The tubes are FY29 (Russian) and the Americans called the tubes 829B. It is a composite tube in which two Cambodian tetrodes are packaged in the same glass shell. Using it in a power amplifier with push-pull output can reduce the trouble of tube selection and match.
The FY29 filament voltage is 6.3V, the current is 2.25A, the screen voltage is 600V, the curtain grid voltage is 200V, the zero letter screen current is 40mA, full letter current is 110mA. The grid bias voltage is -18V, the optimal load impedance from the screen electrode to the screen grid is 13750Ω, and the output power (effective value) reaches 50W when the signal is full.
In order to further simplify the circuit, this unit uses a composite tube 6N3 for preamplification and inversion. In this way, a single 6N3 and an FY29 can be used to complete the power amplifier task, and it has a 10W power output. The sound is soft and smooth, warm and delicate. This is why the tube amplifier has not been completely replaced after the emergence of many new technologies.
This machine is small in size, unique in shape, but strong in thrust. Do not use the power of ordinary transistors or digital power amplifiers to analogize the actual thrust of this tube power amplifier, because of the high power supply voltage and unique output cow structure, the output internal resistance change is relatively small for high and low-frequency signals, and it has good low-frequency driving ability.
This unit is suitable for pushing ordinary bookshelves and most floor speakers. We have tested that the difficulty to push Dynaudio / Dynaudio contour 1.8-floor speakers have also been impressed. We have added a new Bluetooth 5.0 receiver module to facilitate the wireless connection of portable devices such as mobile phones.
|Output Power||10W x2 Class A (= 50w * 2 as class AB amp)|
|The Filament Voltage||6.3V|
|Curtain Grid Voltage||200V|
|Zero letter Screen Current||40mA|
|Full Letter Current||110mA|
|Grid Bias Voltage||-18V|
|Dimensions||215 width X190 height X308|
|Device Weight||Net weight 12.3KG|
What‘s in the box？
|Fosi Audio FY29 Power Amplifier||x 1|
|AC Input Cable||x 1|
|Qingfeng FU29 Push-Pull Tube Amplifier||x 1|