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Post by nuclearfishin on Nov 10, 2010 11:24:57 GMT -7
Hello,
I have an EZG50 which sounds phenominal, but for the life of me can't hear a difference between the pre/post settings. Are they supposed to act like a traditional preamp volume/master volume control? I keep playing with them in all different settings but don't hear much difference other than volume changes. Additionally, anytime I get the volume too loud (above 75%), I get really loud low end feedback, even with nothing plugged into the amp. Is that normal or should I start looking for a bad tube?
Thanks!
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Post by asattwanger on Nov 10, 2010 20:02:32 GMT -7
Crazy because there are a couple vids of the EZG that are pretty dirty. Like cranked bassman dirty.
I hate asking this as I feel weird, but a you light player? My buddy had a MazJr and cranked it was pretty clean for him and totally rockin for me. I might be way off here. I don't know anything about the low feedback thing. Could be a reverb thing. I like reverb things.
DAVE
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Post by nuclearfishin on Nov 11, 2010 10:27:45 GMT -7
I don't consider myself a light-handed player, and don't mind really digging in when I need. I think part of the reason I can't get any dirt is because when the volume gets past 75%, I get a low freq howl, even with the guitar unplugged. The reverb will also make this howl if I turn it up, but even with reverb off, I get the howl from just volume. What I don't understand is if I crank the pre I expect to get at least a little dirt, but nada, still clean--and I don't perceive much volume change when I start turning up the post. I think I'll swap a few tubes and see. Any other advice?
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Post by Jaguarguy (Mike) on Nov 11, 2010 12:37:30 GMT -7
Was this new or used EZG? Mine gets plenty of growl and none of the howl you describe. May be a tube issue.
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Post by mtlrecords on Nov 11, 2010 13:18:39 GMT -7
Sounds like possibly multiple tube issues. Reverb driver tube- check and replace if necessary. Preamp tubes- check and replace if necessary.
The EZG-50 should give you pristine clean to rippin' 60's Bassman/Bandmaster tones and all points in between. If that fails, e-mail Brent @ Dr. Z for further instructions. If you bought it new, then you should be able to take it straight back to the dealer and get it fixed with no cost to you.
Cheers.
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Post by thecryingstrat on Nov 11, 2010 13:37:24 GMT -7
I am getting the exact same low pitch feedback sound!
the sound anyway is as mtlrecords described it. I can get great cleans, and bandmaster bassman growl when turning up...
as for teh feedback low sound. It happens at different pre and post settings. if i dime the post it will be earlier on the pre and if i lay the post a little back i can get some more on the pre before it starts the sound. I tried 3 different v1 tubes, no difference. Should try othe r positions... anything else someone?
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Liquids
Junior Member
Electronics!
Posts: 88
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Post by Liquids on Dec 14, 2010 7:13:10 GMT -7
Send it to the doc. Sound like oscillation, not something that should happen most of the time.
Sometimes it's caused by wire shielding, or can simple be 'chopsticked' via internal wire placement. I would suspect it has to do with the reverb, potentially. A different pre tube might have different capacitance that would 'snub' this more or less, but in general any tube should work without oscillation. I would send it to the doctor. If you plug right in (and if you don't ususally already do so) try that and see if it has any affect - at least for curiosity. Sometimes a buffered signal will play a part.
Pre vs. post - from what I can tell from gutshots and such, the pre is the classic fender volume control.
'Post' is another passive volume control, but it is placed between the third tube preamp stage and the phase inverter. So if you turn up the pre, tube stage one is slamming stage two (though some gain is lost from the tone stack) and two is slamming stage three hard, like a fender tuned up...but if the post is down, then the third stage is not driving the phase inverter too hard, unlike a fender, so you're getting the sweet preamp breakup and (to a lesser degree depending on the setting) a cleaner PI/power amp breakup. Or a combination of the two, to some degree, settings depending.
If you dime the post, it's a lot like a typical fender arrangement, and the pre is going to act like the volume control on a blackface. It all basically allows you to cut amplification in two locations rather than just one, for varying tones and combinations of breakup. Tubes clip nicely and dynamically when you can amplify---> attenuate---> amplify---> attenuate.
Doc does this kind of configuration on most of the amps that have dual gain controls with success, such as the MAZ amps.
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