Power Scaling

[HobbswheresCalvin]

i am sure this has probably been asked, but what is power scaling. where is it located in the series, and where is the circuit for it?

[joCCe]

- http://www.londonpower.com/pscaling.htm
- Power scaling on TAG

[HobbswheresCalvin]

Awesome, thanks.

[PlinytheWelder]

I built a Hall VVR3 into my Express. It's a variation on power scaling and Dana Hall is a member here...
http://www.hallamplification.com/main.html?src=%2F#2,2

[katopan]

VVR is simpler and very effective. Check it out.

[iulker]

Hi guys!

I'm new here, I don't know if I posted in the right place, but I just built and installed a power scaling module for an fixed bias amp, it is a schematic founded on the net with both B+ and BIAS lowering.
Anyway, the thing it's working, somehow, but the problem is that the bias current is dropping way to fast against the plate voltage, so in no time the bias current measured is almost zero when the B+ is around 320V ...
The schematic is the one you probably all know about, two MOS-FETs, n-channel an P-channel, 4 resistors of 100kohm, 2 Zenner of 12V, a dual gang pot of 1Mlin, one 10ohm/5W resistor etc.
How can I reduce the so fast dropping of the bias voltage ?

[UR12]

Hi guys!

I'm new here, I don't know if I posted in the right place, but I just built and installed a VVR module for an fixed bias amp, basically it's a Fender Deluxe Reverb clone, so it is a schematic founded on the net with both B+ and BIAS lowering.
Anyway, the thing it's working, somehow, but the problem is that the bias current is dropping way to fast against the plate voltage, so in no time the bias current measured is almost zero when the B+ is around 320V ...
The schematic is the one you probably all know about, two MOS-FETs, n-channel an P-channel, 4 resistors of 100ohm, 2 Zenner of 12V, a dual gang pot of 1Mlin, one 10ohm/5E resistor etc.
How can I reduce the so fast dropping of the bias voltage ?

Any schematic you find on the net for a "Fixed bias VVR" was not put out by me and I would be careful trying to install something like that without knowing where it came from and who posted it. Our VVR module works fine and there is no problems with bias tracking. So I don't know what you built but it wasn't one of Our fixed bias VVRs and I would appreciate you not using the term VVR to describe it unless it came from Hall Amplification. It confuses people into thinking that it was something that we put out, Stand behind, and support and that is just not the case. Beware of imitations.

[MCK]

I built a Hall VVR3 into my Express. It's a variation on power scaling and Dana Hall is a member here...
http://www.hallamplification.com/main.html?src=%2F#2,2

+1. Same here. Very very happy with Dana's VVR. Installs very easily and works great! Not worth at all trying to build one yourself off un-official schematics etc given its very very reasonable price. Do yourself a favor and order one today. You will not regret it.

[HobbswheresCalvin]

Good to know, i may just do that. I'm still in the test phase on the volume of this amp, vs the volume of my drummer haha. so i may or may not need it....yet

[MCK]

Another option to run at lower volume is to try 6V6 tubes. I liked the sound of my amp with 6V6 in it as well.

[zambo]

Have done a couple VVR from Dana Hall. Very happy with the ease and performance of this product. am ordering 2 or 3 more soon. Worth every penny!

[HobbswheresCalvin]

I am definitely going to use the 6v6 attribute of the amp. I am not sure about the power scaling considering it changes how the entire amp reacts. But i do think i am going to install a PPIMV.

[zambo]

my amp is closest to a liverpool but with a 2 6v6 power section. still cathode biased. Love how it sounds even with the much lower voltages. Would take a vvr power scaling the entire amp over just the ppimv anyday if volume is a concern. my 2 cents.