AB763 Build Completed

[fusionbear]

Been away for a while. But here is a new build I did by the seat of my pants... Just a AB763 preamp with a KT88 power section PT is a Dynaco Clone P782S, OT is a Classictone 40-18067, Choke is a 40-18058

It sounds really sweet...


http://s169.beta.photobucket.com/user/f ... mp%20Build


[IMG:640:480]http://i169.photobucket.com/albums/u223 ... 50a1db.jpg[/img]

[IMG:640:480]http://i169.photobucket.com/albums/u223 ... 622ec2.jpg[/img]

[IMG:640:480]http://i169.photobucket.com/albums/u223 ... 376c58.jpg[/img]

[Blackburn]

Very cool build!

PEC pots are the best!

[alvarezh]

Cool indeed, and with space left for a reverb.

Nicely done.

Congrats!

[NickC]

That P-T-P wiring looks great. Really nicely done!

[xtian]

Awesome, Bear! How daring, for you to build a Fender stylee!

Headroom must be huge with those 88s. Can you get dirty before rattling windows?

[rdjones]

Hey, true point-to-point !
Nice to see this old timey method being used.
Good job.

reddog Steve

[jujudubluz]

looks great,
do you have clips? what kind of power section did you used?

[Teleguy61]

Beautiful work.
That puppy's got to be scary loud.

[fusionbear]

Thanks for all the kind words! Yes, it can get pretty loud, but still not as loud as a regular Twin. It is putting out about 65 watts. I built it for clean tones. I did crank it and it does get some nice crunch, but that was not my intention for this amp. I built it as a "sister" to my JTM45/100 build that I also primarily use for clean tones.

The PT puts about 565v on the plates of the KT88's. The preamp voltages are stock, maybe just a little lower (-2 to -10 vdc on the B+ after the PI). It sounds really sweet. Instead of a normal bright switch, I used a three way selector: 82pf, 120pf, 150pf. It was fun to engineer it "on the spot".

The power section is "book stock" standard LTP PI. The Grid stoppers on the KT88's are 1.5K. I have plenty of Bias voltage available if needed.

The amp sounds like a standard Fender amp. Very different than my JTM45/100 build. That amp always has a glassiness on the high end ala Hendrix. This amp is pure Fullerton/Bakersfield tone...

[jujudubluz]

The rotary Brighton switch's clever!

[jujudubluz]

Meant Bright switch, excuse my ignorance but what LTP PI means?

[NickC]

Meant Bright switch, excuse my ignorance but what LTP PI means?

LTP PI = long tail-pair phase inverter

http://www.aikenamps.com/LongTailPair.htm

[Blackburn]

Meant Bright switch, excuse my ignorance but what LTP PI means?

Long tailed pair phase inverter. Or Schmitt inverter.

[Blackburn]

Meant Bright switch, excuse my ignorance but what LTP PI means?

LTP PI = long tail-pair phase inverter

http://www.aikenamps.com/LongTailPair.htm

You beat me to it!

Next time!

[jujudubluz]

Thank you guys !