Blackface a late 70's Princeton Reverb??

[mingo]

Hi is it possible to blackface a late 70's pull boost Princeton Reverb??

Any other stable mod's that can be recommended?

[mbratch]

It's always possible to blackface. It will just be more changes than would be required for an earlier 70s model amp.

Other mods depend upon your needs. There are the famous "Stokes Mod" and "Paul C Mod" which get you more gain. You can Google search them and find the technical details.

Other things being equal, the most common mod is.... (drum roll).... the speaker! Lots of choices and they all provide a different lean to the tone. :)

[mingo]

It's always possible to blackface. It will just be more changes than would be required for an earlier 70s model amp.

Other mods depend upon your needs. There are the famous "Stokes Mod" and "Paul C Mod" which get you more gain. You can Google search them and find the technical details.

Other things being equal, the most common mod is.... (drum roll).... the speaker! Lots of choices and they all provide a different lean to the tone. :)

thanks

any of them for more clean headroom, more wattage?

[mbratch]

A more efficient speaker will give you more volume at clean levels. I currently use an Eminence Ragin Cajun and it sounds great.

A very popular mod is to install a 12-inch baffle & speaker. This will also give you more volume/headroom because your pushing more air with the speaker, and the Princeton (Reverb) is plenty powerful enough to drive it.

According to the description, "a little more volume" can be obtained from the Stokes mod (http://people.cornell.edu/pages/mt24/Amp/mm/PRtweak.html).

The Paul C mod (http://people.cornell.edu/pages/mt24/Amp/mm/paul_c_mod.html) makes the amp "sound bigger".

And there's a good thread on TGP (http://www.thegearpage.net/board/showthread.php?p=3671603) that discusses these two mods.

[soldersucker]

I just did my 78 a few days ago.The reverb circuit was a bit different clipped out the .002 ossilation cap and changed it to the 2.2k 25 uf blackface cathode configuation.(had 6800 ohm in there).
Pulled out all the pullboost curcuitry.There was also a 22pf cap across the 3.3m resistor in the reverb curcuit that was changed to the 10pf blackface spec.
Mine had a Stokes mod done and i reversed it,if i want a bigger Princeton then i grab a Deluxe problem solved.
All in all they are already 98.5% Blackface but 30min later you can say youve Blackfaced her.

[mingo]

I just did my 78 a few days ago.The reverb circuit was a bit different clipped out the .002 ossilation cap and changed it to the 2.2k 25 uf blackface cathode configuation.(had 6800 ohm in there).
Pulled out all the pullboost curcuitry.There was also a 22pf cap across the 3.3m resistor in the reverb curcuit that was changed to the 10pf blackface spec.
Mine had a Stokes mod done and i reversed it,if i want a bigger Princeton then i grab a Deluxe problem solved.
All in all they are already 98.5% Blackface but 30min later you can say youve Blackfaced her.

that sounds like something i'd lilke to do. where are the instructions to do all that stuff?

thanks

[soldersucker]

No instructions just print off a PR layout AA1164 and stare at it until you can note the differences btn your amp and Blackface and have at her.
http://www.ampwares.com/amp.asp?id=74

[mbratch]

I would recommend schematics as well so you know what the actual interconnects are. It's best if you can find both schematics for comparison. I say this assuming you have the pre-requisite knowledge to do this kind of work. :)