Think I have a tube issue

[JD01]

Dunno how long I've had my H&K now, but it's at least 6 or 7 years. Great amp.

Just not sounding as good as I think it should lately, just a bit dull/boxy sounding.

There's this tube monitoring system on the back, haven't dug through the manual yet, but I'm guessing all the lights should be the same. What you think @Greg_L

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[Tadpui]

That's a pretty cool setup, I've never seen that on an amp before. From what I can gather from their hieroglyphics, no light is good and dim or bright light is (potentially) bad. Does the bottom plate have more information as advertised?

[JD01]

That's a pretty cool setup, I've never seen that on an amp before. From what I can gather from their hieroglyphics, no light is good and dim or bright light is (potentially) bad. Does the bottom plate have more information as advertised?

I haven't extracted it from its location yet. Probably will do in a couple of days. Its tucked away and held in place by cables.

[Armistice]

According to the legend immediately above the four lights, two of the four tubes have "no current", assuming the lights aren't blinking.

Probably not a good thing...

[Greg_L]

That looks to me like you have a tube on each output pair with no current. Not good. Swap the output tubes around and see if the faults follow the tubes.

[JD01]

Was reading up on this in the manual last night.

I think it might be to do with the power scaling feature, if I have the amp down at 5W or 1W tubes are disengaged.
I rarely run it on 40W cos it's just too loud for the space.

The slightly boxy sound wasn't there when I took my headphones off and just stood in front of it, I think it was caused by me getting the signal from the 0W emulated cab in addition to the miced signal... again, I'll check.

[JD01]

Right, had a good play with it this morning and I'm pretty relaxed about it.

I've put it into 0W mode and left it for a mo, all lights come on. Stuck it into 40W mode - all lights off.
What I was getting in my headphones was a combination of a) what the mic was picking up, b) the Redbox speaker emulation built into the amp, c) general bleed from the loud amp in the room into my headphones.

I think I'm normally used to this weirdness in my cans so just ignore it - however, I've not had much chance to record lately (kids) so I was trying to dial in the amp to compensate for it... I've made some strange tonal choices. Doesn't matter though - I'm only arranging at the moment, not recording keeper tracks.

[WhiskeyJack]

That is a very cool feature. I like that.