Matthews Amps offers a wide variety of repair services. My rates are reasonable and I have a quick turn around time. The first half hour of diagnostic work is free with any repairs or services. Listed below are some of the things I can do to either repair your ailing tube or solid state amp or modify.
Re-Tube and Bias
If your amp is not sounding like it did when it was new, chances are all you need are new tubes. Power tubes usually wear out before the pre-amp tubes so it is not always necessary to change all tubes. New tubes require that the bias be re-set unless you have a self-biasing amp. I can also bias your new power tubes for optimum performance. Prices for this service are $50 plus the cost of tubes if the chassis needs to be pulled to access the bias pot or $25 plus the cost of the tubes on amps where the bias control is accessible without pulling the chassis.
If your amp is over 10 years old or it has been longer than 10 years since you last re-cap, you need to replace all of the electrolytic capacitors, especially the filter caps. Bad filter caps can cause a loss of tone and add all kinds of unnecessary noise. I can give you an estimate of what a re-cap will cost you.
Please contact me for any of your repair or service needs. I can do a free preliminary diagnostic (up to 1/2 hour) and give you an estimate for the work.
You can contact me by e-mail by clicking here, or call me at (602) 550-6180.
Vintage Amp Restoration
Do you have an old vintage tube amplifier sitting around gathering dust or happen across one at an estate or yard sale? I can restore the amp to its original condition and make it sound as good as the day it was purchased. Older tube amps, especially ones that have not been turned on for several years, need to have certain components replaced. For example, filter caps can dry out causing leaks and will make the amp either not function or be very noisy. Vacuum tubes need to be replaced and biased periodically.
Some of the other services that I can perform on you vintage amp include cabinet repairs such as recovering or repairing tolex, and replacing missing hardware such as logos, knobs, corners, and feet. I can also replace the fiber of printed circuit board with a hand wired turret board.
1974 Marshall Super Lead Restoration
I recently purchased a 1974 Marshall 100 watt Super Lead head that was in very poor condition. The cabinet needed to be completely rebuilt and the previous owner, replaced the Marshall printed circuit board (PCB) with some kind of homeade PCB. Here are a couple of before pictures of the before:
I completely gutted the chassis except for the transformers, switches and tube sockets. A point to point turret board was constructed and installed in the chassis. The board was populated with all new metal film resistors, Mallory 150 caps, and Weber filter caps. Also, new pots, filter caps, and tubes were installed. The head cabinet was stripped and re-covered in black Marshall Levant tolex. New handles, feet, and logo were also installed. Finally, the back panel, complete with gold mesh, was reconstructed. Here is what the amp looks like today:
The result is a great sounding, high power Marshall amp that has the same circuitry that the original had. With all of the new
components, this amp sounds as good or better as the day it was originally purchased in 1974. This is an example of what I can do to that old vintage amp that you picked up for a song at a yard sale or was sitting in some relatives attic or garage for the last 40 years.
Gulbransen Organ Amplifier Conversion Project
I have recently completed a conversion project using an old Gulbransen organ amplifier. The original amplifier is a basic push-pull amplifier that can be converted to a guitar amp by inserting a tone stack, master volume, and a few other tweaks to the circuit. I gutted all of the unnecessary components drilled the chassis to fit the new pots and jacks and installed all of the new components.
This is a true point to point wiring scheme. All of the filter caps were replaced with new electrolytics. Metal film resistors and Mallory capacitors were also used. All of the tubes were replaced with JJ preamp, power and rectifier tubes. A tone stack (bass, mid, and treble), volume, and master volume controls were also added.
Note the point to point wiring. This is a view from the top.
Here is the view from the front. The client will build his own head cabinet and faceplate. This conversion resulted in a great sounding amp that will produce about 40 watts of tube power. It has great tone and will go from clean to crunch to distortion using the volume and master volume controls.
If you are interested in discussing a restoration project, please contact me here. I have reasonable rates and can usually work within your budget. I can provide preliminary design information and estimates at no cost. You can also fill out an on-line form located at the bottom of my Home Page to request additional information or for a quote.
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