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FDP Forum / Fender Amps: Vintage (before 1985) / The Princeton Reverb II (Rivera era PRII) Conclave

Previous 20 Messages   Next 20 Messages   Newest 20 Messages
ampman91510

USA

Dec 14th, 2011 01:23 PM   Edit   Profile   Print Topic   Search Topic

Hi there, I just modded a PR-2, put a CV-4024 in there, and the reverb tank from a Twin, and a new Weber 12F150 speaker, and ripped out the "lead" circuitry and put in some of my own. It rocks, those are nice little amps.

RivEraEra

usa/east bay sf

Ain't no time to hate
Dec 14th, 2011 01:51 PM   Edit   Profile   Print Topic   Search Topic

Any drawings/descriptions of your lead circuit changes? What socket did you put the CV-4024 into?

Stratopastor

Stockton-on-Tees

Jivin' with cosmik debris since 1955!
Dec 16th, 2011 04:43 AM   Edit   Profile   Print Topic   Search Topic

RivEraEra beat me to the same question... :-)

Stratopastor

Stockton-on-Tees

Jivin' with cosmik debris since 1955!
Dec 17th, 2011 08:44 AM   Edit   Profile   Print Topic   Search Topic

hold tight, CV4024 is a 12AT7, no? Or am I missing some fine detail here? did you put it in V2 where the 12AT7 usually goes to drive the reverb, or somewhere in the main signal path?

ampman91510

USA

Dec 27th, 2011 12:28 AM   Edit   Profile   Print Topic   Search Topic

RivEraEra said: "Any drawings/descriptions of your lead circuit changes? What socket did you put the CV-4024 into?"

I will try to post a schematic. Not sure how to do that, I'm very new to this forum. I'll try to figure it out. :)

The AT goes into the V4 socket of course. Nothin' major there, it's within its operating limits and it sounds fine.

For the lead boost I did two things at once (both foot-switchable, so in other words I disconnected both of the bugs and discarded the internal lead circuitry, and re-used the footswitch bugs for my own purposes). One of them reduces the value of the first stage cathode cap, which makes the sound a little brighter and less bassy. The other thing is I switch in a .0012 uF cap where the mid-boost is, which gives it kind of "half" a mid-boost, mostly on the upper half.

The other thing I should mention is I discarded the 500pf bypass caps between plate and cathode of V1a and V1b. It sounds a lot better that way, especially with the Weber speaker. I do love that speaker, it's nice and fat where it needs to be. Virtually no bass though (although I'm pretty sure that's a property of the amp instead of the speaker).

One of the interesting things I noticed with this amp is it seems to have a "magic value" for the first cathode bypass cap, it's right around 6.6 uF. A small delta in either direction is less good, at least to my ear.

littleuch
Contributing Member
*********

Michigan

T-boned and punctured
Dec 27th, 2011 03:33 PM   Edit   Profile   Print Topic   Search Topic

ampman, did you go with the 25W or 50W Weber? I tried a 25W 12F150, light dope and did not like the result. So much so that it makes me think something was wrong with that specific speaker.

Stratopastor

Stockton-on-Tees

Jivin' with cosmik debris since 1955!
Dec 28th, 2011 07:33 AM   Edit   Profile   Print Topic   Search Topic

ampman, thanks for all this. What appeals to you about the sound of a 12AT7 in v4 (the PI) .... apart from the effect of all the other surgery?

ampman91510

USA

Dec 29th, 2011 02:20 PM   Edit   Profile   Print Topic   Search Topic

littleuch said: "ampman, did you go with the 25W or 50W Weber? I tried a 25W 12F150, light dope and did not like the result. So much so that it makes me think something was wrong with that specific speaker. "

Hi littleuch, I used the 50-watt one, it sounded scratchy when I first got it, like the cone was sticking or something, but after a few loud chords at full power it seemed to unstick and it's been fine ever since.

I very much like the cabinet on the PR-II. It's nice and solid, and it has a lovely resonance that works perfectly with the mid-boost. Oh, let me see, I forgot to mention, I played around with moving the coupling caps in those two stages where they're connected between to load resistors. I moved them right to the plates instead of between the resistors. The amp has more gain that way, and with the mid-boost kicked in and the Weber, it gets this very fat Marshally sound and it's quite loud. I'm not sure (not the expert, more the tinkerer :) but it seems like they set up the gain in the original PR-2 circuit so it wouldn't drive the output stage too hard, they used a big OT but a little choke, and I was a tad concerned that maybe driving the amp harder would overheat something, but it seems to work fine, and it seems to be capable of quite a bit more gain and it sounds good that way.

ampman91510

USA

Dec 29th, 2011 02:31 PM   Edit   Profile   Print Topic   Search Topic

Stratopastor said: "ampman, thanks for all this. What appeals to you about the sound of a 12AT7 in v4 (the PI) .... apart from the effect of all the other surgery?"

