Ampeg B-1 and Ampeg 2-12 cabinet

dadagoboi · May 01, 2011, 02:20:27 PM

http://gainesville.craigslist.org/msg/2349383090.html

Anyone have any experience with either? The 2-12AX7 B-1 intrigues me and the cabinet is just flat out strange. Of course it "sounds great".

Psycho Bass Guy · May 01, 2011, 05:52:23 PM

That cabinet is an early 90's SLM product. It's ok sounding, nothing special. I'm pretty sure the "amp" is just a recent (post- 2000) SVP preamp.

dadagoboi · May 01, 2011, 06:12:08 PM

I found this pic on the net, I think it's late 90's.

What's supposed to be the purpose of the rear facing 12 in the cab?

Freuds_Cat · May 01, 2011, 09:52:17 PM

argh the tyranny of distance again!!! I've been after a B1 for ages

single rack mount preamp with a built in 100w (I think from memory) power amp.

fantastic sound in a very small package. great for using as a very portable good sounding amb, just pug into what ever cab you get hold of at the time.

dadagoboi · May 02, 2011, 01:59:34 AM

It's worth a shot at the asking price, at the least as a pre for my SVP. I'd like to compare it to my Demeter VTBP-201 tube and Peavey Pro Bass 1000 SS preamps in that department. Probably pass on the cabinet.

The owner is a firefighter, in Texas because of the wildfires until Thursday. I'll definitely take a look when he returns.

Psycho Bass Guy · May 02, 2011, 04:41:42 AM

Quote from: dadagoboi on May 01, 2011, 06:12:08 PM
I found this pic on the net, I think it's late 90's.

What's supposed to be the purpose of the rear facing 12 in the cab?

Those are indeed power transistors on that back heat sink. That amp is a new one on me. The reason I'm thinking post 2000 as opposed to 90's is that 90's Ampegs still had solid blackfaces with orange and blue model names and white writing for the functions. IIRC, it was after 2000 that they changed to the gray and black faceplates.

The rear facing 12 is supposed to "reinforce" the motion of the front-firing speaker. They're wired reverse phase to one another. The effect is supposed to stiffen the overall air movement, effectively dropping the air resistance to the cone. It doesn't work in practice because the overall electrical resonance of the driver is much higher than the acoustic resonance of the combined cones and the internal air volume becomes too pressurized for the cab to have any appreciably better low frequency response. It's simpler, cheaper and lighter to just use a single better driver.

dadagoboi · May 02, 2011, 05:43:06 AM

Thanks, Psycho. That cabinet seemed like a cockamamie idea, I appreciate the explanation.

From TB:

Here are the B1-R's specs from the 1995 Ampeg catalog...
150 watts @ 4 ohms

Input -20 dB pad switch Ultra High + 8 dB @ 10 kHz

Primary EQ
Low +/- 9 dB @ 40 Hz
Mid +/- 8 dB @ 200 - 600 Hz
Mid Select + 8 dB @ 80 Hz
High +/- 9 dB @ 5 kHz
Ultra Low + 6 dB @ 50 Hz
Ultra High + 8 dB @ 10 kHz

Secondary EQ
+ 8 dB @ 10 kHz
Limiter Yes
Effects Send and Return
Preamp out/Power amp input jacks
XLR Balanced out
15 lbs.

Freuds_Cat · May 02, 2011, 05:51:06 AM

Seriously Carlo, buy it and try it (The B1) if you dont like it I will give you $200 plus postage for it. (Sadly I know you will like it $:-\$ )

dadagoboi · May 02, 2011, 05:55:07 AM

Quote from: Freuds_Cat on May 02, 2011, 05:51:06 AM
Seriously Carlo, buy it and try it (The B1) if you dont like it I will give you $200 plus postage for it. (Sadly I know you will like it $:-\$ )

Will do, you get it if I don't like it.

Freuds_Cat · May 02, 2011, 06:49:06 AM

Deal!

They come up so rarely that if you keep it and decide in 6 months or so that you dont want it any longer please give me 1st option.

jumbodbassman · May 05, 2011, 08:03:16 AM

put me second on the list

dadagoboi · May 05, 2011, 09:19:32 AM

OK, Jim. I don't know if it's because Ampegs were my first two real amps (after a Silvertone 2-12 piggyback) but I'll always give them a listen. I will be buying it tomorrow.

dadagoboi · May 07, 2011, 09:56:23 AM

Bought it yesterday after playing it thru the weird 2-12 cab which actually sounded OK and looked brand new.

Fairly versatile EQ section with ultra high and low switches and push pulls to vary bass and treble eq shift points. Also a footswitch activated solo circuit with "voice" and "boost" knobs that I'm assuming is some sort of parametric, I don't have a F.S. Effects loop and pre/post eq balanced out. Power is 150 @ 4 ohms, I have no idea. Pre amp section plays nicely with my SVP. IMO my Demeter is a more transparent pre but it also cost a lot more. I'd gig the Ampeg(s) if I had a gig.

Made Jan, '91 (or was it '93, put the cover back on and I'm not sure now). Insides clean and stickered in 3 different places with the inspectors' names. Power transistors are Mexican Motorolas, inspectors were not.

I'll definitely be keeping it around for a while, probably change the pre tubes. They're branded Electroharmonix Made in Russia. Whatever, they're almost 20 years old.

Dave W · May 07, 2011, 12:28:28 PM

Why change a preamp tube unless there's a problem? If you're looking for a change in tone from a different manufacturer, okay, but with a preamp tube, 20 years doesn't necessarily mean it needs replacement.

dadagoboi · May 07, 2011, 12:43:10 PM

Quote from: Dave W on May 07, 2011, 12:28:28 PM
Why change a preamp tube unless there's a problem? If you're looking for a change in tone from a different manufacturer, okay, but with a preamp tube, 20 years doesn't necessarily mean it needs replacement.

Good question. Because it came from the Evil Empire? That's all I got.