Off Topic - Vintage guitar / Amp repair

Started by Elantric, May 18, 2021, 08:28:20 AM

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OldGuitarDude

Quote from: Mrchevy on July 18, 2021, 06:49:49 AM
Steve and Colin, screw'em all, screw work. It's highly over rated. Come to Florida, we'll go fishing, drink beer, and jam till the Arthritis kicks in. ;D

... or the weather blows us away! Still beats working, hands-down! 😁😁😁

whippinpost91850


whippinpost91850

I sometimes wish I had just learned right handed 😩

HAMERMAN409

Same here but a little part of me thinks I would be broke because then there would be so many more guitars I want that they never offered left handed! (Parker Fly, Kubicki Ex-Factor Bass)

I think there are many Lefty's that can adapt to right handed but some that can't and I feel I am in that group that can't. :-)   

whippinpost91850

Quote from: HAMERMAN409 on July 19, 2021, 11:05:16 AM
Same here but a little part of me thinks I would be broke because then there would be so many more guitars I want that they never offered left handed! (Parker Fly, Kubicki Ex-Factor Bass)

I think there are many Lefty's that can adapt to right handed but some that can't and I feel I am in that group that can't. :-)   

I couldn't . It just didn't feel natural

admin

#30


I'm the 5th person to work on this 1959 ES-335 in past 6 months,

Problem: The PAF Neck pickup had very weak output and Neck PU Tone control acted more like a 2nd Neck PU Volume control  .

The PAF Pickup had been rewound by Seymour Duncan 6 months ago, but two other guitar techs worked on this guitar ,last one replaced the entire electrical harness.

The owner was desperate,  and wanted me to do a deep dive and fix the guitar .

Turned out the pickup was rewound by Seymour Duncans shop in Santa Barbara with alternate  copper wire with a higher temperature brown lacquer dielectric insulator,  and apparently one of the bobbins electrical connection was hi impedance and acting like a series capacitor was inserted between the coils-with resulting poor
sound .




Had to completely disassemble the pickup, and located the poor electrical connection. On the final wire wrap turn, had to Strip off a proper amount of the dielectric lacquer and resolder the wires. Also had to install a longer coax shielded  braid cotton wire to mate up with the vol pot .






This early era ES-335, all potentiometers, output jack,  and PU selector switch all must pass through the lower F-Hole.

The typical electonincs access hole under the bridge PU is non existent on this 1959 ES-335 with  " Les Paul " type PU routes in the solid center block
In many respects the 1959 ES-335 pedigree is Les Paul's "The Log" solidbody guitar of 1949

Like building a ship in a bottle, but guitar will soon  back to working again.






Got it all back together,  duplicated all original PU wiring before I started, yet the 1st test after reassembly revealed a "Peter Green/Albert King out of phase tone when both pickups are "ON", so had to disassemble the Neck Pickup again and swap the final polarity, so the Tone when Both Pickups are ON sounds "Dickie Betts/Warren Haynes " ABB proper.



Great sounding guitar , restored

Love my new Mestek DM100 multimeter, extremely fast /accurate measurements for debug.

And my bargain AICase SD2 temperature controlled soldering iron. Outclasses my old Weller - at $19

eUphonic

Quote from: admin on July 31, 2021, 12:14:51 AM
Problem: The PAF Neck pickup had very weak output and Neck PU Tone control acted more like a 2nd Neck PU Volume control  .

[...]

Turned out the pickup was rewound by Seymour Duncans shop in Santa Barbara with alternate  copper wire with a higher temperature brown lacquer dielectric insulator,  and apparently one of the bobbins electrical connection was hi impedance and acting like a series capacitor was inserted between the coils-with resulting poor
sound .

A faultly connection acting like a series cap is something that I've met/repaired more than once, in Gibson pickups or... Duncan ones.  ;D The tone control acting like a volume pot is how I recognize it.

IME, this issue is often due to a broken coil wire staying aligned on itself: the tiny gap of the break changes the broken wire in a cap (measuring most often around 4nF).

It's the first time that I see the same problem due to an incompletely melt lacquer. Thx for sharing and kudos for the repair!  :)

HecticArt

That's some very cool forensic work, it's really fascinating.  Thanks for sharing it. The ship in the bottle reference is another thing that always fascinated me about hollow body guitars. Whenever I think about working on mine, my mind instantly goes to how long it takes to get a pick out of an acoustic guitar, and I start to hyperventilate.

admin

#33
When working on a $30k guitar with $10k PAF pickups, The biggest hurdle is calming your nerves and apply patience and logic during the debug and repair process




( elements often missing in the feverish  vintage guitar world

https://reverb.com/item/42382326-gibson-paf-pickups-nickel-patent-applied-for-1960


My 1973 College entrance exam I had to write a paper , I chose to talk about Seth Lover inventing the Humbucking pickup.

https://reverb.com/news/interview-seth-lover-on-inventing-the-paf-humbucker-and-why-he-left-gibson-for-fender-bacons-archive

HecticArt

I would have expected that with a pickup worth that kind of money, Seymour Duncan would have been a little more careful with their rewind job.

admin

#35
Quote from: HecticArt on July 31, 2021, 12:42:43 PM
I would have expected that with a pickup worth that kind of money, Seymour Duncan would have been a little more careful with their rewind job.

