Ampeg B15-N info....

streetknight · #1 07-31-2011, 07:00 PM

How are these amps? I've found one the guy says is a 66' model, but been in storage for a long time. No clue if it works or not. What would be a good offer to make not knowing the working condition?

Fender4Me · #2 07-31-2011, 07:33 PM

They typically bring about $1000-1400.00 in good working condition. Condition is everything. Great amps. best for studio or practice , maybe a small gig in a small room. Jamerson used one : )

**ddbassGA** · #3 07-31-2011, 07:35 PM

These are great amps, remarkable tone and surprising volume for only 30 watts. Hard to say what a reasonable offer would be without knowing anything a out it. If it's all there I can't imagine it being worth less than $500.

JimmyM · #4 07-31-2011, 11:09 PM

Dude, it's a freakin' B-15! Do you even need to ask?

Have you seen the amp or any pics? Will you get a chance to plug it in before buying? Current cosmetic condition is pretty important to the price. There are just too many unknown factors right now to even give you an idea of what to offer. Chances are it works because they're built like tanks, but if it's beat, that could be a red flag. Just very hard to tell right now till you get more info.

coreyfyfe · #5 08-01-2011, 07:06 AM

If it's been in storage it's probably going to need some work to get in playing shape so keep that in mind. If it works and is in close to original condition, then the price mentioned above holds. If there have been modifications done, parts missing, repairs needed then you have to adjust accordingly. I paid $500 for my most recent one, but it needed a cap job, some cleaning up, a few replacement parts, and a 3 prong cord. It was also retolexed in black and had a jbl K140 instead of the stock speaker. Certainly not complaining about that last part.

johnk_10 · #6 08-05-2011, 08:21 PM

as far as B15's go, if they were good enough for jimi hendrix, they're good enough for me.

‪Jimi Hendrix on The Dick Cavett Show (July 7,1969)‬&rlm; - YouTube

Jazzdogg · #7 08-05-2011, 09:34 PM

Quote:

Originally Posted by johnk_10

as far as B15's go, if they were good enough for jimi hendrix, they're good enough for me.

‪Jimi Hendrix on The Dick Cavett Show (July 7,1969)‬&rlm; - YouTube

Fun clip, John!

Any idea who's playing bass?

johnk_10 · #8 08-05-2011, 09:36 PM

i would think, it's prolly Billy Cox.

**fuzzy beard** · #9 08-05-2011, 09:46 PM

Just asking but if it has been in storage for a long time shouldnt it be brought up on a verarc (i think that is what it is called)?

johnk_10 · #10 08-05-2011, 10:12 PM

a variac would be the safe way to go. it allows the old caps to form easier by bringing up the AC voltage slowly.

nashvillebill · #11 08-05-2011, 11:11 PM

Personally I wouldn't use the Variac, I'd just change the caps out immediately and then bring it up on a dim bulb tester. 45 year old caps? Don't even be tempted to try saving them. It ain't worth the mess when one explodes.

johnk_10 · #12 08-05-2011, 11:23 PM

my '64 B15 still has it's original filter caps and has no issues whatsoever, so when i get a vintage amp of dubious history, i bring it up on a variac for the first time.

AwkwardLoudness · #13 08-05-2011, 11:34 PM

Yeah, have a tech use a variac to fire up the amp first time. Old electrolytic capacitors develop bulges and sometimes cracks when an amp is turned on the normay way after long term storage. It has something to do with the acids inside the caps reacting and releasing gasses. The caps might need to be swapped anyway if they are already in bad shape.

Prices vary a lot for 60s B15N amps depending on location, economy, seller's willingness to ship, etc. I once got outbid on evilBay for a non-working '65 B15N that sold for $1,230. I'd offer at least $500 maybe more depending on condition especially if the speaker is original.

**B-string** · #14 08-05-2011, 11:38 PM

Quote:

Originally Posted by johnk_10

my '64 B15 still has it's original filter caps and has no issues whatsoever, so when i get a vintage amp of dubious history, i bring it up on a variac for the first time.

+1 I am a reformer myself, use a current limiting resistor. If the cap is not shorted or puking itself the dielectric can be 90% of the time reformed.

**ddbassGA** · #15 08-05-2011, 11:39 PM

Ditto. Assume it needs caps and get it done, plus a 3-prong cord. My tech will do both of those updates before he will even flip the switch.

JimmyM · #16 08-06-2011, 12:28 AM

Quote:

Originally Posted by Jazzdogg

Fun clip, John!

Any idea who's playing bass?

I always thought Jimi was just jamming with the house band because they never showed anyone but him. Could be wrong, though.

nashvillebill · #17 08-06-2011, 07:59 AM

I'm gonna be blunt about the electrolytic capacitors.

Don't fall for the "no need to change them" crap. Change them.

They're 45 years old. Their manufacturer predicted they would last five to ten years....they're now 45 years old. Electrolytics have a known failure mechanism: they rely on a mechanical seal to prevent them from drying out. No seal is perfect, and the caps from the 60's or even worse, the 50's were not made that well. Once the electrolyte starts to dry out, the cap begins to fail in a couple of ways that aren't immediately noticeable. First, its capacitance may start to decrease. Second, its ESR starts to increase. These aren't obvious to the naked eye, unless the cap overheats to the point where it bulges or oozes electrolyte, but the cap is no longer performing as intended. A power supply cap on the B+, for example, will begin to have lower B+, going from say 440 VDC downwards to as little as half of that (or worse). Ripple on the B+will start to increase and a slight hum may become evident. Meanwhile as the tube cathode bypass caps lose some of their capacitance, the tube's gain will be altered.

These effects may not be immediately noticeable--the amp still "works", folks may even think "the amp sounds fine!"--but it's not working at anywhere close to its peak performance.

As I've said many times, would you take a car out on the freeway on 45 year old tires? Same thing, those old tires dry rot. They might hold air, but how are they really going to hold up on a hot day at 70 mph?

How's those caps gonna hold up on a hot day when the amp's being pushed hard?

Caps are relatively cheap, and there's what, maybe a dozen electrolytics on these old Portaflexes? I believe Fliptops sells the whole set of 'em, already selected to fit. For the DIY'er, it's maybe $100 to change all the caps, probably double that to pay a tech to do it. BUT if a cap fails--spewing electrolyte--it's gonna take a whole lot more time and money to clean all the crap out of the inside of your amp. I've seen those caps vent, and it ain't pretty.

On a similar vein: Changing out some of the plate resistors, while not anywhere near as urgent as the electrolytics, isn't a bad idea either. I don't hold with the "old resistor mojo" theory, it's a friggin' resistor and low noise, low leakage metal (film or oxide) resistors beat the crap out of those old carbon ones. Leaky plate resistors can be heard as an occassional crackle in the background.

Restore that old amp properly and she'll serve you well!

coreyfyfe · #18 08-08-2011, 06:31 AM

Quote:

Originally Posted by nashvillebill

For the DIY'er, it's maybe $100 to change all the caps, probably double that to pay a tech to do it.

Had my B-15N done a few months ago (ok, probably about a year now) and it was like $95 with a decent set of caps, whatever my tech normally uses. Probably would have been more if I chose top-o-the line stuff, but it's definitely not a costly fix for these amps.