1pc PASS ACA Single-Ended Class A Field Effect Tube Amplifier Board

Description and parameters：

This is a soldered and tested board, please buy 2 if you need a pair.

PASS has been improved with the addition of R15 and a quiescent current of 1.5A.

Improved R15 has been able to output an amazing 11 watts. The price of several thousand 300B is only 8 watts. The downside is that the heat is large, single-ended class A, must be good heat dissipation. Suggested parameters for the heat sink: more than 0.8 kg per side or more than 3.6 kg of external cooling chassis.

PCB size: 88 * 58mm

DC power supply: up to 30V

Power supply power: minimum 100 watts, more than 150 recommended, the output of 18-22V transformer, switching power supply selected 19-24V.

Output power: 30V case output 11.25 watts, single-ended Class A output power calculation method for voltage * current divided by 4.

Output capacitor diameter can be installed up to 22MM, convenient for players to replace the upgrade, general board capacitor diameter fixed, no space reserved for upgrades. All wiring directly welded board to minimize loss, sound positive, on-board LED indication more intuitive.

In addition to the power tube disassembly, other accessories brand new. Choose 9 new soft copper feet IRF240, 100% original.

Selected current 20MA or more, the sound is transparent, low-frequency powerful, high-frequency floating, overtone sufficient, than with K246 and other small current tube good.

Matsushita 1 watt advanced printing resistor, low drift. High temperature still work stable, of course, the cost is not cheap, the effect is also more than 0.25 watts of iron feet 5 ring resistor to improve significantly.

VISHAY input bile capacitor, the machine is very advanced before the use of super lossless capacitors, perfect performance in all frequency bands, the sound is moist, non-red Weimar and green ERO comparable.

The rest of the accessories after careful matching, gold skin Nikon, black and gold Panasonic, in short, which with a good sound, which high cost with which. Especially Nikon FW capacitor sound noble and not lose stability, clean sound with a hint of sweetness.

Good sound secrets and cross-flow control tube, genuine Toshiba white word BC547C, amplification 600 times, the sound field details at a glance, than the amplification of about 200 ZTX tube is too good.

ACA will not be updated, shipping to the above picture parts shall prevail. If case of change, The factory will use the same level or better instead of shipping parts , Thank you!