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Post by digs57 on Nov 5, 2020 14:56:06 GMT -7
Been getting this metallic pingy noise when I flip power/standby switch...have switched out tubes and replaced some pre and power...use levys dampers...even on rectifier...No noise when playing too,sounds great.
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Post by Rhino on Nov 5, 2020 17:38:28 GMT -7
Have you tapped the preamp tubes with a pencil eraser to see if any are microphonic? Just a WAG from here! :-)
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Post by digs57 on Nov 5, 2020 18:33:51 GMT -7
ive replaced them...ill do some tappin tomorrow...thx
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Post by LT on Nov 6, 2020 7:34:37 GMT -7
My Nova was doing something similar. Flipping Standby was causing a noise and a loss of the 'normal' channel. Sent it back to the shop and it's fine now.
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Post by digs57 on Nov 6, 2020 8:00:33 GMT -7
Im thumping on one of the 6n14n and it replicates it somewhat...switched power's again and un/plugged speaker jack could still hear metallic pinging...even holding rect/power's.
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Post by DRZ on Nov 6, 2020 11:30:16 GMT -7
Been getting this metallic pingy noise when I flip power/standby switch...have switched out tubes and replaced some pre and power...use levys dampers...even on rectifier...No noise when playing too,sounds great. I would like to help but I do need to know a bit more details. What amp model is it? How long have you had it ? Did it always do this ? I must say diagnosing a problem over a keyboard is sketchy at best. If it is a metallic ping, my first thought is a microphonic tube any of them can cause this. If it is more like a thud then look to see if your stand-by switch has a Blue Ceramic .01 cap across it. This used to eliminate that snap from high voltage across the switch. If this is the case then this problem should have showed itself from the get go. You may be well served to call Don 216 475 1962 , he can listen to the sound over the phone and help in the diagnosis. DR.Z
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Post by repairz on Nov 6, 2020 12:38:14 GMT -7
a glassy ping coming thru the speaker when the standby is flipped is typically a preamp tube - most often Russian ( Sovtek, TungSol, EH etc. ) if this is NOT what you're hearing, send me a recorded clip of the noise
if it's sensitive enough that the switch tweaks it, you should also be able to hear it when knocking or even tapping on the cab, try it, if it works it'll save you from having to flip the switch constantly while troubleshooting
first, if your amps are MKIIs, turn the master off - this will seperate preamp from output sections - if you still here the ping, and it's definitely thru the speaker, the noise is from a power tube if it turns out NOT to be coming thru the speaker ( is louder behind the amp than in front ) its the rectifier
if the noise stops with the master volume completely down, it's coming from a preamp tube if the amp in question has reverb, turn the reverb control all the way down, if the noise stops then comes back when you turn the reverb the problem is most likely V4 Swap V4 and V5 positions, then try the amp again, if the noise is no longer present, V4 was the problem if there's absolutely no change, put V4 and V5 back where they were originally, then swap V3 and V2 positions if this eliminates the noise, the problem was V3 ( swapping 2 and 3 was only for troubleshooting purposes, the amp's tone and gain will likely be detrimentally affected by having a 12AT7/ECC81 in V2 and a 12AX7 ECC83 in V3, we don't recommend leaving the tubes in these positions) The last preamp tube that would cause the noise you're experiencing is V1, if V4 has been ruled out, install it in V1 in place of whatever is there now ( just for troubleshooting )
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Post by digs57 on Nov 6, 2020 15:24:30 GMT -7
"sensitive enough that the switch tweaks it, you should also be able to hear it when knocking or even tapping on the cab." This is indeed what happens...Bought from humbucker new,is a 2013 modded maz 18 (nr) to a mrk II....will try all of these thx Doc/don for assistance...as said once running its good,no noise from tubes.
"A little update to this.I sent in video to don and determined it was power tube related FWIW"
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