Hoarseman

I appreciate everyone's input. With a recent purchase of a Wiim Ultra and a subwoofer to complete a modestly priced home system...

A quick 'googling' indicates that the 'blue glow' is normal. Probably an LED under the socket.

It's been a couple of decades since I've seen a tube but I never saw one light-up blue. The heater usually glows orange like a dim...

According to Fosi website this amp uses the TPA3116 class D amp. Tubes in the preamp ? There's a video review on the site, it looks...

6A2 is a heptode, and 6J1 is a pentode. The latter has a couple of pins which are wired together, and if the blue LEDs didn't constantly...

The blue is definitely leds. Power tubes can have a blue glow too but it's not that pronounced. It looks like the heaters are remaining...

There used to be tube TVs with quick power on as a convenience feature that did this in the 1950s/60s, but it's obviously neither good...

Also, running the heaters without any HT will result in cathode poisoning and the consequent early failure of the tube. What was done...

Surprisingly I have had no problem touching the tubes when they are on. Barely warm - nowhere near hot.

Thanks for your responses, all. Based on those I have taken comparison on/off photos. The amp was relocated to a different cabinet and...

Depending on the capacity of the filter caps and the lack of a way to drain them when you switch the power off, those little valves...

So the tubes you put in looking at pictures look like they are more open to see the heater vs what the Fosi comes with. Some amps leave...

So didn't it do that before the tube swap? I don't see how that could be the case, it would be a very odd coincidence. Is it just the...

Hi folks I just upgraded the tubes on my Fosi T20 amp to a matched pair of Voskhod 6J1P-EV and I love the improvement in sound. There's...

I indeed got lucky with those Polks In the end I decided to go for a Wiim Ultra as the system hub, to get the various source outputs...