1st full tube amp Oldchen EL34

Understood and again this was an opportunity but not a nirvana situation. I have the top of the Line LSA HYBRID that drives my Thiel CS5s and totally pleased. I have a bardominium playground for my grandkids and this is where I like to tinker. Heresy’s, Chorus 1s, and Quartets are the available speakers at this location. I change between Bryston, Mitsubishi, Lexicon, NAD, and other assorted amps. Most I have brought back from dead. And most sound better today than when new due to better parts. Never opened a tube amp and I have a significant amount of respect for the damage they can do if mishandled. Variac on-site and have still smoked some things in the past. 😉

I have run my Quartets with a 4 watt Decware Mini Torii and a 6 watt Grommes PHI-26  both sound great the quartets and tubes makes if sound like a liver performance

The first thing I would do is replace the rectifier tube (assuming it's tube rectified and that the tube is of Chinese manufacture).

A quick Google showed an inexpensive Oldchen single ended EL34 based amp with a 5Z3P/rectifier (2) 6N9P small signal tubes and (2) EL34's (one per channel).

Is this the amp?

A failing rectifier tube can wipe out the EL34's plus other passive parts of the amp which is why I would start by swapping in a known to be reliable tube.

Reasonably priced one's (for 5Z3P) would be a Russian 5C3S (all I've seen were manufactured by Svetlana) or a GE 5U4G (both run around $30, while other brands start @ $100+).

That done I would just listen to it for 3+ months before changing anything else.

The 6N9P signal tubes are equivalent to 6SL7 (not familiar with current prices and/or what people like for this tube).

I'm not Anti-Chinese tube on a whole as I've heard some of their EL34's, 2A3's, 300B's and 12ax7's that sound quite good, but their rectifier tubes seem to have a bad rep for reliability.

Before you start tinkering inside learn how to safely discharge the power supply capacitors.

DeKay

Thanks DeKay. I have worked with capacitors in ss amps so I understand the need to discharge for safety. I will order the rectifier and see what happens. I believe this is the same amp. May have also been labeled Laochen on other units. 

Rectifier is currently PSVANE