The Last Bass Outpost
Gear Discussion Forums => Bass Amps & Effects => Topic started by: dadagoboi on May 01, 2011, 01:20:27 PM
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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".
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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.
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I found this pic on the net, I think it's late 90's.
(http://i976.photobucket.com/albums/ae241/cata1d0/Jim%20D%20JAEbird%20II/ampeg_b1_guts.jpg)
What's supposed to be the purpose of the rear facing 12 in the cab?
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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.
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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.
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I found this pic on the net, I think it's late 90's.
(http://i976.photobucket.com/albums/ae241/cata1d0/Jim%20D%20JAEbird%20II/ampeg_b1_guts.jpg)
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.
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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.
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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 :-\ )
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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.
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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.
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put me second on the list
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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.
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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.
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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.
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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. :-[
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Tubes last much, much longer than people think. Most of the tubes in my '67 blackface Bassman were in it when I got it 40+ years ago.
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I think power tubes don't last as long as preamp tubes and when they go they can cause serious havoc. Preamp tubes just stop working. I changed all the tubes in my B-15N as a precaution. I can't tell a difference between the new ones and the 1965 ones.
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Good question. Because it came from the Evil Empire? That's all I got. :-[
Wise decision Carlo! Evil empire indeed :vader: ;D And here I was thinking you were just an anarchist and come to find out you're a closet Republican :P
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Is there a difference? The ultimate 'small government' is anarchy, no? ;D
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The EH tubes are OK in my opinion although with a few exceptions most of the modern tubes I've tried tend to get a brownish (read that as you will) tone to them after about a years worth of my usage. I find the EH's rich sounding but a little brittle when pushed. I like the modern Tung-Sols personally. Correct me if I'm wrong but I believe the EH's and the Tung-Sols are made in the same factory. Mores the Irony :-\ .
I spent about 2 years tube rolling 12AX7's and U7's through my SVP-PRO. IMO the JJ's, EH's, Sovtek, etc are all quite acceptable tubes but I found one thing amongst all of the bu115h1t (of which there is much) on the inteweb to be true, The old Telefunken tubes (even a lot of second hand ones) have beaten all other tubes I've tried in all aspects of sound and longevity. Just my opinion. I'm not one of these "if its not NOS then its crap" people. As I said I do like the new Tung Sols. I did a direct comparison between a vintage Tung Sol and the new ones and found the sound to be of the same quality but a bit different to each other. The new tube had more sparkle to it and the old tube had a more creamy smooth sound. Both great sounding tubes though. The other tubes I like were then Raytheon black plates. They made gazillions of these tubes in the 60's and 70's for the organs of the day, a lot of them labeled Baldwin etc. So they are still fairly easy to find and not as expensive as some of the other more "talked up" tubes. The problem I found with the internet was that most of the opinions regarding tubes came from either gu1tardists or Hi Fi buffs and I discovered during my tube rolling that taking their descriptions seriously was next to useless when you put the tube in a bass amp. It just sounds different.
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Thanks, Freud! I'll give the modern Tung Sols a shot. I've also got 2 different pairs of 12AX7s from my Demeter I can try. Don't remember what they are right now.
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Good question. Because it came from the Evil Empire? That's all I got. :-[
Say what? ??? 1991 or later is post-Evil Empire.
You have a couple of vintage Boris Yeltsin Signature tubes there. I'm sure they're worth a small fortune. Very small.
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Say what? ??? 1991 or later is post-Evil Empire.
You have a couple of vintage Boris Yeltsin Signature tubes there. I'm sure they're worth a small fortune. Very small.
I figure it took at least 2 years to get that stuff shipped...I've worked in a Commie country, gummint controlled bidness moves slowly. The USSR Ruble didn't stop being printed until 1992.
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I figure it took at least 2 years to get that stuff shipped...I've worked in a Commie country, gummint controlled bidness moves slowly. The USSR Ruble didn't stop being printed until 1992.
Mike Matthews would have found a way to get them out. :-X
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The SLM-era Ampeg tonestack responds pretty favorably to tube changes. Telefunkens are really nice, but especially for a Fenderbird, I would suggest an old Mullard. Their preamp tubes really do make just about any amp sound "Marshally" without changing the amp's inherent character. That was my secret that I used on my old guitarist's Fender Prosonic. If you want a Mullard without paying inflated vintage prices look for "IEM" branded 12AX7's. That was Mullard's lesser used export designation. Just make sure the tube says "Made in Great Britain." A lot of later IEM's are's Tesla or Philips rebrands, which are still great tubes, but don't sound the same.
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Thanks, Anthony. I'll keep an eye on Ebay to see what shows up at a reasonable price.
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BTW, it's "IEC," not "IEM." I didn't realize I had typed that until I looked at my post again.
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Thanks!
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The SLM-era Ampeg tonestack responds pretty favorably to tube changes. Telefunkens are really nice, but especially for a Fenderbird, I would suggest an old Mullard. Their preamp tubes really do make just about any amp sound "Marshally" without changing the amp's inherent character. That was my secret that I used on my old guitarist's Fender Prosonic. If you want a Mullard without paying inflated vintage prices look for "IEM" branded 12AX7's. That was Mullard's lesser used export designation. Just make sure the tube says "Made in Great Britain." A lot of later IEM's are's Tesla or Philips rebrands, which are still great tubes, but don't sound the same.
Anthony is correct. Mullard was owned by Philips as was Amperex Holland and a whole raft of other tube companies with different brand names around the globe from Brazil to South Africa, Japan even the Hendon factory here in Adelaide. They swapped stock between different Philips companies if they were short just to add to the confusion. More specifically the Mullard factory at Blackburn in Lancashire is the source generally regarded as making best of that brand.
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I have both the B1 single space rack amp and the 2-12 cab with 3 rack spaces for the gear. It works and sounds wonderful. I don't have a lot of "time"on the tubes either, neither piece has been gigged, and both are almost like new. Actually, I would be willing to sell them, if anyone is interested because I have other rigs, that are more portable, and the cab is pretty heavy because the speakers have massive magnets and the wood in the cab is heavy. I live in North Carolina, near Greensboro, so give me an email or reply if you have any interest.
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The reason for the front and rear facing speakers is to get direct and reflect off the back wall frequencies, which helps with harmonics and allows the length of the bass wave to develop. Also, you could place the amp in front of you and have the rear facing speaker act as a monitor for you while you play. I've built other cabinets using similar design and it works really well! I get some really deep clean sounds, with the direct/reflect speaker placement and the phasing does pump more air that way, in spite of other opinions.