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Hoffman Amps Forum image Author Topic: Fender '65 Princeton = 15W - Fender '65 Deluxe = 22W - both have 2 6V6 - How?  (Read 3234 times)

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Offline leevc5

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Is there a way to coax 22 Watts out of my dual 6V6 '65 Princeton reissue? Really curious how the Deluxe can get almost 50% more output from the same 2 6V6s... :dontknow:
Could I get 22W out of my 5E3 clone?

Offline sluckey

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Quote
Is there a way to coax 22 Watts out of my dual 6V6 '65 Princeton reissue?
Yes. Replace the transformers with Deluxe Reverb PT and OT and set the bias.

Quote
Could I get 22W out of my 5E3 clone?
Probably have to convert to fixed bias. Or replace the PT and OT and run 6L6s.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline Blind Lemon

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Change the phase inverter also to LTP?

BL

Offline Blind Lemon

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 Wait before you do any of that.

Try it through a good efficient 12" speaker.

You'll be surprised.

BL

Offline leevc5

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Quote
Could I get 22W out of my 5E3 clone?
Probably have to convert to fixed bias. Or replace the PT and OT and run 6L6s.
[/quote]

Thank you Sluckey and Blind Lemon (aren't all lemons blind?)
Does anybody have an adjustable bias circuit mod for the 5E3? Wouldn't that allow me to try different settings and find the optimal headroom and tone combination?
Probably the right answer is trust that Mr. Fender got it right as that seems to be what I've found when playing around with mods in the past...I always end up going back to his circuit...a Jim Marshall I am not.

Offline Blind Lemon

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What did you say???? I couldn't see you.  :l2:

Look at the 5E4 Super schematic. But you won't get 22w.

BL

Offline sluckey

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I would copy Hoffman's Princeton Reverb adjustable bias circuit. Fixed bias will likely change the character of the 5E3.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline Ed_Chambley

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5e3 with a 6g3 tone stack a 100 spl speaker change the first bypass cap to 4.7 uf and first coupling cap to .22. Everyone will start telling you to turn down

Offline shooter

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Quote
a 100 spl speaker
no, 4 and you won't hear 'em yelling  :icon_biggrin:
Went Class C for efficiency

Offline alerich

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It's worth noting that once you change the OT, PT, the phase inverter to a long tail and maybe the speaker to a 12" you really no longer have a PR. Especially the OT. I tried one of those BillM TO20 PR replacement OTs that he developed with David Allen in my PRRI. It did help the low end fartiness like they said it would but it also changed the character of the tone in a manner I did not like. I put the original OT back in. I bought a second PRRI. One of those "Navy Blues" FSR runs with blue tolex and a Celestion Alnico Blue 12" speaker. It's a fine speaker and I love the amp (I run them in stereo - the other one has a Celestion Alnico Gold 10") but side by side it's not quite as "Princton-ey" as my amp with the 10". All of the suggestions above with lead your PR in the direction of the DR which is no longer a PR. I think the concertina PI gives the PRRI much of its charm.

I should also mention that my original PRRI is also an FSR run. One of the ones with the tangerine and white tolex and a Jensen P12R Alnico 10" 25W speaker. Once I bought the blue PRRI with Alnico Blue I pulled the trigger on the Alnico Gold thinking it would be a substantial improvement over the P12R. It wasn't. It's a great speaker and I do like it but it was not a massive improvement over the IMO very nice P12R. It would probably make for a nice upgrade to the stock Jensen ceramic 10" speaker.  I guess what I am trying to say is that you have to weigh all of these changes individually and do them one at a time and make sure it yields what you are looking for.

Best mod I made to both PRRI amps? Installing 14" Fender tilt back leg kits. Major improvement in overall tone and projection.
« Last Edit: March 18, 2018, 01:09:15 pm by alerich »
Some of the most amazing music in history was made with equipment that's not as good as what you own right now.

Offline sluckey

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Best mod I made to both PRRI amps? Installing 14" Fender tilt back leg kits. Major improvement in overall tone and projection.
:thumbsup:
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline jim

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There is a logarithmic relationship between power and loudness.  Power will be need to be increased 10 fold to make the amp sound twice as loud.  Replacing transformers is expensive--consider replacing the amp
if volume and headroom are your concern.  All these mods will definately change the tone of the amp as well.    Jim
The music industry is a cruel and shallow money trench--a long plastic hallway where thieves and pimps run free and good men left to die like dogs.   There is also a negative side.

 


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