loud pop sound when turning off tube amp.

[thevoice]

hi, i am new to this forum. hopefully someone can help me with my tube amp.

i am using tube pre and rogue audio stereo 90 power amp. the trouble is turning the power amp off, a loud pop is heard coming from both speakers

is this normal for tube amp and any damage to my speakers?

thanks for all replies.

 

[Steve Williams]

Do you mute and turn down your preamp first and follow the rule that amps are last on and first off

Welcome to WBF

 

[DaveyF]

Depending on the amp, the loud turn-off transient (or pop) can be normal. The amp dumps DC into the speakers as the caps let go. My ARC D70Mk2 does this and is well known for this issue, as were many ARC amps of the same period.
There is no danger to your speakers. As Steve said, if you follow the rule ...Amos ( who the hell is he) sorry couldn't resist Steve-- Amps are last on and first off. The preamp should be on mute while you are doing this.
However,a quick check with your dealer or amp manufacturer would also be appropriate, because with your particular amp, this might not be normal.

 

[thevoice]

yes i always turn the volume to zero and wait 5-10 minutes for the caps to discharge then turning off the power amp.

when i say loud, i really mean loud.

thanks.

 

[mep]

yes i always turn the volume to zero and wait 5-10 minutes for the caps to discharge then turning off the power amp.

when i say loud, i really mean loud.

thanks.

Do you mean you turn the preamp volume to zero, turn the preamp off, wait 5-10 minutes, and then turn your amp off and it pops? Has your amp always done this? Have you called Rogue and asked them if this was *normal* for your amp?

 

[RogerD]

hi, i am new to this forum. hopefully someone can help me with my tube amp.

i am using tube pre and rogue audio stereo 90 power amp. the trouble is turning the power amp off, a loud pop is heard coming from both speakers

is this normal for tube amp and any damage to my speakers?

thanks for all replies.

Does the amp have a protection circuit? Has the DC offset been checked.....could be a leaky coupling or power supply cap.

 

[Steve Williams]

a cap would now be my next guess

 

[DonH50]

There should not be a pop IME. I would turn the power amp off first and let it discharge, then turn off the preamp. Preamp on first, wait a bit, then turn on the amp. My old SP3a1 took a few minutes for the output to stabilize. This was not a problem driving a tube amp, but before I figured out what was happening and learned to wait about 5 minutes or so before turning onthe power amp I blew fuses in a few direct-coupled SS amps and a few speakers.

 

[LL21]

Do you mean you turn the preamp volume to zero, turn the preamp off, wait 5-10 minutes, and then turn your amp off and it pops? Has your amp always done this? Have you called Rogue and asked them if this was *normal* for your amp?

Yes, i would mute preamp, turn off amp. Then turn off preamp. I can mute my amp, and even then, if i mute preamp and amp...then shut off pre first...the amp's DC protection will occassionally trigger and put the amp temporarily into protection. i have done it by accident...

 

[thevoice]

Do you mean you turn the preamp volume to zero, turn the preamp off, wait 5-10 minutes, and then turn your amp off and it pops? Has your amp always done this? Have you called Rogue and asked them if this was *normal* for your amp?

1 turn the volume to zero
2 wait 5-10 minutes
3 turn off the amp
4 wait for another 1 minute
5 turn off the pre.

thats my sequence. the cap or caps are the trouble maker. rogue audio has offered to repair it but i am not america.

 

[LL21]

thats the right sequence of course. sorry to hear about the problem. hopefully, a good local audio tech can help...should hopefully be a straightforward fix. good luck.

 

[DonH50]

You should be able to turn off the amp immediately after turning the preamp's volume to zero, then wait 5 - 10 minutes before turning off the pre-amp.

If you did not have this problem before, you either have a bad (leaky) coupling capacitor (in the preamp or the amp), or a bleeder resistor has opened up. Either way you risk damaging your amp and speakers if you can't get it fixed.