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Post by birthofahero on May 11, 2012 9:27:54 GMT -7
It could be super simple, as I am sure it is, but my 38sr makes some really nasty breakup type noise when I play. I am running straight guitar into amp. It could be a bad tube, but the tubes are all glowing at least. Could be a blown fuse? I just dont know, so any help would be really appreciated as this is my only amp and I need it! Just as I'm sure all of you need your Z's to work ;D
Anyway, thanks.
Edit: It is sort of a breakup sputter as if I was playing thru a terrible cable with some of the connections broken. I have tried different cables all with the same result, I am just trying to describe what I am hearing.
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Deleted
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Post by Deleted on May 11, 2012 10:21:50 GMT -7
Chassis bolts could be lose. Or it could be tube related.
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Post by birthofahero on May 11, 2012 12:28:09 GMT -7
Its gotta be tube related. It sounds much more serious than the chasis bolts being loose. Plus, the sound is coming from the speaker so it must be internal. I'm a little scared...
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Post by doctorice on May 11, 2012 13:22:37 GMT -7
Most likely a tube problem. In addition to trying different cables did you try a different guitar? I know, unlikely that's the cause, but it's a simple check. Tubes all seated nice and snug? Tube retainers too? (Some say the amp sounds better with the preamp tube covers removed.)
If it's something really hard to track down, you can arrange for it to visit the factory. The Z team will fix it. I had to send my MAZ 18 back once. Came back sounding better than ever as the factory performed a power supply update that occurred sometime after I got my amp.
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Post by birthofahero on May 11, 2012 16:38:41 GMT -7
Yea, I might consider sending it in. Its a 2002 model so it could use a check/tune up. It was working fine just yesterday. I haven't checked it with a different guitar. The Z and my tele are my only weapons.
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Post by birthofahero on May 12, 2012 8:22:17 GMT -7
I took out each tube, one by one, and inspected each one to see if it was burnt or microphonic.I didn't see either problem with the tubes so I replaced them, turned the amp back on and the sound went away.I don't know if it was as simple as a tube being loose but its gone and I might be more worried than before lol. I don't like not being able to pinpoint what the problem was. Makes me feel like its going to happen again.
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Post by BritInvasion on May 12, 2012 13:53:31 GMT -7
Most likely you had some oxidation on one or more tube socket pin sleeves. Pulling out and re-inserting the tube scraped the oxidation away and restored full electrical contact. You may want to consider spraying the sockets with short blasts of Deoxit.
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Post by pcns on May 14, 2012 5:53:40 GMT -7
in addition to cleaning the plugs on your cables from time we also need to remember to clean the tube socket sure am glad this was something simple God bless, Todd
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Post by birthofahero on May 15, 2012 5:49:30 GMT -7
That's funny you say that. I cleaned all my connections (amp, guitar and pedals) with some cnc cleaner about 2 months ago. So could it really be dirty again?
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Post by sparrowhawk (Bob) on May 16, 2012 8:52:54 GMT -7
That's funny you say that. I cleaned all my connections (amp, guitar and pedals) with some cnc cleaner about 2 months ago. So could it really be dirty again? Very possible that it's a bad contact on one of the tube pins. I've had this happen to me. Pick up a can of DeOxit cleaner (not the protector) and some Q-tips. Pull one tube at a time, spray a Q-tip with the DeOxit and clean each pin on the tube. Squirt a small ammount of cleaner (emphasis on small) into the tube socket and re-insert the tube. I do this once a year (also clean the cable ends and jacks for my amp and effects) and I swear it helps the tone. DeOxit is great stuff. A few years ago I helped a friend restore an 40-year-old British car. Some of the electrical switches were so oxidized that there was no current flow through the switch. A little DeOxit, a few flips of the switch and the lights went on.
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Post by birthofahero on May 17, 2012 10:02:09 GMT -7
Ok, the sound is back and it only seems to happen on certain notes/frequencies, specifically the note "b". It is a very high screeching sound. It is close to the sound of fingernails on a chalk board, or at least the feeling that you get from that. I wish I could describe it better.
I took out the tubes and sprayed some CNC cleaner on the pins. Is that different than deoxit? I only had 3/4 extra power tubes and 4/5 extra pre amp tubes and that didnt seem to help. I'm really not sure what else to do except send the amp to the doc but I dont have the money for that and this amp is my daily driver. So if I can do it in-house, that would be the best scenario. Thanks for your help.
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Post by birthofahero on May 23, 2012 9:57:57 GMT -7
It seems to happen randomly. I havent heard it in about a week or two. I could really use some help with this. Also, if there is another forum that I could post to, let me know.
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Post by doctorice on May 23, 2012 10:58:13 GMT -7
Here's something you might try to see if it's a tube issue.
