It is currently Mon Mar 16, 2020 8:28 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 42 posts ]  Go to page Previous  1, 2, 3
Go to page Previous  1, 2, 3
Author Message
Post subject: Re: Just got to play a 1964 AB763 Tremolux on my lunch break
Posted: Wed May 30, 2012 5:19 am
Offline
Professional Musician
Professional Musician

Joined: Sun Nov 20, 2011 3:16 am
Posts: 2337
aclempoppi wrote:
Right guys! This is my pick and choose of what I prefer from Leo's designs.(built into a '68 Bassman chassis) Arjay,the power section is of the straight 763, 2X6L6 with bias adjust design. The normal channel is a generic two stage 763. The bass channel is of the 864 design, with tone stack caps focused on a guitar's frequency. The plate load resistors and cathode resistors are focused on a more mid frequency-gain response(ala Marshall). The negative feedback circuit is backed down, to allow a more raw sound out of the power section. It just happened to be a '68 Bassman reject head from the collector, I worked for. So yeah, it's in a custom 2X10 combo cab. Hope that clears up any misunderstanding. It cooks quite well! My amps are destined for my grandson and friends, with full documentation. Art


Art, I'm wondering if Fender did not have AA763 & AB763, but other amps did.
I could be totally wrong. But if true, then you might be taking a Fender Bassman chassis
and adding a non-Bassman circuit modification to a Bassman circuit. Is this accurate?
If so, it sounds real custom & real cool. I couldn't locate a Bassman with AB763 design.
Just 6G6B, AA864, AA165 & AB165. Again, I could be wrong. But, I love variations & mods.
Toppscore


Following are some interesting links and comments/quotes.
http://www.harpamps.com/micKfender/AA763-vs-AB763.html
http://acruhl.freeshell.org/mga/main/aa ... ab763.html
http://acruhl.freeshell.org/mga/main/AA ... AB165.html
http://www.unclespot.com/AA763vsAB763.htm

"Blackface Bassman came in two circuits, the AA864 and the AB165. The former is considered to be the last real Bassman circuit, although it could be argued that the 6G6 (or 6G6A) actually was the last traditional Bassman. The AB165 is notable because of the equal number of gain stages, which enable the two channels to be linked ("jumped"), resulting in added gain and a different, and to some ears better, tone. The AB165 circuit continued into the Silverface amps. This circuit also includes a "hum balance" pot instead of a bias adjustment, but it is extremely easy to change back to bias adjust.

The Silverface Bassman circuit changed to AA568, AA270 and AA371, according to the Fender Field Guide (http://www.thevintagesound.com/ffg/), but the two most popular circuits for BF and SF are the AA864 and AB165. Neither of them are (IMHO) very good for bass, but sound great for guitar.

The AB165 chassis is often used as the basis for a "Bassman combo" such as this 2X10. Notice the jumpered channels. It has one Jensen RI C10Q and one Celestion G-10 Vintage.
http://i53.photobucket.com/albums/g41/B ... combo3.jpg
This is a really nice sounding amp, with plenty of mids and a loud clean sound up until about 4 on the volume control and then a gradual onset of tube (and speaker) breakup, similar to many Fender amps."

"I would like to see a schematic of an AB763 Bassman. I have no source for that schematic. The first BF schematic for a Bassman that I have seen in any source is the AA864, August of 1964. Other BF Fenders..DR,SR,TR, Bandmaster for example) were first drawn up in July of '63(AB763), but the BAssman lingered on using the 6G6B circuit through '63 and early '64, to the best of my knowledge and that of the resources that I have seen. Anything might be possible, though. I would venture a guess that if a person had a documentable BF BAssman with a tube chart that read AB763 and it had a circuit different from the 6G6 or the AA864, one might have a very desirable one-off. ONe offs from FEnder are rare. I have a one-off '63 Pro, so I know that Fender did odd things and some of those examples escaped the factory somehow...but it is a rare thing."

