Reviews on JungSon amp/preamp combo: JA-1/JA-99C

Have a 200 watt integrated that is nice but has developed a slight hum, very difficult to find a repair person that can take on a supposed Class A transistor device with no access to a schematic or manual.

Have you contacted the seller? Well, many Chinese sellers don’t stay in business long to take care of after service, so you may be out of luck. That’s I’m worrying about too. When I addressed the possible repair situation to the seller (Mr. Yong Lee), he said I can send my amp to their service center in US.
I hope no such occasion occur in the near future. Even though you might not have bought yours from Yong Lee, you can still ask him about their repair center in US. His email is admin@china-hifi-audio.com.

If you do get a hold of him, ask why he came to my house looked me in the eye and lied straight to my face. Ask him why Stewart had to make good on his crappy amp because Jungson wouldn't honor their warranty. I would ask him myself but once someone has proven to me their word is worthless what is the point? Do you get the idea how I feel about Jungson? Best of luck to you, anyone fool enough to do business with them.

Yes, I see that you had a terrible experience with Jungson and Jungson dealer. I am not sure though whether it is an exceptional event or a rather widespread event. 
All I can say is, buyers of Jungson gears need to be aware of the reliability and after service issue. I knew those issues, and I still purchased them, so if something goes wrong and if I don't get proper service, I guess I was a fool and it is all my fault. 

Actually the experience with the dealer was fine. The problem is the dealer had to step up and make good out of his own pocket. Months later he told me they gave him the same treatment and so he never placed another order and completely dropped all Jungson gear. Before that he had sold me a couple Jungson interconnects and a power conditioner. The conditioner was crap quality on the outside but good parts on the inside so rather than sell I gutted it and the transformer and stuff is still in my system to this day. The interconnects also were poor quality, the finish started going bad the first year and looks horrible today but they are now just sort of spares. Some things are worth keeping around if only to remind you who not to do business with ever again. Jungson is definitely a never again.