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Post by dmac252 on Oct 1, 2015 9:25:59 GMT -7
I picked up a MAZ 18 JR 1-12 about 6/7 months ago, it was having some static issues so I replaced all the tubes with recommended replacements( maz 18 sett from tubestore) I continued having periodic static bursts so I thought I would just take it to a local Reputable amp builder/repair shop. I've had it back for a while now and I started to get some of the intermittent static bursts, not as frequent as previously
I Typically use a few pedals on the front end but not always. When not using the pedals the amp now seems lac-luster and in order to get any reasonable volume I have to run volumes at 10 or near. I don't recall that being the case in the past. I recall this great amp being much more responsive without pedals.
I checked back with the repair shop and got the following info, they made some changes based on what they saw.
1.changed the cathode resister from 150 ohms to 330 ohms because the tubes were running too hot
2. added 2 1 watt 470 ohm screen resisters to prolong power tube life
Any comments would be appreciated
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Post by benttop (Steve) on Oct 1, 2015 10:41:21 GMT -7
How nice of them to redesign your amp and not say anything to you. I suggest you consider sending it to the Z factory for refurbishment. Their pricing is not stratospheric, and you will get the real deal when it comes back.
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Post by mauiman(Bill in Texas) on Oct 1, 2015 10:45:15 GMT -7
How nice of them to redesign your amp and not say anything to you. I suggest you consider sending it to the Z factory for refurbishment. Their pricing is not stratospheric, and you will get the real deal when it comes back. +1000.
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Post by dmac252 on Oct 1, 2015 12:01:19 GMT -7
How nice of them to redesign your amp and not say anything to you. I suggest you consider sending it to the Z factory for refurbishment. Their pricing is not stratospheric, and you will get the real deal when it comes back. +1000. is the +1000. eluding to more than $1000.for fixin her up :-(
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Post by headshrinker (Marc) on Oct 1, 2015 12:21:49 GMT -7
When you get those static bursts, any chance you or someone else had a cell phone on and within 20 feet of the amp? If so, it was the amp picking up the phone sending out a signal to communicate with a tower. It's a common thing with amps and phones, especially with AT&T. I'm with the folks above on the mods. Unless you asked them to mod your amp, I would go back and tell them to return it to the way it was. Those tubes are run hot for a reason, EL84s sound better when they are hot. That's why AC30s, back in the day, sounded so good once they had been on for a while. True they did melt components some times and catch fire, but they sounded great. The Maz runs them, hot but there is plenty of ventilation to keep the fires down. My take is,EL84s are cheap as tubes go. If you get a few less hours out of them, it's worth the amp sounding better.
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Post by dmac252 on Oct 1, 2015 14:04:56 GMT -7
When you get those static bursts, any chance you or someone else had a cell phone on and within 20 feet of the amp? If so, it was the amp picking up the phone sending out a signal to communicate with a tower. It's a common thing with amps and phones, especially with AT&T. I'm with the folks above on the mods. Unless you asked them to mod your amp, I would go back and tell them to return it to the way it was. Those tubes are run hot for a reason, EL84s sound better when they are hot. That's why AC30s, back in the day, sounded so good once they had been on for a while. True they did melt components some times and catch fire, but they sounded great. The Maz runs them, hot but there is plenty of ventilation to keep the fires down. My take is,EL84s are cheap as tubes go. If you get a few less hours out of them, it's worth the amp sounding better. Well there is always a cell phone somewhere near so I guess that is a possibility. I am bringing the amp back the shop tomorrow to reverse the Mods since I did not as for them. Agreed about the tube life not an issue for me. not withstanding would these mods potentially cause the issues I am now experiencing, or maybe that's a question for the Doc.
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Post by "Z" Steve on Oct 1, 2015 14:20:15 GMT -7
You can email him or he may respond here re your question and problem(s).
also, the + 1000 was an "AMEN" or whole hearted agreement with the previous post
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Post by dmac252 on Oct 1, 2015 14:25:12 GMT -7
You can email him or he may respond here re your question and problem(s).
also, the + 1000 was an "AMEN" or whole hearted agreement with the previous post Just gotta learn the lingo Thanks
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Post by headshrinker (Marc) on Oct 1, 2015 16:33:10 GMT -7
Running the tubes at something other than what the amp's design was based on could make the amp have lackluster performance. Not an expert in electronics, but if the mods biased the tubes colder or had a similar effect it would account for the difference in volume and oomph. It probably isn't the cause of the static bursts. It's likely a tube(s) or the phone thing. Put the phones in airplane mode if you can and see if it eliminates them. Also be sure and try another cable and guitar to make sure it's not them. I would also make sure the connections from the amp to the speaker are good.
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Post by Maddog on Oct 1, 2015 18:25:22 GMT -7
Like Marc said, rule out cell phone interference first. It can be a real static maker.
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Post by digs57 on Oct 2, 2015 9:53:18 GMT -7
I was having the same issue with a classic 30 and was really frustrated as to why I wasnt getting the volume I needed.Thirty watter ought to have more juice and was this close to offing this thing...and going back to blue's jr...or something!!!
Reading about tube socket cleaning...there are some of the problems sometimes when connections seem tight but are in need of retentioning the socket and a good cleaning...as well as input jacks,Tube pins,ect...Did the cleaning and this thing kicks the b/jr out of the park...Tone and vol at lower volumes...completely different animal now...bill(blim) has a good pictorial (retentioning) of this process...good luck...a lot of help here to walk you through.
*fwiw I did my maz 18nr studio this morning...it already was pretty up to snuff,not much change...I guess its really issue dependent*
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Post by mazzynate on Feb 7, 2016 22:20:09 GMT -7
Well there is always a cell phone somewhere near so I guess that is a possibility. I am bringing the amp back the shop tomorrow to reverse the Mods since I did not as for them. Agreed about the tube life not an issue for me. not withstanding would these mods potentially cause the issues I am now experiencing, or maybe that's a question for the Doc. So it's been a while... what happened? Did everything work out?
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Post by zpilot on Feb 8, 2016 20:05:12 GMT -7
Running the tubes at something other than what the amp's design was based on could make the amp have lackluster performance. Not an expert in electronics, but if the mods biased the tubes colder or had a similar effect it would account for the difference in volume and oomph. It probably isn't the cause of the static bursts. It's likely a tube(s) or the phone thing. Put the phones in airplane mode if you can and see if it eliminates them. Also be sure and try another cable and guitar to make sure it's not them. I would also make sure the connections from the amp to the speaker are good. +++++ Also, keep those 4 mounting screws on the outside of the cabinet tight as that affects the shielding.
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