[renaudrenaud]

I am exactly on the same mood. Living in China since 2 years an half I spent less than 500$ for the whole system with the Lii Fast-15, audio player, little DAC and little amp. The most expensive part was the wood for the panels. I was very impressed by the result.

Few months ago I learned we will stay two more years in China, so I decided to buy again a turntable. Then I told myself I would like to listen the panels with a tube amp.

Except the turntable, everything is ultra cheap equipment and the results are so nice.

[aricml]

I also ordered one of these and some additional tubes to try (at that price why not?) and reading a bit about it, I'm pretty sure I will want to rewire the leads to those anodes with something perhaps safer.  Does anyone know a good source for the caps for those pins?

[renaudrenaud]

Which one did you ordered?

[Tyson]

Wait, there are unsafe caps in this amp?

[aricml]

I ordered the FU-19 one with the wood sides in the link below

https://www.aliexpress.us/item/3256805709492361.html?spm=a2g0o.order_list.order_list_main.5.21ef1802jLu98g&gatewayAdapt=glo2usa

Tyson, I am not saying anything is unsafe, just that I will feel better with some rated wire on the leads going to the anodes. On another forum I saw this modification that seemed reasonable.

[Jon L]

LOL. That reminds me of Pipi Longstocking 



Yeah, it probably is a good idea to change that external anode cap wire to something else.  I still can't believe I haven't even opened this amp or try to modify it, but it definitely is a case of "don't fix it if it ain't broke" for me.  Let me wait to see what more people say about the A300 version with silver case.  Heck, I might buy myself a third one 

[renaudrenaud]

Hello! I have some big noise in one channel 😭

Don't have any time right now to investigate.

[FullRangeMan]

Hello! I have some big noise in one channel 😭

Don't have any time right now to investigate.

Keep us posted...

[renaudrenaud]

Arf...

I have an extremely low knowledge in electronic. I can more or less read a schematic but I cannot understand it, I can identify some components and see vaguely the signal path.

So I've done 2 things:
1 - change the FU 19 tubes from left to right and right to left. No change, this is on the right channel
2 - opened the amp to see if something was loose, bad soldering or smell a burnt component: nothing on, this side.

The next easy step I can do is to buy the preamp tube and try a swap.

If you suggest some things to test with a simple multimeter, I will receive your information with great pleasure and enthusiasm (but I usually do some arduino things under 5V, the tube amps are dangerous in my point of view).




I also asked a friend to call the seller. I am in China, do not speak Chinese and I need some help. Usually the sellers are very friendly. I hope the amp will be fixed in one way or another (I was just thinking to buy another one, the cheapest in green painting, I like the vintage look).

[FullRangeMan]

A scar at my right hand confirm that tube amps are very dangerous, they work with hi voltage.

To work at it is need rubber shoes, no rings, no watches, rubber gloves, security glasses etc
I could start sniff at the input tube, after the transformers, power and after the OPTs.

Take most care, only 30V DC already can kill you
(your heart gets out of pace and you die).
Do you can change the input tube for a new one?

EDITED

[renaudrenaud]

I've just ordered 2x6n2-EB, will receive in 2 or 3 days.

Arf, re-plugged the previous little class D amp and I am crying...

The current one:



Do you think it is a stupide idea to switch the amp on without the pre tube to test if the hum is still here?

[renaudrenaud]

Also I found a funny sticker for the amp

[renaudrenaud]

Ok, the seller is sending another 6n2!

Will give you some information in 2 or 3 days!

[opnly bafld]

Do you think it is a stupide idea to switch the amp on without the pre tube to test if the hum is still here?

Yes you can try that.

[renaudrenaud]

Yes you can try that.

Done. I don't have any hum like that. So I think this is the 6n2 at 90%.

[opnly bafld]

Done. I don't have any hum like that. So I think this is the 6n2 at 90%.

Try it with that tube in and the hum side output tube removed.

[renaudrenaud]

Try it with that tube in and the hum side output tube removed.

Hem, what is the logic?

[Jon L]

It's interesting the long chassis version uses different film and electrolytics caps compared to wide chassis version. 
Do try different tubes, but next thing I would check are all the electrolytic caps.  One MUST discharge all the electrolytic caps completely and use proper multimeter for that.  Still, this amp should still be under warranty/return-period, so if not a tube issue, I would ask for a new replacement amp.

[renaudrenaud]

I received the tube(s) yesterday, changed it and now the amp is alive and kicking.

I ordered immediately after the fail 2 new tubes and a friend of mine called the seller: he sent immediately a new tube. So now I have some spare.

Regarding the warranty, let me explain this is a western concept.I live in China, bought in China with Taobao and this is Ying and Yang, for one broken amp there will be one working.

For the different components between the wide and long chassis, the seller explains the long one is marginally better. Don't care too much, I think I will buy also a long wide version, it's too much fun for the price of 100/120€, I mean it is really inexpensive and the sound is pure joy, a touch of tube but not caricatural.

Thanks for the help guys and enjoy your time listening your tubes.

[renaudrenaud]

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