All thats very useful thanks. All the speakers that are around on eBayUK are the ones I have no reports for!

I'll keep looking for an RW&B or a Texas Heat I think

I've been thinking about what to pair with a g12-65 in a 2x12, thinking of going with a Celestion vintage 30, but there seem to be quite a few Eminence speakers on eBay Uk at the moment, the problem is there are so many different models. I know the Texas HEat and red White and Blue are well respected, but there are few of those about, so does anyone know much about all the other models?

I know Pickmaster put this link up a while ago

http://www.woodys-guitar-world.co.uk/listen.htm

and there's some useful info there but not all models unfortunately. Could do with some more info since they seem to be very well priced at the moment.

Have fun. They won't know what hit 'em!!

I have reworked the drawing and I'm going to use two relays so I can sort the problem properly. One relay will switch both the send and return signals so i get a proper bypass and the other realy will do the footswitching and LED's.

Will order the relay board from Nik and put the wheel in motion. I will also need to replace the hardwire bypass switch on the rear panel with a 3PDT version in order to separate the return signal completely.

Wll keep you posted.

I have an original and did most of the Zucker mods and it didn't change the volume that I noticed. I also did some of pickmasters mods, still no change.

When you have master at 3 o'clock and the volume at 12 oclock, what do you have to have the OD level and ratio at to achieve the same audible volume ?

This is probably getting a bit obsessive, but to get true bypass switching I think I'm going to need to install another relay since I need to be able to switch both the  send and return signals to prevent the volume loss problem.

Needs a little bit of re-thinking. Volume loss is not severe, just annoying since I went to all this trouble to avoid a volume loss!!   

OK chaps, theres one error on the layout, I've connected tthe incoming signal to the wrong pole of the main bypass switch. Its just on the drawingnot on the real thing. Will edit and post new one asap.

More seriously ther is a volume drop even in bypass compared with when the unit is disconnected and looking at the wiring the Recovery pot is still connected and is draining some signal  I guess. The recovery pot behaves strangely when in FX mode also, it gets louder to about 2 o'clock then loses a small amount of volume therafter.

Might have to rethink the wiring

Some of the early OTS builders decided to mover the OD trimmer to the rear panel, myself included, and this allows you to explore the possibilities much more easily. You are right that the hole is too small for a standard pot and since I did this mod myself I just went out and bought a small pot. I guess Nik has supplied a standard pot and you will have to drill this out if you want to do this. Now this will prevent you installing a Full/Half Power switch in this location so you will have to make a choice here, or find an alternative location for a Full/Half power switch. This switch hole is I believe a hang over from the original D*mble which was 100watt (see below) You could easily move the Mains and Standby switches, utilising the now now longer used Ground switch hole, this would free up a switch hole next to the OD trimmer.

Before you make that decision, the 100w versions have a simple half power option which takes two of the 6L6's out of circuit. The will possibly be a slight reduction in tone (I have yet to A/B both versions side by side but when I have used amps with this facility it always loses a very slight something on half power, it sounds less 'big' somehow), but it is an easy mod. If you are building the 50watt version the only power switching option you will have is a Pentode/triode switch for the 6L6's. If you are an obsessive about tone don't waste your time with this, it is a big tone sucker! Consider getting a good attenuator instead. If you do want to do it you'll have to contact Nik for the layout drawing.

Have fun!

Thats usefull to know thanks. I don't like a hard edged o/d either. Just got rid of a Crowther hot cake and an Xotic BB+ because they were boths quite hard edged. I've got an Xotic BB and thats great, go figure!.

Volume is very deceptive. At home Vol7 (for single coils) Master5 seems massively loud, but at a rehearsal its just OK. I've never had my master above 7 yet and we have a very loud drummer.

I also have swapped v2 for a 5751 which reduces the OD volume quite a bit, so its in the same ball park as the clean channel.

I do know that the DC-30 is reputedly a very loud amp for 30 watts and I'm looking forward to giving it a try (kit has arrived, I just need some time to get it put together).

What do you like about them in particular?

34mV vs 36mV is fine I think. I also think most manufacturers quote a high bias value, I think they want you to wear them out more quickly, but I have it on good authority (my amp tech) that biasing colder will produce a better clean.

Its also governed by the trimmer setting.

Read pickmasters tweaks. Most of the other tweaks found on this board are intended to tame the O/D channel.

Turn the power on, take it off standby and let it warm up for 5 mins or so. (however if this is the first time with a different set of tubes ie a change from 6L6 to El34, don't wait, get the bias into the right ball park staight away)

Turn master and volume down to 0.

Turn on your multimeter and select volts (DC if its not autodetect) (mV across the 1ohm resistor = mA)

Plug black probe into black socket and red into red. You might have to hold them to make contact if they don't fit well. Take the reading. Then move the red to the other red socket. If the valves are matched the readings should be similar.

Use the pot to get where you need to be, keep checking both sides. Play it. Try it hotter or colder within reason, find you're own preferred bias.