Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: crashtm1 on July 03, 2015, 09:20:50 am

Title: Need help identify Twin
Post by: crashtm1 on July 03, 2015, 09:20:50 am
I'm going to look at this tomorrow..

 I believe it's a BF chassis in possibly a retolexed can.
 OT is E606-2-40 (1962, week 40)?? That doesn't seem correct. 62 would be Twin-Amp and 72 silver face?? Yes?
I'll be checking other trannie, pot, chassis and speaker numbers..
Any help is great appreciated.
Title: Re: Need help identify Twin
Post by: crashtm1 on July 03, 2015, 09:21:25 am
Pic2
Title: Re: Need help identify Twin
Post by: crashtm1 on July 03, 2015, 09:27:00 am
Pic 3
Title: Re: Need help identify Twin
Post by: Willabe on July 03, 2015, 09:30:48 am
You'll know when you open it up. BF amps had the cloth covered push back wire and the blue molded coupling caps.
 
It does have BF face/back plates.

But the back plate says 100w RMS and it has an A-off-B ground switch, that's not BF circuitry.
 
Title: Re: Need help identify Twin
Post by: eleventeen on July 03, 2015, 11:09:50 am
Agree w/Willabe, thinking more like the "2" is 72.


Look for:


covered up master volume pot hole.
the "folded lip" along the top of the sheet metal on the rear panel (=late late 70's)
possibly altered hole where the AC access. plug
Some blackface have brown coupling caps, the question is, is this actaully silverface

If you go to Google images and look up "68 twin reverb chassis" and then repeat the exercise with different years, you'll get a better idea of the general differences.

Usually, the pot codes are just about the best tell. Bias pot = easiest to see.
Title: Re: Need help identify Twin
Post by: DummyLoad on July 04, 2015, 12:03:04 am
the "grounded" accessory outlet on the rear also indicates that it's likely an early 70's silver face model someone replaced the face plate with a blackface model and had the cabinet re-covered.


-pete
Title: Re: Need help identify Twin
Post by: crashtm1 on July 04, 2015, 11:30:14 am
Ok... Got it...
Everybody's help was a huge plus!!
Thanks to to all, I learned a lot..
'72 to the bone!!

I took a few pics and will
Try to post.
 Did the brass grounding plate continue on to the MV pot? This one doesn't.
 
It is an old retolex, but not a scratch on it and every well done. Almost too well done?
She needs a cap job badly..
$450
Title: Re: Need help identify Twin
Post by: DummyLoad on July 04, 2015, 11:39:07 am
buy it: give it a complete electrolytic cap job, install AB763 plan, replace jensens with jbl d/k/e 120, play it for many more years to come.


--pete
Title: Re: Need help identify Twin
Post by: crashtm1 on July 04, 2015, 02:54:41 pm
Pic4
Title: Re: Need help identify Twin
Post by: DummyLoad on July 04, 2015, 04:15:41 pm
def. early 70's. has been worked over already. 


--pete