B-15N Parts

[Dan Bozek]

A friend of mine was just given a ’69 Ampeg B-15N!! Found in a basement deal. (I’m not even going to start about how that makes my head explode because I’ve been wanting one for so long, but the good fortune of a friend is a wonderful thing.)

It doesn’t turn on right now, and I believe problem #1 to address is that the fuse looks blown. He’s gonna get a replacement tomorrow. But, even though the speaker/cab and everything is in pretty good cosmetic shape, I think it’s going to need some parts and TLC. Justin or anyone else that has a couple of these guys and keeps them properly maintained, is there a good place to get tubes and parts that you use or maybe any good online resources that you can think to pass on?

Basically I know what a treasure this amp is and I want to make sure that it gets fixed up proper in the hopes of then borrowing it frequently for sessions. He he he. :^D

[rickdog]

Wow, what a treasure! That's definitely worth the cost of restoration!

The age of the amp and the blown fuse are suggestive of bad power supply filter capacitors. But just in case they're not blown yet, the amp should be powered up slowly on a variac or they probably will blow out. Unless you have experience resurrecting old tube gear, it would be best to have a good tech check it over and try to power it up.

Check out fliptops.net for parts.

Oh, and we want pics! And sound clips when it's working!

[Dan Bozek]

Originally Posted by rickdog

Wow, what a treasure! That's definitely worth the cost of restoration!

The age of the amp and the blown fuse are suggestive of bad power supply filter capacitors. But just in case they're not blown yet, the amp should be powered up slowly on a variac or they probably will blow out. Unless you have experience resurrecting old tube gear, it would be best to have a good tech check it over and try to power it up.

Check out fliptops.net for parts.

Oh, and we want pics! And sound clips when it's working!

Thank you.

[JimmyM]

Just find a good reliable tech in your area and you will be fine. B-15's are super easy to work on for techs, and all the parts are available through Fliptops or some other source.

[Dan Bozek]

OK, guys. This story took a big pause here in 2012 because the guy didn’t want to part wit or fix the amp… Well, it turns out that he’s now willing to part with it, so I’ll be picking it up later tonight!! YAY!! Pictures to follow. :^)

It looks like I’m going to definitely have to get the transformer/cap kit from Fliptops and re-tube the whole thing. Should be a fun project, really. Like fixing up a historic race car or something. Ha ha ha.

Immediate question: A good case company? I don’t really have the cash to do ANY of this right now, but I figure I should include a good case in the plans.

[Dan Bozek]

Well, here are the true "before" pictures!! I just brought it into the studio. The gunk at the base of the right transform looks suspect because everything else looks dusty, but perfect. No corrosion on the tubes or sockets, etc... Original speaker moves. Mo dry rot. I've not seen the "Ampeg" labeled Sylvania 6L6s before. Pretty cool!! I've also got three Tung-Sol 6SL7s in there which are supposed to be valuable as I understand it.

Super stoked. I don't have a lot of money to get this guy showroom perfect all at once, but it'll be my pet project for the winter maybe.

[redhed]

SWEET! Looks just like my '64! Fliptops.net is a great place for parts and tubes.....

[Dan Bozek]

Originally Posted by redhed

SWEET! Looks just like my '64! Fliptops.net is a great place for parts and tubes.....

Yup!! That’s where I’ve been looking/reading. There is a legendary amp doctor around here that I’m going to have take a look at it for me, and then I think I’m going to get the parts from FT.net and do the work myself because it will be more fun. If not, I know he can handle it.

[bassfran]

Congrats on your great score, Dan. The restoration will be well worth it.

[Dan Bozek]

Oh, here is a great question that I didn’t think of with these guys until now… When I get this puppy working, what’s the best way to run a length of cable to keep the head in the CR and the speaker in the amp room? It has those funky (to me) four pin speaker jacks… I’m not even sure what those are called to Google…

Or is it just better to leave the whole thing in the amp room and use a Radial SGI from my pedal board, etc… I like the idea of having the head next to me at a session though.

EDIT: I guess the "extension speaker" jack is 1/4". Get a run of speaker wire with 1/4" and the Austin Powers connector on the other?

[Dan Bozek]

I spent about 4 hours today completely working over the cabinet with Simple Green and a toothbrush, and then a little New Vinyl. Turns out, when you get 50 years of gunk out of that cool checkered tolex, it's blue, and looks fantastic!! So much so that I'm thinking about getting a replacement grill cloth (got some sort of stain on the original.) Original square magnet speaker is rockin too.

I'm gonna start cleaning up the head next, and have the amp doctor take a look at it. It seems like when I pulled it open that everything is in fantastic, clean shape except for the transformer that I originally thought was the trouble.

