|
|
Post by hugo on May 26, 2005 12:23:16 GMT
I have a National Glenwood amplifier 2x12 which was made in the mid-sixties I believe that I am trying to put back in shape. Trying to know what the specs of this amp / speakers are. (particularly what impedance in ohms need to be respected for the speakers) The speakers says Jensen Special Designs, 220403, 5507C12PSC73972. Looking on a Jensen website, similar speakers are rated 8/16 ohms. So are they 8 or 16 ? The two speakers are connected in parallel so if they’re 8ohms, that means the amplifier would be 4 ohms ? Any source of additional info on that amp would be appreciated. The amp looks very similar to this picture found here on this website (main difference it does not say “Vibrato” on the back plate).   |
|
|
|
Post by Michael Messer on May 28, 2005 8:17:32 GMT
Hi Hugo,
I have not responded to your question because I don't know the answer. These amps are in Canada with Colin, so you really need to talk with him. I guess he is away or busy, otherwise he would have answered your question.
Shine On,
Michael.
|
|
|
|
Post by Colin McCubbin on May 28, 2005 19:09:53 GMT
Hi Hugo,
The sales brochure I have is, sadly non technical. As for power output it just says "8 modern tubes deliver 35 watts of clean surging power" .... Written by a salesman, not a technical guy!.
I don't know the speaker impedance either. Are yours working? if so you can detatch them from the output transformer and measure the coil dc resistance with an ohmeter, this usually gives a value close to their AC impedance. If you haven't the speakers then I can dig my amp out of storage and see what mine are.
Aloha,
Colin
|
|
|
|
Post by Colin McCubbin on May 28, 2005 20:08:46 GMT
I've also fired off emails to a couple of guys who collect amp schematics, waiting for replies. And spent the last hour searching the web for info, to no avail. I'll keep at it!
|
|
|
|
Post by Michael Messer on May 30, 2005 11:56:53 GMT
Thanks very much to Lee (member of this forum), I have just received a schematic diagram from VALCO MFG CO Chicago 1951. I will post it on the forum when I get a spare moment to deal with it!
Shine On,
Michael.
|
|
|
|
Post by Colin McCubbin on May 31, 2005 23:31:25 GMT
Hi Michael, Lee sent me this many years ago, it is one of several I'm going to post at Notecannons one day. I think this is probably the one you have, but if it isn't then even better, we've found another! No one has a Glenwood circuit diag as far as I can see, obviously it would be a bit more complex than the one above. Aloha Colin |
|
|
|
Post by Michael Messer on Jun 1, 2005 8:18:50 GMT
Hi Colin,
Yes that is the same as the one I have. Thanks for putting on the forum. As for the Glenwood amps, I have no idea where we would find their schematic diagrams. We just have to keep hunting!
Shine On,
Michael.
|
|
|
|
Post by ruffrecords on Jun 2, 2006 22:10:37 GMT
Hi Colin, Yes that is the same as the one I have. Thanks for putting on the forum. As for the Glenwood amps, I have no idea where we would find their schematic diagrams. We just have to keep hunting! Did you ever find this schematic? My neighbour has one of these that we would like to get going (I am an electronics engineer brought up on tubes) but there is little I can do without a schematic. Ian |
|
|
|
Post by Colin McCubbin on Jun 5, 2006 13:34:24 GMT
Hi, I sold my Glenwood to a tube enthusiast, Pat Monford. His email is vintage1@telus.net . We never found a schematic, but if you contact him he may well be able to help you. I know he has the amp running. Pat's site is devoted to tube gear and schematics and is at: www3.telus.net/public/vintage1/index.htmGood luck! |
|
|
|
Post by frednjulie on Nov 21, 2010 22:45:52 GMT
I am currently looking for the same schematic, If anyone has turned one up please let me konw.
Thanks,
Fred
|
|
