At ISW, I specialize in the repair of vintage vacuum tube design based guitar, bass, and keyboard amplfiers. These circuits typically operate at DC volatges in the 300 to 600v range and as such the components in the amps are subject to high heat, vibrational, and shock stresses, and for those reasons, require periodic maintenance.  Beyond the replacement of tubes and cleaning of controls, the components most often replaced are the resistors and electrolytic capacitors ("E-Caps"). Typical service life for the "E-caps"is 15-20 years subject to how often and the environement in which the amp is used.

    For solid state amps the usual offenders are the output power transistors. and power supply components.

Typical repair services include (but are not limited to):

- Replace output tubes or transistors

- Replace preamplifier tubes

- Check\adjust bias on output tube amplifiers

- Replacement of E-Caps

- Cleaning\replacement of potentiometers, jacks, switches.

- Modifying amplifier designs to improve performance and tone

- Noise (hum) reduction

- Converting an ungrounded amp (two wire AC) to grounded (three wire AC) specifications.