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Post by ksquared on Oct 6, 2019 15:13:45 GMT -7
My Z-Luz started making a frying noise. It also cuts in and out a bit. Here's a clip. (It starts about 7 seconds in.)
But strangely, after this happened, I left the amp on standby for about 20 minutes, then returned and played more, and the frying noise was gone! I'm hoping someone here can help me troubleshoot. My (albeit limited) experience is that most issues are caused by a tube or something simple.
I had a thread about this same issue a few months ago, but at the time it not as acute as in the clip. I troubleshooted by replacing the power tubes (with the stock JJs) and using de-oxit on all connections. This seemed to work, until now. Also, at that time a longer warmup (like several minutes) seemed to help. The amp was purchased new in April 2018, but FWIW I believe it was at the dealer for two years or so before I bought it.
Any advice?
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Post by purpletele on Oct 6, 2019 16:11:55 GMT -7
My Z-Luz started making a frying noise. It also cuts in and out a bit. Here's a clip. (It starts about 7 seconds in.)
But strangely, after this happened, I left the amp on standby for about 20 minutes, then returned and played more, and the frying noise was gone! I'm hoping someone here can help me troubleshoot. My (albeit limited) experience is that most issues are caused by a tube or something simple.
I had a thread about this same issue a few months ago, but at the time it not as acute as in the clip. I troubleshooted by replacing the power tubes (with the stock JJs) and using de-oxit on all connections. This seemed to work, until now. Also, at that time a longer warmup (like several minutes) seemed to help. The amp was purchased new in April 2018, but FWIW I believe it was at the dealer for two years or so before I bought it.
Any advice?
I have a similar issue in my Z-Plus which I am certain is a pre-amp tube. I keep trying to identify it, but then it clears up. I am not in a critical situation so I am taking my time. If you want to get down to business, then start by ordering at least one of each pre-amp tube that you don't have, for example a 12AY7 or 12AT7, I don't know the configuration. Start at one end and roll them until you find the culprit. If you haven't had to change these until now then that makes good sense for timing. BTW, The video sounded a lot like my Z-Plus
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Post by premiumplus (Dave) on Oct 10, 2019 10:39:57 GMT -7
That's exactly what I'd do...
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Post by ksquared on Oct 11, 2019 14:10:13 GMT -7
Thanks. I'll give it a try (if and when the problem returns). As I understand it, the pre-amp tubes in a Z-Lux are:
V1: First Stage, V2: Tone Stack Driver, V3: Reverb Driver, V4: Reverb Recovery, V5: Tremolo, V6: Phase Inverter
Any educated guesses as the likely culprit before I go one by one? I'm thinking V2 or V6. I should have a spare 12Ax7 handy.
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Post by purpletele on Oct 11, 2019 17:31:40 GMT -7
Thanks. I'll give it a try (if and when the problem returns). As I understand it, the pre-amp tubes in a Z-Lux are:
V1: First Stage, V2: Tone Stack Driver, V3: Reverb Driver, V4: Reverb Recovery, V5: Tremolo, V6: Phase Inverter
Any educated guesses as the likely culprit before I go one by one? I'm thinking V2 or V6. I should have a spare 12Ax7 handy.
I’d start with V6 then V1, then V2
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Post by ksquared on Nov 8, 2019 9:07:15 GMT -7
Hi all. So my problem hasn't gone away. I took the amp to an open jam last night. After about 2 hours of goodness, it was back to sizzling bacon and I had to shut down. At high volume, the noise sounded a bit like excessive preamp distortion blended with the "normal" output. The noise seems to come on at random. It's often not there at all (which is why I haven't sent it off for a a repair yet) and makes it hard to troubleshoot. So far, I have done the following:
1. DeOxit jacks and tube sockets 2. Replaced all power tubes (based on some Internet info that JJ had a bad run of 6v6s about the time my amp was built). 3. Replaced V1, V2 and V6 with the tubes recommend on the Z website. (V1 and V2 were not the ones currently recommended, for whatever reason.
I have not bothered with V3, 4 or 5 as the reverb works fine and I'm not using the tremolo. Should I try before sending it off for a repair? Anyone have other advice? I like to try to DIY things, but my knowledge here is pretty sparse...
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Post by purpletele on Nov 8, 2019 9:26:32 GMT -7
Hi all. So my problem hasn't gone away. I took the amp to an open jam last night. After about 2 hours of goodness, it was back to sizzling bacon and I had to shut down. At high volume, the noise sounded a bit like excessive preamp distortion blended with the "normal" output. The noise seems to come on at random. It's often not there at all (which is why I haven't sent it off for a a repair yet) and makes it hard to troubleshoot. So far, I have done the following: 1. DeOxit jacks and tube sockets 2. Replaced all power tubes (based on some Internet info that JJ had a bad run of 6v6s about the time my amp was built). 3. Replaced V1, V2 and V6 with the tubes recommend on the Z website. (V1 and V2 were not the ones currently recommended, for whatever reason. I have not bothered with V3, 4 or 5 as the reverb works fine and I'm not using the tremolo. Should I try before sending it off for a repair? Anyone have other advice? I like to try to DIY things, but my knowledge here is pretty sparse... My bacon frying on the Z-Plus was from a set of power tubes that were fairly new. They were mesa tubes from my tube dealer. I since replaced them with JJ's. All good now. You may want to try a new matched set of power tubes, that's what the shop will do first.
