:

Dominik Thanks to Steve and Kremator for th... -- 5/18/2000 11:00 AM