To be or not to be....

[idiotwithasolderingiron]

play thru a 2x10 before you decide... I'm finding that 10's just dont have the bass response of 12's, even in a 4x10 closed back cab...

[zaphod_phil]

Just increasing the B+ on it's own won't make an 18W that much cleaner. For a cleaner sounding amp, your best bet is to apply the "Jason's Mods", which are mainly some resistor changes to the PI, power stage and power supply. Details are in the downloads section. However, when dimed, the modded amp will still get pretty dirty. So it depends how loud you want to go with the clean sound. If an 18W with Jason's Mods still doesn't have enough clean headroom, you may need to build the 36W version, with an extra pair of EL84s.

It may also make more sense for you to start by building your TMB amp, as that will give you a regular 18W-like Normal channel, as well as the TMB/Plexi channel to play with, while you build your tremolo 18W

[RedPlanet]

Thanx. Might that be a good thing (SS Rec) to do while doing the Jason Mods as well?

Would one Celestion Blue be OK for the Trem Amp for Cleans? And one G12H for the TMB?

[zaphod_phil]

Those sound like very good speaker choices, if you're building 1 X12 versions. Yes, you could do both mods at the same time. As the official max voltage rating for EL84s is 300V (many 18Ws run them at 330-350V), I wouldn't want to try the SS rectifier (voltage boost) trick without Jason's Mods, as they help control screen grid current/voltage better. You can actually run EL84s at crazily high voltages, if you keep their screen voltage below 300V. Adding a few extra zeners in line with R25 should help on that front as well...

[RedPlanet]

Thanx man. Well sounds like a plan. It'll be a little while before I do anything but I think its good to start thinking about it. I've got to waite till November before I can buy the Stuff. I'm gonna hit you up when I get the stuff and maybe you can help me out on the Extra Tweaks.

[RedPlanet]

Oh and by the way Yes I'm a little ticked at the Chinese right now but I'll get over it. It has really nothing to do with Music Gear. They are very much affecting industry in the USA right now and I'm feeling it.

[Graydon]

He had suggested I use 2x12 for the clean amp with a Couple Celestion Blues but I only want 1x12 for the compactness of it. Is he saying use two speakers to add to the Clean Headroom and would using a Solid State Rectifier give more Clean Headroom? I might consider 2x10's for the Clean Amp if two speakers would be much better for the Clean Amp. Would that be a Good Choice? That way I could maintane the sise of the amp to be as small as the other.

A 1-12 will be fine with a Blue. You'll still get the loudness of the Blue. I don't think you'll get much more clean headroom from using a SS rectifier. It is more a result of the preamp and phase invertor design.

You could accomplish what you want with two 1-12 combos. Put a Blue in the clean one and a Greenback in the dirty one. You can set up the reverb or other effects as I described in my reverb thread on either amp or even both amps.

I would stay away from 10s unless you have tried them and you think that is truly the sound that you want.

[RedPlanet]

Thanx. Looks like I'm on the way to building just got to waite tillI get my bonus before I can buy the stuff.