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Post by Chilly Gibbons (Todd T.) on Nov 9, 2019 5:05:39 GMT -7
Are you seeing an accompanying light show from the back of the amp during the frying noise events? Intermittent shorts or arcing in power tubes will often come with sparks and flashes inside the offending tube.
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Post by ksquared on Nov 11, 2019 10:01:31 GMT -7
Are you seeing an accompanying light show from the back of the amp during the frying noise events? Intermittent shorts or arcing in power tubes will often come with sparks and flashes inside the offending tube. I replaced the power tubes already, but I'll look again. I'm going to replace V6 again with a new tube, because when I replaced it before it was with a tube that I can't vouch for (as I've completely forgotten where it came from). If that doesn't fix it, then it's on to the shop. Thanks for all the ideas.
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Post by ksquared on Nov 25, 2019 8:33:39 GMT -7
Just wanted to post the resolution for anyone paying attention. I worked with Don at Z repairs to troubleshoot and the tube in V3 was the culprit. All is good now.
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Post by Chilly Gibbons (Todd T.) on Nov 25, 2019 8:40:05 GMT -7
Great! Thanks for posting.
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Post by Jaguarguy (Mike) on Nov 25, 2019 9:27:16 GMT -7
Just wanted to post the resolution for anyone paying attention. I worked with Don at Z repairs to troubleshoot and the tube in V3 was the culprit. All is good now. Don is great to work with! Glad you figured it out!
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Post by marasciallo on Jun 21, 2020 11:13:51 GMT -7
Hello all, I listened to the audio clip and it sounds exactly like the issue I'm having. I replaced all power tubes and it seem to have worsened. It randomly comes and goes even though it seems to be more common on certain notes. I wrote to zrepairs one week ago but I coundn't get any reply yet. Here is my sound clip. I would like to start troubleshootin as long as I can be sure that I'm not damaging any other components.. drive.google.com/file/d/1Uo0vcfBoJKVO6ifORKiOvH3sIAu29XtA/view?usp=sharingThanks for your help.
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Post by Jaguarguy (Mike) on Jun 21, 2020 11:44:06 GMT -7
Hello all, I listened to the audio clip and it sounds exactly like the issue I'm having. I replaced all power tubes and it seem to have worsened. It randomly comes and goes even though it seems to be more common on certain notes. I wrote to zrepairs one week ago but I coundn't get any reply yet. Here is my sound clip. I would like to start troubleshootin as long as I can be sure that I'm not damaging any other components.. drive.google.com/file/d/1Uo0vcfBoJKVO6ifORKiOvH3sIAu29XtA/view?usp=sharingThanks for your help. Welcome to the Forum - a lot of great people and information here. New tubes are a crap shoot these days - even they can be bad. Try Doc's trouble shooting process here drzamps.com/info/faq-troubleshoot/
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Post by Chilly Gibbons (Todd T.) on Jun 21, 2020 15:14:25 GMT -7
Kind of sounds like something rattling, either on or inside the cabinet. Make sure everything with a screw head is tight and definitely pay attention to the preamp tubes. Sounds like there could be a questionable one there. Good luck tracking the noise down and keep us posted.
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Post by marasciallo on Jun 22, 2020 4:32:31 GMT -7
Thank you all for your suggestions! Do you think there is a risk of damaging the amp playing it with that defect going on during troubleshooting?
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Post by Chilly Gibbons (Todd T.) on Jun 22, 2020 6:42:05 GMT -7
Thank you all for your suggestions! Do you think there is a risk of damaging the amp playing it with that defect going on during troubleshooting? It wont damage anything. You might need a helper that can get the amp to produce the noise while you troubleshoot though, especially if its a pesky rattle.
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Post by daddyelmis (Greg) on Jun 22, 2020 7:28:26 GMT -7
Hello all, I listened to the audio clip and it sounds exactly like the issue I'm having. I replaced all power tubes and it seem to have worsened. It randomly comes and goes even though it seems to be more common on certain notes. I wrote to zrepairs one week ago but I coundn't get any reply yet. Here is my sound clip. I would like to start troubleshootin as long as I can be sure that I'm not damaging any other components.. drive.google.com/file/d/1Uo0vcfBoJKVO6ifORKiOvH3sIAu29XtA/view?usp=sharingThanks for your help. Did you see the post above about emailing Don at the shop and getting his input? The OP replaced the V3 tube to solve his problem
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Post by marasciallo on Jun 22, 2020 16:06:42 GMT -7
Tried to put back on the set of old 6v6 and I haven't been able to recreate the noise. I'll keep playing that way and see if it was a bad power tube.
Thanks for your help!
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Post by LT on Jun 23, 2020 8:12:11 GMT -7
Tried to put back on the set of old 6v6 and I haven't been able to recreate the noise. I'll keep playing that way and see if it was a bad power tube. Thanks for your help! If you email Don, be patient. I think the factory is still catching up from being closed. He will respond though.
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