Ampeg b15 live tone

[MR PC]

Yeah, $100, that's the low end of the ballpark price. And the 421A is the right speaker for that amp. A neo speaker in there is just going to be weak/muddy once you start pushing volume and the speaker gets hot.

 

[Grissle]

That's what I thought. I've got two of them but l thought it might be too much of a hassle trying to sell them for so little? Also an old B-15 would be my holy grail amp and it would be nice to have one on hand. I've also got an old JBL E-140 that I bet would sound great with B-15 or V4B.

 

[Groovy_Gravy]

pump that b15 thru an 810

 

[bluehevy75]

The damping on the back wall of the cabinet removes some of the mud. Maybe you can try adding a little more material (mattress foam or dense spun polyester from a fabric store) to see if this helps clear it up at high volume levels. If you have an old blanket or something similar, that could work. It's a simple test and might be worth a shot. Too much damping can be a problem. You have to find a balance that works.

I've got the inside covered with pink insulation (the thick kind). This helped a lot when I did it.

Are the other materials better?

 

[bluehevy75]

I'm assuming with a 7 piece soul band and a crowd of 100, the B-15 is just a stage monitor.
If not, the main concern is what does it sound like in the house which I would assume to be very quiet.
If it is just a stage monitor, it doesn't sound like the right amp for your application if this happens consistently.
OTOH, I've had amps that sounded great on stage and throughou the house PA at one club, and sounded horrible on stage at others either do to being placed in a 90 degree corner with masonry walls, hollow stage, or odd shaped rooms.
You HAVE to sound great out front, and being inspired by your tone on stage is important but not the primary concern IMO.

I'm with you. I've worked hard lately to find out what sounds good out front and then make adjustments according.

Currently the b-15 is not just a monitor. It is unmic'd and I'm not using a direct box. So the b15 is putting out the only bass sound.

We aren't trying to be loud. We want people to be able to have a conversation while we play. We do want a nice, articulate, tight, well balanced sound. If I need to break out the v4 then I need to break out the v4.

 

[bluehevy75]

I'm looking now at buying an Altec 421a. I like the amp too much and want to really see what the limits are. Currently the neo probably an issue.

I will have some work done on it too over the Holidays.

Once I've got the amp in a little better shape I will begin to really figure out what gigs it can handle and when the V4 will come out.

I often find my amp on stages, in a corner, next to walls covered with thick curtain material. How is that affecting my tone? Is that just sucking all my highs up?

 

[Jim C]

I have a pair of 421's in an old Peavy 2x15 cabinet that sound very good (to me)

 

[JimmyM]

Corners do reinforce lows for sure.

 

[MR PC]

I used to turn the B 15 cabinet completely around up on a chair in the corner, when the onstage volume became an issue and the amp started to get cranky/peaky sounding. Primitive situations, primitive moments in music, require primitive solutions.

 

[bluehevy75]

I'm having a tough time finding the 421a except on ebay. And I really don't want to buy a speaker off ebay.

1. I can buy a beat up one and get it reconed locally for a total of $200.00.

or

2. I recently found a JBL e 130 for $100.

Thoughts? From what I read people seem to like the JBL e 130 but it seems like the 140 gets even more love.

How comparable is the 130 to the altec 421 a?

KH

 

[JimmyM]

Not very. IMHO, you need the extra mids of the 421a to make the Thiele cab B-15's sound right.

 

[bluehevy75]

Good to know. Thanks Jimmy.

 

[bluehevy75]

Well party people…I'm still working on the speaker...but my amp guy at the shop said I've been running on one power tube…my bias was all wrong…and some of my pre amp tubes need to be replaced.

That should make a BIG BIG difference in the sound of that amp when cranked.

Will get it back sometime next week and will let you know.

Amp tech says go with 7027's. Some on TB say there is "no difference" between 6L6 and 7027 but we'll see. Price for 7027 is nearly the same.

 

[JimmyM]

Modern 7027's are nothing more than 6L6's with a different pinout. Don't know if I'd agree with your tech guy, but if he has a stash of NOS 7027's and rewires your sockets properly, it might be OK. I'd get a second opinion, though...hopefully David Beans-on-toast will be along in a while to be the second opinion.

 

[beans-on-toast]

The NOS 7027A is about the same as a 6L6GC in your B-15N. Depending on the make, the two types are either identical or the 7027 is built a bit better. There are some 7027's that are taller and may not fit under the tube cage so check that out.

