Expert help needed speaker ident

[DanJ]

Hello all,

I need some help from the experts. I have a set of old Oaktron speakers. They are 12 inch with built in tweeters. Does anyone here know anything about them? I got them in a lot of PA gear and they sound pretty good. Any info would be apprectiated. Thanks.

DanJ

[Enzo]

You got anything like model number or other info printed on rear of speaker cab? Got numbers off the drivers inside? Got pictures?

[DanJ]

Whoops, sorry. They are model CA-12. They have The EIA code of 918839 and another number C73512268 stamped on it also.

I have pics, but there too big to post here. I can e-mail them though.

Thanks

DanJ

[Rob Mercure]

Oaktron did make their own speakers at one time but their manufacturers code is "934" none of the numbers you supplied crosses to any idex I've got but perhaps others may have better info. Could there be other numbers stamped on the speakers - sometimes I've seen them stamped on the actual paper cone.

Rob

[DanJ]

Rob,

I got the manufacture code from the Weber VST site. It lists oaktron as 918.


I've posted some photos, hopefully someone has some info about them.

http://img214.imageshack.us/img214/3717/speaker1be8.jpg



http://img91.imageshack.us/img91/8545/speaker2qa7.jpg

http://img119.imageshack.us/img119/9074/speaker3ic0.jpg



Thanks again,

DanJ

[Rob Mercure]

Dan,

Good sleuthing - I got my numbers from Ned Carlson's old site at Triode and another list that I found somewhere. But manufacturers often had several numbers so I'll add another for Oaktron.

Rob

[Todd Hepler]

DanJ -

I have a set of these in an old Airline/Montgomery Ward amp that I got recently. They are not the original speakers, but sound great!

I did modify the speakers in that I removed the entire tweeter structure. The woofer by itsself is 8Ω, so no impedance issue there.

Looks like yours are late 60's, maybe? Mine are early 70's at best, and have slightly different bell cover with a large sticker.

I had -0- luck in searching online for info on Oaktron and I can not offer any advice as to power handling, although the M-W amp mine are in is ~30 Watts or so, and they seem to have been in there for some time.

-Todd

[DanJ]

Todd,

Thanks for your input. I understand the on line search. I couldn't find much either. But I agree, I just briefly tested the pair I have and they sounded really good, haven't put them fully to the test yet, but I like what I've heard so far.

Thanks again,

DanJ

[Mars Amp Repair]

Informational post;
I had a Monkey Wards GVC-9058A head in for service. With new 6l6gc's it would squeal like a pig (not a sign wave..more like a pulse). Older Fender type 6l6gc's worked just fine. Perhaps some of you have seen this issue before. This is only the 2nd one of these I have had experience with.

Not having the nos to spare for this amp I had to figure out why it was doing this, besides it bugged me that it wouldn't work with any 6l6.

If I moved the B+ wires around (yes, just the B+ wires) for the 6l6's, the squeal would change. Bridging the electrolytics had absolutely no effect.

Removing all tubes but the driver & outputs still produced the squeal, so it was between the driver & the outputs.

Adding snubber caps to the plate load resistors in the inverter stage had a negative effect.

Removing the negative feedback had no effect.

I finally added output screen limiting resistors of 470 ohms to the 6l6's & voila...no more squeal. Stock this amp apparently does not have the limiting resistors. Apparently some interaction with the output screens & the rest of the circuit....

I thought this might be helpful for others. glen - Mars Amp Repair