Trinity Plexi conversion to 36watt Help!

[baron]

Hi all.
I recently built a Trinity S111 and really love the tone. I want something more tighter and without as much sag when i attack the strings and something with that big fat tone of the larger Marshall amps.

I have considered the metroamp 50/100 plexi heads but i think those amps may be too loud even in band rehearsal scenario? Quite a lot of $$ too.I have also considered the VHR Hiwatt 50/100.

I guess i am after that Zeppelin, Free, The Who, ACDC, Wolfmother, The Datsuns etc tone even the Black Keys - Marshall and Big Muff sound.

At the moment i am considering buying the Trinity Plexi kit and a set of GDS 36 watt transformers.

Is it possible to build this doing a solid state rectifier and will this sound ok/good without a GZ34 tube?

Has anyone compared a 36 watter to the metroamp stuff? I can't seem to make a decision.

Would i be able to get assistance from the forum here as i relied heavily on the instructions from Trinity but with the 36 i would need to know exactly what i need to alter in the Trinity plexi circuit to do the solid state thing and extra tubes.

Thanks All!!

[zaphod_phil]

A 36W will be nearly as loud as 50W. The rule of thumb is that you have to multiply the power output by 10 to double the loudness. Also if you're using EL84 tubes the tone won't be much different from a regular SIII 18W. Possibly, you just need to tighten and beef up your SIII. Put in SS rectifiers, with zeners to drop the voltage back to regular 18W levels. Use a bigger cathode cap on the power tubes, 1000uF or above, with a 180 ohm bias resistor. If you really want to beef up the tone consider putting in 6V6s. IIRC all of Trinity's 18W chasses have the extra holes for 6V6 tubes.

[FireLewis]

Hello,

I got a 36 watt with GDS trainnies. Solid state recitifier, 100ohm sag R, high filtered 100uf and 47uf . It sound killer now. Cause I made a 18 watt first and it was enough tight for my taste and now wow. I'm in classic rock terrritory all the way.

Do it, I'm sure you'll love it.

One of my friend got a plexi 100 watt. And trust me it's not a shame compare to it, for sure the 100 watt is a lot louder with more headroom, but its a way too loud anyway. And for the tone, I founded my 36 watt is more balanced, and the disto sounded mellower and more well defined than the 100 watt. That's my opinion and taste but... it's killer. I love it in both a 4x12 caband 2x12 open back cab.

Louis.

[FireLewis]

that's right itsclose to 50 watt

[zaphod_phil]

I got a 36 watt with GDS trainnies. Solid state recitifier, 100ohm sag R, high filtered 100uf and 47uf . It sound killer now. Cause I made a 18 watt first and it was enough tight for my taste and now wow.

If you built an 18W with SS rectifier and big filtering, it would also be as tight, especially if you took replaced the 100 ohm sag resistor with some zeners to drop a fixed voltage instead. Also using a huge cap at the power tube cathodes would make the amp tighter and stiffer. Using 6V6s instead of EL84s would make the amp more beefy in the low end.

I have considered the metroamp 50/100 plexi heads but i think those amps may be too loud even in band rehearsal scenario?

With the higher power you get more clean headroom. An 18W is only a little less loud than a 36W or 50W, but it has less clean headroom. So if you'r looking for increased clean headroom, then a 36W or 50W is a good idea. If you're more interested in overdrive and distortion, then the 18W should be fine.

[FireLewis]

Hey Phil,

I did not experiment with zener. My question may seems stupid but how to know wich zener use?
Depend on the voltage probably, but how to calculate?

Thanks.