5150 Silent recordings?

[BombshellBill]

Hello all, ive been browsing these forums for a while, first time i've felt the need to post, since most times my questions get answered elsewhere here.

obviously if i'm running the amp without a cab i'll need a dummy load. i have built a purely resistive variable load (2,4,8,16) that i'll use.
i've read that purely resistive loads can put more stress on your amp than a normal speaker or a reactive dummy load. of course, that's when there's signal coming through the power amp.
my idea would be to utilize a switching jack at the preamp out of the 5150 so that when plugged into, the signal would no longer proceed to the power amp and only go through the cable inserted.

would this work and effectively make for a silent record even though the amp is full on? since the power tubes would be on, but seeing no signal.

i've looked at the schematic for a few minutes and can't find J42 where the preamp line is supposed to run to.

 

[AntonioPetrole]

What you have to do is run the signal out the fx send and in the return leave a cable plugged in (that has the inside wires tied off to eachother I believe). I did it that way and it works like a charm. I honestly much prefer the sound of even having mine at .5 on the post gain mic'd then silent, but the way I mentioned works. The reason you have to have something in the return is because I believe the 5150 only blends the signal from the FXloop to the actual signal so you have to kill it (not sure if that is correct, just what I remember from what I have read)

 

[DavePiatek]

I use a Palmer PGA04 with the speaker sim turned off. It burns off the power from the amp and gives you a line-level signal and includes the sound of saturating the power tubes. From there I run it into Mellowmuse IR1a and Impulses if I'm trying to avoid micing up a cab/being loud.

 

[BombshellBill]

well, what i'm actually trying to achieve here:

use the preamp of the 5150 in its entirety, fx loop and all (hence preamp out) and run the preamp out to a VHT 2150 power amp.

 

[TheWinterSnow]

well, what i'm actually trying to achieve here:

use the preamp of the 5150 in its entirety, fx loop and all (hence preamp out) and run the preamp out to a VHT 2150 power amp.

um ok. Anyway, the resistive load is fine, its not causing more stress on the power amp.

 

[BombshellBill]

mmk, now what if i wanted to leave out the dummy load?
what would it take to put the power supplies to respective parts on a switch so i could flip a switch one way and have the amp function as normal, and the other way to turn off the power amp section completely and still have the preamp section live through the preamp out?

 

[TheWinterSnow]

mmk, now what if i wanted to leave out the dummy load?
what would it take to put the power supplies to respective parts on a switch so i could flip a switch one way and have the amp function as normal, and the other way to turn off the power amp section completely and still have the preamp section live through the preamp out?

With the 5150 not possible. Also with cross talk even with defeating the signal to the power amp in the FX loop you will still need a load.

Moral of the story, if you want to use the preamp in your 5150, you need a load, no matter what you do.

 

[BombshellBill]

alrighty then, thanks for the info!

 

[AntonioPetrole]

With the 5150 not possible. Also with cross talk even with defeating the signal to the power amp in the FX loop you will still need a load..

I forgot to mention that. I have the 5150 combo so I didn't even think of it