Package: Yes
Channels: 1
Maximum Power Per Channel: 101-130W
Model Number: GW
Brand Name: QXMY
name: Goldmund rear
channel: mono amplifier board
Circuit Board: Adjustable Class A
Power supply: Dc 18-50V 200W
Watt: Watt: : 150W 4Ohm
Tube series: Discrete tube amplifier
Heatsink: not include heatsink
Whether assembling: PCB board only
Express delivery: Free Shipping
Type: Home Amplifier
Package: Yes
Channels: 1
Maximum Power Per Channel: 101-130W
Model Number: GW
Brand Name: QXMY
name: Goldmund rear
channel: mono amplifier board
Circuit Board: Adjustable Class A
Power supply: Dc 18-50V 200W
Watt: Watt: : 150W 4Ohm
Tube series: Discrete tube amplifier
Heatsink: not include heatsink
Whether assembling: PCB board only
Express delivery: Free Shipping
Type: Home Amplifier
goldmund tube output mono amplifier board
adjustable A discrete goldmund rear amplifier
PCB board only
Technical parameters:
Output power: 150W / 4 ohm load; (Total harmonic distortion THD + N <0.2%), DC +-50V, 4 ohm load measured.
Speaker Impedance: Available 4-8 ohms.
PCB size: 100 * 67MM.
Power supply: DC Dual 18-50V transformer 200 watts or more, the need to replace withstand higher voltages higher capacitance.
Introduction:
goldmund rear circuit, according to the circuit diagram can be seen in front of that section of line structure and shop a little like rear imitation M arantz , can do low-frequency sound control and have good performance, FET (2SK170 FET do differential input) can good inhibitory drift, the overall sound quality is very good, performance is more crisp treble, bass dive very deep (Power should be enough), to promote the management of import T oshiba C5171 + A1930, a small tube is MPSA42 + MPSA92 (ON Anson America), 2SK170 T oshiba original.Low-frequency performance of sound intensity, two pairs on the tube push the general basic floor boxes is more than enough, more delicate vocals.
1. There are 1% precision resistors metal film resistors (apart from 1W to 5W 5% accuracy as well as the non-inductive resistor outside), using a P hilips Cbb CBB capacitor capacitance.
2. small electrolytic capacitors have Nippon have NOVER and LELON other famous capacitor. To ensure the stability of the circuit, and noise removal clean.
3. 2SC5171, 2SA1930 T oshiba bipolar transistors, the role is to promote the management. 2SD669 imported H itachi NPN silicon tube, 2SD669 is operated in single ended class status, the positive and negative half-wave signal by 2SD669 alone, so there is no crossover distortion, and even harmonic richness of timbre There are some moist role, and thus enlarged board very resistant, but 2SD669 is working in a large current of 50mA status (normal op amp, amplification integrated only a few milliamps), to deal with large dynamic music signal easily obtain the most realistic sound performance Play ultimate effect .
Parts DIY Commissioning notes :
1) After completion of welding heat sink installed (note tubes and fins to be well insulated), adjust VR2 (1K precision adjustable resistors) makes the quiescent current 50MA around, VR2 clockwise quiescent current becomes large, counterclockwise decrease the
Namely: the output OUT is the voltage across point A about 11MV (R35 voltage across the output resistance of 0.22 Ohms resistor value is divided by this quiescent current), A point is a test hole, PCB is labeled, in the output (OUT) side.
2) the midpoint zero, adjust VR1 (500R close adjustable resistance), so that the output (OUT) to ground (ie, across the terminals of the amplifier output)Zero mV; generally ten within a few millivolts are OK,
Product pictures:
Note that this amplifier power is rectified and filtered DC power supply after a double, not directly connected to the transformer
Recommend shop rectified and filtered with a trumpet-protected power strip:
PCBboard silkscreen with component values are very convenient DIY
This link is only PCB board ,
Done board link:product/goldmund-tube-2SA1943-2SC5200-output-mono-amplifier-board-adjustable-A-discrete-goldmund-rear-amplifier-Free-Shipping/1123215_2045124859.html
Diy board link:
The Installation image for reference
Circuit design for reference
Friends interested in the reference circuit for learning and communication