Soundcraftsmen DJ900 amplifier *FULLY SERVICED*

Description

Soundcraftsmen DJ900 power amplifier
Serviced:
*replaced all electrolytic capacitors with quality Nichicon and Elna audio caps
*replaced large power caps with upgraded size/voltage caps
*soldered all speaker wire and power wire crimp connections
*set bias voltage to spec
*set pcr regulation voltage
*set and tested temp protection voltage
*repainted cover
*tested distortion and played
This model is a powerful, tough built amp. The DJ900 is the heavy duty version with 6 output transistors per channel and is the same as the PM860 in a different case. 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 and Elna. 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. The cover got repainted. This amp got the full treatment because it was in good condition and I felt it was a worthy candidate. Someone will enjoy this and know they get the best sound and fresh parts to last. Thanks for looking and check out my other vintage stereo gear!
*It has some light scratches and normal wear for it's age.
Specs:
-205 watt RMS per channel 8 ohm, 300 watt RMS per channel 4 ohm,  450 watt per channel 2 ohm
600W 8 ohm and 900W 4 ohm in mono bridged operation
-THD <0.05%
-IMD  <0.05%
-TIM immeasurable
-S/N >105 dB
-Damping factor >250
-Slew rate >40 V/uS
-Rise time <2.2 uS
-Frequency response +/- 0.1dB 20hz-20khz
-input sensitivity 1.5V for rated power
freq.           A   %THD       B
20hz     .0060                 .0050
1khz     .0109                 .0117
5khz     .0138                 .0152
10khz   .0158                 .0149
20khz   .0150                 .0150
%IMD   .0042                 .0027