MOTM

In a message dated 10/22/99 9:23:34 PM, synth1@... writes:

>The head amp is a "chop job". It *is* a blackface (chassis #A09196) Super
>Reverb Amp.
>But somebody put the "guts" in a custom Fender-ish case. Has Tung-Sol 6L6
>output
>tubes, which means about 1967 (!?!). I'll post to rec.whatever and try
>to
>pin it down. 

I kind of wondered about this since a few years ago a guy at work was tell me 
about a Twin Reverb he had -- I think he mentioned jamming or auditioning for 
some metal band or something and using his Yamaha solid state amp (yuck!). 
When I asked him about his Twin he said he needed more power (?) and didn't 
like the sound (??) and how when you turned up the Intensity to get more 
volume (???) it never got that loud, to which I replied "NO!" and he said 
"but you know how you..." "NO!" We went on for a while and I persuaded him to 
let me see it. It was a total mess, tolex ripped off one of the corners. That 
corner joint had completely failed. Some absurd master volume mod using the 
intensity knob (see lumbo reference below). A whole bunch of other stuff. All 
I could think of was cutting the cabinet down to make a separate head so I 
could use my 25 year old 4 X 12 SMF (same as Sound City) cabinet -- three 
guesses what SMF stands for. He didn't want to let the Twin go, and when he 
got it back he couldn't believe it was the same amp, he had no idea how much 
power it was supposed to have.

As far as the black face goes, in the section of the book about Fender it 
says: "many of the black faced amps, even the few produced by the early CBS 
company are identical in specifications and performance. Only the very early 
silver faced amps suffered from engineering changes that made them less 
desirable for players as compared to the previous generation of amps."
 
>The cabinet has 2 Sunn "Guitar Transducers" speakers, 15" each. There are
>2
>small tube ports
>and a wooden "shelf baffle" inside. The back has a 1/4" plug and the 2
>speakers are just in parallel.
>The damn thing had 36 screws in the rear cover plate.


Whose idea is it for 15' guitar speakers? I seem to remember almost as many 
screws on my old Orange cabinets, and I was reconing speakers all the time.

In a message dated 10/22/99 8:46:29 PM, jlarryh@... writes:

>Hey, anything in that book about the Dual Showman?  While Paul was awaiting
>his shipment, I actually purchased a Dual Showman (head only).  Although
>this one is in fine working order, a schematic would be nice to have. 
>However, back when I went to 'lectronics school, we learned to fix tube
>amps without schematics.  The Dual Showman uses the same 6L6 push-pull
>arrangement as the super reverb and bandmaster, except it has two pair
>in
>parallel.  Officially, Fender rated it for 85 watts I think.

85 watts is what I remember too. If you are looking for a good single book 
for tube amps, then I strongly recommend this one. I got it several years ago 
at (the legendary) Mc Cabes Guitar Shop where it was recommended as the best 
amp book for a variety of different amps. It's about 750 pages, with about 
450 pages (!!!) of different schematics (though almost no text about any 
particular amp), I paid about $30 for mine, and I'm sure you can get them 
from Antique Electronics in AZ. It is made by the guys who make Groove Tubes 
so you get a lot of that stuff too -- sort of free advertising.

If you just want schematics for the Dual Showman, I could photocopy those off 
for you (there are a few different schematics, though I don't see any 
noticeable difference in general), though in the book they are about half 
scale so they might not show up so well on an enlargement.


>> The Supers I'm familiar with were 40 watts (I think) at 2
>> ohms with the 4 10s in parallel.

>Wow!  I didn't remember that the total speaker cabinet impedance was that
>low.  I guess I always assumed that the 4 speaker cabinets were series
>/
>parallel so that the cabinet impedance was the same as one of the speakers.
> Of course, I was only 17 and slightly influenced by recreational drugs
>when we were using these things in high school.  

Yeah, working on your "killer sounding Marshall" under the influence of 
"killer lumbo" can get you...well...killed!
 
However, the wattage you
>remember should be about right. 2 6L6s should yield about 35 to 45 watts.
>I
>think about 22 or 23 watts each was about all the heat the plate could
>handle.

Yeah, that's from memory, but the 2 ohm output impedance is from the 
schematic (2 ohms? What were they thinkin?), as is the parallel speaker 
arrangement. So, if that cabinet is 8 ohms that's a fair difference. I've 
been using my Deluxe (8 ohm output) for about 20 years with a 12" 16 ohm 
Celestion, and I really like the sound of it. But I "recently" received a 
Vibro Champ which wasn't working (same guy). After I got it going, it blew 
away my other Champ both in terms of volume and tone -- I came to the 
conclusion that the Champ I've had for a long time had its 4 ohm speaker 
replaced with some type of 8 ohm speaker (apparently this is a common problem 
with champs), so there must be somthin to this impedance thing.

Thinkin you should send the cabinet to Larry (to complete his Dual Showman), 
and the head to me (as scrap of course), though I don't know what I'd do with 
a 2 ohm head.
JB