Hi Stratopastor, you ask a great question, when I first got the amp I didn't really know what to expect, I was thinking "Princeton Reverb" and I've had several 70's PR and love them, so I was expecting something along those lines. But this Rivera stuff is a little different, isn't it? :)

I didn't take a look at the schematic till after the amp arrived, and when I saw the long-tailed PI I went immediately to the stash of AT's. I tried several, and the CV-4024 seemed to sound very nice with this amp. It has a nice breakup, that's one of my most important things I listen for when experimenting with tubes, I like the amp right in the initial mild-breakup area, and if that sounds good then that's probably the tube I'll use. (I play a lot of southern rock, that kind of stuff, sometimes I'll dial up the preamp so it's just barely starting to break up when playing a very loud chord, and then raise the volume till the output stage starts crunching a little, that's just about the sweet spot for me).

When the amp arrived it still had the original Fender-branded 7025 in it, and that sounded fine, it was more gainy and maybe a little darker sounding (it sounded nice though, kind of like an old RCA or something). And, it sounded more like a Princeton Reverb with that tube. With the AT in place, it sounds more Deluxe-ish, it definitely has the Deluxe vibe, except it doesn't have any bass to speak of (relative to a Deluxe Reverb, let's say), and I attribute that to the difference in the cabinet. The PR-2 cab seems to love the midrange, so I tried to get the amp into the area where it was pumping lots of midrange right into the cab, and it sounds great, real fat. If I really need the Stevie Ray sound though, I have to go to the bigger amp and the 15" speaker. :)

Stratopastor

Stockton-on-Tees

Jivin' with cosmik debris since 1955!
Dec 31st, 2011 07:24 AM   Edit   Profile   Print Topic   Search Topic

thansk ampman, that's really helpful. I'm going to try that when I get home (visiting friends for New Year right now).

Wishing a Raucous and Happy New Year to the entire conclave! Anyone playing their PRII to help folks see the new year in?

littleuch
Contributing Member
*********

Michigan

T-boned and punctured
Dec 31st, 2011 08:11 AM   Edit   Profile   Print Topic   Search Topic

No NYE gig this year. I've been sick since October, had a slight reprieve earlier this month and just got hit full force again with some new bug. :-(

I still have to get my new set of Tung Sol RI's in my PRII. Have a safe and happy New Year.

Stratopastor

Stockton-on-Tees

Jivin' with cosmik debris since 1955!
Jan 1st, 2012 06:31 PM   Edit   Profile   Print Topic   Search Topic

oh, man - get well soon. I've still got Tung Sol RI 6V6s in my PRII - still sounding good after 3 years of medium use.

JayFloyd

USA

'83 strats
Jan 12th, 2012 09:10 AM   Edit   Profile   Print Topic   Search Topic

Hi Guys,

I am also a PRII owner.

I had sold my Marshall 1987x which was just too loud and too ice pick-y for my needs. I used the money to purchase, and upgrade my PRII.

I added a Weber FC12, which is a clone of a Fane Crescendo. (I am a Gilmour fan), I like it a lot. I would love to try the Celestion Blue.
The speaker it came with, looks like the Fender 12F, but with no markings. It was also very ice picky.

I have a bugle boy 12ax7 in V1, and some other misc NOS tubes. I bought some NOS RCA 6V6's for the power section.
I have considered snipping the snubber caps. There is a video on YT where the owner says he snipped his, and it sounds great, but don't want to do anything I can't simply put back.

I moved my reverb tank to the bottom of the cab., I must admit, I did not notice a difference.

I play an '83 Strat through my PRII. I have a thing for '83 Fenders. I had an Elite, but had to sell it.

I use the PRII as a clean platform for my effects. I run it with the master wide open, and adjust the volume to taste. EQ knobs are all somewhere in the middle, treble boost is on, and mid boost is on. I like the reverb around 3, presence around 3.

I use a Tonebender, a Colorsound Power boost, and an Effectrode Tube-Vibe, along with a Fulltone TTE. They all sound great with the PRII.

I used to use a Fuzzface. It sounds good at quiet home volumes, but not louder gigging volumes. The Tonebender sounds great at any volume. Although I am a Gilmour fan, and he used a Fuzzface, I think the Tonebender fits my playing style better.