[JimmyM]

Couple things for you, Dan...

---Best not to use the ext speaker jack by itself because of the way the output transformer works. Your best bet is to get a long extension speaker cable with the 4 pin jacks. Or just set the whole thing up since there's no fan to make noise. Nice to be able to control EQ in the control room but it's not necessary.

---If you replace the grillcloth, get some black felt to lay on top of the wood of the grill. The grillcloth will rattle against the outer grill if you don't. Back in the day, Ampeg used foam rubber but it disintegrates over the years (that's why you see so many dirty grillcloths on old B-15's), while the felt holds up.

[Dan Bozek]

Originally Posted by JimmyM

Couple things for you, Dan...

---Best not to use the ext speaker jack by itself because of the way the output transformer works. Your best bet is to get a long extension speaker cable with the 4 pin jacks. Or just set the whole thing up since there's no fan to make noise. Nice to be able to control EQ in the control room but it's not necessary.

OK. What are the name of those connectors?

Originally Posted by JimmyM

---If you replace the grillcloth, get some black felt to lay on top of the wood of the grill. The grillcloth will rattle against the outer grill if you don't. Back in the day, Ampeg used foam rubber but it disintegrates over the years (that's why you see so many dirty grillcloths on old B-15's), while the felt holds up.

Hmm… Interesting. Even if I keep this grill cloth I’ll have to take a look and see what’s happening under there. Since I’m basically pulling everything apart to clean and fix up anyway, if the foam rubber is all but gone I might felt it up now.

Thanks, man.

[JimmyM]

4 pin XLR connectors. www.fliptops.net sells them or you can make them yourself. Just remember to wire pins 2 and 3 together. This was Jess Oliver's idea to prevent people turning the amp on out of standby when a cab wasn't plugged in. Never caught on, but pretty forward thinking for its day.

[Dan Bozek]

Originally Posted by JimmyM

4 pin XLR connectors. www.fliptops.net sells them or you can make them yourself. Just remember to wire pins 2 and 3 together. This was Jess Oliver's idea to prevent people turning the amp on out of standby when a cab wasn't plugged in. Never caught on, but pretty forward thinking for its day.

Huh. Cool. I did not know that, and I'm glad I do now. It is a pretty good idea. Thanks.

[jmjbassplayer]

That's the way I rock. It's nice.

[JimmyM]

BTW, Dan, yours is older than 69. This is what a 69 B-15N looks like:



Since yours is blue check, it was made between 65 and 67. Check out www.unofficialampeg.com/dating.html to figure out how to date it by serial.

[Dan Bozek]

Originally Posted by JimmyM

BTW, Dan, yours is older than 69. This is what a 69 B-15N looks like:

Since yours is blue check, it was made between 65 and 67. Check out www.unofficialampeg.com/dating.html to figure out how to date it by serial.

I'll have to double check later, but I'm pretty sure the cabinet SN was 12,000-something, which makes it a '65.

Wild to think how old that is—especially considering that I'll only be turning 32 next week!! Ha ha ha.

[JimmyM]

I didn't get my first B-15 till I was 40. You're doing way better than me

Another thing I might suggest to you if you want to unbolt the head for studio use is to get a second chassis tray for it. That way, all you have to do is unscrew the two bolts that hold the head onto the chassis tray instead of screwing with unbolting the head from the shockmounts. You could also build yourself a second lid with plywood or OSB and a few lag bolts, and then you wouldn't have to unbolt anything. Doesn't have to look sharp since it won't be onstage, but it makes life easier by doing one or the other. Actually, the second lid would probably be better than the second chassis tray since then you won't have to worry about anything rattling once you remove the head.

Justin, do you have to do any special rigging to your B-15N's to make them work for separating in the studio?

[Dan Bozek]

Originally Posted by JimmyM

Another thing I might suggest to you if you want to unbolt the head for studio use is to get a second chassis tray for it. That way, all you have to do is unscrew the two bolts that hold the head onto the chassis tray instead of screwing with unbolting the head from the shockmounts. You could also build yourself a second lid with plywood or OSB and a few lag bolts, and then you wouldn't have to unbolt anything. Doesn't have to look sharp since it won't be onstage, but it makes life easier by doing one or the other. Actually, the second lid would probably be better than the second chassis tray since then you won't have to worry about anything rattling once you remove the head.

Yeah, that’s not a bad idea at all. A lot of my gear is always set up at my home base studio (because I’m the only staff engineer and end up playing or having others use it on most projects) so I can see the head taking up residence in another tray somewhere in the control room. But, like you said, there isn’t a fan, so I don’t know. If the knobs are basically going to stay in the same sweet spots for the most part I might no bother. I guess we’ll see.