Wagner Amp Repair

Wagner Amp Repair BY APPOINTMENT ONLY: Located on the east side of Erie in Harborcreek, specializing in maintenance, repairs & mods of guitar/bass amps (esp.

tubes), pedals, mixers/PAs. NO CAR AUDIO OR KEYBOARDS

Do you like small, compact, lightweight, powerful vintage amps? If so, this one’s got your ticket punched. Doing a littl...
04/10/2026

Do you like small, compact, lightweight, powerful vintage amps? If so, this one’s got your ticket punched. Doing a little research on this first generation Walter Woods MI-100 amp, I learned that it was designed to compete with the much larger and heavier Ampeg SVT amps. This certainly lives up to that.

Owner requested a new power switch and power cord, plus cleaning of the controls. To access the power switch does require a fair bit of disassembly, but as long as you’re paying attention, it isn’t difficult to do. I will caution that there’s a hidden toggle switch in the heat sink fins that I didn’t catch initially when removing the rear. More on that later.

Cleaning the pots and jacks was straightforward. The owner asked for a toggle instead of the pushbutton for the power switch. I was able to find a mini toggle that fit in the space and had sufficient ratings for the duty it was to handle. I also swapped out the power cord for a new one. In doing so, I also rewired the fuse to be on the hot side of the incoming power and adjusted the filter module input wiring to accommodate the brown/blue international color scheme for the hot and neutral wires.

Once those were done, the unit was powered on and voltage rails were checked. They were reading about half of what I was expecting. After studying the circuit traces, I flipped that hidden toggle and was able to confirm that the voltages are back to where they should be. Seems that toggle switch was a 120/240 power switch. The amp was reassembled and tested again. Overall, this was a very interesting amp that impressed me with the design, features, sound and package.

Here’s another fun vintage amp where the owner requested a fairly significant conversion. He requested implementing some...
02/28/2026

Here’s another fun vintage amp where the owner requested a fairly significant conversion. He requested implementing something similar to what the guitologist video did. One thing you’ll find on a lot of these old amps is that the amp in front of you doesn’t always match (even closely) the schematic for the amp. That required tracing out the existing circuits to understand what the components were doing.

The amp had some prior work done to it, but wasn’t in great shape. Significant rework was performed. All new electrolytic caps, updated heater wiring, single input jack, add bright switch, change tone stack to Marshall style, add a mid pot, new OT with multi-taps and impedance switch. The original footswitch has the buttons too close so a new footswitch control jack for typical 2 button footswitch was added to rear panel. The reverb transformer was shot so we went with the option to convert both the transformer and the reverb tank (and RCA jacks) to the more common Fender style for less than the replacement transformer for the original. The power switch was replaced; a new purple jewel lamp was installed along with a 3-prong power cord. Add in some new matched EL84 tubes, clean the pots and jacks and she’s now able to sing in many tones. The owner is ecstatic with the transformation.

11/27/2025

Happy Thanksgiving to you and your loved ones!

Here’s another fun amp. The request was to modify the Peavey Windsor to add more gain. While there are a handful of mods...
11/15/2025

Here’s another fun amp. The request was to modify the Peavey Windsor to add more gain. While there are a handful of mods for this amp out there, I wasn’t able to find exactly what I was looking for. So, it was time to get a little creative and combine some ideas from others as well as do a few tweaks myself.

First up was to clean up all of the dust. Then pull the chassis and see if anything needs attention before surgery. As is typical with amps of this generation, you’ll find cracked solder joints around many of the jacks that see high usage. The pots and jacks were cleaned and resoldered to ensure a good connection. All tubes tested strong so no need to change them. For the mods, I either changed or removed a handful of resistors and caps, plus rewired the circuit in a few places and ended up with more gain than the circuit originally had. Overall, it has much more gain than stock while retaining clarity.

This 80s rocker came in with complaints of no sound. Once the chassis was pulled, there were signs of components overhea...
10/26/2025

This 80s rocker came in with complaints of no sound. Once the chassis was pulled, there were signs of components overheating. Luckily the outputs and reverb tank were still good. Issue was that the low voltage power supplies were not functioning. For this amp, it is common to be related to a bad reverb tank, but not in this case. The low voltage supply was rebuilt. The reverb driver transistors were changed out and a balance resistor tying their bases (found on newer versions of this amp) was added. All pots, jacks and contacts were cleaned and it’s back in business.

Another updated list of the various manufacturers of guitar/bass/keyboard amplifiers, plus mixers, PAs, pedals, and othe...
08/30/2025

Another updated list of the various manufacturers of guitar/bass/keyboard amplifiers, plus mixers, PAs, pedals, and other equipment that I've serviced.

This late 80s amp wasn’t producing the full sound range except if the stereo chorus was turned on. From the outside, you...
08/23/2025

This late 80s amp wasn’t producing the full sound range except if the stereo chorus was turned on. From the outside, you could see a few of the jacks were broken. Once inside and the board was pulled, several cracked solder joints were exposed.

