trinityamps.com

My Trinity Plexi kit has arrived(merry x-mas to me)started turret board +vrm board last night,brings me to a question,reading on 18watt.com sounds like a lot of users are running VRM lowered B+ to PI +power tubes only,not all the tubes,advantages/disadvantages here?For now I am planning on following the included schematic and running lowered B+ to all tubes
also need some clarification on mounting and isolating MOSFET,do I put mica washer down on chassis,then heatsink compond then mount MOSFET,just need some clarification on this before I mount VRM to chassis(I/m a rookie here do not want to screw this up)
took the liberty of attaching a couple pics(my 1st board populated,not soldered)
a mock up of Trinity 18 chassis in Marshall Haze 15watt head cab being used for this build,note gonna use 1meg pot with on/off switch in place of main power switch,looks kinda funny but makes it work in this smaller chassis


PS JUST WANT TO SAY VERY HAPPY WITH TRINITY KIT+TRANSFORMERS EXCELLENT INSTRUCTION PACKAGE AND CUSTOMER SERVICE/SUPPORT HAS BEEN 1ST RATE

Good looking build so far!
As for the heatsinking, a thin layer on BOTH sides of the mica. Think of it as a filler for microvoids in the surface of the aluminum and the mosfet.
As for the VRM..It's a matter of personal preferences. Controlling only the PI and o/p tubes, allows the preamp tubes to run at their designed spec. and therefore should sound the same at all power settings. By controlling all tubes, the drive to all the tubes lowers as the B+ is lowered so thereby reducing the need for a Master volume which some thing is a better solution. It's farely easy to change between both arrangements.
Stew

Thanx Stew,will be able to install VRM now,I am going to wire up VRM to control all tubes for now as you say can be changed later,built that board last night with no meter to doublecheck resistors,good thing didnt solder yet,had 47k+470ohm mixed up(+ one other mistake)
Next "rookie" question,cannot source 1meg switched pot in calgary either have to order or change to a 3 position switch for on/off/standby,can I copy the switch arrangement from Triwatt schematic to accomplish this?,basically 1 switch controling on/off standby then my VRM pot in other switch location,

The Triwatt switch would work here, smart switching design.

Some argue that standby switches aren't even necessary with amps with tube rectifiers. I don't necessarily agree. Just throwin the idea out there for ya.

Sure you can use the triwatt arrangement. Personally, I'd put the VRM control on the back but that's just me. The front panel is beautiful without weird knobs in switch positions ect. I have London Powers' "power scaling" installed in a 50 watter and I find I pretty much put the control on one of 3 positions. bedroom, jam session or full.
Stew

I wanted the VRM control up front for ease of access but that does look wrong doesn't it(as wrong as a handmade 18 watt amp in a cheap headbox?)here is another pic with knobs and switches in right locations

I may be doing another build after this one(also with VVR),even tighter for space,will probably use the Triwatt style switch in that one,as for no standby I have a little 18watt lite 2b made from a Hammond AO-44 chassis and transformers,it has no standby switch and have had no problems
yes I think I will leave the 2 switches up front and put VRM pot in back(with boost and cascade switches)

Provided you control the PI's rail voltage as well as the power amp's, then there isn't actually any need for a post-PI MV. The main Volume controls for each channel will do the job fine. It also gets rid of the need for the 0.1uF caps at the input jacks, while it adds a little more complexity into the power rail with some diodes and stuff. Typically preamp tubes tend have better clarity and definition when run at higher voltages. However, the VRM-ised Trinity amps I've tested, with the whole amp voltage being controlled, the clarity still sounded pretty good at quite low volume levels. Just a few pros and cons to consider....

BTW where do you get empty Marshall Haze head shells from?? Makes the amp look real cool!

_________________
Great tones come in small glass jars!

Unfortunately had to buy the haze complete(traded tiny terror +cab for it)
sold haze working chassis on e-bay to fund purchase of trinity kit.Was going to build my "lite 2b"into one of those marshall micro stacks,then found this deal.Hope it turns out well cause I think Stephen had to work up a sweat custom punching a chassis for it(had to be 17"or less to fit in headbox)

Ya I noticed those chicken heads are almost beak to beak in places!
Stew