Dougs Stout beginnings

[Ed_Chambley]

Made all my changes, wired as per Steve. Just need to hit send and my parts are ordered from here. I have two Hammond 290CAX on the way, got em free   I just watched some videos on the 1968 Marshall SuperLead and oh boy would that be a nice amp to drive the neighbors crazy

Best sounding amp I ever played was a super lead 100.  They are REALLY a tad too much for the house tho.

[lego4040]

  If I only knew how, Id make that into a 20 something watt amp. Unless it exists, Something like the Trainwreck Version A3 From Doug's Schematics PDF's would work for that vintage Van Halen sound. Need a board tho

[Ed_Chambley]

If I only knew how, Id make that into a 20 something watt amp. Unless it exists, Something like the Trainwreck Version A3 From Doug's Schematics PDF's would work. Need a board tho

Just double a Vox AC10 for your power section.  Need to have 4 tubes.  EL84 is probably the closest in distorted tone to EL34.  Nothing really is like a EL34 and believe you me I have tried to get a superlead tone using less watts.

I did play a SE KT88 build once that had the 2203 preamp and it was closer than what I was trying.   Well harmonic wise it was.  I think a lot of guys are playing AC30's for this reason.

[lego4040]

So the PT that I pulled out of this build and replacing has found a home. After hearing Dougs Plexi clips I looked at the pdf and low and behold the PT I have will work perfectly. My outputs are on this level for this build, If Doug stocks the Mercury's soon I will stop giving my kids lunch money and buy their OT for this I will

[DummyLoad]

be kind to your children - they'll usually be the ones that pick your retirement home or nursing home...   


--pete

[lego4040]

I installed the 8 to 9 pin adapter plate, it works great but make sure your 9 pin is 3/4 not 7/8. I thought the ones I have waiting were 3/4 but are 7/8". So I needed to order the correct size. Can't open up to 7/8" to close to screw hole.

[lego4040]

I ment to mention these are new on Doug's parts web page, nice and simple washer

[lego4040]

My two free PT's came in today

[lego4040]

Got the PT in with minor hole adjustments on chassis and she slid right in. The voltages are much better off this one, never mind the reading on the meter there, I made a better and safer test rig and wanted to show it. I had 285-0-285 on the taps I will use. 335-0-335 on the other.

[sluckey]

Any progress?

[lego4040]

Yeah Steve I managed to get the PT in and word back up. I forget to order the smaller diameter 9pin sockets for these adapters. I have the big 7/8" ones, I wound up copying those plates and making a 7/8" one but I don't want to drill out chassis. I'll post my progress pic

[lego4040]

I finished these up tho. P90 fretless CBG and a banjo style CBG for a friend

[lego4040]

Finally got around to putting 9 pin sockets in and start wiring this thing back up. I've been swamped at work and working on my other project.

[lego4040]

Finished the wiring, some  triple checking tomorrow and I'll fire her up

[lego4040]

Amp up and running with only minor trouble shooting. Here are my readings and please let me know if it's running to hot, I checked against Doug's and they're close. I did change the 470k going to pin 1 down to 220k. I was going to change some values to wreck values on a similar amp but I wanted to get this up and running.  Now I'll slap it back in cab

[PRR]

Plate dissipation calculation:

The 0.0914A is both plate and screen current. On EL84 I would expect it to be 10% screen, so 0.082A plate current.

The plate-Cathode voltage is 333V-12V or 321V

321V*0.082A is 26 Watts. 13W per tube.

Technically over-spec but probably fine for your purposes.

[lego4040]

So amp is ok but pretty much dimmed out. To drop that down should I go with a bigger cathode resistor like the 250ohm?