Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: p2pAmps on December 14, 2015, 08:10:30 pm

Title: Now.... My Twin-Completed
Post by: p2pAmps on December 14, 2015, 08:10:30 pm
Ok fellas,

I tore down the 76 Twin tonight after talking about it for far to long.  She is going to get the full AB763 treatment complete with, you guessed it, Hoffman G10 eyelet boards. 

(http://p2pamps.com/mytwin/1.jpg)
(http://p2pamps.com/mytwin/2.jpg)
(http://p2pamps.com/mytwin/3.jpg)
(http://p2pamps.com/mytwin/4.jpg)
Title: Re: Now.... My Twin
Post by: DummyLoad on December 14, 2015, 08:29:12 pm
scrap the octal sockets. reuse the 9 pin sockets. pots? meh... 


--pete
Title: Re: Now.... My Twin
Post by: p2pAmps on December 14, 2015, 08:30:21 pm
Not me DL, All new sockets, pots, etc...  Worn out pots don't sound cool :)
Title: Re: Now.... My Twin
Post by: DummyLoad on December 14, 2015, 09:37:29 pm
Not me DL, All new sockets, pots, etc...  Worn out pots don't sound cool :)


cool! from the pile i assumed you were recycling some parts & pieces...


--pete
Title: Re: Now.... My Twin
Post by: mresistor on December 15, 2015, 01:29:05 pm
That's going to be a nice twinkie.  :icon_biggrin:
Title: Re: Now.... My Twin
Post by: bnwitt on December 15, 2015, 02:21:13 pm
I would probably toss the brass plate and use a Hoffman style wire ground bus soldered to the pots.  But that's just me.  Someday I'm going to find some kind of use for all of the Fender brass plates I have in the shop.  Christmas tree ornaments or something.
Title: Re: Now.... My Twin
Post by: p2pAmps on December 15, 2015, 02:31:43 pm
I would probably toss the brass plate and use a Hoffman style wire ground bus soldered to the pots.  But that's just me.  Someday I'm going to find some kind of use for all of the Fender brass plates I have in the shop.  Christmas tree ornaments or something.

Yeah Barry.  You know I use those brass plates all the time and my rebuilds are super quiet...  No issues so far with the ones I have done (well over a hundred).  I'm thinking about adding one in my BGE LOL  (inside joke)
Title: Re: Now.... My Twin
Post by: Ed_Chambley on December 15, 2015, 02:44:39 pm
I would probably toss the brass plate and use a Hoffman style wire ground bus soldered to the pots.  But that's just me.  Someday I'm going to find some kind of use for all of the Fender brass plates I have in the shop.  Christmas tree ornaments or something.

Yeah Barry.  You know I use those brass plates all the time and my rebuilds are super quiet...  No issues so far with the ones I have done (well over a hundred).  I'm thinking about adding one in my BGE LOL  (inside joke)
I keep the brass plates as well, but I make them shine.

Mike, what do you do with all those old CTS pots you do not reuse?  If you want to get rid of them send me a PM.  I am not so interested in the linear pots, but I really like the taper to the audio pots.

BTW, looking good as usual and you just gotta have a Twin, you just cannot play the Bakersfield Don Rich thing without one. :icon_biggrin:
Title: Re: Now.... My Twin
Post by: p2pAmps on December 15, 2015, 02:57:26 pm
I would probably toss the brass plate and use a Hoffman style wire ground bus soldered to the pots.  But that's just me.  Someday I'm going to find some kind of use for all of the Fender brass plates I have in the shop.  Christmas tree ornaments or something.

Yeah Barry.  You know I use those brass plates all the time and my rebuilds are super quiet...  No issues so far with the ones I have done (well over a hundred).  I'm thinking about adding one in my BGE LOL  (inside joke)
I keep the brass plates as well, but I make them shine.

Mike, what do you do with all those old CTS pots you do not reuse?  If you want to get rid of them send me a PM.  I am not so interested in the linear pots, but I really like the taper to the audio pots.

BTW, looking good as usual and you just gotta have a Twin, you just cannot play the Bakersfield Don Rich thing without one. :icon_biggrin:

Hi Ed,

I usually hang on to those pots for spares.  I did however just sell a ton of them on eBay for 20ea!  As far as making the brass shine I'm more interested in getting all the old corrosion off, and mine was pretty bad.  I bet there was 40 year of old beer inside this thing...

This amp belonged to a friend of mine Dad.  I was 16 when he bought it from Jack's House Of Music in Sacramento.  I helped him load it in the car.  It was the coolest thing my ears had ever heard at the time.  Factory JBLs and man it's heavy.  When he passed away the family gave the amp to me.  It was pretty beat down and in bad need of a resto so here we go.  The tolex is totally ruined too.  I plan to do a AB763 and rid the Master and hum balance stuff.  May as well as it's a gut job anyways. 

