preamp tube wiring

[tubefan]

I have a question best suited to those who are familiar with an 18 watt (as in the 18watt.com builds) and a peavey classic 30. I built an 18 watt but i really like the sound of the C30 preamp thru the 18's power amp section. So i want to build a C30 preamp (just the dirt chan) into the 18. So the question is, what problems might i run into in wiring the preamp tube's power and heaters? It's been a while, but i seem to recall the 18's heater weren't the same, but can i leave them like they are and what might be the consequences? Noise? Any other considerations i should think about would be helpfull too, as i'm more of a hack.

[Enzo]

The heaters are a separate circuit from the audio. If you want to lift the C30 preamp circuit and build it elsewhere, you are not obligated to use th PV heater circuit too. All you need to do it get the 6 or 12v across each heater. DC will have the potential to be quieter, but plenty of great sounding and quiet preamps have AC heaters too. Good practice makes good results regardless of the approach.

PV runs the heaters on DC and wires the 3 tubes in series across -36VDC. You could do that, but likely your power tranny doesn't have a winding for 36volts. SO just run the heaters on 6 or 12. You wanna make it DC? fine.

[tubefan]

Thanks Enzo. So i guess i will just leave the tubes wired as they are now as far as heaters. As for plate voltage i guess i can leave that too and see how it sounds then change it to PV specs if no good?

The heaters are a separate circuit from the audio. If you want to lift the C30 preamp circuit and build it elsewhere, you are not obligated to use th PV heater circuit too. All you need to do it get the 6 or 12v across each heater. DC will have the potential to be quieter, but plenty of great sounding and quiet preamps have AC heaters too. Good practice makes good results regardless of the approach.

PV runs the heaters on DC and wires the 3 tubes in series across -36VDC. You could do that, but likely your power tranny doesn't have a winding for 36volts. SO just run the heaters on 6 or 12. You wanna make it DC? fine.

[Enzo]

I am sure a wide range of B+ will work, up to you what sounds best.

I am amused by you wanting to build "just the dirt channel" from the C30. There is only one channel through the amp, set it to DIRT and it adds in V2. SO you almost have to build the clean channel in the process of building the dirt. Yes, of course there would be stuff to leave out, but most of the signal path is shared.

[tubefan]

I am sure a wide range of B+ will work, up to you what sounds best.

I am amused by you wanting to build "just the dirt channel" from the C30. There is only one channel through the amp, set it to DIRT and it adds in V2. SO you almost have to build the clean channel in the process of building the dirt. Yes, of course there would be stuff to leave out, but most of the signal path is shared.

Well, i only use the C30's dirt channel so i just figured i can leave out the switches and pot and whatever else. This will likely only be a home amp too, so i'm not concerned with output grind. Sounds pretty good with the C30 pre running thru the 18's power amp skipping the pre. Quite a bit like a boutique amp with a master. I assume it'll be even more dynamicly responsive when they are both in the same chassis running off the same PS.