Hi Sugarhi, I meant to have selectable channels... Not to have several preamps running through eachother... In that case you are definately right... But many commercial amps have multiple channels, each with their own sound. I'm not one hundred percent sure, but I believe that each "channel" on a combo amp is actually a differnt preamp, and that they all feed into one power amp. My main question from a diy perspective, is whether or not you can have all the outputs of the preamps connected to the input of the poweramp stage at one time (ie have all the preamps in parallel, and getting powered, whether or not all of them have an input signal). In this formation, each preamp would have it's own input jack as well as controls, and in theory you could plug into two or more channels at a time (either with an external a/b box, or have different instruments/mics plugged into the differnt channels). This would definately be the simplest way to go.
The other way I would think to do this is to have a single input, and use a double gang rotary switch to route the signal and power to the preamp circuit that you wish to be using at any one time. The outputs of each preamp would still be all connected to the single input of the poweramp, but the difference is that no power would be sent to the channels that are not used.
I guess that you could also use the stereo-jack method to cut the ground if you wanted to still have a jack per preamp, but not have power flowing to the unused preamp channels.
I wonder also, I guess if you can have two preamps feeding signal to the power amp simultaneously? I don't see any real reason why you can't... Would you need to stick a mixer stage in between?
Anyway, I still think it would be really cool to build a DIY gainclone amp with multiple "voices"...
The other way I would think to do this is to have a single input, and use a double gang rotary switch to route the signal and power to the preamp circuit that you wish to be using at any one time. The outputs of each preamp would still be all connected to the single input of the poweramp, but the difference is that no power would be sent to the channels that are not used.
I guess that you could also use the stereo-jack method to cut the ground if you wanted to still have a jack per preamp, but not have power flowing to the unused preamp channels.
I wonder also, I guess if you can have two preamps feeding signal to the power amp simultaneously? I don't see any real reason why you can't... Would you need to stick a mixer stage in between?
Anyway, I still think it would be really cool to build a DIY gainclone amp with multiple "voices"...