Gibson EH 150 restoration

[mattnorthrop]

Hello!

I recently acquired a 1938 EH 150 and am currently restoring it. I was wondering if anyone happens to know of a schematic for this model, since the schematics that are easily available are either the early or the late versions of the amp (not this version with 3 6C5s).

There was another thread from several years ago that looked very promising, but the links are dead.

Thanks for any help!

-Matt

[Trout]

Originally posted by mattnorthrop
Hello!

I recently acquired a 1938 EH 150 and am currently restoring it. I was wondering if anyone happens to know of a schematic for this model, since the schematics that are easily available are either the early or the late versions of the amp (not this version with 3 6C5s).

There was another thread from several years ago that looked very promising, but the links are dead.

Thanks for any help!

-Matt

One thing about those old Gibsons, they varied as much as Chicago's weather amp to amp.

Are you certain it is not actually a EH100? They used 6C5's in those.
The 50's version
EH100 Schematic W/6C5's

The 60's Version
The 60's version

OR,

Could it be the EH160 in a EH150 cab like a transition year?
EH160 w/6C5's

I'll dig in my archives to see if I have others.

[mattnorthrop]

Many thanks for your reply.

The chassis is marked EH-150. The guy I bought it from said it was a 1938 model, which seems to fit with the Gibson Amp Project website's (hem.passagen.se/ekabjan/GibsonAmps.htm) listing of a EH-150 model with a three 6C5s and one 6F5 preamp section. Also, it does have the 5U4/6l6 power section that fits with the EH 150/185 circuit.

I think you are right, though, that its some sort of a transition circuit.


Again, thanks for your time!

-Matt

[mattnorthrop]

So, I think I just luckily stumbled upon it at this website:

http://prewaramps.com/gibsoneh-15.htm

Pretty fascinating pictures of one of these.

[Trout]

Originally posted by mattnorthrop
So, I think I just luckily stumbled upon it at this website:

http://prewaramps.com/gibsoneh-15.htm

Pretty fascinating pictures of one of these.

That baby looks sweet, Nice Find.

I just added that schematic to my collection,

Good luck getting it restored, I bet it will be a great amp when its done.

[dsavitsk]

Here's another version of this I downloaded from here at some point. I love the parafeed phase splitter. One of these days I'm going to build something like this.

[mattnorthrop]

Awesome. Thanks for the schematic.

[mattnorthrop]

Thanks for your help with tracking down the schematics. I Got around to going over the amp, and it sounds great.

However, I have a question for those of you familiar with these:

How loud are these amps, typically? This one does not seem to be as loud (or maybe breaks up earlier?) than something of comparable output, like a fender tweed deluxe (or is this comparable?). The instrument channel proper is not loud at all (not much louder than just strumming a solid body). I replaced all the filter caps, coupling caps and any drifting resistors, and the B+ lines, as far as I know, seems ok (400v+). The amp sounds good (distortion on the mic channel turned up is pretty amazing), but is just not very loud.

Could any of you all with more experience enlighten me? Is this amp functioning as it should, or is there a potential volume problem?

Thanks again for all your help!

[Trout]

It might be a symptom of the low efficiency field coil speaker?

I would think you should be nearly as loud if not close to bettering a Tweed Deluxe.

Part of the charm of those oldies is in studio use. Not overly loud, but outstanding distortion and fairly fat cleans.

[mattnorthrop]

I can't help but wonder what it would sound like connected to an magnetized speaker (I'm not going to do that, though!).

Thanks for your help!