The Steel Guitar Forum

Gentlemen, and Ladies,

I have a Model number "M31-4" JBL 15" speaker that was taken out of and old SG Gibson amp that was made in the 70's. Believe it or not it is a 4 ohm speaker.

Has anyone ever heard of this model speaker, and have an opinion on it? Also would anyone know of a good repair shop to recone it if it would be needed?

I thought I might use it with a Twin (external jack)along with the 2 JBL 12's to add just a little more bottom end.

Thanks for your time,

Jim Gaines

I had an M 30 in an old Sho-Bud Amp. I think that one and the M 31 are very similar if not the same as the D130. Mine sounded great, but wouldn't handle a lot of power. It was 8 ohm and had a grey frame and alum dust cap. 4, 8 16 ohm coils all were common in JBL's.

Yours should sound nice. Woody Woodell, Nashville has a great reputation for doing fine repair work on the old JBL's.

I have two Sho-Bud "Christmas Tree" steel amps.....one has a 15" JBL D-130F 8 ohm speaker and the other one (mid to late 60's vintage?) has a 15" JBL M31 8 ohm speaker. Both amps work great & sound very similar....the M31 speaker seems to be just a tad "warmer" sounding to my ear. I know that JBL speakers were used in the old "Kustom" amps (60"s & 70"s), perhaps the M31, but I'm not sure. I think that the Baldwin Co. owned Kustom for a time back then, and maybe also owned Sho-Bud during that period as well....hence a possible connection.

Is the Twin wired to accept a 4-ohm extension speaker? I'm no expert on Twin Reverbs but you want to be very careful about impedance matching with a tube amp, it's even more critical than with a SS amp.

Perhaps one of our Fender gurus will chime in here with more detailed information...

Thanks to all who responded and hope others will as well.

Thanks again,

Jim Gaines

Hello John, or Jerry can you help me to get a year date on my Christmas Tree amp S/N 1068???
I'm gussing because the S/N# is stamped on the back side of the chassie It might mean Oct.of 68.
What do you think?
It also has the M-31 8ohm 15" JBL.
Also how would a 15" BW do as a replacement?
Thanks
Larry

The numbers stamped on my two Sho-Bud amps are "0649" and "1172". I'm not aware that these numbers are significant in regards to a particular month/year of manufacture. I was given to believe that the amp stamped with the number "1172" was of "mid-60's" vintage, but I have no way of knowing for sure. If anyone knows of a contact or resource through which the year of manufacture could be ascertained through these numbers, I would certainly be interested.
I have not considered changing the stock speakers in these amps, as I am pretty happy with the sound.
Cheers, John J.

Thanks John
I am not going to change the JBL out unless something go bad. After the work Ken Fox did on mine it is like a different amp, lots of more power. I have been playing a Derby thru it, but the Emmons LeGrande II sounds good in it too.
Larry

Sorry Larry, I know nothing about dating these amps.

As to the speaker swap, If necessary, I would think a Black Widow would work just fine. Should be no problem. Just try to replace with one of the same impedance. [4, 8 ohm, etc.]

I'd hang on to that Lansing though if I were you.

My '74 session 400 has an M31 4 ohm in it and I'm reasonably sure it's the original speaker. If you search the old forums' electronics section for jbl m31 you'll find some interesting info.

I believe that the Kustom Sidewinder 100 amp had a 15ins JBL as I owned one back in 1972. Sold it when I moved to Spain but it was a great Amp. I know it was grey in colour and most Kustoms at that time were 4 ohm output. Hope this helps some
Jim from Spain

I was told the M-31 is the code JBL used back in the day for the Peavey speaker aplication. I too have one , and it cane from an old peavey amp.