al
76 posts
May 08, 2012
11:29 AM
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http://www.reverbnation.com/#!/alprice
HI folks.
I Wondered if anyone could give me some info on the element i have inside my GB 520 D. I bought it around the mid 80's. What i do know is that it's a dual impedance element..that is hi and lo z..and the number is 99s556. Whats puzzling me is that i'm pretty sure it's been wired hi-z,but the mic is wae too hot to use. I mean it's pretty much unusable it's that hot.
Is this the way these elements are ment to sound? I have not used it in years,but i'm sure it always acted that way.
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Kingley
2008 posts
May 08, 2012
11:45 AM
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I know this may sound silly Al, but have you tried swapping preamp valves on your amp for lower values (swap 12AX7 for 12AY7 or 12AU7)? That might help.
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al
77 posts
May 08, 2012
11:52 AM
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http://www.reverbnation.com/#!/alprice
Good question Paul. I have. And i'm still using the valve set up you suggested to me a long time back. I've also tried it in allsorts of other amps and it still howls like a howly thing.
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Kingley
2009 posts
May 08, 2012
12:07 PM
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I'd check the wiring on it, to ensure it's wired correctly. You can download wiring diagrams from the Shure website. If I remember correctly those elements have a resistor across them. If it does maybe it's possible to change the value of it? My best advice would be to check out Dave Kotts site www.greenbulletmics.com see if it that has any advice. If not, maybe try sending Dave Kott or Greg Heumann an email. I'm sure they could offer some advice.
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Fingers
163 posts
May 08, 2012
12:17 PM
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@All i have the same mike! i know it sounds simple but have you tried swapping the wires round in the jack plug? worked for me this is my go to mike!
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MP
2238 posts
May 08, 2012
12:22 PM
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hi al!
i bought one of those in the 80s too. mine was wired low so i had it wired to high. the 99s is a screamin' loud element and can be a feedback monster.
i'd try what Kingley suggests. one thing i would definitely do is mod the mic. change out the hard wired cord for a screw-on connector of the Switchcraft variety. then you could buy an inline volume control from Blows Me Away.(Greg Heumann)
even if you don't swap your amps tubes, with an inline VC you could decrease the output 1/4 turn. this will not affect the tone appreciably. it will make your feedback problem much more manageable.
another thing to remember is that if your amp has more than one tone knob- low, mid, high- turn down the highs a lot (on some amps off is best). if it is a single tone knob, err on the side w/ more bottom.
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MP
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rainman
4 posts
May 08, 2012
1:37 PM
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Here is a review on youtube by goldenbug using that element. He mentions that the element is very loud. Adding a pot would be a good idea to make volume more manageable. www.youtube.com/watch?v=QmmfNqryzag
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Greg Heumann
1602 posts
May 08, 2012
5:21 PM
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These elements do have a bright edge that can contribute to feedback. It is indeed possible to wire it wrong but if memory serves you can't make it louder than using the proper high-Z wiring. If you look at the back of the element there are two terminals on the left and one on the right. The one on the right is positive (this is different from almost every other CM) and the lower (closer to the front of the element) terminal is the negative for high impedance. Low impedance uses the 2 left hand terminals. You can drop the output a little bit by using the upper left terminal instead of the lower one. Only you can be sure what wire is then connected to the tip and sleeve of your 1/4" plug.
Also - make sure the setscrew is present in the cable exit hole, and that there aren't any openings in the shell other than a pin-hole sized vent hole.
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/Greg
Last Edited by on May 08, 2012 5:21 PM
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jbone
899 posts
May 08, 2012
8:30 PM
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the tube config i've used for a few years now is p1, 12ax7, p2, 12au7, and p3, 12au7. this allows all the signal into the amp and then it gets tamed some in p2 and p3. this is used in both my silvertone 1482, single 12, about 20-25 watts, as well as in a replica '59 bassman with some very harp friendly speakers and the channels jumped. my bullet has a 99af556, i think, which is plenty hot but not insane. true it will feed back at higher volumes but the breakup is so good i use it esp in the silvertone anyway. it would help to have a vol pot but as yet i have not been able to afford one.
my other hotass mic is a e-v m43u military mic, modded by Greg H with a transformer to make it hi z and a volume pot as well. the advantage of a volume pot on a mic is that you can be at one level for comping and accents etc, and then crank up more for solo stuff if you need to. these hi z mics feed back "at rest" which means that when you are not playing through it, that's when it will howl. depending on what and where i'm playing and who with, i keep it turned all the wya down until solo time, than blast, and turn back down in between.
cupping will also make a difference in feedback possibility. the tighter the cup the more the feedback, at least this is true for me with the silvertone. if it is just below feedback at rest but feeds back with a tight cup, i can deal with that by moving the mic away from the harp and not cupping tightly until i solo.
there are plenty of ways to deal with a "too-hot" element. i'd rather have the power and find ways to deal with it than use a lesser mic and try to pump it up.
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