1937 Gibson guitar amp

[rick57]

Pardon the ignorance in this area, but what does EH stand for?

And what does that mean in practical benefits =

Cheers

[J Epstein]

My guess (based on their guitar nomenclature) would be E lectric H awaiian.

-j

[cavalino]

Originally posted by Trout


Interesting, I looked at the Gibson service manual thats downloadable

Click Here Adobe Needed
And there are 2 entirely different schematics for that model.
The one posted in the original thread here is Similar but not exact. Possibly a 3rd Version of the EH150?

I have a really nice field coil speaker from a Vintage Stromberg Carlson Unit I had planned on using to build one of Gibsons early amps as a winter project. So I had downloaded the entire manual. 128 or so megs!!!
Gene

Yes... the schematic in this post is a third version of the amp. It is sort of a "hybrid" of the two schematics you found (i.e. using a transformer instead of a 6N7 as a phase inverter tube, 6L6 output tubes instead of 6N6 dual triodes, etc.)

Good luck with your eh-150 project. I'd be interested in hearing about the sound you get from the Stromberg speaker. I don't know if the Stromberg's field coil is the same inductance as the Gibson's coil, but the B supply should be pretty forgiving.
Jim

[cavalino]

Originally posted by J Epstein
My guess (based on their guitar nomenclature) would be E lectric H awaiian.

-j

You're right. the "EH" stands for "Electric Hawaiian". The amp was sold as a set which included a beautiful Hawaiian lap-steel guitar which is also called an EH-150. The "150" part of the name was actually the selling price of the amp and guitar set.

This amp was really made famous by the great Charlie Christian who played an "ES-150" archtop guitar with it. The "ES" stands for "Electric Spanish" and Gibson still uses it with most of its archtops/hollowbodies today.

[amperex]

I repair & tune guitar amps in lower NW MI. I got in an old Supro field coil 12" model with PP 6V6GTs. It had a 6J5 preamp & I believe a 6SC7 driver plus 5Y3GT rectifier.

This amp blew all of us away with the incredable sonics. Cranked full tilt, this amp screams out blues & rock like no other amp I ever heard. The Supro 1624 dual tone with the Rola 12" (not later models with the Jensen P12R) is close in performance.

[Enzo]

Hey Amperex, I'm down here in Lansing sitting in my amp shop.

Gibson is infamous for the schematics not matching the amp. They often and rather liberally changed the innards of their amps through the production runs. I have the paper copy of that MAster Manual, and I often have to leaf through it to find the schematic for somethhng that is other than it seems. SOmetimes the Epiphone drawing fits the Gibson model and vice versa.

I have serviced three different GA15RVT in recent times and each was different. One matched the book, and the other two I had to draw the schematic by hand. Not a rare occurrance with Gibsons.

[Trout]

Originally posted by cavalino


Good luck with your eh-150 project. I'd be interested in hearing about the sound you get from the Stromberg speaker. I don't know if the Stromberg's field coil is the same inductance as the Gibson's coil, but the B supply should be pretty forgiving.
Jim

The 12 inch Stromberg Carlson Field coil speaker I have has a 850 ohm coil, Darn near a perfect match for a clone version of the eh(or at least in 1 or more of its versions).
The Original Stromberg amp that drove the speaker had a pair of 6V6Gts driving it. I also have the original OPT, But Seeing as it was more or less a Amplified Victrola(78rpm only) I suspect the OPT wont exactly cut the mustard so to speak.

The Speaker appears rock solid though, Clean as new.
If I wasnt in the middle of 3 other projects + Honey Dues I would be already building it.
Gene

[JimHoboken]

Joel,

I also would like to thank you if you're still around.

I have spent countless hours searching the web and calling techs all over the country looking for this schematic.

I had originally contacted Gibson and it was not one that they had in their records (although they sent me the other 2) and Schematic Heaven before Miles, Aspen, Rudy, Rich, and many, many others.

Thank all of you for your patience (if you happen to read this) but mostly, I want to THANK YOU for getting me to this milestone with my EH-150's.

Sincerely,

Jim Dilworth

[f.leghorn]

There is a "fourth" version, which is actually the first version of the EH-185; it uses the transformer PI but the three preamp tubes are 6J7s with plate & screen wired together in triode mode!

Gibson must have gotten a deal on 6J7s!

[Sorr]

I tried the schematic link, but it no longer works.
My version has 4 x 6C5 and 1 x 6F5.
Does anyone have this schematic?