The bad jacks were replaced. The gain pot shaft was badly bent so the pot was replaced. Numerous solder joints were reflowed, the board cleaned, new thermal grease applied to the outputs and all pots and jacks were cleaned. But, once that was all working correctly, it still didn’t sound quite right in the cabinet. That’s when it was determined the speakers were miswired out of phase. Correcting that and now the amp sounds like it should.

It’s not everyday that rack mount gear comes thru the shop. The complaint on this particular EQ unit was the sound would...
07/20/2025

It’s not everyday that rack mount gear comes thru the shop. The complaint on this particular EQ unit was the sound would cut out intermittently and it didn’t always work. Tearing into the unit revealed there is not a whole lot to go wrong.

A careful inspection of the board revealed a factory manufacturing process defect. I’m not surprised that this would sometimes work. One of the power supply pins to one of the opamps had no solder at all. The pin would occasionally touch the solder hole enough to power the chip, but definitely not a reliable joint.

Removal of the board requires careful removal of the k***s. You will need a slotted screwdriver to loosen the wedge type connection on them. Once the board was pulled, solder was added to U4 pin 8, and a handful of other solder joints that were either cracked or had insufficient solder were touched up. With those issues taken care of, the unit is working correctly again.

Here’s an amp that needed a lot of TLC to get it working correctly again. Original complaint was that the Channel 2 tone...
06/06/2025

Here’s an amp that needed a lot of TLC to get it working correctly again. Original complaint was that the Channel 2 tone board needed the pots attached, the amp had a buzz and one of the pads for the caps had lifted. Opening up the amp revealed some very sketchy repair work done in the past.

The amp came in partially disassembled and several wires not connected inside the preamp module. For the preamp module, several of the traces and pads were damaged on both Channel 2 tone controls board as well as the main preamp board, including V5 socket, which were repaired. The tone control board pots were installed and secured. Other traces were rebuilt. The normal jack was worn out and replaced. New shielded wire was run from the input.

Of special note was the nail that was semi-soldered to a wire to act as a pin in the interface harness connector. Bad wiring in the harness was replaced. Other sockets in the harness were damaged and had to be replaced as well. New signal wires were run in the harness. Several new crimps and the connector is back to proper contacts.

For the power amp module, all of the wire nuts were removed and wires were soldered directly instead. Some of the existing wires were damaged and replaced. Harness connector sockets and pins were corrected. Numerous solder joints on the power amp board were cracked or poorly done from prior work so they were corrected. The hum balance pot had burned open so it was replaced. The bias string was very out of spec and rebuilt.

Cleaned all pots, jacks and contacts. Installed and biased the customer provided replacement tubes. Finally, we have a great sounding, solid amp again.

This cool little vintage looking, old school TV shaped Ibanez amp came in with complaints that it stopped working. The p...
04/20/2025

This cool little vintage looking, old school TV shaped Ibanez amp came in with complaints that it stopped working. The power light also wasn’t working. It should be two channels of fun, with one having the tube screamer sound added to it.

All of the tubes tested strong so that wasn’t it. Pulling the board revealed several bad solder joints, especially on the pots and jacks. This is a common failure mode of many amps that come across the bench. Reflowed those bad joints, cleaned all the pots and jacks. Power on bulb just needed to be screwed in as it had worked itself loose. Amp is back to rocking out.

Unit came in with only the power light functioning. Getting any sound out of it wasn’t happening. The chassis was pulled...
03/22/2025

Unit came in with only the power light functioning. Getting any sound out of it wasn’t happening. The chassis was pulled and a visual inspection was performed. The preamp tube tested strong. There were no obvious signs of burned components, though one of the power amp harness connectors was a little discolored. The harness and connector were cleaned and the power amp chip was checked for shorts, which none existed.

Next up was checking the power supply. The problem was traced to a couple failed resistors. While they looked ok, they were reading significantly off. One of the resistor pads easily lifted from the board due to the prior overheating of the failure so a jumper bus was installed. Several of the solder joints were touched up, the boards and jacks were cleaned, and the amp was back to working correctly.

Owner’s complaint was that the amp had no output, the tube indicator LEDs were red, and that the speaker enable switch i...
02/09/2025

Owner’s complaint was that the amp had no output, the tube indicator LEDs were red, and that the speaker enable switch is broken. Power tubes showed signs of running hot. Once the chassis was pulled from the cabinet, a visual inspection indicated some poor soldering around several of the tube sockets. One of the resistors in the bias circuit also shows signed of discoloration.

The bias adjust potentiometer had failed open, causing the loss of bias on the power tubes and them running hot. The overheated bias resistor was replaced. A new bias pot was installed, as well as a new speaker enable switch. The tube socket solder joints were reflowed. A new matched pair of JJ 6L6GC tubes were installed and biased. Cleaned all pots, jacks and contacts.

Address

Erie, PA
16510

Opening Hours

Monday 12pm - 6pm
Tuesday 12pm - 6pm
Wednesday 12pm - 6pm
Thursday 12pm - 6pm
Friday 12pm - 6pm

Telephone

+18147462939

Website

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