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Post by bigboki on Jan 30, 2020 21:12:08 GMT -7
I managed to purchase used 20th Anniversary Stangray head during Black Friday sale at Long McQuade (Canadian music store chain and official Dr Z dealer in Toronto. What a wonderful amp. It is so good that I am selling off all my other amps. Simply they are not played anymore After about a month, unfortunately I started having issues. It is really weird. It would start normal, I would be able to play for about half an hour (on apartment level low volume) and then the noise will start coming up. It will start low, and then will become louder and louder until is way too loud (the noise). Amp itself will sound as good as normal - just with a lot of noise. If I turn off stand by, it will sound with a loud pop. If I turn down the volume, there will be no pop. Also (I think) if I switch power off instead of standby there will be no pop. Now comes weird part. If I turn it on again in couple of minutes - most of the time the head will perform normal whole day! It was like that for about a week (1st time in a day quite then noise, then off / on, and works good) and then V4 power tube died (blue light on tube). All 4 EL84s are Sovtek. I head Mesa matched pair EL84 on hand and I used one to replace broken V4 power tube. Amp was back to normal for couple of days. Then the same thing start happening again. It is still under L&M warranty (both for used and I purchased extended one), so I can take it to them for check up, but wanted first to check with you and Dr Z himself. Since I am in Toronto, ON, Canada, I cannot easily send it to Dr Z for full checkup (which I know would be the best solution). Thank you very in advance!
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Post by Ridgeback on Jan 30, 2020 21:24:10 GMT -7
Could be a microphonic ef-86 in V-1. They are notoriously touchy and it's always good to have a spare anyway. Best I can do. Good luck.
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Post by bigboki on Jan 30, 2020 21:54:13 GMT -7
Could be a microphonic ef-86 in V-1. They are notoriously touchy and it's always good to have a spare anyway. Best I can do. Good luck. Thank you for the response. I tried one more thing today which I forgot to mention. I put a Kingsley tube preamp pedal into Effects return and plugged into the pedal directly - basically used Stangray as power amp only. The same thing happened. Also what I noticed as well - sometimes when noise comes - if I move the speaker cable - the noise might disappear sometimes completely, sometimes just for a moment. That does sound like what you are saying - microphonic pre amp tube?
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Post by j4gitr (John) on Jan 31, 2020 5:09:09 GMT -7
The el84’s are a matched quad. You should probably replace all 4 at the same time, or at least in pairs. You mentioned you only replaced. #4. My $.02. Perhaps the phase inverter as well. check out doc’s troubleshooting video. drzamps.com/info/faq-troubleshoot/
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Post by bigboki on Jan 31, 2020 6:34:44 GMT -7
Great suggestion - I was not aware of that video!
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Post by bigboki on Jan 31, 2020 6:53:10 GMT -7
I forgot to mention - there are no issue with the fuse - it is not blowing up.
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Post by bigboki on Feb 16, 2020 6:20:02 GMT -7
Update on the issue! I finally received my tube set and all replaced power tubes with matched quad JJs. At first run amp was back to its glorious sound. On the second - the noise came back. Looked a little bit more around - checking cables etc - it seems it is faulty speaker cable! Replaced it with another one and so far so good.
Thank you all for help!
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Feb 16, 2020 8:32:22 GMT -7
Welcome to the forum! Nice that you seemed to have located the problem...
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Post by bigboki on Feb 16, 2020 8:36:39 GMT -7
Thank you for the welcome. It is really nice community around here! No wonder, wonderful Dr Z company and Dr himself, best amps, best community - everything falls to perfect place
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Post by Chilly Gibbons (Todd T.) on Feb 16, 2020 9:14:10 GMT -7
And now you have new tubes as well! Bet she sounds great!
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Post by bigboki on Feb 16, 2020 9:55:30 GMT -7
She sings like an angel!
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Post by perryr on Feb 16, 2020 12:01:37 GMT -7
Wow, hope its resolved, That would be a tuff one to find!
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