Not impressed with the latest work from SD's official repair shop, (Seymour retired, and its one of his employees who does the custom work today) this same 1959 PAF pickup was alredy inspected and rewound, and reinspected on three occasions over the past 6 months in santa barbara, and  few big name guitar repairmen in California  already worked on this same guitar, claiming it was "OK" (not!)
Im no stranger to this type repair as it was my full time job 1980-1986 at Valley Arts Guitar Repair in Studio City, CA, where I repaired pickups for Larry Carlton, Duane Eddy, Mundell Lowe, and many more - often on their #1 axe.
https://www.vguitarforums.com/smf/index.php?topic=82.0

One aspect of working on the "real deal" 1959 P.A.F (Patent Applied For) humbucking pickups is it allows me to compare performance and characteristics vs my stash of 2010 era Gibson BurstBucker 3 "PAF" clones - extremely close.



Gibson USA -Massman Ave, Nashville - I'm on far right)
(I was employed as a subcontractor by Tronical 2009-2010, and worked a few weeks in the Gibson Massman Ave plant in Nashville  and was provided a few spare parts for my Dark Fire as thanks for helping the world understand the plot/purpose of these guitar's capabilities,

permanently destroyed by the "Robot Guitar Ads and the follow up the  cheap mobile home paneling look of the Dusk Tiger ,

and Henry's "we are not luddites" Firebird-X  marketing campaign, and his flagrant overspending buying Baldwin, Wurlitzer, Steinberger, Kramer, Valley Arts,  Cakewalk, Onkyo, Tascam, Phillips consumer electronics,  fate caught up to  Henry J


This could be a movie script: download and Read
GIBSON GUITAR CORPORATION vs. D.N. CROWE
https://www.vguitarforums.com/smf/index.php?action=downloads;sa=downfile&id=69

HecticArt

#36
Quote from: admin on July 31, 2021, 12:55:55 PM
Not impressed with the latest work from SD's official repair shop, (Seymour retired, and its one of his employees who does the custom work today) this same 1959 PAF pickup was alredy inspected and rewound, and reinspected on three occasions over the past 6 months in santa barbara, and  few big name guitar repairmen in California  already worked on this same guitar, claiming it was "OK" (not!)
That's a shame.


And I thought you were taller......  ;D


admin

#37
Quote from: HecticArt on July 31, 2021, 05:12:52 PM
That's a shame.


And I thought you were taller......  ;D

Tony from Tronical (Center) is 6' 6"

gumbo

...other guitarist in my band is 6'8''...I get a lot of laughs telling the audience we are identical twins and that's why he has a white guitar and I have a black one so that people can tell us apart.   ;)
Read slower!!!   ....I'm typing as fast as I can...

admin

#39
Next up



1963 Gibson Firebird III Frost Blue

Restore electronics back to stock ( currently out of phase pickups, wonky PU selector. Non functional Neck PU Tone pot.

Observe non original chrome tailpiece and chrome ABR-1 Bridge,  and gold speed knobs instead of standard black top hat knobs

While pickups and tuners are original nickel plated

chrish

The double decker pot on my Wilcox Atlantis guitar has a volume knob and pulling up on that knob it functions as a tone knob. However that tone knob is acting like a volume knob.

However no mag pickups.

Not a big deal for me as I generally don't use a tone knob on a guitar, however I do wonder where the problem could be?








sixeight

Quote from: gumbo on July 31, 2021, 07:49:41 PM
...other guitarist in my band is 6'8''...I get a lot of laughs telling the audience we are identical twins and that's why he has a white guitar and I have a black one so that people can tell us apart.   ;)

I am 6'8" as well and have used that very same joke with a vertically challenged person too.

"We are identical twins. Only our mother can tell us apart."

admin

#42




History of VersaTone Amps - used by many LA Session players in the Late 1960's

https://www.seanodonnell.com/versatone/

https://www.thegearpage.net/board/index.php?threads/new-old-amp-day-audio-guild-imperial.2213971/#lg=_xfUid-3-1638573345&slide=0

http://magnatoneamps.com/audioguild.html
Audio Guild Corporation


By 1961 or 1962 Don Bonham had ended his relationship with Magnatone other than a licensing agreement for his vibrato.
http://magnatoneamps.com/bonham.html

Bonham incorporated the Audio Guild Corporation (AGC) in 1966.

In addition to amps branded "Audio Guild", AGC made OEM amps for other retailers including the aforementioned Versatone, Universal, and Panaramic & Titano. Ernest Deffner, a partner in Pancordion Accordion Co., bought Titano Accordion Co. in 1965. Following the acquisition, both Titano and Pancordion switch OEM sourcing from Estey to AGC.

AGC also manufactured amplifiers for Versatone.

Circuits
There were several circuits made by AGC, all of them well engineered. Most, if not all, centered around 7591A power tubes. Reverb and vibrato effects were used on guitar amps. Some models had stereo output transformers with four 7591A power tubes, although unlike some of the Magnatone stereo amps, the AGC's were engineered to send different parts of the signal to one amp, and other parts to the other (high frequencies to a 10" speaker in an open back chamber of the cabinet, and low frequencies to a 12" speaker in a closed back chamber).

Cabinets
The cabinet designs were unique. AGC obviously wasn't in the business of cloning Fenders, Magnatone or Ampeg designs. Some cabinets had had three chambers, one for the amp, one for one speaker in an "open back" design, and one speaker in a sealed back chamber. Single speaker AGC combo's were made as sealed chambered cabinets. All of the AGC's I've seen used Utah ceramic speakers, but other speakers might have been used as well.