This type of VVR Circuit I include as a base option on my amps, but how it's hooked up is dependent upon what the customer wants... (it will take the voltage to zero if turned all the way down). These circuits support up to 50 watts of dissipation safely.

It can be used as a master volume by wiring it in right after the first smoothing cap after the rectifier. This way it browns out the entire circuit, including the power tubes...

OR

You can use it as a variac to brown out just the preamp tube(s) at any point in the power supply, to add some grind to the circuit by starving the plates a bit.

Basically, I use it as a tone shaping circuit that doesn't sit in the actual audio path, and by drilling it into the chassis from the start, it allows some flexibility down the road.

I hope this helps.

Edited: I guess I should rephrase the 50 watts of dissipation and say it can handle the current of a 50 watt amplifier safely... Sorry for the misstatement...

frankenstein,

Send me a link to your amps. Thanks for the info sound interesting!!

Actually, we're not on the web at the moment. We're solely building through word of mouth (believe it or not, doing quite well at it right now) and on consignment for 5 guitar shops. It's enough to keep us busy at night and on the weekends... We just today put up the walls in the new workshop, and I'm dying to get everything up and organized...

The business itself is a fairly new venture even though I've done a significant amount of work for the guitar shops in the past, both in the way of repairing and boutique builds.

That's fantastic, nothing like your own work shop!

What do you do for the amp chassis?

We bend and drill our own with a 24" sheet metal brake, Greenlee punches, and of course, the ubiquitous step drill bits... LOL My partner is a sheet metal tradesman by trade.

The cabinets are built by a mutual friend of ours that is a cabinet maker, though his day business has been a bit tough lately. He's been doing some combo cabs for us lately that are astounding!

Shoot, I was hoping to get a 27" long chassis made.

Yeah, unfortunately, 24" is it. Although, I gotta say, you can fit a whole lotta components in a 24".

Coming soon (After the holidays that is...) 17" x 24" CNC... Woo Hoo!!! It wont be fast or pretty, but will sure beat etching circuit boards with acid and peroxide!!!

OH man that is sweet! The hardest part though is the programming with the software, unless you know that already. So will you have two programed paths, one for the milling then one for drilling?

What one did you buy?

Actually conversion to G-Code is handled through a PERL Script within Eagle PCB and then dumped to either Mach CNC or K-Cam. My day job is running the IT department for a manufacturing firm, so I work with scripts like this all of the time. Same G-Code with a Tool Change to home...

The controller was bought in kit form, and we are building the gantry from scratch.

Because my partner has access to much larger scale CNC equipment than what we will have, through his job, he has been machining the parts on off-hours with the blessing of the owner. He just wants to see if we can do it, which I know we can. The design is based off of the JRGO CNC design which is very common.

I know most of this conversation is very off topic and I certainly don't want to hijack the thread any more than I already have. I'll post some info in a new thread on how we pull this off, but will only do so after we can verify it works as to not give any misinformation. We'll get it together with some pics and video of the assembly, along with the shop itself.

It's a very exciting time... and I want to share what I can...

I am a novice programmer, I run custom CAD programs at my work and do side programming. I recently ran into essi machine code maybe you can help me understand it:

viewtopic.php?f=17&t=619

Hello RMS, how does the PPIVMV compares to danas VVR or Power Scaling?

I have read the VVR or Power Scaling are good for low volumes.

Never used the VVR, I am sure its worth a try though.