Replaced large power capacitors with upgraded higher rated capacitors. Set power amp bias voltage. Set and tested phase control voltage and temperature protection voltages and operation. This model is a powerful tough built amp with MOSFET output transistors. It was designed with the specific demand of keeping up with the dynamic range in digital music.It uses phase control regulation to regulate running voltage and self adjusts to temperature sensed at different spots on the heat-sink and transformer. It will run without shutting down even at the lowest impedances. All electrolytic capacitors were replaced with audio capacitors from Nichicon (MUSE and Fine Gold series).
The power capacitors were replaced with 13,000uF 100V capacitors where the originals were 11,000uF 75V. The new ones are also rated for a ripple current of over 15 amps each and an 18,000 hour life-span. That will keep up with the most demanding power hungry music for a long time. The PCR temp and voltage settings were adjusted and tested for performance and thermal stability. It was then tested for distortion and was less than half of rated spec.
Thanks for looking and check out my other vintage stereo gear! Old parts in last photo. Tested for THD+N on a Tektronix AA501 distortion analyzer into 8ohm at rated power levels. 205 watt RMS per channel 8 ohm, 300 watt RMS per channel 4 ohm, 450 watt per channel 2 ohm. 600 watt RMS bridged 8 ohm.
Frequency response +/- 0.1dB 20hz-20khz. The item "Soundcraftsmen Pro Power Three Power Amplifier FULLY SERVICED & TESTED" is in sale since Monday, November 4, 2019. This item is in the category "Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Amplifiers & Tube Amps". The seller is "1vintagestereo1" and is located in Clintonville, Wisconsin. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, South africa, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Israel, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Grenada, Barbados, Bangladesh, Bermuda, Bolivia, Egypt, Guadeloupe, Iceland, Jordan, Sri lanka, Luxembourg, Macao, Martinique, Maldives, Pakistan, Reunion, Uruguay.