Princeton Reverb vs. Deluxe Reverb: technical differences

[56_Special]

Can anyone fill me in on the major differences between these two circuits? For example, how do they differ in terms of NFB, filtering, tonestack, etc?

 

[wyatt]

Besdies the obvious (the speaker, the omission of the Normal channel on the PR, etc.), the next biggest issue is the PI; the PR uses a cathodyne (or "split-load") phase inverter that runs out of headroom much faster than the DR's long-tail pair phase inverter.

A little more on how each works and the differences here:
http://www.300guitars.com/articles/article-demystifying-the-phase-inverter/

If we exclude speakers (which can contribute night and day changes to amp tone) that than the PI may account for a significant percentage of the tone and feel differences between the two amps. Otherwise, you have different smaller iron in the PR which can affect voltage at the PT (lower B+ voltage means lower headroom, but more touch responsiveness) and tone at the OT. And there is more negative feedback on the DR. Filtering differences are negligible. The only major difference in the preamp is the DR's bright cap.

 

[soldersucker]

I have both and aside from the technical differences you can see on the schems the Deluxe is the smallest gig-worthy Fender in the vintage lineup.Sure you can add a 12" and stokes it etc....but you are still fighting an uphill battle with the Princeton.

 

[56_Special]

Besdies the obvious (the speaker, the omission of the Normal channel on the PR, etc.), the next biggest issue is the PI; the PR uses a cathodyne (or "split-load") phase inverter that runs out of headroom much faster than the DR's long-tail pair phase inverter.

A little more on how each works and the differences here:
http://www.300guitars.com/articles/article-demystifying-the-phase-inverter/

If we exclude speakers (which can contribute night and day changes to amp tone) that than the PI may account for a significant percentage of the tone and feel differences between the two amps. Otherwise, you have different smaller iron in the PR which can affect voltage at the PT (lower B+ voltage means lower headroom, but more touch responsiveness) and tone at the OT. And there is more negative feedback on the DR. Filtering differences are negligible. The only major difference in the preamp is the DR's bright cap.

Thanks for the response. So the PI difference is mainly a difference in internal gain-staging? Does the PR have a bright cap?

I have both and aside from the technical differences you can see on the schems the Deluxe is the smallest gig-worthy Fender in the vintage lineup.Sure you can add a 12" and stokes it etc....but you are still fighting an uphill battle with the Princeton.

Depends on your gig. Lots of people gig with them. Jim Campilongo springs to mind. But I take your point: its not going to hang with your typical rock drummer.

 

[TimmyP]

I have both and aside from the technical differences you can see on the schems the Deluxe is the smallest gig-worthy Fender in the vintage lineup.Sure you can add a 12" and stokes it etc....but you are still fighting an uphill battle with the Princeton.

I disagree. My boss drug in a BF PR with a dead OPT and speaker. I put in a Mojo DR OPT, did the PI B+ mod (higher), changed the coupling caps (10% of original value IIRC), and put in a new Alnico Jensen. (I may have also opened the NFB.) The thing wails.

 

[hasserl]

Yeah, a well set up Princeton wails, that's for sure.

Another major difference is the Vibrato used in each amp, the PR uses a bias vary type vine (trem) where the bias of the power tubes is "wiggled" to create the tremelo effect, the DR uses a roach type where the preamp signal is vibrated. IMO the bias vary style is more lush and preferable.

 

[soldersucker]

I disagree. My boss drug in a BF PR with a dead OPT and speaker. I put in a Mojo DR OPT, did the PI B+ mod (higher), changed the coupling caps (10% of original value IIRC), and put in a new Alnico Jensen. (I may have also opened the NFB.) The thing wails.

Umm yeah that was my point without some surgery a Princeton is still a practice amp unless you are Jim Campilongo.

 

[mbratch]

Does the PR have a bright cap?

No bright cap in the PR.