Princeton 6G2 build

jtcnj

jtcnj

Ambassador of the Crossroad
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I'll started this a couple of weeks ago but only had time to really move on it this past weekend.
It is another junk repurpose diy chassis build that will get a head cab.
It is meant to be all go and not much show, but hope it comes out neat at least.

Iron is Hammond 290CAX PT and 1760E OT.
I will add a 8/16 or 4/8Ω speaker impedance switch haven't decided which.

The donor chassis stock
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Trying to figure how in 'ell to make it all fit together and allow for good lead dress practice.

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Will update as I progress, if anyone is interested.
Might be worth a good laugh at least.
 
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In the meantime, I used the OTHER half of the old 1991 sub woofer project cab for a 1x10 featuring a WGS Veteran 10.
the yellow and black is roofing insulation I used as a cabinet damping material.
Never sounded quite right, but I never had a decent power amp for it either.
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some more #2 fir plywood I had laying around since the late 1980's for a 1/4" baffle.
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A little off center, but it will be our little secret
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I think I got a little bit schmarter by putting a little silicone caulk behind the T-nuts before setting them with the drill press chuck.

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I am no skilled woodworker as you can see, but sometimes "good enough" is well, good enough.
(I say that a lot)

The burns are from cutting off the brads that were too long. I couldn't find the right length crown staples at Harbor Freight.

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Arrrghh!
I will effort resolving the pic issue directly.

@Gahr Yes Brownface Princeton
my first build with built in tremolo, or any effect.
 
jtcnj said:
Arrrghh!
I will effort resolving the pic issue directly.

@Gahr Yes Brownface Princeton
my first build with built in tremolo, or any effect.
Click to expand...
Nice. Brownface Fenders are really cool amps. Nice choice of speaker as well. I have one of those in my Gibson GA-5 Skylark. Sounds lovely.
 
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Finished cab. I made a few minor mistakes along the way; as usual.

The only two things I am less than happy with are:
I didnt allow for the grill cloth material thickness in determining the depth of the baffle cleats.
I was careful with placement of them, but that mistake causes the baffle to not be flush with the cabinet edge, or slightly recessed.

Grill cloth is a little uneven, but tight. Good enough on that one.
I trimmed the little corner cloth bits after the pics were taken.
The mounting screws for the jack plate are not positioned evenly; shouldn't hurry.

I did skim coat the front edge with filler and did some repair with wood glue/ sawsdust to the 2 bottom corners before paint to make it a little nicer.
Other than that, I am good with the worn or distressed look. It is real after all and not relic'd.

Cheap ebay feet and handle finish things up.
The original port is way over sized for this cabinet and I consider it an open back; which is what I wanted for this American voiced speaker.

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Very cool.
That cabinet turned out just fine.
And the amp build project...
So much more personalized than a pre fab amp KIT.
I love the repurposed electrical box chassis.
This sir, is a seriously hackworthy project.

Did you use hole saws for the tube socket openings?
It looks like they were punched out with the Greenlee punches.
Nice & clean.

I think this is one of the more "creative" gear forums in existence.

Great job so far. Looking forward to fire up day.
 
The octals were punched, the 9-pins hole saw.
For some reason I had a hard time getting the screw mounting holes for the sockets lined up right.
Fatigue maybe, didnt land the center punch right or it walked a little.
 
I have a preliminary running chassis!

Some of my voltages are a bit high, some close to the Fender layout.
the odd one is the v1 plate voltages are 202v +- vs. 135v on the layout.
There is a 20% spread and wall voltages are higher today.
I multi-meter verified all my resistor values before install.

I left the OT plate leads long until NFB polarity confirmed, and some other things to tidy up or address.
I meant to twist the trem pot wires together, as in 67Plexi pic above.
I had some initial problems with the bias supply, but for now it is bias as cold as it will go as I debug things (-40.5v, vs. stock -35v)

Maybe the B+ voltages will come down some as I bias the power tubes they will pull more current.
Seems like a lot for v1 though.

The center pot is a pre PI master volume (takes the place of the 1M PI grid leak resistor).

Everything works, it is not very loud though and sounds very thin - I hope due to the cold power tube bias.
Pots maxed with the trem grounded, almost dead quiet; no filament hum.

I played it a bit as part of startup operation, not to judge tone.
Sometimes I get a "heartbeat" which varies withe Speed pot.
I have 2 or 3 different oscillation run away noises that come and go with different combinations of the vol, tone , MV pots, trem grounded or not.

So, I have some tuning to do, but I have a running chassis with signal throughput that is clean and then breaks up as the volumes are ramped up.



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