At 2:52, "Freight Train". I got to see Elizabeth Cotten play, back around 1980 or so. It was a triple bill, with Taj Mahal, Sonny Terry and Brownie McGhee.
Nice work as always. Sounds like your a Doctor Who fan as well. Hope you and your wife are well. Looking forward to the real playing test of this amp. Take care
Nice work man! I do have a question though,, with those speakers not working in the way they weren't wouldn't that be putting a no load situation on the output transformer?
Thanks, again Lyle - exemplary work, as always. I'm curious, though, about the differences between the AA763 circuit and the AB763. Did you ever locate a AA763 diagram?
Thanks. Not for a Twin but for a Super Reverb. This had the filtering from the AA763 but the main board was populated like the AB763. “Pure” AA763 would have had two 100k plates on the PI and a very few other minor differences. I assume this was a transitional amp using up the remaining AA763 doghouse boards and tube charts.
Nice work as allways! Any special reason you changed the diodes going straight parallell instead of ending in the same hole? I changed my diodes the same way as you did but used 1N4006´s. Safe?
Maybe the black paint was a factory inspection thing, like someone had been through and verified all the diodes were ok before they put the board in an amp and hit it with mains
This is the most plausible reason, but it's still weird that they only did the paint on this board. Maybe they didn't expect any of the diodes to need replacing in the life of the amp - they probably never dreamed it would still be in service 57 years later.
I need to ask why you are using a 47u cap ? most will automatically replace with 100u. I know that 47u is original value but will it be robust enough? Love the work.
I think you can go way, way lower. Like under 10uf. The voltage rating is the important bit. A lot of people use 100uf because they're commonly available @ 100v
With bias filter caps you want the smallest value that gives adequate filtering with a fast initial charge up time. Marshall and some Fenders use two 10uf caps. Most Fenders used a single 25uf or 50uf cap. 100uf is fine - I've certainly used them myself - but it has a longer initial charge time. If I was only ordering parts for this amp from a "guitar amp parts vendor" I would have added an F&T 100uf 100V to the cart to have everything with one shipping charge. But as I was ordering some parts from Mouser, a more well-stocked vendor, I got this 105 degree 10,000 hour 47uf 100V cap.
@@PsionicAudio Lyle, thanks for the reply. This is valuable info that is not usually discussed when trying to keep old amps still going. Cheers Tim King
I'm not versed in what the actual process is/can be. I could Google it and then pretend to have known, but I like occasionally saying a simple "I don't know."
@@sharkair2839 I think if it's just a rub they make it round again somehow. Not sure exactly but I know there are guys who save old vintage celestions from being reconed. Or maybe they attach a new paper voicecoil to the old cone possibly. I will look into it and get back to you.
At 2:52, "Freight Train". I got to see Elizabeth Cotten play, back around 1980 or so. It was a triple bill, with Taj Mahal, Sonny Terry and Brownie McGhee.
You know it aint no lie....awesome dead tune... one you don't hear often too
I like it, your attention to detail is outstanding.
Something very satisfying about watching your solder technique.
Great work!!
Awesome... setting the bar at a level of its own. Cheers.
Looking forward to seeing the progress and I hope the owner re-comes those old C12N’s
Nice work as always. Sounds like your a Doctor Who fan as well. Hope you and your wife are well. Looking forward to the real playing test of this amp. Take care
Bonus points for Dr. Who!
Aha!!! I just witnessed your top secret doming technique!!
Black paint on diode solder joints to allow Fender to tell if it had been tampered with when in for warranty service ?
Nice work man! I do have a question though,, with those speakers not working in the way they weren't wouldn't that be putting a no load situation on the output transformer?
Did I hear Daleks in the background at around 8:20???
Thanks, again Lyle - exemplary work, as always. I'm curious, though, about the differences between the AA763 circuit and the AB763. Did you ever locate a AA763 diagram?
Thanks. Not for a Twin but for a Super Reverb. This had the filtering from the AA763 but the main board was populated like the AB763. “Pure” AA763 would have had two 100k plates on the PI and a very few other minor differences.
I assume this was a transitional amp using up the remaining AA763 doghouse boards and tube charts.
Nice work as allways! Any special reason you changed the diodes going straight parallell instead of ending in the same hole? I changed my diodes the same way as you did but used 1N4006´s. Safe?
I don’t remember now - probably just a whim on the day. 4006s can fail more easily than 4007s.
Enjoy the new script format.
Maybe the black paint was a factory inspection thing, like someone had been through and verified all the diodes were ok before they put the board in an amp and hit it with mains
This is the most plausible reason, but it's still weird that they only did the paint on this board. Maybe they didn't expect any of the diodes to need replacing in the life of the amp - they probably never dreamed it would still be in service 57 years later.
Dalek❕🪦🪫🔌📻🎛🔊🤖
I need to ask why you are using a 47u cap ? most will automatically replace with 100u. I know that 47u is original value but will it be robust enough? Love the work.
I think you can go way, way lower. Like under 10uf. The voltage rating is the important bit. A lot of people use 100uf because they're commonly available @ 100v
With bias filter caps you want the smallest value that gives adequate filtering with a fast initial charge up time. Marshall and some Fenders use two 10uf caps. Most Fenders used a single 25uf or 50uf cap. 100uf is fine - I've certainly used them myself - but it has a longer initial charge time.
If I was only ordering parts for this amp from a "guitar amp parts vendor" I would have added an F&T 100uf 100V to the cart to have everything with one shipping charge.
But as I was ordering some parts from Mouser, a more well-stocked vendor, I got this 105 degree 10,000 hour 47uf 100V cap.
@@PsionicAudio Lyle, thanks for the reply. This is valuable info that is not usually discussed when trying to keep old amps still going. Cheers Tim King
Is it possible to put a new voice coil on an old cone? Instead of new cones? Is that even possible?
I'm not versed in what the actual process is/can be. I could Google it and then pretend to have known, but I like occasionally saying a simple "I don't know."
i don't think there is a way to get to the voice coil without ripping out the speaker cone.
@@sharkair2839 I think if it's just a rub they make it round again somehow. Not sure exactly but I know there are guys who save old vintage celestions from being reconed. Or maybe they attach a new paper voicecoil to the old cone possibly. I will look into it and get back to you.
It’s sad to see a pair of Jensen C12N’s with cones that good fried.
Somebody loved that amp hard!
4001's or 4007's ?
4007s.
4001s would have burned immediately.