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Official Ampeg Portaflex Club

Those intentional atonal notes can make the song. It's only bad when you keep playing after everyone else has stopped.

It never fails, dress after setting up. ;)

I found that if you play a good note quickly enough, right after a bad one, then it will sound OK. So that's an inadvertent leading tone. Yeah, that's it. Yeah, leading tone. I planned it that way.
 
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Jesse Oliver wrote:
AMPEG RE-ISSUE OF B-15N 4/2/95
(ITEMS FOR CONSIDERATION)

INCREASE POWER TO 100 WATTS, (4) 6L6's
LINE OUT + BAL. LINE OUT
FORGET THE 16 OHM SERIES EXT. SPKR. JACK
(ADD PARALLEL SPKR. JACK)
USE 12AX7's FOR PREAMPS & D.I.
KEEP THE PLEXIGLAS "Ampeg" LOGO
(WITH PERSONALIZED MONOGRAM AVAILABLE)
FIND A BETTER "IDIOT PROOF" WAY OF
CONNNECTING SPEAKER.
FIND A BETTER TOP CLOSURE SYSTEM
ULTRA MIDRANGE CONTROL
OPTO COUPLER LIMITER (SELECTABLE)
MOVE ALL POWER SUPPLY ELECTROLYTICS TO
INSIDE OF CHASSIS (MORE ROOM FOR O.P. TUBES)
ADD EFFECTS LOOP.
MAKE ONE VERSION FOR THE "PURISTS"
AND ONE VERSION FOR TODAY'S MARKET*
kEEP THE "POTTED" TRANSFORMERS TO RETAIN
THE CLASSIC LOOK.
KEEP THE LORD SHOCK MOUNTS FOR CHASSIS.
ADD TWEETERS (WITH ON/OFF SW.

*INCREASE POWER OF BOTH VERSIONS
(NOBODY'S THAT PURE)

Anyone know why he went for 12AX7 instead of 6SL7?
 
Anyone know why he went for 12AX7 instead of 6SL7?

The 12AX7 is readily available and the quality is getting better all the time. Price wise, it makes financial sense.

When looking to optimize harmonic richness, I still prefer the sound of the 6SL7GT. Just my preference. Having said that, there's a lot of vintage studio gear that uses 12AX7's. They can't be all that bad. :laugh:
 
My 1963 Hofner 500/1 and Heritage B-15 :)
They sound great together. Even the cat likes it :laugh:

image.jpeg
Hofner has released a 60th anniversary edition of their famed 500/1 violin bass. Imagine 60 years. They sound great though a B-15.

Hofner Releases the 60th Anniversary 500/1 Violin Bass | Premier Guitar


This is an old video that Hofner produced showing all that goes into building one of these fine instruments. I'm fortunate to own an oldish one.

Building the Höfner Violin Beatle Bass - YouTube
 
My 1963 Hofner 500/1 and Heritage B-15 :)

I played a 500/1 in a band back in the late 60's. The band owned it so I'm not sure how old it was but it had a lot of mileage on it. The neck was separating from the body. So much so that it had a flat carpenter's pencil jammed into the neck joint to keep the angle right and the bass playable. I guess that a neck reset would have fixed it. Even still, I liked it because of the light weight. I've had mine for over 30 years and it has no issues at all.
 
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My 1963 Hofner 500/1 and Heritage B-15

I love seeing all the pictures and stories in this group about original B-15 amps from the sixties. It is my dream to own one someday, but they are rarer than hen's teeth where I live in western Canada and not well suited to long distance shipping. So I patiently wait and watch.
 
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I love seeing all the pictures and stories in this group about original B-15 amps from the sixties. It is my dream to own one someday, but they are rarer than hen's teeth where I live in western Canada and not well suited to long distance shipping. So I patiently wait and watch.

Shipping is always stressful. I looked for two years to find the one that I have. It can be like that for some amps.

The big advantage of your Heritage is that it doesn't need any extra outlay like a vintage amp does. If you want a restoration project, that's a different story.
 
Shipping is always stressful. I looked for two years to find the one that I have. It can be like that for some amps.

The big advantage of your Heritage is that it doesn't need any extra outlay like a vintage amp does. If you want a restoration project, that's a different story.