If your tech is modifying your amp in a way that raises the B+, that would be a reason to go with the 7027. If you are pushing your amp, you might want to try a solid-state rectifier module in place of the 5AR4 tube and see how you like it. It might give you the clarity that you are looking for.

Bottom line, if you like the result with the 7027 installed, go for it. He can install the 7027's and you can try it, then try a set of 6L6GC's and see. In terms of wiring for each tube type, you never know what was done to the amp. Someone might have wired the amp to use the unused pins on the tube socket. So despite what the schematic says, check the amp wiring to be sure.

Did he tell you why he feels that the 7027 is the way to go in your amp?

 

[DavidEdenAria]

The mention of the Altec 421A here brings up a question regarding this speaker. I have one (that was thrown in (for free), on a deal on a pair of Altec 418Bs). It has a badly torn cone. I would appreciate any opinions on having this thing re-coned. Are these worth the cost to re-cone? I see the spec sheet lists it as being 17 pounds, but every time I move this thing it seems to become heavier. I would not pay to ship it to be re-coned. There is a local guy around here, who would probably do it, but this guy is not so easy to deal with. I have always wanted to try my hand at this, but now is not a good time for me to learn, or experiment with speaker re-coning. If I got this for free, is it worth maybe a hundred bucks to have it re-coned? Would it be worth a try in a double baffle B-15 cab? (I've got two B-15 cabs. One, with a JBL, and one with a Jensen, so I don't really need this speaker, but it is not doing any good without a cone). If I have the local guy do it, it will be with whatever kit he chooses. The original voice coil, and aluminum dust cap are good. Should I just have this guy replace everything, with whatever kit he decides he wants to use, or is there a certain kit that is best to use?

Thanks for any opinions on what to do with a damaged Altec 421A.

Exactly how big is the tear?

Reconing Altecs is not cheap as you know.....I have successfully repaired MANY vintage speaker cone tears with layers of strong tissue paper and either Elmers wood glue or Weldwood contact cement...some times rubber cement.

I got this info from the late Ted Weber Sr. at Weber speakers.

 

[DavidEdenAria]

I'm having a tough time finding the 421a except on ebay. And I really don't want to buy a speaker off ebay.

1. I can buy a beat up one and get it reconed locally for a total of $200.00.

or

2. I recently found a JBL e 130 for $100.

Thoughts? From what I read people seem to like the JBL e 130 but it seems like the 140 gets even more love.


KH

Have you tried a Peavey Black Widow, which is a JBL copy of sorts with the huge voice coil?

Some studios prefer these with B15N's.

 

[DavidEdenAria]

I've got the inside covered with pink insulation (the thick kind). This helped a lot when I did it.

Are the other materials better?

I don't like fiberglass in a speaker cabinet, the risk of it getting inside a speaker coil and its just a mess to work with....I pulled ALL of it out of my early 60's Fender amps!

Just use polyester pillow stuffing or better yet, Acousta-Stuff which is used by hi-fi builders.

Otoh, if it sounds fine to you and is not loose and shredding apart, the pink insulation is probably okay.

 

[DavidEdenAria]

The NOS 7027A is about the same as a 6L6GC in your B-15N. Depending on the make, the two types are either identical or the 7027 is built a bit better. There are some 7027's that are taller and may not fit under the tube cage so check that out.

If your tech is modifying your amp in a way that raises the B+, that would be a reason to go with the 7027. If you are pushing your amp, you might want to try a solid-state rectifier module in place of the 5AR4 tube and see how you like it. It might give you the clarity that you are looking for.

Bottom line, if you like the result with the 7027 installed, go for it. He can install the 7027's and you can try it, then try a set of 6L6GC's and see. In terms of wiring for each tube type, you never know what was done to the amp. Someone might have wired the amp to use the unused pins on the tube socket. So despite what the schematic says, check the amp wiring to be sure.

Did he tell you why he feels that the 7027 is the way to go in your amp?

Remember, if you go with 6L6GC you can get more clean power with 7581...I have a few I use in my 71 Fender Super Reverb....a LOT of clean bottom end punch!

Derek Trucks uses these in his Super Reverb as well.

 

[beans-on-toast]

I don't like fiberglass in a speaker cabinet, the risk of it getting inside a speaker coil and its just a mess to work with....

Not to mention the health hazard. Flipping the amp exposes you to fibers and glass dust. It would never pass regulatory approval today.

Spun polyester from a fabric store works well. I like to use wool felt. There are a host of good alternatives that are available.