Finally finished it yesterday at about 7pm. I reckon about 20 hours in total but since this was only my second amp build I reckon I would be much quicker next time. Much quicker than the 11 week wait for a built version!

Not as neat at the factory built versions but I'm happy with it. Its gone to my amp tech now for testing and powering up, setting the PI balance and biasing. I do hope he does it quickly!

Has anyone tried disconnecting the neg feedback? I suspect on the OD channel things might get a bit uncontrollable, but I'd still like to know.

Yeah, done that and moved the FET and OD trimmer to the rear panel.

Just finished the build, will pass it to my amp tech tomorrow for him to test it for me.  Other mods will wait a while, since I'm sure what most people are doing is fine tuning for their guitar and speaker combination.

Next job is build some cabs.

Great , thanks. though I'll leave enough wire to be able to swap them over!.

Cheers

Hywel Harris

I've seen that the photos and the layout don't match as regards the OT primaries. The blue and brown become reversed in the photos. I also remember reading that one guy had a problem with squealing noises (feedback I guess) and that his OT primaries were reversed and was cured when he swapped them.

So which is correct, the layout or the photos?

Blue to V4 or V5?

Many thanks

Hywel Harris

Thanks very much for that explanation. I don't intend trying anything until I've built my cab (and decided which speakers to put in it) and played with the amp for a month or so.

Cheers

Hywel Harris

I wonder if you could give some background to these mods and what each change was intended to cure. I have little knowledge of electronics and am trying to understand how things work.

I'm assuming the following. The 'snubber caps' are those on V2 socket? And the mid cap is the one on the far right of the main board?

The current layout has a 220k for the preOD resistor already with a 100k pot.

Did the removal of the filter cap and resistor on the effects loop sockets have an effect even when the loop was not used?

Many Thanks

Hywel Harris

Fred, you need to ground the shielding at the pot end, but not the other. Here's what I did.

Trim about 20mm of the outer sheath away. Un-weave(?) the shielding, move it all round to one side and twist it tight. Tin it and trim it back to about 10mm long.

Prepare a piece of black wire with 10mm of exposed wire, tinned.

Lay both wires on a piece of wood with the exposed wires next to one another and solder them together. Slip a piece of heat shrink tube over the thin wire and push it over the solder joint. Shrink it.

Fold the wire back, slip a larger piece of heat shrink over the lot leaving about 10mm of the inner wire exposed, shrink it. You can see this in the photos. Now you can strip the inner core and solder it to the pot tag and then do the same with the earth wire.

At the other end, trim about 20mm of outer sheath and the shielding leaving only the inner core. Cover the end of the outer sheath with some more heat shrink so the shielding is well covered.

Cheers

Hywel Harris

I'd be very interested in how both the Marshall cab and the Blues perform. Don't turn it right up though with the Blues! I don't think my budget will stetch to two of those, I could have another Ceriatone for that price.

Cheers

Hywel Harris

I'm in a quandry, there are far too many choices. I can rule out Jensen P10R's since I already have a 4x10 cab ready but its not covered in the right colour to go with my Overtone (cab not made yet) I'm going to make a 2x12 cab and a combo and see which I like best.

I'm hearing a lot of good things about Emi RW&B, and not just in here, and also Texas Heat's. So for my 2x12 I think I'm going to go with one of each since the Texas is supposed to have a bigger bottom end and the RW&B a brighter top. I know the Texas Heat is less efficient but I'm not sure thats going to make a lot of difference.

For the combo I'll try each in turn I think.

Any other suggestions, I know a G12-65 is well thought of, but is acknowledged not to have the top end of the RW&B. What about G12H Heritage? And Weber speakers? So many choices, but the Eminence are better priced in the Uk than the  Celestions, about 2/3rds the cost so I'm drawn to them.

OF course I could just use two the same!!

Thanks

Hywel Harris

I'm guessing that the thinner wire is for early in the signal chain and the fatter is for the likes of the shorts across the output jack sockets. The long brass wire is for the busbar above the pots.

You will need the longer screws for the 5 small boards since they, with their insulating backing board are too fat for a short screw to fit. I used the short screws everywhere they would fit!

Yes the voltage regulator is bolted through that hole.

The brass busbar is only connected to the pot terminals as shown, with one wire coming down to an earth lug by the volume pot. The soldered wire hold it in place in mid air. I guess this is to ensure that all circuit grounding goes in the correct place to reduce the possibility of noise.

So is the current layout incorrect? I'd like to know before i get to that stage.

Thanks

Hywel Harris

Those grommetts are for the holes that the transformer cables thread through.

No I'm in Nottingham I'm afraid.

Cheers

Hywel Harris

Fascinating read ic-racer. Well beyond my knowledge level much of the time but still very interesting.  What I had in mind was something a lot more basic, for someone following the Ceriatone build religiously. I reckon if I had read your write up before ordering it might have put me off!!

Cheers

Hywel Harris