Princeton Reverb with a Twist.

[DummyLoad]

Nothing to write home about, but it's quiet, the reverb absolutely melts yer ears and the tremelo is very lush sounding. this one took me a while. i was managed to to make only one wiring error on this one in the tone stack ckt (wired 250pf to bass pot, not treble pot, doh!) she's found a new home at local studio, but problem is... i don't want her to go.    wiring is my typical hap-hazard mess, but it works well.

gear pr0n.











 

[eleventeen]

Looks good to me! (Which may be a negative!)

No shortage of chassis real estate. What influenced your 9-pin tube layout?

[DummyLoad]

thank you! and yes, no real-estate shortage. the chassis line goes from really cramped 10x17 to 16x17 - it's going in a studio, and they're not too worries about the size. all that room made the wiring that much easier.

What influenced your 9-pin tube layout?

signal flow... it's the fender plan - only right to left + the reverb tank had to fit on the top chassis and far enough away from AC ckts.

lastly, the white mallory 150's strategically placed in the ckt. sound better... 

 

[RicharD]

I just took it for a test drive.  It's delicious.

[Fresh_Start]

Thanks for sharing those gut shots.  Looks really nice!

I just took it for a test drive.  It's delicious.

Excellent!  Any tweaks to the standard circuit?  What transformers?  Are those Penta preamp tubes & if so which ones?

Cheers,

Chip

[RicharD]

Iso only uses NOS tubes.  Probably GE.  As I recall, he changed the 3M3 to a 2M2, added a dwell pot (small tank), and added grid stoppers.  He'd be the better / more accurate person to describe the circuitry.  I was only the cheerleader on this one.  I didn't twist a single screw although I did help with the milling of the chassis.  The amp is very rich in the classic "Fender" sound.  With the volume cranked and the tremelo on, there's a schweet fade when the AC signal exceeds the DC tremelo pulse.  Probably not the most apt description, but it's really fun to play, especially for the right hand.

[DummyLoad]

Excellent! Any tweaks to the standard circuit?  What transformers?  Are those Penta preamp tubes & if so which ones?

thank you!  :-)

some tweaks -  47nF PI to 6V6 G1 coupling caps. 2.2M bridge resistor instead of 3.3M, 1K5 grid stoppers on 6V6, silver mica instead of ceramic disc caps, short tank & dwell pot. 50uF 1st & 2nd PS filter stage caps. trannies are magnetic components. it does sounds very nice. :-) if i were a decent player there would be sound clips...

the tubes are all NOS; sylvania for all pre-amp tubes, RCA smokey glass 6V6GT, and Tung Sol (not tungsolski) 5U4GB. the sylvania 12AT7 reverb driver is a black plate variation.

thanks,

--ISO   

[phsyconoodler]

Think that chassis is large enough?Looks very nice though.

[DummyLoad]

Think that chassis is large enough?Looks very nice though.

that series chassis (par-metals 14 series) jumps from 10" deep to 16" and 10" is too cramped with a reverb tank w/o funky L-brackets and whatnot to mount it to. so yes, it's large enough...  it is designed to be used exclusively in a rack; 16" depth should not be a problem for most rack cabinets.

the big picture is that chassis easily integrates into single channel super reverb, JTM45, twin, or any 2 or 4 power tube setup with reverb and tremelo with only minor machining mods for PT, OT, and additional pair of output tube sockets, if needed.