1964 Ampeg B-15NC Thoughts

[Turbocharbo]

Hey folks

I'm considering swapping my super clean 1966 Ampeg B-15N for a 1964 B-15NC. I've always wanted a double baffle cab which was my initial motivation for doing the swap but now I'm learning that the 1964 circuit might be the most desirable one to get. Why is that? Is it because it's a turret board design with the tube rectifier?

I was also considering an early 60s random navy flare B-15 which was quite a bit more expensive but I'm not that interested in dishing out extra cash just for collector value.

Thanks!

 

[Bill Whitehurst]

I know very little about B15s, but I do know enough to guess the double baffle and tube rectifier might be the reason the NC is more collectable.
Maybe a little more warm.
I do know, for sure, that given that choice there is no wrong answer.

 

[beans-on-toast]

The '64 NC is sought after by many. It's the classic revision, double baffle cab, eyelet board (easy to fix) There are detailed images of a pristine one in the TB Portaflex Wiki:

https://www.talkbass.com/wiki/vintage-showcase/#3-all-original-1964-b-15n-in-detail

Each revision had slight circuit changes. They all sound a little different but nothing dramatic. The'64 is cathode biased 25W, later revisions were fixed bias 30W.

 

[Turbocharbo]

Thanks for your responses, guys!

Is the '64 circuit any different than the early 60s random navy flare B-15? I'm trying to understand why the early 60s one go for that much more.

Also, this is the speaker that comes with the '64. I haven't had a chance to take it apart to look at the codes on it but I gather that it's not original to this amp, right?

 

[Patrice B]

Thanks for your responses, guys!

Is the '64 circuit any different than the early 60s random navy flare B-15? I'm trying to understand why the early 60s one go for that much more.

Also, this is the speaker that comes with the '64. I haven't had a chance to take it apart to look at the codes on it but I gather that it's not original to this amp, right?

Looks like a CTS square magnet? I don't know which speaker should be OEM though…

 

[Jim C]

Something to consider is that these are older amps and component values will have drifted some.
I speculate that 3 of the exact same model will all sound a little different.
Just make sure the 64' sounds really good to you regardless of porting, circuit, or age.

 

[agedhorse]

Absolutely, you want to play it and be sure it works for you before spending the money.

 

[beans-on-toast]

Looks like a CTS square magnet? I don't know which speaker should be OEM though…

The '64 did have a CTS ceramic square magnet. No knowing if it is original. There should be a date code on the frame. '63 was a Jensen Concert speaker.

 

[Short4since64]

My first amp was a B-15N, '61 vintage with the octal speaker connector. B-15s are a bass player's crack - after playing one everything else is just chasin' it. Speaker cabinet design science didn't exist in the early 60's, but Oliver hit one right out of the park with the double baffle, as against the Bassman little league infield fly. Mine had the Jensen Concert series, as far as I know that was OEM on all the double baffles, although the speaker on the picture may be OEM as all the general replacement CTS speakers were painted black - the wiring is horse hackery however, Ampeg never used clear speaker wire). As long as the transformers are good, everything on those amps is a standard off the shelf part. The "C" version was the last to use a 4 meg treble pot, later versions used the same 1 meg pot for bass and treble, it also used discrete components for the tone control network instead of the Centralab ceramic packaged circuit. This changes the voicing. Mine had the original 5U4 replaced with a plug-in silicon rectifier (I fix amps, recommend this for any B-15, gives a little more balls and about 4 more watts, and of course put on a 3 wire cord and get rid of the ground switch, there's 400 volts on the speaker connector so make sure it's in good condition before you get electrocuted. Been there, shocking experience).
The reason the double baffle versions go for a premium is simply that the cabinet sounds way better. It has been cloned (I have two) but without the original speaker they don't sound the same.