Smokey Valve Amp!!
Posted: Fri Nov 29, 2013 2:22 pm
One of my Art Audio Maestro's began to look very sick last night :-(
I recently revalved both with 2 octets of EL34s and they were working sweetly for over a week but I had seen an ominous sign during installing the valves.
In my rush to hear them with the new valves I just switched off the power switch and the standby switch on both and left them connected to power while I pulled the old valves and pushed home the new ones.
On one of the amps i noticed the little signal valves start lighting up as I was loading the EL34s so immediately pulled the power leads....thought it strange how this could happen with both switches off but maybe there is more to valve amps than I thought!
Anyway last night the one which started lighting during valve installation was running away fine for several hours of sweet music until I went and switched everything off.
Went away for a few minutes and came back and I could hear a little tizzzzing sound and then noticed some smoke starting to waft from said amp....pulled both power cords immediately!!
Certainly learned that leaving old valve amps connected to the mains even with the amps switched off is not as as safe as I thought, probably lucky I was still in the room after switching them off but most likely fried one of the transformers.
Pulled the bottom off this morning (before anyone asks YES the mains was disconnected :-)) and all the capacitors and resistors look good so some fun and games ahead methinks.
Time to pull out the Primare Solid State for a while and see how it sounds until I get to the bottom of this.
Looking back at some old threads I seen the HiFi Clinic mentioned for repairs.....any update on where to go for repairs in Ireland would be appreciated rather shipping back to the UK?
The central heating will have to do a little more work for a while until I get this sorted!!
Cheers,
Pearse.
I recently revalved both with 2 octets of EL34s and they were working sweetly for over a week but I had seen an ominous sign during installing the valves.
In my rush to hear them with the new valves I just switched off the power switch and the standby switch on both and left them connected to power while I pulled the old valves and pushed home the new ones.
On one of the amps i noticed the little signal valves start lighting up as I was loading the EL34s so immediately pulled the power leads....thought it strange how this could happen with both switches off but maybe there is more to valve amps than I thought!
Anyway last night the one which started lighting during valve installation was running away fine for several hours of sweet music until I went and switched everything off.
Went away for a few minutes and came back and I could hear a little tizzzzing sound and then noticed some smoke starting to waft from said amp....pulled both power cords immediately!!
Certainly learned that leaving old valve amps connected to the mains even with the amps switched off is not as as safe as I thought, probably lucky I was still in the room after switching them off but most likely fried one of the transformers.
Pulled the bottom off this morning (before anyone asks YES the mains was disconnected :-)) and all the capacitors and resistors look good so some fun and games ahead methinks.
Time to pull out the Primare Solid State for a while and see how it sounds until I get to the bottom of this.
Looking back at some old threads I seen the HiFi Clinic mentioned for repairs.....any update on where to go for repairs in Ireland would be appreciated rather shipping back to the UK?
The central heating will have to do a little more work for a while until I get this sorted!!
Cheers,
Pearse.