Tube amps popping on shut down...Arrggg!

[challenger1]

Just replaced my Bryston 3B ST(not a good match once I heard the Quickies in there place) with a set of Quicksilver Mid-Mono's EL34 versions that are driving my Klipsch Lascala's 1994 vintage. My normal shut down is to put the Audible Illusions M3A pre-amp in MUTE and then turn off each Quicksilver one at a time. When I turn them off I get a loud popping out of the Lascala's. Is this fairly normal for tube amps to do this and is there anything I could do to prevent this or lessen? Any help would be appreciated.

[russ69]

Call Mike but it's a bad power tube.

[challenger1]

Hoping that isnt the case,they are newer EL34's. Thanks and I will give Mike a call on Monday also.

[tube fanatic]

If you don't mute the preamp, but simply turn the volume all the way down, do you still get the popping? Also, is the popping present if nothing is connected to the amps' inputs? Popping at turn off is often related to arcing in the on/off switch which is, of course, amplified and carried through to the speakers. The fix is quite simple if you find the popping bothersome.

[Chris A]

When I turn them off I get a loud popping out of the Lascala's. Is this fairly normal for tube amps to do this and is there anything I could do to prevent this or lessen? Any help would be appreciated.

A much more permanent solution... http://www.firstwatt.com/f3.html

Chris

[tigerwoodKhorns]

Amps pop, they just have time delay to prevent hearing the spike. Maybe your amp does not have this circuit (I do not know if tube amps do tis, it has been a while since I have had a tube amp).

I am also surprised with the Bryston. That is a very good amp. I had a pair of 7B ST's and they were great amps.

[russ69]

Hoping that isnt the case,they are newer EL34's. Thanks and I will give Mike a call on Monday also.

Same thing happened to mine. It's just one tube gone bad and it causes the amp to thump on shutdown. In my case the amp still sounded fine but Mike said the output would have been 1db down but I didn't notice.

[challenger1]

Talked with Mike Sanders at Quicksilver Audio,Wow, calls me on Sunday after leaving a message on Saturday,this guy is awesome. He was saying the same thing about the On/Off switch,its probably arcing,the amps are low number models(#53and54). Could you elaborate a little more on the simple fix for this? Could it be just a matter of popping off the bottom and using some De-Oxit on the On/Off switch(dirty)or new switches altogether ? Hope so,I think I could handle that,LOL.

[muel]

At the risk of starting a power cord conversation I will tell you that I use a power strip to turn off and on vintage amps. This eliminates wear and tear on those irreplaceable on/off volume controls as well as making mono blocks a one switch operation. Also, when starting up turn the amp on last and when shutting down turn the amp off first.

[Taz]

At the risk of starting a power cord conversation I will tell you that I use a power strip to turn off and on vintage amps. This eliminates wear and tear on those irreplaceable on/off volume controls as well as making mono blocks a one switch operation. Also, when starting up turn the amp on last and when shutting down turn the amp off first.

I agree with this procedure. I turn off source, CD player, after turning volume all the way down on preamp, Then turn power amps off with power strip switch. Finally turn off the pre-amp. This has given me the softest shut down with that particular tube set up. On the S/S units I like to turn off power to speakers, turn off unit, then turn speakers back on. This stops any speaker noise at shutdown.

,,,,,,,,Taz

[tube fanatic]

Talked with Mike Sanders at Quicksilver Audio,Wow, calls me on Sunday after leaving a message on Saturday,this guy is awesome. He was saying the same thing about the On/Off switch,its probably arcing,the amps are low number models(#53and54). Could you elaborate a little more on the simple fix for this? Could it be just a matter of popping off the bottom and using some De-Oxit on the On/Off switch(dirty)or new switches altogether ? Hope so,I think I could handle that,LOL.

No, unfortunately, Deoxit won't help in this situation. The fix requires soldering a .1 uf class X2 or class Y2 suppression capacitor across the primary of the power transformer. It will totally eliminate the problem. Where are you located? I'm in NJ and would gladly help you out with this if you're not too far away. Maynard

[derrickdj1]

I use a power strip to turn off and on vintage amps.

The power console is what I use for my vintage amps. I originally got it so I would not have to get up to turn the amps on since they don't have 12 volt triggers. I can also monitor the amps power use to help detect if something is wrong with the power usage.