1st full tube amp Oldchen EL34

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

+1 dekay.

Capacitors on tube amps can knock you on your butt a week after last use.

And as long as you know what you’re not getting, you’ll be fine.

Have fun and stay safe!

JD

The Psvane 5U4G receives good reviews for reliability/sonics from what I just Googled.

The cheap 5Z3P’s and 5AR4's are the one’s I’ve read bad things about.

How does it sound?

I ran a friend’s Chorus II’s with my little 2A3 kit amps years ago and liked them (hated them with her SS amp).

DeKay