1. Grab an oven mitt or a towel. You're going to be holding onto hot tubes! 2. Fire up your rig and get the bad sound to occur, if you can. 3. Put your guitar on a stand and put a capo on it so that you can pluck the "offending" note without needing to fret the guitar. 4. Hold onto each tube in sequence, pluck the guitar and see if the bad sound goes away when you're holding a particular tube. 5. If it does you've found the trouble spot. Swap in a known good tube and try again. 6. If you still have a problem it could be the tube socket. It might need mechanical adjustment, such as tightening the sleeves (which the tube pins go into).
I was getting a breathy "ghost note" overtone in my MAZ but only in a certain restricted range of notes. It didn't matter which string I played the notes on. After doing the above, I identified a tube socket problem and sent the amp to Maple Heights.
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Post by birthofahero on May 24, 2012 10:03:45 GMT -7
Great advice! I'll try that asap. I have a show tonight so I really hope it's just a tube problem.
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Post by birthofahero on Jun 6, 2012 12:40:27 GMT -7
I am certain that it is a tube socket problem. I too your advice and looped the same note and was able to replicate the buzz I was hearing. Holding v5 and v6 made a LOT of noise and popping when I just touched them, in fact they were the only ones I touched because I was afraid of what I might do to the amp. After turning everything off and letting the tubes cool, I felt the tubes in v5 and v6. V5 felt particularly loose and v6 felt a bit loose as well. So I am led to believe that the problem is a loose connection. How can I fix this? Home remedy or send it in? Is it a job only for the docs precious hands or can I do it locally? Thanks for he help guys.
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Post by doctorice on Jun 6, 2012 12:57:24 GMT -7
My advice would be to contact Dr Z and arrange to send it in. It probably will be like a new amp when it comes back.
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Post by wubberdubber on Jun 7, 2012 22:08:42 GMT -7
If you're CAREFUL, you could take a small pair of needlenose pliers and put a SLIGHT angle on the tube pins so that it will grip in the socket better. I personally would consider this a temporary thing until I could either re-tension or replace the socket...and if that's not something you're comfortable doing yourself, then it's off to the tech.
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Post by birthofahero on Jun 8, 2012 7:54:41 GMT -7
Its not that I am uncomfortable doing any of that, Its just that I have no idea how to re-tension the sockets, or replace them. My roommate is pretty darn good with a soldering iron. However, I would probably feel better if I just sent it in to the doc. Any ideas how much something like that costs? Should I be sacred to ship it?
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Post by Jaguarguy (Mike) on Jun 8, 2012 8:31:50 GMT -7
Should cost about $70 or so for them to look at it plus whatever parts they are gonna need for the fix. You can send either Brent or Don a note and they can give you a better idea. No reason to be scared of shipping - just make sure you put it in a sturdy box well protected. You can use either peanuts or bubble wrap to make a good protective barrier. Should probably run $30-40 depending where you are. Then again, you could take a road trip to drop it off and them have them ship it back to you. One of my favorite road trips! 6 hours round trip but I've never regretted it I've done this with several amps and they come back sounding as good, if not better, then new!
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Post by doctorice on Jun 8, 2012 10:07:02 GMT -7
I've shipped several amps to Dr Z for work. As Mike (Jaguarguy) said, the key is to pack it well. Importantly you only need to send the amp chassis in. That saves a fair amount on shipping costs.
It's easy to remove the chassis. Just take it slow and careful.
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Post by birthofahero on Aug 23, 2012 13:59:19 GMT -7
Ok guys, I have been really busy the last few months and havent got a chance to jump on the site but I have an update. Fist off, its worth noting that all the components of the amp tested correctly (ie. transistors, capacitors etc)
I recently took it in to a well known amp guy here in town and he tested some tubes and a few were pretty bad, got some new pre amp tubes and 4 brand new sovtek (yuk!) power amp tubes. That did not fix anything so we replicated the issue again and it was indeed a pre amp tube connection problem. By touching the problem tube (second pre amp tube from the right) we could instantly tell that the tube was loose. We made sure that the tube covers were rather tight and he tightened the tube sockets, tested the amp which sounded fine, no more problems and sent me on my way. I was actually in the middle of moving from Oklahoma to Washington and I did drive the whole way there. Fast forward a week and I finally get to play my amp in Washington but guess whats back? Yes, the awful noise.
So, I have pretty much isolated the problem and believe I know what to fix but I wanted to get your input on it. I believe (as does the tech in OK) that the actual tube socket is too shallow thus causing some bad connections with the pins. The guy actually said that he thought the sockets and covers were pretty cheap and recommended that I change them.
So there it is, sorry for the long message and I hope everything is clear enough. Has anyone experienced this or have any insight? Thanks again.
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Post by Deleted on Aug 23, 2012 14:44:22 GMT -7
Cheap sockets? I would send it to the Z Shop if it was mine. Doc is known to use top quality components. If it is a component problem I would bet he'd fix you up proper.
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