Ampeg VT-22 Ohm question

[caliwebman]

I am struggling here a bit and need a little help please. I have what appears to be an Ampeg V4 yet on the back, behind an installed volume control, is printed VT-22. It is a stand alone head that looks like a V4 (Has no speakers). Anyways, I cannot for the life of me seem to get a crystal clear sound out of it and I believe it has to do with incompatible 4x12's and/or wrong OHM settings. Here is the setup:

HEAD:
VT-22 or V4

SPEAKERS:
Yamaha S412 III Impedance Nominal 8 ohms Minimum 8 ohms Continuous 240w
- with -
Marshall 1960BV w/mono & stereo selector at 4ohm & 16ohm respectfully or i think in stereo at 8 ohm 8 ohm.

Question being, will these two 4x12's work together with the VT-22 and if yes what ohm setting should the Ampeg be on? I would guess 4ohms?

Any help would be dearly appreciated.

Thanks!

 

[agedhorse]

The will sort of work together, but the Marshall speaker will need to operate at 16 ohms paralleled with the 8 ohm cabinet et will result in about a 5.3 ohm load. The amp should be set for 4 ohm operation.

 

[beans-on-toast]

V4 and VT-22 is electronically the same amp.

Not getting a clean sound could be due to many things. The power tubes might need biasing or the tubes have an issue. Biasing this amp requires changing a resistor. A tech should check the amp out to ensure that it is performing up to spec.

The amp has a switch on the back to set the impedance, 2, 4, or 8 ohms. There are two parallel speaker output jacks. Set it to 4 ohms as was mentioned. That impedance switch is horrible and may need to be cleaned by a tech for it to work properly. Back to having a tech look at the amp.

 

[6thplanet]

The impedance switch in my V4B needed cleaned, it would sound distorted when moved.

 

[caliwebman]

Thanks for the replies guys. Still, it seems regardless of my settings it certainly doesn't come out clean as it should. Me thinks that beans-on-toast nailed it, I had forgotten that a few years back I did change the tubes and never got it Biased. That HAS to be it! Thanks again !!!

 

[agedhorse]

Thanks for the replies guys. Still, it seems regardless of my settings it certainly doesn't come out clean as it should. Me thinks that beans-on-toast nailed it, I had forgotten that a few years back I did change the tubes and never got it Biased. That HAS to be it! Thanks again !!!

Maybe, maybe not.