Can't find any info on this amp. Anyone know?

[hpattern]

I recently purchased this Epiphone amp from a 70 year old gentleman who purchased it new. The model is EA15-Zephyr. It has tremolo with a remote switch. The serial number stamped into the faceplate is 56246. It appears to be a 1959 model based on some of the numbers from the components such as the speaker and tubes. What intrigued me about this amp is the condition. It is cosmetically perfect. I thought it was a reissue. What tipped me off was the old musty smell. Everything appears to be original including the tubes which are all dated coded 59-**. It has the original price tag hanging inside ($223.75 W/C) the W/C being with cover. The tolex is unlike any I have seen in the past. It has a diamond pattern and is a champagne or platinum color. the amp works but there is a rather loud hum that increases in volume as the volume on either channels is increased with no instrument plugged in. It has a pristine schematic stapled to the inside and does not appear to have any replaced internal components. One of the Astron paper-in-oil caps has some corrosion on one end maybe from some leaking. I have search extensively on the internet and cannot find any info on it. The closest model number I can find is the EA-15RVT. The RVT appears to be a later model and looks similar but has a greyish tolex and has reverb. I wonder if this amp was a prototype or one produced in very low numbers. I understand that after Gibson bought Epiphone and switched production to Kalamazoo that they did produce some models in very low numbers. BTW, it does say Kalamazoo on the faceplate. I can send pictures to anyone who may be interested in taking a look. I do want to fix the hum but I want to make sure that I do not wreck the amp. Hopefully it is something simple like a tube or cap. Thanks! for looking!
Nick

[martin manning]

There is an EA15 (RVT) Epiphone listed here: http://www.gibson.com/service/tech/schematics/ It has trem and reverb... that is the one you found, I guess. Other than the addition of the reverb, it it the same?

The hum is more than likely from deteriorated power supply caps. Some gut shots (post them here) would be very interesting, and if you can get a good clear image of the schematic so much the better.

[Structo]

Yes please post pictures of your amp.

That is always a dream, finding an amp that is otherwise brand new condition.

So yours has tremolo but no reverb?

$224 in 1959 dollars is $1,698.83 in today's dollars!

It will most likely need all new electrolytic capacitors along with a three prong cord installed.

The tubes may indeed still be fine.

A clearer schematic
http://www.el34world.com/charts/Schemat ... zephyr.pdf

[Firestorm]

What's the tube complement? With Gibson amps, you sometimes have to wander through the schematics until you find the closest one. For example, the more common Ephiphone EA-15RV (maybe a bit like yours, but with reverb, no trem and grey tolex) is identical to the BA-15RV Gibson made for Bell. Of course, Gibson changed their minds more often than Fender, so you may have to sketch out the circuit yourself.

As Martin says, power supply filters are a first priority. Also check for deteriorated grounds and possibly leaky coupling caps. Tubes, of course, too.

[hpattern]

Here the gut picture

[hpattern]

Here's the face place

[hpattern]

Here's the schematic

[hpattern]

Another angle

[hpattern]

One more

[hpattern]

Tube compliment is:
(2) 6V6GT
(1) 5Y3GT
(1) 6SQ7
(1) 12AX7
(2) 5879

[martin manning]

Very nice! If you are not comfortable working on tube amps you'll have to find someone who is. The large tubular electrolytics should be replaced. I see 20uF for the reservior, and 3x 10uF filters on the schematic, which will be distributed between the two cans, maybe 20-10, and 10-10? I can't tell from the picture. Antique Electronic Supply is one source for similar caps, but there are others. You may have to look around to find something that is a close match if you want to keep it looking original inside. Can you get a close-up of just the inside of the chassis? Maybe two shots, left-side and right-side.

[hpattern]

Thanks for the info. I was hoping to keep it as original looking as possible. Would I need to look for NOS Oil in Paper or does anyone still make them. The specs on the upper one that I think is leaking is: Astron EZ-10160 10+10 MF 450 WVDC it has 2 red wires and 1 black coming out one end. They are very easy to get to so I would mind changing them out myself. I have done a little work, mostly on Fenders.

[hpattern]

This is the other end of the chassis

[martin manning]

Look here: http://www.tubesandmore.com/scripts/fox ... 2=02_MULTI

The one you are describing is two 10uF caps in one can with a common ground. I would recommend replacing all of the power supply's electrolytic caps. Leaking or not they are surely dried out and not up to spec. You are lucky to have the schematic right there; you really don't need anything else.

[martin manning]

Is that white cap on the far right of the circuit board a 10uF electrolytic?