Princeton Mods Complete Paul C and Stokes

[Ed_Chambley]

I posted this a while ago.  Guy wanted more from his princeton.  The stokes brings the plate to 320 of the PI and the Paul C mod sounds better with 4m7 in-place of the 2m2.  Tubeswell recommendation.  Tried both, but the 4m7 kept it cleaner up the dial.  Used a Blackface Deluxe PT and OT.  Plates on the PT rose to 420.  Massive change and is no longer a Princeton.  Guy loved it, but brought it back.  Wanted a 12 in it.  I used a vintage 30.  Can't really tell you what it sounds like unless a mini twin.

Reverb upgraded with 6 springer and dwell and 3 knob bias vary tremolo with dual bias.  Cathode on PI measures 64vdc and screen 314vdc.

Problem.  When he brought it back I noticed a noise when the volume is turned down and a noise when the volume is dimed.  May be a bad pot.  I will check it later. Not bad, just not used to hearing amp hiss from a princeton.  If anyone has experienced this, please chime in as the pot was fine when it left my shop.

Bypassed 2.2uf/1500 at v1 a and b.  Used a 22uf at the PI.  All in all it is quite nice.  No bass flab.  Definitely will get over a drummer now.  Added a 25k mid pot and a raw.  Cool amp, but I have no idea what to say it sounds like.  Just loud and clean fender.

[HotBluePlates]

...  Guy wanted more from his princeton.  ...  Used a Blackface Deluxe PT and OT.  Plates on the PT rose to 420.  Massive change and is no longer a Princeton.  Guy loved it, but brought it back.  Wanted a 12 in it.  ...

Sounds like the guy wanted you to turn his amp into a Deluxe Reverb (or a Pro Reverb, but with 1 speaker and 6V6's). 

[Ed_Chambley]

...  Guy wanted more from his princeton.  ...  Used a Blackface Deluxe PT and OT.  Plates on the PT rose to 420.  Massive change and is no longer a Princeton.  Guy loved it, but brought it back.  Wanted a 12 in it.  ...

Sounds like the guy wanted you to turn his amp into a Deluxe Reverb (or a Pro Reverb, but with 1 speaker and 6V6's). 

Exactly, I mentioned in the initial thread I had offered to build him a Blackface Deluxe, but no.  It would not have cost him but a few more dollars and he would have had 2 amps.  He was focused on the dual bias and the ability to use NOS tubes that were not necessarily matched.  I attempted to explain idle current and how they would only "match" at idle.  It doesn't really sound anything like a Deluxe, but it does sound good.
I appreciate your explaining amplifying the Hz you want.  Guy thought I was some sort of genius. I told him you guys were the ones who really did the configuration, I was just the hack with a soldering iron.
I ended up with an original set of transformers from 73 and what looks like a CTS 10 speaker. And a few dollars.  I think what he really wanted is a sleeper, what we used to call some hot rod builds when I was young enough to roll around in oil and grease.  I did not try 5881, but I'll bet it is better with them.

[HotBluePlates]

I think what he really wanted is a sleeper, what we used to call some hot rod builds when I was young enough to roll around in oil and grease. 

Which might have been the point of the original Mesa Boogie. I *think* they were originally a 50w amp, 12" speaker and extra gain stage shoe-horned into a blackface Princeton combo.

[Ed_Chambley]

OK the fish is biting.
I remember playing one of those things.  Couldn't believe how much came from such a small place.  The extra gain stage is something of interest and makes sense.  What were those early Mesa's called.  Mark 1, or was it earlier that that?  I would like to see a schematic for one.  I have a set of transformers for 50 watt 6L6's.

I did not really care for the amp at the time, but I remember it well.  I was stuck using it in Daytona Beach and it was way to punchy for what my band was doing, but since then I usually play Modern Country and me thinks it would work well for that.  However, my memory ain't what it used to be.