1952 Fender Pro

John Billings · Post by **John Billings** » 30 Jan 2007 2:46 pm

I have a strange '52 Pro Amp. It's not tweed! It's painted with some sort of heavy-machinery paint. Dark gray with some flecks in it. Now here's the story.
Years ago, I was using my '56 Pro for 6-string, and I was pushin' it awfully hard. I decided I needed a Tweed with 4 power tubes instead of 2. A Twin Amp. So I headed down to Nashville, and went to Corner Music. They had a half dozen tweed Twins. But they wanted over $800 for them! (now you know how long ago it was!) I saw one up in back that was painted gray. I figured I could get that one cheap cuz someone had ripped the tweed off. When I asked the owner, "How much?" He told me that was the only one that was not for sale. It was part of his personal collection, and that it was a "52, AND, that was the original finish! He called it something like "Rocktek??" I returned to Cleveland very disappointed.
A couple weeks later, I went to Ross Music in the Falls, and there was a '52 Pro Amp with the exact same painted finish! Bought it of course. I've seen one other amp with this same finish besides the Nashville Twin and my Pro.
Has anyone any input about these oddities?
JB

Al Sato · Post by **Al Sato** » 30 Jan 2007 9:58 pm

Does your amp have a 15" field coil speaker? What are the tubes? Thanks.

Al

John Billings · Post by **John Billings** » 31 Jan 2007 5:45 am

It has the octal preamp tubes. 2 6L6's (When I got it, it had Mullard EL-37s!) It originally came with a 15" speaker, not a field coil speaker. At some point in it's life, someone built a sub-baffle board which fastens to the lugs for the 15" speaker, so no damage done. It has an ancient Jensen 12" in it right now.

Sean Nolan · Post by **Sean Nolan** » 5 Feb 2007 8:37 am

I've also got a TV Front Pro I'd love to pick your brain about. Mine has a Jensen P15N in it with a 1952 date code, and the output transformer is bolted to the side of the amp, not to the chassis or speaker frame. The output transformer seems vintage correct but has some re-solders. The guy I bought it from was very honest and said he knew the speaker had been reconed and the cabinet re-covered years ago when his dad owned it, but other than that he thought it was stock. I've always wondered if this is the way it came stock, or did someone just mount the output transformer to the cabinet instead of the speaker frame after the recone? Maybe even the P15N was an upgrade to a Jensen field coil speaker that the output transformer used to attach to? How's your's set up?

What I really, really am interested in is if you ran your's long with the Mullard EL37's in it, and if anything horrible happened. Mine's currently got a set of RCA 6L6 Black Plates that sound great but I've run it with a pair of Mullard El37's and the tone was fantastic. The power transformer got a little warmer than usual, but nothing extreme. People warned me to stop using the El37's in it as they draw more filament current than 6L6's (1.6 amps vs. 0.9 amps for each tube) and I'll blow the power transformer. Even though this amp is a bit hacked up I'm trying to keep it as original as I can because it sounds great and is a piece of history too, but if I could run it with the EL37's I'd love it even more.

Thanks for any thoughts you can share.

Sean

John Billings · Post by **John Billings** » 5 Feb 2007 9:19 am

Sean, mine is a wide-panel Pro Amp. The model number is 5B5, serial number 3298. It never had a fieldcoil speaker. I'm thinkin' that someone modded yours, cuz I've never heard of Fender mounting an output tranny the way yours is mounted. But if your amp is a '52, and the speaker is a '52, maybe during the changeover from fieldcoil to the newer type, Fender did something odd,,,,,,,,,,?
I didn't use it much with the EL37s, cuz I have the 56 Pro that's just a better sounding amp with 12AX7s instead of the octals, which can be a bit noisy. I bought the amp cuz it was rare, and cheap. When I took it to my tech, we noticed that the input jacks were not doing what we expected. We opened the amp up, and found that the way it was wired was unique! There were labels on two of the wires that came from the jacks. One said "to echoplex" and the other read "from echoplex." My tech returned the wiring to spec. When he replaced all the caps, he actually took the old paper caps apart, and inserted the new caps inside the old ones. So it still looks original, and he proved to me how anal he is! Best tech ever.
The amp sounded great with the EL37s. But then, any amp I've tried those in has had a great improvement in sound. Great tubes and big $$$$$ these days.
What year and model is your Pro? Serial number?

Jim Sliff · Post by **Jim Sliff** » 6 Feb 2007 1:37 pm

The oddly-mounted OT is not stock. Neither is the gray-paint "Fender", but I've heard of some dealers doing special coverings/paint jobs themselves back in the 50's, so that may be what the deal is with the gray amps.

As far as EL37's - with fresh caps and grid resistors I wouldn't worry at all. I've run a pair in several vintage Fenders (although right now they are in my Holland Little Jimi) and I've never had a PT get inordinately hot...the PT's are pretty well over-engineered for the amps to start with.

But I would NOT run them in an amp that has never been...or only partially been...serviced. I'd also be cautious and check the bias, even in a cathode-biased amp. They usually need to be run a bit lower than NOS 6L6's or even 5881's (another great tube in tweed Fenders is the Tung-Sol 5881 - I keep a bunch on hand and they are just stunning).

Edited to add: the dealer-based special colors - specifically these gray ones - *were* done at Fender as Chris Lucker reminded me last night. Fender used to do a few special runs for specific dealers, and this was one of them - so the gray WOULD be "stock", sorta, since it came from the factory that way. Somewhat akin to the rare "Kitchen" Marshalls that were branded for a specific dealer.

With 50's Fenders all sorts of exception to "the rules" can be found. the side-mounted transformer isn't one, but there have ben many variations in coverings, some in parts values, and a zillion in paper labels. It drives the vintage police, who diss anything that apears to have a wrong-type screw, bats.

This thread made me get out my 5D3 wide-panel Deluxe last night and plug my 1000 into it...man, what tone! I'm having a Gibson GA50T (wiht 1-12" and 1-8" Jensen Alnico) restored right now and I can't wait to hear THAT one as well!