FU-50 12Wx2 hifi tube amplifier kit

[siliconray]

Product Link:
FU-50 HiFi 12Wx2 SE tube audio amplifier

If you think 6P3P amplifier is not loud enough, or it's too simple for you, this FU-50 kit is for you. FU-50 is know as "little 300B", because it's sound like famous 300B.

This kit use 6j8p or 6n8p as preamplifier. It can output 12W x 2 power, lound enough for a big room.

Features and spec:
5Z3P tube rectifier
6J8P preamplifier
FU-50 power amplifier
Output Power 12Wx2
Load: 4Ohm or 8Ohm
Silkscreen stainless steel chasis

Part List
Tube and socket
- 8Pin tube socket x 3
- FU-50 socket x 2
- 5Z3P x1
- 6J8P x 2
- FU-50 x 2
Capacitors
- 450V/330UF x 1
- 400V/47UF x 1
- 400V/22 UF x 1
- 0.47UF film x 2
- 35V/470UF x 2
- 100V/100UF x 2
Resistors
- 39K 3W x 1
- 220K 3W x 1
- 1K 3W x 4
- 470K 3W x 6
- 680Ohm 3W x 2
- 100K x 2
- 100Ohm x 2
- 4.7K x 12
Accessories
- Silkscreen stainless enclosure
- 150W power transformer
- 3.5K to 4/8 ohm OP transformer x 2
- 2H 250ma choke coil x 1
- RCA connectors x 2
- Power switch x 1
- Output Connectors x 6
- Cables
- Shrink tubes
- Shielded cables
- Rubber foot x 4
- Wiring cables
Schematic

Product Images




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FU-50 Single End 12W x 2Tube Amplifier Kit

[radiostar]

Hello,


Please would you be so kind to explain difference between 6J8P and 6N8P versions.

Thanks

[costis_n]

Originally Posted by siliconray

. FU-50 is know as "little 300B", because it's sound like famous 300B.

Where did you get that off? i am making a GU-50 amplifier and it would be cool to state that.

[siliconray]

A few years before a man (a guru of tube amplifier) wrote an artical about 300B and FU-50. In the artical he mentioned that the curve of FU-50 is very close to 300B when working in troid mode. THat's why it's called little 300B, very interesting.

[siliconray]

Hi Radiostar

6N8P is newer design. It use troid 6N8P as preamplifier, which has better sound than 6J8P, especially in medium frequency range. The components are also upgrated in the newer version. 6J8P version will not be continioud when the stocks are sold out.

[bobrown14]

How long is shipping time to the USA for this Tube Amp Kit?

Cheers,

Bob

[siliconray]

Sea shipping takes 2 months according to recently records. It takes about $50. Air+ground shipping takes 2 weeks, $120 for shipping. air+ground is faster and safer. A few sea shipping packages were openned by the custom for some reason, some components are missing

[costis_n]

Originally Posted by siliconray

A few years before a man (a guru of tube amplifier) wrote an artical about 300B and FU-50. In the artical he mentioned that the curve of FU-50 is very close to 300B when working in troid mode. THat's why it's called little 300B, very interesting.

The FU50 (which is the chinese version of GU50) looks nothing like the 300B, but still it is interesting. So you understand that a link to that article is in order. Also, there is no way that you are getting 12 Watts from a FU50 , in triode connection with 310Volts. Look at the curves! 12 watts from a GU50 is with 550Volts, pentode mode. I am working on such an amplifier.

[siliconray]

Hi Costis

The aritcal is published on a magazine. I'll try to find it. But I don't think you can read it in Chinese.

Thanks for figuring out the max power problem. I also realized that the 12W is impossible. I'm quite new to tube. Actually I knew little about tube before involved in this business. the 12W is just copied from the supplier's words. The supply voltage is about 340V, the max power should be around 8W according to my calculate, am I correct?

[siliconray]

One correction: the manufacturer's data about max power is wrong. FU-50 don't have 12W when working in troid mode at 310V. The max power is around 8W. Can't edit the first post, please keep this in mind.