Lights out JJ 2a3

[fled]

Bit of a bizarre question but on one of my jj2a3 40w valves the heaters have stopped glowing. 

It hasn't effected the performance in any way in fact the small amount of buzz I had on that channel has totally disappeared, and the system as a whole is playing better than ever. 

So the question is why have the lights gone out. 

Cheers all

Phil 

 

[JANDL100]

So the question really, to maximise sound quality, is how to stop the other 2a3 from glowing. 

Sorry I can't help. Yes, it does seem bizarre. 

 

[rabski]

Bit of a bizarre question but on one of my jj2a3 40w valves the heaters have stopped glowing. 

It hasn't effected the performance in any way in fact the small amount of buzz I had on that channel has totally disappeared, and the system as a whole is playing better than ever. 

So the question is why have the lights gone out. 

Cheers all

Phil 

Is it there for show?

If the filament has totally died, the valve won't work. Possibly it's still there, but partially failed. Or the supply to it has partly failed so it's a lot dimmer. Or in fact the other one is brighter and getting more voltage than it ought to have.

 

[Jazid]

Summat wrong there,  you need a tech to sort it swiftly. If it sounds better now there was almost certainly something wrong before the valve filament stopped working.

The filament may have snapped, or the filament supply might be faulty. If the former stop using it because if the snapped filament touches the valves anode there will be a loud noise and magic smoke. That could be expensive

 

[Jazid]

If that's a VTA SET then the valves are not for show. Lovely looking amp!

 

[fled]

OK still playing but the light came on briefly but now have disappeared again. 

I guess this is an amp problem not valve. 

Knowing zip about electronics. 

 

[fled]

Swapped the valves around all working as it should. So amp problem I think. Humm is back on that channel. So maybe lose connection? 

Need to find someone to take a look. Which is going to be tricky where I live. 

 

[fled]

Bit of a running commentary but it now clearly is dimmer. 

BTW these are monoblocks. 

I assume it's the supply line. 

I will definitely need a tech to look at, but from what I've described if some knowledge wizz on the wam could sort of point me in the right direction. 

As I understand its 2.5v line, so what could have failed? The tube socket is a little lose in the hole. If it was a duff connection here it just won't work, would it? 

Phil

 

[Jazid]

It could be a loose connection in the socket, the pins not mating tightly to the socket. This might behave as you are describing. Or it might be a loose connection between the wire supplying the socket and the socket. If you wiggle the valves only do it with the power off, there's a lot of volts on the other pins waiting to cause trouble. If the valve socket is a bit loose it needs to be looked at, could cause mischief.
Also worth taking the valves out of a cold amp and give them a clean with isopropyl alcohol or similar to remove any oxidation that has built up.

Sent from my BLA-L09 using Tapatalk

 

[Psilonaught]

I'm having my valve monos rebuilt by a very knowledgeable valve amp repair place in Essex.

Depending on your location I would recommend them, based on my experience with them thus far (they have completed the work yet)

 

[Juancho]

If this a push-pull amp then the symptoms you describe are exactly what happens when the heater supply to one of the output valves fails. You will still get output (if you listen carefully you should find the output lower on that channel). The amp then hums because you've lost the self cancelling effect of the push pull pair.

 

[Juancho]

PS the heater supply could of course 'fail' because of a faulty socket

 

[bencat]

Although they seem to be more for guitar amp repairs it might be worth contacting this company as they are close to you in Poole .

https://www.jbamprepairs.co.uk/

 

[Psilonaught]

Although they seem to be more for guitar amp repairs it might be worth contacting this company as they are close to you in Poole .

https://www.jbamprepairs.co.uk/

the guys in essex doing mine are primarily guitar amp repairers too, I guess it must be quite common to do pro and home audio valve repair