Tube Amp question(s)?

[Mr 9finger]

Well, mainly fx loop questions. I've read other post about people plugging pre amps into their and bypassing the heads preamp and using the power amps. So can you do the opposite? What I mean is, can you bypass the power stage and run the preamp of the head or combo into an external power amp safely?

Hypothetical scenario. Lets say I have the a small 20 watt EL84 based head and one of the old Marshall power amps(you know, the ones that weigh as much as a Yugo), and I need more power, watts, volume, you get the picture....

Can they be safely conjoined at the preamp to work together as one amp? Obviously, it's going to change the character of the amp etc...

[crguti]

Re: Tube Amp question(s)?

you can take any preamp and connect it directly to the FX return of your amp. The fx loop must be serial or you will get some volume and noise issues if it's parallel.

[Koreth]

Re: Tube Amp question(s)?

Metallica used to do just that. They had their Mark IIC+ heads which were run through Marshall heads, using the Marshall heads as power amps.

[CTN]

Re: Tube Amp question(s)?

This is a good question....I'm just wondering...the amp being used as a preamp only - does its power section need to be connected to a speaker load in order to not harm the output transformer?

[Mr 9finger]

Re: Tube Amp question(s)?

That would be my main concern, and if it is safe, how do you go about hooking it up?

[crguti]

Re: Tube Amp question(s)?

This is a good question....I'm just wondering...the amp being used as a preamp only - does its power section need to be connected to a speaker load in order to not harm the output transformer?

yes, you always must connect the power section to a speaker load, no matter if you are using just the preamp section.