Fender Twin.........

[jackthehack]

They frown on you disassembling things at GuitarCenter; tried out one of the '65 Twin Reverb reissues a while back, definitely does not have tubes soldered in, but couldn't see circuit board. Think it is supposed to be the AA769 schematic. It's been a long time since I played through a real '60s Blackface Twin, but the reissue didn't seem to have as much power or "crunch", but could be my recollection, I guess....

Its AB763, by 69 they had the dual bias thing, mostly grid bias, with medium value grid resistors to "even things out" between unmatched tubes.(it sucked bad).  They went from bias level, to bias balance, to "self balance" and back to bias balance. 

Its the speakers Jack.  Old twins had JBL or higher end Oxford speakers.  Todays Twin... sadly... has crap.  Putting a set of Vintage 30's in a Twin is good.  Putting old JBL D120's is better. 

Wish I'd known that a couple of weeks ago; it's that time of the year and somebody was giving one away on the local Craigslist...

 

[-CB-]

Gotta remember this too Jack,

Any of the Twin Reverbs... AB763... right on up to the last of the 105w models (sort of 77/78ish I think), ALL have the same transformers, and same basic circuit.  You can retrograde any of them into the AB763 type.... with a little bit of patience and very few parts.

When they came out with the 135w Twin Reverb, and its UltraLinear output... those are really not retrogradable, except with great expense - as both the power and output transformer must be changed, and a choke added.  The entire power supply must be refabricated, and the bias supply refabricated.  Its doable... but the cost makes it unworkable.  Not to fear, those 135w Twin Reverbs have their own cult following - Steel Guitar, Bass, Keyboard and Jazz players.  The amps are beyond clean.  A pair of EV speakers (JBL  D120's wont cut it), and a cabinet with 2 JBLD130's and two horns, and you got on hell of a clean sparkly rig.  I know of two Jazz players that swear by this setup - its so clean and the bottom end is just "there".  Not boomy, not farty, but there - solid as a set of silicone-grown's.

 

[jackthehack]

I meant someone had a '65 reissue posted for $525, went quick... Speaking of speakers, did JBL go out of the guitar speaker biz? Was looking up what a set of E-120s were going for and it looks like they're discontinued without any replacement?

 

[neilium]

When they came out with the 135w Twin Reverb, and its UltraLinear output... those are really not retrogradable, except with great expense - as both the power and output transformer must be changed, and a choke added.  The entire power supply must be refabricated, and the bias supply refabricated.  Its doable... but the cost makes it unworkable.   Not to fear, those 135w Twin Reverbs have their own cult following - Steel Guitar, Bass, Keyboard and Jazz players.   The amps are beyond clean.  A pair of EV speakers (JBL  D120's wont cut it), and a cabinet with 2 JBLD130's and two horns, and you got on hell of a clean sparkly rig.   I know of two Jazz players that swear by this setup - its so clean and the bottom end is just "there".  Not boomy, not farty, but there - solid as a set of silicone-grown's.

I had one of those. Couldn't make it work for me. Almost hi-fi sounding. I could see a pedal steel player making it sing, though.

 

[-CB-]

I meant someone had a '65 reissue posted for $525, went quick... Speaking of speakers, did JBL go out of the guitar speaker biz? Was looking up what a set of E-120s were going for and it looks like they're discontinued without any replacement?

Oh yes....decades ago.  The E was the successor to the D, and frankly, the D was the better speaker.  The "poormans" JBL was the EV-Force12, and its has a good tone, a more solid bottom end, but not the transparent glass like top the JBL had.  There really is no good substitute for the JBL.  The EV/M is voiced totally differently.  Celestion can't touch it (but I like Celestion speakers).  Eminence never came close with anything they had.  Reissue Jensens are crap warmed over... they really suck, esp for the price you pay for them.

Fender has supposedly worked on a 12 inch and 15 inch "JBL" toned speaker with Eminance, and its available as a special order if you can get a dealer to order parts for you.  I think its in the 15" Twin Reverb they did, and in the Steel King amp they produce.