Parasound HCA-1200II HCA1200 II Stereo Power Amplifier

Price: $1,039.99 + $79.99 flat-rate ground shipping to US mainland states only

S/N = 185685

Description:


NOTES:

1. Amp developed problems due to age
2. We corrected a short that was blowing a fuse, and we replaced the fuse
3. We repaired internal voltage regulators, so that all internal voltages are correct
4. We replaced capacitors and other defective components
7. Bias was set so crossover distortion was not visible on our scope up to 20 kHz (crossover distortion minimized)
8. DC offset was checked and is 1 mV or less per channel, so offset servos are working properly
9. Bridging function was checked
10. We checked flatness from 100 Hz to 10 kHz, and the channels were flat to within 5%
11. After service, measured power output at 1 kHz into 8 Ohms, one channel driven, is 236 W RMS for the left channel & 233 W RMS for the right channel at clip for Vline = 123 VAC RMS (our mains vary between 118 & 123 VAC)
12. Total bridged power was more than 648 Watts RMS at 1 kHz into 8 Ohms at the onset of clipping
13. Factory distortion spec. is limited: < 0.06% at full power with no impedance specified. We measured < 0.03% at full power into 8 Ohms, which was just shy of 212 W RMS, both channels driven, for Vline = 118 VAC.

A great sounding amp: a John Curl design with JFET input stages & power MOSFET drivers with BJT output stages. We also provide distortion performance which is a good indication of the health of the amp. This type of information is extremely hard to obtain from other eBay sellers.


Special Features per the manufacturer: 

• THX certified by Lucasfilm Ltd. 
• Massive 1kVA power transformer sources 200 W RMS per channel into 8 Ohms 
• 60,000µF computer-grade capacitors in power supply 
• Multiple polystyrene film bypass capacitors in power supply 
• Cascode Class A input stages with matched J-FET pairs 
• Hand picked MOSFETs in high voltage driver stage 
• 10 pairs of 50MHz, 15 ampere bipolar output transistors 
• Output transistors direct-coupled to speakers without LRC network 
• DC servo direct-coupled audio circuits with 3Hz roll off 
• Linear tracking, instantaneous-acting DC servos • High-bias Class AB operation 
• Gold-plated metal structure RCA input jacks 
• Multiple temperature sensors and silver-cadmium relay protection 
• FR-4 glass epoxy circuit boards, double-sided for precision 
• Proprietary quick-settling bias circuit obviates warmup period
• AC power cord included