Mark 4 Pulling the power tubes?

[maeshuggah]

Hello,

I'm considering removing the output tubes of my mark 4 short head. so I can
use it in my rack as a preamp for my strategy thru the slave out(di).

If I connect the slave out (di) from the mark 4 to my strategy mono Input It should work as a preamp eh?
Wouldn't pulling the output tubes eliminate the need for a load on the output transformer of the Mark 4?.

Or am I crazy :roll:

Any help would be greatly appreciated

 

[Boogiebabies]

The output transformer always needs a load. The DI works off of one of the output taps and is buffered to line level to work with mixing bords and power amp inputs. Adversely, using a dummy load will effect the tone of the DI a its signal is derived from the OT's secondary.Dummy loads or shorted usually have sub par tone as they are not a true tube output section and will not react like the amp was designed to with a full tube complement.

My advice would be to leave the tubes in and used a speaker load, but use the pull silent function to use it as a preamp. When you use this, the presence control is not in the circuit as the pull silent circuit works just before the EQ drops in to the phase inverter, but the graphic EQ will function to allow you to dial in more than enough EQ frequencies.

The pull silent circuit is activated by pulling the master volume knob.

 

[Russ]

Yeah, pulling the power tubes and running the amp is a bad idea. So is running without a load on your transformer. I fully agree and support what Boogiebabies has said. Just leave them in there and connect a speaker as you normally would but then pull the silent out on the front of the amp. At that point it is safe to run your amp as a preamp using the effects loop out or the DI out whichever you like better.

 

[maeshuggah]

Alright sounds good (no pun intended)

Thanks guys for the info.