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Post by geryguitar on Aug 7, 2019 1:16:54 GMT -7
Hi,
I received my new MAZ 8 Head last week. In triode mode there is a "always-on-hum", independent of any pot positions and if there is a guitar plugged in or not. I replaced V3 and the EL84 for testing, hum unaltered here. Is this hum inherent by the single ended design or is there any solution?
Thx for any idea! GeryGuitar
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Post by 195db on Aug 7, 2019 2:57:52 GMT -7
Normal.
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Post by Jaguarguy (Mike) on Aug 7, 2019 5:46:10 GMT -7
Welcome to the Forum! There's a lot of good information and people here. As for your problem, it would be helpful if you could take a video so we could hear what is going on with your amp. There will be some hum from your amp but it should not be excessive. You say your amp is new - new to you or new from a dealer? If new from a dealer take it back to them to have them check it. If it's just new to you, I'd suggest contacting Don at Z amps to get his advice. It may need a trip back to the mothership where for a reasonable fee they will make sure it is in perfect running condition (I do that with all my "new to me" Z amps). Some of the standard things to check include making sure all chassis bolts are tightened, making sure there isn't cell phone interference (don't ask me how I know this one), make sure the effects loop is cleaned, try a different wall socket with the amp.
These amps are built like tanks so I'm sure someone will be able to help you out.
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Deleted Member
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Post by Deleted on Aug 7, 2019 6:09:15 GMT -7
Do you have the EQ bypass plugged in and engaged?
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Post by dcarver on Aug 7, 2019 13:47:44 GMT -7
Hi Gery. Welcome to the forum. Something isn't right with your MAZ 8. The reason I say that is based on your statement, "at any pot positions". If I dime my V, MV, Reverb and Cut knobs, (in pentode or triode mode) I can make my Maz 8 hum. At normal levels, it's dead quiet. Check all the usual hum sources: 1 plugged into a well grounded circuit 2 no overhead fluorescent lights. 3 no variable light switches on. 4 if it's a used amp, clean everything (pots, jacks, tube sockets). 5 sit (or stand) at least 4 or 5 feet from the amp at a about a 45 deg angle to the grill when you play. 6 turn your guitar through 180 deg to find the quietest position. 7 anything I haven't thought of. What output tube is in your amp ? Check out this thread for info on tubes that are working really well in my Maz 8. ztalk.proboards.com/thread/80485/tube-rolling-maz-8If your amp hums with nothing plugged in to it, and all the knobs zeroed, somethings wrong. Could be a bad tube, out of spec component (ie filter caps, etc.) , some kind of RF interference, etc. Start a process on elimination. Change 1 thing and try it. Take it to a friends house. Does it hum everywhere you plug it in ? Good luck. A Maz 8 can be dead quiet. You just have to work with it. Keep us posted on your results. Just re-read the OP. Does your amp only hum in triode mode ? Quiet in pentode mode ? What EL84 did you put in for testing ?
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Post by "Z" Steve on Aug 7, 2019 15:55:34 GMT -7
^^^^^ all great suggestions
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Post by 195db on Aug 7, 2019 17:10:21 GMT -7
The reason I said it's normal is mine does the same thing. It's a 2013 head I got almost a year ago and had the updates done immediately. The triode mode had the hum before and after the updates. Like a single coil hum that you don't hear when playing. Spoke w/ Don and he said that's normal.
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Post by dcarver on Aug 7, 2019 18:57:20 GMT -7
The reason I said it's normal is mine does the same thing. It's a 2013 head I got almost a year ago and had the updates done immediately. The triode mode had the hum before and after the updates. Like a single coil hum that you don't hear when playing. Spoke w/ Don and he said that's normal. ^^Interesting^^ Does your amp hum with nothing plugged in and the knobs turned down? Do you only get hum in triode mode ? Pentode mode is quiet ? Do you have one of Perry's 6n14n output tubes ? I just checked my amp (2016 combo) again. Pentode & Triode mode, both volumes at 10:00, reverb at 9:00, cut at 2:00. Xotic strat with RV-60 single coils plugged in. They aren't hum cancelling pickups. If I put my ear about 3" from the grill, I can hear a very slight hum. More than 6" from the grill I can't hear it.
