Showing posts with label Repair. Show all posts
Showing posts with label Repair. Show all posts

Thursday, August 8, 2013

Fret Job Gibson ES-175 (1971) by Gryphon Stringed instruments

I've have an old Gibson ES 175 that was lurking in my closet because I had worn the frets down by playing  it for the better part of 30 years. This guitar has been through my younger crazy days and is special to me because it's always been reliable and has great tone. However, the frets were becoming non-existent. I decided to take my guitar to Gryphon Stringed Instruments for consultation and repair. The decision was a easy, do it.

The following are some photo's showing the various stages of the work accomplished and photographed by James Hingston.
Gibson ES 175 (1971)
 Backside Burst

42 years of playing will wear a fret thin!
The Gibson ES 175 "fretless wonder!"
The guitar was playable but required more finger pressure to fret the note.
At Gryphon Strings - James Hingston's bench
 Frets removed waiting for fret board level
Checking the fret board level. Not too bad!
Sanding the fret board.
 Making that 41 year old rosewood flat!
Cleaning the fret slots - Important!
Frets radius prepared to match fret board
Cutting the tange to fit neck binding.
Ready to trim the edges. 
Hammering in the frets - Almost done! 
Frets before fret job look almost non-existent.
Frets after re-fretting. Wow!
Nice tall and round frets product great tone and intonation.
 Fret board looks like new too!
Nice new bone nut (save the original) looks nice

The guitar now plays effortlessly. I had been missing the tone of this guitar and had substituted by playing an archtop with floating pickups. The problem with the floating pickups is that they also pickup the drummer and make playing over a loud drummer virtually impossible without feedback. With the ES-175 design, feedback isn't an issue anymore. Besides, these old humbucker seem to get better with age!

I was lucky and got my guitar in and out in a relatively small amount of time. James work was impeccable, detailed and he is an excellent collaborator. The entire staff is top notch and you can rest assured that your instrument will be handled with the utmost care and attention. If you are vacillating about doing a fret job - don't procrastinate! If you love the guitar then get a fret job but if like the guitar - sell it and get a new guitar from Gryphon Stringed Instruments. I am only sorry I waited as long as I did because now I have a new vintage instrument that sounds awesome and will last many many more years.

James Hingston completed the fret work and documentation on this page. Additionally, James is a talented artist and has his own web page. I encourage art enthusiasts to visit his page and support his creativity.
http://www.jameshingston.com/

Thanks! Scott

Friday, August 10, 2012

Fender 65 Twin Reverb Reissue - Volume knob


The Fender 65 twin reverb reissue uses a smooth shaft potentiometer. The knob has a set screw that prevents the knob from spinning independent of the potentiometer shaft. Some times the shaft and knob spin independent of each other and when this happens you cannot control the switch. One might think that applying some crazy glue or similar type of glue will alleviate the problem. However, to service an amp, the pot knobs must be removed in many cases. However, to be clear, the pot "top hat's" don't need to be removed to take the chassis from the cabinet.

The switch below had a knob glued on very well, so well that when I tried to extract the knob, the shaft failed inside the potentiometer and ruined the switch.

You can see a shiny spot where Cyanoacrylate was applied

The Potentiometer is ruined (right side)

In the photo below you can see the volume potentiometer shaft extended from the its original position.

The repair isn't difficult but the parts aren't available at Radioshack and take time to procure. Time is usually what most people have little to spare. Therefore, don't glue your knobs to the pot shafts!

The picture below gives you an idea of what the inside of a Fender amp looks like when you take it apart.The picture below is of the potentiometer board with potentiometers attached. The board is attached to all the externally adjustable potentiometers for this amp (Fender Twin Reverb 65 reissue)
Fender 65 Twin Reverb reissue Amp Schematic link - 

Fender 65 Twin Reverb reissue Service manual link -

 PCB backside with clip pot soldered by factory

I used a solder sucker to remove the solder - clip is removed thereafter

Broken Fender clip potentiometer after removal 


Nice New potentiometer prior to installation

Example of improperly seated clip potentiometer

Clip potentiometer properly seated and ready for soldering

Fender clip potentiometer carefully soldered to the PCB

No solder should leak to the top side of the PCB

No solder visable on the top side - this is good!

Fender clip potentiometer is ready for chassis installation

The Fender potentiometers and PCB are ready to install into the chassis. I will now re-tube this amplifier and check and adjust the bias if needed. Burn in will be completed and then I'll check the bias again and if stabilized, I will then do a final test and finally return the amplifier to the customer. Cheers!

Updated - 12/09/14.
I've had a few requests for parts and such. So here are a couple of links that could help you if you have similar issue to the one I outlined above.

Schematichttp://ampwares.com/schematics/65_twin_reverb_@20manual.pdf (use this link to find the part number needed)

Parts: http://darrenriley.com/product-category/fender-parts/ (buy the parts from Darren - I have and it was a good experience, quick, accurate, and they even sent me some swag! :)