I have never had the original foot switch, but, I tried a Boss FS6 foot switch with the PRII, and it seems to work. I do prefer the sound without the FS though.

I am not currently in a band, but was when I bought the PRII. We played everything from the Doors to Foo Fighters. I used a Rat at the time, and it handled itself great. It cut right through, stomping all over the other guitarist with that nice sparkly Fender sound. I don't think I ever had the volume over 3 or 4, with the master all the way up. It had no problem keeping up with the drummer.

I have been playing since 1982, and this is my favorite amp that I've ever owned.

These are my two favorite YT videos (not mine)

Here

(This message was last edited by JayFloyd at 09:28 AM, Jan 12th, 2012)

JayFloyd

USA

'83 strats
Jan 12th, 2012 09:23 AM   Edit   Profile   Print Topic   Search Topic

I had trouble posting the links, this is my other favorite PRII video

Here

Stratopastor

Stockton-on-Tees

Jivin' with cosmik debris since 1955!
Jan 12th, 2012 11:09 AM   Edit   Profile   Print Topic   Search Topic

hi Jay... all you have to do with the snubber caps is, for each cap, clip one leg very close to the tube socket, and tape the leg up. If you want to reverse it, remove the tape and re-solder.

Everyone, I have finally put my dates/quantities info for the entire Rivera-era range on the web. For a month they're exclusive to the FDP so if you'd like to see it, email me (include your FDP handle) and I'll send you the link.

(This message was last edited by Stratopastor at 05:58 AM, Jan 13th, 2012)

littleuch
Contributing Member
*********

Michigan

T-boned and punctured
Mar 14th, 2012 06:09 PM   Edit   Profile   Print Topic   Search Topic

I am starting to wonder if I'm having a malfunction of my treble pot. There seems to be no difference engaged/disengaged in boost mode and the range is very dramatic from 0-10 (think wah-wah). Gahhhh!

(This message was last edited by littleuch at 06:10 PM, Mar 14th, 2012)

Stratopastor

Stockton-on-Tees

Jivin' with cosmik debris since 1955!
Mar 17th, 2012 04:35 AM   Edit   Profile   Print Topic   Search Topic

hey Larry

Now you come to mention it, if I leave the mid and bass some way up, as I usually do, and simply yank the treble right across its range, it does sound dramatic, a bit like a wah. I guess that because the treble pot is actually a 'balance' control with all the top end on one side and the mid+bass on the other, and you're sweeping between the 2. It's not really wah but it's similar.

And, there's not much boost to be had on the treble pull boost either. But I'm not worried about it.

Different subject - here's a link to my Rivera-era serial number/mfg quantities research "results"..

Rivera-era dates and quantities

Stratopastor

Stockton-on-Tees

Jivin' with cosmik debris since 1955!
Mar 17th, 2012 04:41 AM   Edit   Profile   Print Topic   Search Topic

While I'm here, Cap Job News -

let me thank Greg B in Australia for pointing out there's now a second source for the cap can, made in Germany. I used the US-Made CE cap can and it's fine, but it's good to know someone else is making them.

Go to catalogue/capacitors/1.Authenticaps...

Frag Jan Zuerst!

MonkeeMind

Atlanta

Nothing Exceeds Like Excess!
Mar 23rd, 2012 11:20 AM   Edit   Profile   Print Topic   Search Topic

I built a foot switch for my PRII & it's awful!

Hi all!

After years of putting it off I built a foot switch using the diagram on Stratopaster's website. It all went together well, and as far as I can tell was assembled correctly. The LEDs toggle on & off, and the reverb switch works. The problem comes with the tone suck that occurs when this thing is plugged! The usual big full clean sound gets horribly brittle with a huge volume drop.

Considering the cautionary warning on the PRII website concerning this accessory I can't say I wasn't warned, but I'm pretty disappointed how this little project turned out.

Anybody else here have a different experience with the foot switch?

ampman91510

USA

Mar 26th, 2012 04:18 PM   Edit   Profile   Print Topic   Search Topic

Man, I love my PR-2! I'm thinking of selling it though, 22 watts just ain't enough for what I do. Great little amp, new Weber, reverb tank from a Twin, the devil's own tone mods... great stuff! I like the pine cab and the fat tranny, nice fundamentals in this amp. Anyway, I'm off to KT88-land, so I guess if anyone wants a PR-2 gimme a shout. :)

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FDP Forum / Fender Amps: Vintage (before 1985) / The Princeton Reverb II (Rivera era PRII) Conclave




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