A60 Reference Accuphase A60 Current Feedback Board PCB Bare Empty Board

• Golden Throat A60 is a flagship machine of the first generation, with high and low frequency density, quite good control power, and excellent level of detail. The circuit is a fully symmetrical structure with current feedback. The main feature of this circuit is that it adopts a complementary push-pull circuit from the input stage to the output stage. Slew rates in the hundreds of volts per microsecond are easily obtainable and drive capacitive loads fairly well

After welding, the midpoint can be stabilized within less than 10MV without zero adjustment. You can test the midpoint to verify

The circuit already has a rectifier circuit, so it is only necessary to connect the transformer, no need to attach a rectifier board. Wiring installation is very convenient. The fully symmetrical architecture combined with the precise transistor pairing makes the midpoint very stable without debugging.

A60 circuit module, current feedback, the main feature of this circuit is that it adopts a complementary push-pull circuit from the input stage to the output pole, which can easily obtain a slew rate of hundreds of volts per microsecond, and has a good driving ability to capacitive loads.

Japan Omron + UPC1237 protection circuit to ensure safe and reliable output, protect the speaker, Japan 50A Sanken rectifier bridge, mid-point servo circuit, make the output more stable, no need to adjust zero

Adjust the quiescent current of the large tube to 100-300mA per tube, the board has 1 TEST point, and test the voltage drop of 2 terminals to 20-60MV,

Matters needing attention: Remember to add mica sheets when installing the large tube. The mica sheets must be covered with thermally conductive silica gel,

Operating voltage: AC24VX2 ~ AC42VX2 plus AC12V Remarks: AC12V is used to protect the circuit Output power: 200W 8 ohms 300W 4 ohms Distortion: 0.002% SNR: >100dB PCB size: 195*80mm

***With Toshiba 2SC5200.A1943, good guts, delicate, full tone, slightly dark ***With ON series high-power tube, the tone is bright, the layered overtone is very good, and the sense of restraint is strong ***With Japanese Sanken high-power tube, deep dive, good strength, strong and powerful low frequency, but statically try to achieve 200MA or more per tube

The circuit resistance is standard 718 resistance, the protection circuit is Japan's Omron, and the input tube is Japan's Toshiba HIFI quality control 2SC2240 2SA970 precision pairing. It is promoted as the ON tube king NJE15034/35. The high-power tube can be matched with 6 pairs of Dongzi 2SC5200.1943 or 4 pairs of Sanken tubes. Of course, it can also be matched with ON tubes,

Main filter selection: You can choose ELNA ADUIO and Japanese Nikon KG as the main filter, but I like KG capacitors. Not much difference in price

Ring cow: 500W ring cow with separate power supply for each channel, output voltage 36-0-36 0-12 36-0-36 0-12

Personal comparison, thanks to the excellent circuit structure, the precise HIFI tube 2SC2240 2SA970 2SA2705 2SA1145 pairing, and the circuit parameters that have been revised countless times, regardless of the low frequency effect, the sweetness of the human voice, and the high frequency transparency. machine is better