You'll find that sort of thing over at the Amp Garage.

Mine has always dropped volume a lot in Jazz. I think its designed that way. Has yours changed in some way?

I have been thinking in recent weeks (after having tried a Redplate Astro Dust, a very impressive amp indeed) about how to implement switching of the slope resistor. In essence what you have to do is switch after the caps following the slope resistor, which led me to the conclusion that that was probably how Henry does it with the 6 position Blackface->Tweed rotary.

So does anyone know what the effect of having dual slope resistors would be? ie one for bass and one for mids. How to model this in terms of tonestack behaviour. Or would it just be a matter of trial an error.

I did find a 12 way rotary switch on Mouser which can be  ordered as a 12x1, 6x 2, 4x3 way etc. The only problem with trying to implement this is where to put all the components. The Redplate amps have a set of additional turrets in a cluster which I would assume would be for these connections.

PM'd

Best keep schtum then!!!

That sounds fantastic Doc. Are you using the cut control on the OD channel?

Not if I can help it!

Better to ask on The Amp Garage.
http://ampgarage.com/forum/viewforum.php?f=4&sid=a5971c399f6b90430456199d74307c0d

Something is still amiss with your voltages. V1b and V2b (both pin 6's) are both now 20%+ on the high side.

What is the voltage at the OT Centre tap?.

Next step is to download all the pics from the website and start redressing your leads to look identical, that is routing, and length. Very important this, you might need to unsolder some and shorten some others. Google 'Dumble Lead Dress ' and you'll find loads. It seems to me that what you have is oscillation in the od circuit. So give special attention to V2.

Despite what all the c-lator proponents say, you cannot get the same dynamics/harmonics with a master volume/attenuator/powerscaling as you get when the power section is being driven hard.

Thats why a 5-7 watter and a 12-15 watt OTS would be a very good idea. Fuchs have done that with their Casino range and I'd bet they're onto a winner with it. TR similarly.

This is where you need to check your values. See resistors highlighted in pink. There is a B+5 which I've not labeled as for these purposes its not relevant, it is the FET supply.

Pins 1 and 6 are the anode (plate) which are connected to the B+ nodes so check the values of your resistors against the layout for your amp.

Pins 2 and 7 are the grids, ignore them for now, you need to get your plate volts right before you go any further.

Follow the B+ from the rectifier and you will see a number of resistors in series which create the correct plate voltages for each tube. Each dropping string resistor creates a node, usually labeled B+1, B+2 etc. The big caps simply smooth out the AC ripple and for the purposes of testing can be ignored. Its easier to see how this is arranged if you look at a schematic rather than a layout. If you get one of these wrong then you will be dropping the voltage too much or too little and the tube will not function as designed. If you get one wrong early on it has an effect on all the nodes down the string.

OD trimmer?

Thanks Doc,

Weight isn't an issue, its for studio use only and I put casters on it as well as side handles.

In a 2x12 D style cab what would you pair with an EV Doc? Mine has a Emi Red Fang Alnico but only because I got it when they were £120 just before they went up to £200. My mate who i built the cab for has bought an EV and is looking for something similar to the Red Fang so I have suggested he try my Gold, but what about Fanes or Taydens?

Any thoughts?