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Post by 195db on Aug 7, 2019 19:33:48 GMT -7
The reason I said it's normal is mine does the same thing. It's a 2013 head I got almost a year ago and had the updates done immediately. The triode mode had the hum before and after the updates. Like a single coil hum that you don't hear when playing. Spoke w/ Don and he said that's normal. ^^Interesting^^ Does your amp hum with nothing plugged in and the knobs turned down? Do you only get hum in triode mode ? Pentode mode is quiet ? Do you have one of Perry's 6n14n output tubes ? I just checked my amp (2016 combo) again. Pentode & Triode mode, both volumes at 10:00, reverb at 9:00, cut at 2:00. Xotic strat with RV-60 single coils plugged in. They aren't hum cancelling pickups. If I put my ear about 3" from the grill, I can hear a very slight hum. More than 6" from the grill I can't hear it. Yes it's only in triode mode. It was retubed when I sent it in but I don't know what tubes are in there. Never bothered to look. I can't remember the last time I used triode mode so I'll have to check if the knobs affect it.
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Post by geryguitar on Aug 8, 2019 5:39:12 GMT -7
Dear friends,
thanks for all your your help! Here is my feedback to your questions:
* I bought the amp new from ProGuitar in Germany (about 500km away) * Cassis bolts are tight * No phone interference, it is the typical power cycle hum (50Hz). * I tried different sockets, no other of my amps show this hum. * I replaced v3 with a JJ12AU7 and the EL84 with two PM EL84S just for testing, absolutely the same amount of hum. * EQ bypass switch and pot positions have absolutely no effect on the hum, it is solid as a rock. * Hum is always there, with and without guitar plugged in. * In pentode mode the amp is perfectly silent. * The EL84 is near to the big power transformer. Maybe there is a interference, but why only in triode mode?
I also mailed with ProGuitar's Ron Mehl, he wrote this is "normal" as user 195db wrote above. I will do a video this evening but I'm not quite sure if my iPhone can capture down to 50Hz.
Greetings from Vienna/Austria! Gery
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Post by DRZ on Aug 8, 2019 6:27:45 GMT -7
A slight low level 50 Hz hum in Triode mode is normal in a export MAZ 8. Actually it is normal in all Triode mode amps to some degree. Do a Google Search of Triode Amp Output hum. If it's quiet in Pentode then there is nothing wrong with your amp. If this is too troubling for you , then I would suggest returning the amp to Ron.
DR.Z
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Post by dcarver on Aug 8, 2019 18:41:19 GMT -7
So... I was obviously totally wrong. Geryguitar, sorry I told you your amp was messed up.
And Doc, thanks for shedding light on this. I had no idea a 50 Hz Maz 8 has a slight hum in triode mode but not in pentode. Ya learn something every day.
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Post by geryguitar on Aug 12, 2019 1:34:03 GMT -7
Dear dottore & all other,
thank you all for your support. I can live with that since live this no issue and I prefer the pentode mode anyway.
Kind regards Gery
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Post by premiumplus (Dave) on Aug 12, 2019 5:32:41 GMT -7
Hi Gery...glad you decided to live with it. I prefer the pentode mode as well, it's so full of punch and harmonics.
It's a great amp and one of my favorite Z's. Any single ended class A amp is going to have a tiny bit of hum because they lack hum cancelling push-pull output tubes. A push-pull output stage acts in terms of hum cancelling in a similar fashion as a humbucking pickup does.
I can easily live with that tiny hum. The tone and harmonics are worth it. Enjoy your Maz 8, it's a classic.
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