I have read along with many of the restoration projects in this group and get swept downstream in a hurry... Way over my head. I'm really very happy with the sound of my Heritage while I wait for a working survivor B-15 to show up in my part of the world.
 
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Hey all!
New member to TalkBass here. Hope you don't mind one of those ego-Maniac 6 string guitarists invading your forum. :-)

So why am I here. Well that's a 30 year plus answer, which I'll try to compress in as few words as possible before I loose you.

Back around 1982 I was offered a tube amp that was not working, if I wanted it, and wanted to put the work in to get it functioning. When it showed up, low and behold, it was a B-15 Porta-flex. Being a guitar player, I wasn't in much of a rush to dig into it, but I noticed that the mains fuse was blown, and the fuse holder was pretty beat up. So, I put it aside as a project that I would get to shortly. After all it was the early eighties, and I was playing through a monster 150W solid State combo. Metal baby! Good god, what an awful tone I had. lol.

Anyway, that where it stayed. But I kept telling myself I would work on it soon. 4 house moves and many years later, I believe that time has finally arrived. Procrastination anyone?

In my mind, my memory of the amp, seemed to get worse and worse...by that I mean, every time I thought about dragging it out, I imagined the Amp looking worse and worse, to the point of when I was ready to flip open the top, I expected this mess of rust, and unidentifiable stuff growing all over it. Figured it would be no more that a bunch of random parts I might be able to sell to satisfy some other G.A.S.

To my surprise. It didn't look that bad at all. Same blown fuse hanging out of the broken holder, same questionable tubes, but not the disaster I expected.

I have been trying to do some research, dating, etc. on this cherished amp, and think I have more questions about this baby than when I started. I also found this place in my research and after reading a quite a few dozen posts in this thread, it became apparent that if there were answers to be had, this is the place. The knowledge here is pretty impressive.

So that's my story, and I'm sticking to it. ;-p

Future plans for the Amp? well I want it up and running, thick it would make a great stereo amp for my guitar rig next to my vintage JCM800. Although I did promise my Bass player in the local old timers band I play in that he could borrow it for a few months. Personally, I think he's planning on me having an accident so he can elope with the amp. Haha.

So here are the questions.

Dating. The serial number on the AMP and inside the Cab is 000007. Seems it is 1965. The EIA code on the original square magnet CTS speaker is 137466. Which I believe is 46th week of 1964. The tricky part. The label on the inside of the cab has the model number pre-printed as B-12-NC, but it has been scratched out and a hand written B-15-N just below. There is a second label with B-15-N pre-printed Partially stuck over and alongside the the scratched out label. Side note: The handwritten B-15-N printing is very reminiscent of J Oliver's hand written notes from 1995 on the heritage B-15. I found those notes here in the Portaflex Wiki. Probably not him, and I'm just wisking on a flight of fancy, but leave an old guy to his imagination. We ain't got much left but that.

Anyway, as we know....Pics, or it didn't happen.

Here you go: I'll post the serial numbers pics first, then others so this post doesn't take 2 pages by itself. Again, thanks for reading this and thanks for any help that anyone might want to volunteer. I do have a replacement fuse holder and a new set of tubes on the way. Thank you Fliptops!

Rj7NNYw.jpg


7dHMXQj.jpg
 
Nice amp. It will need more attention than just the fuse holder changed. Probably the power supply and bias electrolytic caps changed. A good cleaning including the pots and jacks with deoxit.

Don't lend the amp out, you'll never get it back.

As for the date, what you are seeing on the cabinet label is not unusual. The best way to refine the date is to look at the codes on the pots inside the chassis. They are CTS pots so look for a code starting with 137 as you did with the speaker. I like the pento-naught-7 serial number.

BTW, Jimi Hendrix played through a B-15 on the Dick Cavett show. He sounded pretty good. Every time the video is posted on youtube they take it down.


hendrix B15.jpg
 
#533 Jarfly89

Ampeg was not an exact science back then, and scratched out labels happened fairly often. And it's very possible that it was Jess' handwriting, as he was the overseer and actually did work at Ampeg, and wasn't the cult celebrity that he became over the years.
 
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