Gibson amp question

[Bill Ashton]

A quick side trip to a music store out of my area yesterday revealed a strange Gibson amp that I wonder about...

I would guess it early 70's, though it was marked "60's Tube Amp!" It was a tall tube or hybrid amp, two dissimilar 12" speakers over/under, with what looked like a wood grain contact paper panel on the top. If I remember back through the haze of times past, when using tremolo, a large rectangular pilot light would pulse with the throb and this had that red lamp; there was also a yellow reverb light (don't know what that could possibly do).

Seemed to be a twin chassis amp, with the power amp on the bottom...doesn't make any sense but only seemed to have two "6V6" sized tubes plus one miniature between the transformers, though it was reduced lighting so maybe I missed something.

If there was a model name other than Gibson on the control panel I missed it (or perhaps can't remember it)...it this enough of a description for anyone to identify this beast? I looked on eBay, and while there is one that looks like perhaps it was the same vintage, it is not the same amp (Gibson "Falcon") but much smaller physcially.

 

[capnjuan]

Hi Bill; did it have black tolex? Was the cabinet shaped like this Gibson bass amp? The last round of Pre-Norlin, lower-cost Skylarks (6BQ5s) and Falcons (probably 7591s) were in tall, shallow black cabinets reminiscent of Guild Mavericks and several Univox models with stick-em-on paper. If it was a Falcon, the tubes are probably 7591s and the 'extra' one on the lower chassis an OA2 that Gibson used on several models as a screen voltage regulator. Also, the second speaker might have been a passive radiator like the bass amp linked above. Due to poor sales and lack of collector interest, there isn't much information about these on the web and the version didn't rate an Honorable Mention in Wally Marx' book.

 

[Bill Ashton]

No Cap', it was more like this: http://cgi.ebay.com/Gibson-Falcon-Amp-P ... 1c10c0ee38 The difference being the controls were on the top panel, and it was about twice as tall. Kills me I cannot remember the name, but it did have that wierd Gibson "particle into a wall" logo...

 

[capnjuan]

Ok; I'm busted too on the Falcon's tube set ... the linked amp has 6BQ5s not 7591s. Like I said, there isn't much love out there for these later '60s / early '70s models ... hurriedly skipped over by W. Marx to get to the Norlin era transistor 'G' models ... G-20, G-30 where (pretty sure) the number are watts output. Lots of pressure then on the amp market from the Asian Invasion.

 

[capnjuan]

Hi Bill; maybe one of these?

 

[Bill Ashton]

That is the cabinet configuration but not the amp; the control panel was facing upwards on the top of the cabinet, between the uprights...yeah, I told you it was wierd!

Correct me if my postulating is wrong, but I am thinking that the output tubes, physically small as they were, were 7xxxx types such as in various Ampegs, which might give it enough uumph to drive two twelves? The twelves were dissimilar in so far as they had to different size ceramic magnets, though I am guessing they were both Oxfords...

 

[Bill Ashton]

Found it! Or at least one almost like it...

Must be a Gibson Duo-Medalist, although it was a 2-12' instead of this 4-10" configuration...actually the schematic shows 1-12" speaker.

It was in better shape than this one. On the site I got this from, the schematic could be expanded, so it indeed shows a split chassis, with three tubes on the bottom...two 7591's and a 12AX7...so, I wasn't going crazy! The top preamp has the usual Gibson array of 6EU7's and such. What kind of output would a pair of these tubes produce on a good day?

Woof, doggies!

 

[capnjuan]

Whoa! ... the controls looks like the Phaser Bank controls on the Starship Enterprise ... The schematic shows 400V on the plates and the 7591 Tube Data Sheet indicates 25 watts @ 400V. Functionally the same as the Guild Maverick Lead ... reverb, trem, solid state rectifier, and same 7591s. Interesting ... in the 'off' position, the footswitch grounds the output of the reverb can ... in the 'on' position, it doesn't just unground the reverb signal, it turns a tube 1/2 on to turn the reverb light on. I guess this 'Duo-Medalist' was their medium-power model offering ... several 7591 fans here and the 7591 is back in production.

 

[Bill Ashton]

Yeah I saw that about the reverb light, as I followed the circuit to see exactly what was up...I guess we file that under "waste not, want not" for the unused tube section.

I was hoping the lamp would be doing something wierd like the blue panel on the old Pioneer stereo reverb...

What is the tonality of a 7591, a dark growler or clean like a 6l6?

 

[capnjuan]

What is the tonality of a 7591, a dark growler or clean like a 6l6?

Hi Bill; you may have to wait for default or matsickma for the best answer but tilted more towards 6L6s ... cleaner, brighter, maybe even a little warmer than 6V6s. Thinking about buying it? If so and if you're as tooly as Zulu, you might could do the caps yourself and treat yourself to a fresh speaker with the money you save.

 

[tele4tone]

Less break up with a 7591. I like the 7591...but I am a guitarist and I use pedals.

 

[Bill Ashton]

Well, I also could not remember the price it was tagged...actually found the store's website but no info on their used equipment...then as luck would have it, they had an ad in the little newspaper I got yesterday when I was at Union Music with Chazmo..."Gibson all-tube amp from the '60's, $650," or something to that effect...

Uh, no thanks

 

[capnjuan]

It's a lot easier if you know somebody who has one or somebody standing up out there swearing that has the best tone ever. At $650 plus miscellaneous fix-'em-up expenses ... it's a lot of money on a gamble ... not to mention that you're paying retail when that same amp might change hands on CL / eBay for $400. The better buys in 7591 amps are Guilds, Ampegs, or Gibson's earlier crest-version GA19RVT/Falcon that sells all day long between $375-$475.

 

[Bill Ashton]

Yeah, as coyote-ugly as this beast was, i think my eyes glazed over at the thought of the blinking tremolo-light, ala Selmer... :lol: :lol: :lol:

And you are right about the Crest series, someday, someday...

The first good amp I ever used was in the 8th grade when my little band rented two Epiphone amps...I think they were "Zephyrs"...and I still pine for one. Probably not very good, but a long way from a tweed Champ in 1966!

 

[capnjuan]

Well ... I was trying to avoid mentioning cosmetics ... beauty bein' in the eye of the beholder and all ... the fact is in good running condition like your Zephyrs, practically anything from back in day will produce lots of tone and pleasure ... having enough power to play Shea Stadium is another thing. It would be a lot of fun to sit around (drinking beer) and listening to people play a variety of amps blind ... so the listeners didn't know what they were listening too ... I bet there'd be a lot of high fives for amps that today don't carry much weight ... acoustic guitars would be fun too.

By way of interest, this a long and (sadly) slow-loading Ethan Winer vid discussing why we hear and remember what we do. It's leveraged off modern audio exotica in sound reproduction but the fundamentals are there; that is in large part, we tend to either hear what we want to hear (and disregard the rest) or hear what we are expecting to hear; fresh tubes? Gotta be a tone uptick right? Well ... the first 20 mins of the vid ... despite the nuisance is time well-spent. Also, just to prove that Winer has a sense of humor, here he is playing 37 overdubbed cello parts ...

For that $650, you could buy just about any Epiphone that shows up on eBay ... J