I certainly don't need another amp but it will be fun getting her back into shape.  I may gift it back to my old friend once its done.  He has a 63 Jazz Master that would go well with the Twin.
Title: Re: Now.... My Twin
Post by: eleventeen on December 15, 2015, 03:38:10 pm
Excellent. You're quite the hurricane on these. Now I see your point about blasting the thing down to the bare bones and not trying to scavenge anything other than trannies. By the time you're done.....



Title: Re: Now.... My Twin
Post by: p2pAmps on December 15, 2015, 03:47:54 pm
Excellent. You're quite the hurricane on these. Now I see your point about blasting the thing down to the bare bones and not trying to scavenge anything other than trannies. By the time you're done.....

It is quite honestly faster and better when I just blow em down.  If the customer is dead set on me salvaging each I will certainly do that but in my mind its a bad choice.  Now if you have some museum piece you are trying to preserve then put it behind glass and leave it alone.  Most all the guys I deal with want to play these amps and tour with them.  I can do a full frame off on a twin in 8 hours from soup to nuts, sometimes faster if I'm in a good mood!
Title: Re: Now.... My Twin
Post by: bnwitt on December 15, 2015, 05:40:27 pm
I would probably toss the brass plate and use a Hoffman style wire ground bus soldered to the pots.  But that's just me.  Someday I'm going to find some kind of use for all of the Fender brass plates I have in the shop.  Christmas tree ornaments or something.

Yeah Barry.  You know I use those brass plates all the time and my rebuilds are super quiet...  No issues so far with the ones I have done (well over a hundred).  I'm thinking about adding one in my BGE LOL  (inside joke)

Well it's time that shows the weakness of the brass plates.  I've had slews of them in here which were corroded and causing issues but most of them were in amplifiers which had been left in garages or high humidity environments.  That is when the galvanic index shows it's face.  I do think you could install them in the BGE with no issues though. :laugh:
Title: Re: Now.... My Twin
Post by: p2pAmps on December 18, 2015, 12:47:21 pm
New pics

(http://p2pamps.com/mytwin/5.jpg)
(http://p2pamps.com/mytwin/6.jpg)
(http://p2pamps.com/mytwin/7.jpg)
(http://p2pamps.com/mytwin/8.jpg)
(http://p2pamps.com/mytwin/9.jpg)
Title: Re: Now.... My Twin
Post by: Platefire on December 18, 2015, 01:26:04 pm
Nice work mscaggs!!! I can tell this will be one happy twin when done. Platefire
Title: Re: Now.... My Twin
Post by: eleventeen on December 18, 2015, 07:21:51 pm
Oooooh...1/4" drive deep sockets. Yum!
Title: Re: Now.... My Twin
Post by: John on December 19, 2015, 05:37:47 am
Oooooh...1/4" drive deep sockets. Yum!




"What, they didn't issue you those? Hmph"


(from Get Smart)
Title: Re: Now.... My Twin
Post by: EL34 on December 19, 2015, 11:05:00 am
Looking good Mike


That's gonna be a big build
Lots of wires and hookups on a Ab763
Title: Re: Now.... My Twin
Post by: p2pAmps on December 19, 2015, 09:06:34 pm
Looking good Mike


That's gonna be a big build
Lots of wires and hookups on a Ab763

Thanks Doug.  Yeah they aren't to bad.  I just did a twin for a guy and decided to finally do my own.  It started off as a 76 master volume twin.  All that is going away...  I have a BF faceplate coming to cover up that master hole.  I was 15 when that amp was bought and I loaded it in the car for my friends Dad!  Gotta fix it...
Title: Re: Now.... My Twin
Post by: p2pAmps on December 21, 2015, 08:02:53 pm
Moving slowwwwww

(http://p2pamps.com/mytwin/10.jpg)

(http://p2pamps.com/mytwin/11.jpg)
Title: Re: Now.... My Twin
Post by: p2pAmps on December 25, 2015, 06:14:39 am
(http://p2pamps.com/mytwin/12.jpg)
(http://p2pamps.com/mytwin/13.jpg)
Title: Re: Now.... My Twin
Post by: Platefire on December 25, 2015, 09:54:21 am
It's moving slow cause you got all the knobs set on "1" turn them to "10" :icon_biggrin:
Title: Re: Now.... My Twin
Post by: p2pAmps on December 26, 2015, 01:14:11 pm
Chassis is done and sounding awesome.  Only bump was a bad 12AT7 in the reverb which I quickly tossed in the trash.  The amp is so different now for the better.  My little video was my old 335 with dead strings and an iphone...

All the torturous pics are here:  http://p2pamps.com/mytwin (http://p2pamps.com/mytwin)

(http://p2pamps.com/mytwin/28.jpg)
(http://p2pamps.com/mytwin/29.jpg)

https://www.youtube.com/watch?v=jwLa7VNLoqg&feature=youtu.be (https://www.youtube.com/watch?v=jwLa7VNLoqg&feature=youtu.be)
Title: Re: Now.... My Twin-Completed
Post by: Platefire on December 28, 2015, 02:06:30 am
Super Neat work, Great Job!  :thumbsup:
Title: Re: Now.... My Twin-Completed
Post by: DummyLoad on December 28, 2015, 11:51:33 am
 very nice!!

--pete
Title: Re: Now.... My Twin-Completed
Post by: EL34 on December 28, 2015, 03:05:51 pm
Looks good, sounds very clean :)

I noticed your youtube description has AS763 instead of AB763

 I left you a youtube comment
Title: Re: Now.... My Twin-Completed
Post by: p2pAmps on December 28, 2015, 03:16:40 pm
Looks good, sounds very clean :)

I noticed your youtube description has AS763 instead of AB763

 I left you a youtube comment

What Doug, you don't like my AS763?  LOL...  I fixed that and the spelling too of 'frame"...
Title: Re: Now.... My Twin-Completed
Post by: JJones on December 28, 2015, 07:40:25 pm
Beautiful work!  Very clean.

And I love the green pilot light!  :icon_biggrin:

Thanks for sharing!
Title: Re: Now.... My Twin-Completed
Post by: p2pAmps on December 29, 2015, 11:00:21 am
Now it's down to the part I really would rather not do.  Since its my personal amp I guess I'll do it - TOLEX!  Yuck

Notice that 70s cabinet is not finger jointed...

(http://p2pamps.com/mytwin/31.jpg)
(http://p2pamps.com/mytwin/32.jpg)
Title: Re: Now.... My Twin-Completed
Post by: Platefire on December 29, 2015, 11:43:57 am
Yelp, the corners are always oh so fun!
Title: Re: Now.... My Twin-Completed
Post by: Fresh_Start on December 30, 2015, 11:47:47 am
Is the quality of pine the same for 50s, 60s and 70s, or did that decline too?  Not that it looks terrible, just surprised by big knot on edge.

Please show us the finished Tolex!

Happy New Year everyone,
Chip
Title: Re: Now.... My Twin-Completed
Post by: p2pAmps on December 30, 2015, 01:53:27 pm
Is the quality of pine the same for 50s, 60s and 70s, or did that decline too?  Not that it looks terrible, just surprised by big knot on edge.

Please show us the finished Tolex!

Happy New Year everyone,
Chip

Well I'm not really sure if this cabinet is Ponderosa Pine or not.  Fender did cut corners on the end joints with a few dados instead of finger joints.  Knots in the wood never surprise me as I have seen many like that.  in the end it will be fine.  Waiting for the glue to flash and the bottom will go on, then I'm finished with the tolex - beer time :)

I'll probably bolt her all together tonight and bask in my glory that she finally got rebuilt after thinking about it for 3 years


Title: Re: Now.... My Twin-Completed
Post by: p2pAmps on December 30, 2015, 04:49:00 pm
https://www.youtube.com/watch?v=KkMQQh9IXWw&feature=youtu.be (https://www.youtube.com/watch?v=KkMQQh9IXWw&feature=youtu.be)
Title: Re: Now.... My Twin-Completed
Post by: Willabe on December 30, 2015, 04:58:16 pm
Beautiful inside and out!    :bravo1:
Title: Re: Now.... My Twin-Completed
Post by: p2pAmps on December 30, 2015, 06:15:41 pm
Beautiful inside and out!    :bravo1:

Thanks Willabe.  This one is going to my son Zack who is 15.  He is a pretty good piano player and his Yamaha CP300 sounds pretty good through this twin. 
Title: Re: Now.... My Twin-Completed
Post by: drew on December 30, 2015, 10:08:34 pm
What glue do you like for the to!ex?
Title: Re: Now.... My Twin-Completed
Post by: PRR on December 30, 2015, 10:17:41 pm
I think the big knot must be CBS.

California had good wood, if you bothered to pick the piles. That knot is begging to "get ugly" under the Tolex. The few naked Leo-era carcasses I have seen didn't have such glaring boo-boos.

However it is 40 years later and that knot is still hanging in, and from here it does not look like a problem. And if it does ghost-through Tolex, you say "See! It isn't chipboard! The tone is in the knots!"
Title: Re: Now.... My Twin-Completed
Post by: p2pAmps on December 31, 2015, 06:06:36 am
What glue do you like for the to!ex?
I used the glue you get at Mojotone.  First time I used this stuff and I like it.  You do have to be patient.  I applies it to both the cabinet and the tolex and then waited about 2 hours in my warmed up garage.  The tolex stayed put really nice.  I've tried spray contact cement and had issues of the material lifting.  I have even tried some hardcore upholstery high temp stuff and it was barely ok. 

So.... My son Zack is enjoying (HIS) newly rebuilt twin :) 

(http://p2pamps.com/mytwin/zack-twin.jpg)
Title: Re: Now.... My Twin-Completed
Post by: Fresh_Start on December 31, 2015, 02:29:49 pm
He must've been a VERY good boy last year!

Beautiful work.

Chip
Title: Re: Now.... My Twin-Completed
Post by: eleventeen on December 31, 2015, 03:08:28 pm
The great thing about giving a kid a Twin with JBLs is, there's very little chance he can lift it.
Title: Re: Now.... My Twin-Completed
Post by: bnwitt on January 27, 2016, 10:36:12 pm
Very nice work indeed