"I also understand that some folks hold the '65' circuits as bad things. REgarding the AB165 BAssman, after reverting to a true bias situation and yanking those two 220K resistors connected to the power tubes' plates, imho that amp is a rock monster....or hot country amp either. IT does some OD that no other BF/SF amp does. There is no reason to my ear to take one back to the AA864 circuit, which is the circuit that most point to as the best BF BAssman circuit. The AA864 is cleaner, but I like it hot; and those 3 gains of stage in each channel lead to a hot Norm ch and the ability to daisy chain the channels for thick power if you want it."

_________________
Image


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Just got to play a 1964 AB763 Tremolux on my lunch break
Posted: Wed May 30, 2012 6:45 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
aclempoppi wrote:
Right guys! This is my pick and choose of what I prefer from Leo's designs.(built into a '68 Bassman chassis) Arjay,the power section is of the straight 763, 2X6L6 with bias adjust design. The normal channel is a generic two stage 763. The bass channel is of the 864 design, with tone stack caps focused on a guitar's frequency. The plate load resistors and cathode resistors are focused on a more mid frequency-gain response(ala Marshall). The negative feedback circuit is backed down, to allow a more raw sound out of the power section. It just happened to be a '68 Bassman reject head from the collector, I worked for. So yeah, it's in a custom 2X10 combo cab. Hope that clears up any misunderstanding. It cooks quite well! My amps are destined for my grandson and friends, with full documentation. Art


Copy Lima Charlie, Art......modded to suit your specs.

Being as the amp's a silverface, nobody's gonna miss it (in a historical sense). And it sounds like the alterations would be reversible back to stock if necessary.

It sounds pretty tasty, actually.

Rawk On!

8)

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Just got to play a 1964 AB763 Tremolux on my lunch break
Posted: Wed May 30, 2012 7:10 am
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Sat Mar 31, 2012 6:38 am
Posts: 593
Retroverbial wrote:
aclempoppi wrote:
Right guys! This is my pick and choose of what I prefer from Leo's designs.(built into a '68 Bassman chassis) Arjay,the power section is of the straight 763, 2X6L6 with bias adjust design. The normal channel is a generic two stage 763. The bass channel is of the 864 design, with tone stack caps focused on a guitar's frequency. The plate load resistors and cathode resistors are focused on a more mid frequency-gain response(ala Marshall). The negative feedback circuit is backed down, to allow a more raw sound out of the power section. It just happened to be a '68 Bassman reject head from the collector, I worked for. So yeah, it's in a custom 2X10 combo cab. Hope that clears up any misunderstanding. It cooks quite well! My amps are destined for my grandson and friends, with full documentation. Art


Copy Lima Charlie, Art......modded to suit your specs.

Being as the amp's a silverface, nobody's gonna miss it (in a historical sense). And it sounds like the alterations would be reversible back to stock if necessary.

It sounds pretty tasty, actually.

Rawk On!

8)

Arjay

I'm all for making the amp sound right to YOU, after all... it's yours right Art?

_________________
...I for one, sure would appreciate the return of intelligent conversation, spirit of assistance and the simple yet effective ignoring of those who can't seem to hang with that...
Best regards,
rob


Top
Profile
Post subject: Re: Just got to play a 1964 AB763 Tremolux on my lunch break
Posted: Wed May 30, 2012 7:20 am
Offline
Rock Star
Rock Star
User avatar

Joined: Wed Feb 17, 2010 11:38 am
Posts: 4333
Location: Tennessee
Arc-n-spark wrote:
Documentation? I have to keep that now too?

Not me,since Arjay is my step-son now and heir apparent,he already knows more about my amps than I do....no documentation needed. :lol: :lol: :lol:


Top
Profile
Post subject: Re: Just got to play a 1964 AB763 Tremolux on my lunch break
Posted: Wed May 30, 2012 9:30 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
Rebelsoul wrote:
Arc-n-spark wrote:
Documentation? I have to keep that now too?

Not me,since Arjay is my step-son now and heir apparent,he already knows more about my amps than I do....no documentation needed. :lol: :lol: :lol:


:mrgreen:

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Just got to play a 1964 AB763 Tremolux on my lunch break
Posted: Wed May 30, 2012 1:04 pm
Offline
Professional Musician
Professional Musician

Joined: Sun Nov 20, 2011 3:16 am
Posts: 2337

NOW ~ we know there is an AB763 Fender Bassman!

Another example of:
NEVER SAY NEVER, or
ALWAYS NEVER SAY NEVER.

Perfect.

Toppscore 8)

_________________
Image


Top
Profile
Post subject: Re: Just got to play a 1964 AB763 Tremolux on my lunch break
Posted: Wed May 30, 2012 1:07 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
OK guys. Plz remove those gloves. Someone may get hurt. :(


Top
Profile
Post subject: Re: Just got to play a 1964 AB763 Tremolux on my lunch break
Posted: Thu May 31, 2012 1:40 am
Offline
Professional Musician
Professional Musician

Joined: Fri Jun 26, 2009 6:53 pm
Posts: 2252
Location: Harvard IL
All I meant by documentation, is that I drew up the schemo and the color code wiring and component layout, for future reference. Yeah, the amp is plenty bogus!!! Sure didn't mean to highjack your thread, Demaria.Daniel !!! Art

_________________
None of Us are free, if One of Us is chained !


Top
Profile
Post subject: Re: Just got to play a 1964 AB763 Tremolux on my lunch break
Posted: Thu May 31, 2012 6:59 am
Offline
Hobbyist
Hobbyist

Joined: Sun Nov 06, 2011 5:47 am
Posts: 78
aclempoppi wrote:
Sure didn't mean to highjack your thread, Demaria.Daniel !!! Art


Not at all, that custom Bassman sounds fascinating! :shock: I'd love to hear it


Actually this got me wondering if there were BOTH AB763 Tremoluxes and AA763 tremoluxes. There's an AA763 head selling on eBay as well which made me curious. With a little research I managed to find schematics for both circuits, so I guess they made both. However any database of Fender amp models only ever seems to list one or the other so it's a bit confusing.

While we're on it, can anyone describe to me the tonal differences between AB and AA circuits? I read that it's very minor, mostly a slight difference in the amount of gain. Anyone care to elaborate?


Top
Profile
Post subject: Re: Just got to play a 1964 AB763 Tremolux on my lunch break
Posted: Thu May 31, 2012 7:01 am
Offline
Hobbyist
Hobbyist

Joined: Sun Nov 06, 2011 5:47 am
Posts: 78
Oh and btw the 65 Deluxe and the 62 Super at Capsule were both SOLD, still in the shop but I couldn't give them a try!


Top
Profile
Post subject: Re: Just got to play a 1964 AB763 Tremolux on my lunch break
Posted: Thu May 31, 2012 7:37 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
demaria.daniel wrote:
Actually this got me wondering if there were BOTH AB763 Tremoluxes and AA763 tremoluxes.


Indeed, there were.

The only apparent difference on the two schematics seems to be a minor value change to the resistor tying both cathodes of the phase inverter together. The AA circuit uses 27K while the AB has a 22K. I would think any sonic difference would be negligible under most conditions.

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Just got to play a 1964 AB763 Tremolux on my lunch break
Posted: Thu May 31, 2012 1:19 pm
Offline
Professional Musician
Professional Musician

Joined: Sun Nov 20, 2011 3:16 am
Posts: 2337
aclempoppi wrote:
All I meant by documentation, is that I drew up the schemo and the color code wiring and component layout, for future reference. Yeah, the amp is plenty bogus!!! Sure didn't mean to highjack your thread, Demaria.Daniel !!! Art



"Bogus" is BEAUTIFUL :!: :!: :!:

Aclempoppi!
Check out my BEAUTIFUL Bogus 1983 Paul Rivera Fender Concert II:
http://www.ebay.com/itm/300648476303?ru=http%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_sacat%3D0%26_nkw%3D300648476303%26_rdc%3D1\
The designer OUT-MODDED Paul Rivera himself :!:

He makes a list of the modifications in the description area.
He added a NFB (Negative Feed Back) control on the Right Side of the faceplate.

"Modded Bogus is THE BEST :lol:

Toppscore 8)

_________________
Image


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 42 posts ]  Go to page Previous  1, 2, 3
Go to page Previous  1, 2, 3

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: