A) Turn the mic up and amp down - overdrive the preamp tubes. B) Turn the mic down and amp up - overdrive the power tubes.
"They're both valid approaches. Depends what you want to hear. I prefer the mic up fairly loud. Plus - if you're in the "B" camp, one slip of the volume control at your mic and its feedback city."
I like turning my mic down and amp up. It gives the sound a sizzle; an edginess; a presence. The notes leap out of the amp. (fuzzy description; I hope you get the idea).
Greg is right-- when you do this, you have to be sure not to turn the volume control past, for example, 6 o'clock, where the control goes from 1 to 12. I have over-rotated the control on many a gig and got feedback.
What to do about this?
Here's my proposed solution: A removable stopping apparatus in two parts: One piece attaches to your mic shell, the other to your volume control knob. Together, they would prevent the control from rotating further than halfway. Ideally, it would be something that could be easily removed or adjusted whenever you wanted to go back to playing with full rotation of the control; just as a guitar capo is easily placed on another fret or removed entirely.
Picture this: Most volume knobs have a threaded hole into which a short bolt is screwed deep enough to clamp the potentiometer shaft protruding from the mic shell. Replace that short bolt with a longer bolt, long enough that a quarter or half inch sticks out from the knob once fully screwed in. Next, attach a "bump" to the mic shell. Position it so that the protruding volume control bolt hits the bump at the 6 o'clock position.
The "bump" on the mic shell could perhaps be housed in a track that allowed you to slide it toward the volume knob when needed as a stop, and slide it away (towards the cord end of the mic) when full rotation of the volume knob was desired.
Any thoughts? Greg, you feel like putting your machining skills to work to create a "proof of concept"?
I can appreciate the thought you have put into this but as,for example, Gregs V/C knobs have a white indent on the knob ,why not just put a corresponding mark at(say) 6 on the body of the mike?
How about an electrical solution: a push-pull pot wired to give two different ranges?
(spam filter, third time lucky?)...
I can't stop rockin to save my soul I don't even wanna try Stuck like glue to that rock n roll Until the day I die I can't stop rockin' I can't stop rockin' I can't stop rockin' Goin' a keep on rockin' til I'm outta control
Last Edited by MindTheGap on Mar 03, 2015 3:23 AM
That's an intriguing idea, Wolf. Allows you to use the VC as an attenuator (like the Squeal Killer) more safely. It could be done but would increase the size and cost of the control. I think people who use the existing control this way learn very quickly to simply not turn it up too far! The actual feedback point also changes with the situation, such as room size - so it would have to be adjustable easily, without tools.
@MindTheGap - that's a nice idea - but they don't make those pots in anywhere near a small-enough size to fit inside my volume controls. (They don't make detent-pots that size either.
I'll let it ramble around in my brain for a while...... ---------- *************************************************** /Greg
Well, I have built all of my mics. The push pull idea is doable in a bullet shell. Plenty of room in there. One may even consider putting a cap in there on one pot to vary the tone. High cut maybe or a pull to bright for leads. Ha Ha, both the same now that I think about it! I like it MindTheGap!!
Wolf, you could use a fixed stop on the mic shell and use a splined shaft on the pot. Make the knob "quick release" and reposition the knob on the shaft to set your V level. Now all you need is a custom knob and a peg or bump stop on the shell. Pretty cool!
At one point I was wondering if there wasn't a solution for controlling effects run on my computer from my microphone. I eventually got in over my head (or at least past my attention span and budget) but the road I was heading down would have used a wireless computer mouse and the associated USB dongle. The idea was that a mouse already had several buttons (particularly if you get into gaming mice) and a scroll wheel and you can map their functions in software. There are DIY circuit boards you could use to set up simple circuits. My idea was to disassemble the mouse buttons and put them into a more stage friendly configuration. What I was after, particularly, was a two tiered volume button to toggle between vocal and harp, but there were lots of possibilities. I even had a alternate shell shape in mind so you wouldn't be accidentally hit buttons.
The best part would be if you were running it through a laptop you could configure the buttons to trigger a variety of options.
I should have remembered Greg's volume controls (I have two) when I described my thoughts on this. The concept is equally applicable to his controls.
Cotton's idea sounds doable.
The idea of looking at a corresponding mark on the body of the mic is not something that would work for me. I'm constantly adjusting the volume control as I play, depending on whether I'm accompanying or soloing, and depending on the overall volume of the song.
I adjust by feel and sound. I'm not going to take the mic away from my mouth to look at a mark, especially while playing.
Some corners of the stages I'm on are dark. My eyes aren't what they used to be.
I really think it would be useful to have a physical stop, one that does not require even the quickest glance at the setting.
@Wolf I think that it would be impossible to set a mike up with one setting for the least feedback,in that every venue or gig has a different soundscape. I played one place every friday night for a year,had my sound purrfect,then one night it was verging on feedback all the time.What was different?They had glasssed off a smoking area.About 4 square metres of glass and the result was i had to adjust my amp settings. Even if you had a physical way of telling where you are on the V/C when it's feedback free, during the gig it won't be relevant when the amount of absorbent (eg people) changes throughout the night. But it is an interesting subject and if there is an answer someone here will come up with it.
indigo - ok, how about two pots, one you use as a trim to set the max level and one you use as the conventional VC.
Set the VC to max, then trim for whatever mic and amp settings you want to use in a particular room. Then you can used the VC on it's full range without worrying about feedback.
When more audience members arrive, with their increased sound absorbing qualities, you can nudge up the trim, and nudge it down as they thin out.
Last Edited by MindTheGap on Mar 04, 2015 1:45 AM
a clean preamp pedal would give the same result, just turn it so your mic wide open is at the max volume you want going it. not very likely to bump the pedal gain knob, easy to change your max level to suit room etc....
If the VC is mounted on the mic shell you could use a chicken head knob and have a pin to put in holes (non-leaking!) drilled around the circumference of the knob. Maybe like a pin from a Cribbage board? But there would still be problems, because on any given night you just cannot set one max volume.
Aside from the acoustic properties of the room and the crowd at any given time there is also the volume level of the band, which amp you are using, what the tone settings are, where the amp is placed, and where you are standing.
I have one of Greg's controls on a biscuit mic with a CM element, and I thought I knew the limits on how far I could turn the volume knob before feedback. Then I played with a loud band through my Knight 2 - 6L6 amp through a Cannabis Rex in a 1 - 12" cab. I started out with a limit of about 1/2 turned up before squeal. I continued to adjust the amp settings and mic settings throughout the night as needed. By the end of the night I was playing really loud and just short of the mic being wide open, w/o feedback, something I thought was impossible.
Perhaps you could use a graphic EQ pedal to have a separate limit threshold set and to fine tune frequencies? This would be a simple approach, and the Fish and Chips pedal is cheap. In addition to fine tuning frequencies a graphic EQ pedal can add gain or even attenuate the mic/effects signal going to the amp. With EQ flat, there is a detente in the middle of volume slider for the unitary volume with the pedal on or off. Obviously, if you change the EQ settings this is changed. This could give you an easily altered limit without modifying your mic.
I think it is best to just learn to dynamically adjust the mic and amp as needed at the gig. We all learn to bend to different pitches with different harps tuned to different keys. This is a learned skill. It is something we adjust on the fly as we switch keys and harps and bend to pitch.
I just consider the squeal to be negative auditory "feedback" to help me learn. As we get better at managing our harp/mic/amp instrument we squeal less often. I think that learning to manage our mics and adjust mic volume, amp volume, and playing volume in real time is just another skill we need to continue to develop no matter how long we have played. Each situation is different.
By the way, I now squeal far less frequently at amplified gigs than when I began, but there usually is still one or two brief reminders each time. Brief, because I cut it back immediately and adjust. ----------
Doug S.
Last Edited by dougharps on Mar 04, 2015 8:21 AM
"I have one of Greg's controls on a biscuit mic with a CM element, and I thought I knew the limits on how far I could turn the volume knob before feedback. Then I played with a loud band through my Knight 2 - 6L6 amp through a Cannabis Rex in a 1 - 12" cab. I started out with a limit of about 1/2 turned up before squeal. I continued to adjust the amp settings and mic settings throughout the night as needed. By the end of the night I was playing really loud and just short of the mic being wide open, w/o feedback, something I thought was impossible."
Exactly my point. Conditions change during the night. A lot. It's a clever idea, but in practice I think it would be constantly frustrating. It will definitely be "wrong" more often than "just right" if you try to do this with a fixed value (like the push pull knob.) Just turning the knob of a "regular old volume control" back down if/when feedback occurs is so easy and quick in any case.....
But - if you're handy with electronics there is no harm in trying ANY of this stuff - I do it all the time!
I understand the point, made by a few, that one fixed stop will not allow you to adjust for room conditions, etc.
However, every volume control already has a fixed stop-- just at a different position. At full rotation, it stops. Usually it's the ll o'clock or 12 o'clock position. The disadvantages of a fixed stop should equally apply to unmodified volume controls, no?
I just want to move that stop at a different point in the circle.
NO - the fixed stop is FULL VOLUME. That is what it is (0 ohms from signal + to the amp input +). You want a stop at some point less than full volume. But there is no "right" point. You could do the same thing by just adding a resistor in line with the control so that there was always SOME minimum resistance, allowing you to turn the amp up further. But my point (and others') is that you can't choose a "right" value. A better solution:
I could make a custom control with two pots. I'll make you one if you want. One knob is regular volume, the other is "maximum volume point."
It is interesting enough to try. Contact me off line if you want to pursue it. ---------- *************************************************** /Greg
This solved A LOT of the same issues for me (agreeing with Walterharp): "...a clean preamp pedal would give the same result, just turn it so your mic wide open is at the max volume you want going it. not very likely to bump the pedal gain knob, easy to change your max level to suit room etc..."
"I could make a custom control with two pots. I'll make you one if you want. One knob is regular volume, the other is "maximum volume point." "
I believe a lot of volume pedals are built this way. Or perhaps it's the other way around (second pot sets the minimum volume). My Behringer volume pedal has two knobs, but I forget if the second sets max or min volume. I'll have a look at it later. Either way, it's potentially a useful thing to have on an inline VC too! ----------
I'm interested in the premise of this thread. This notion of turning down the mic and thus opening the volume to the power tubes. Is this an electronically sound concept? Aren't you just turning up the volume? And so doesn't it depend on the preamp set up? I'm just trying to get the idea straight in my mind. I reduce the signal from my mic, so I turn up the amp volume. If my volume control is between stages of a 2 stage preamp, doesn't that mean I am increasing the signal from the preamp before it reaches the power tube? Maybe I'm just extra vague this week. I'm sure I used to understand this.
morn gents! ...nice thread to ponder. Tis an old dilemma...for sure. For me...and my 2 cents. I wish I wasn't so dependent on vc's. But since I am... When I set up. I turn the vc up 3/4's. Then, set my amp to the sweet spot, while NOT mic'd through the PA, yet. Then, I dial in the monitors first, then the mains, then both. If I can't hear myself (vocals and harp)clearly enough, we reset until this is DONE! Once this is achieved, I rarely need to go back to my amp and do anything. If I need more, it's there on the mic. And I just step away from the amp a little more. Doing this gives me the control I prefer, when the rest of the band, as usual, starts to creep up louder and louder. It's mostly a guitar player thing. They all wear ear plugs...which defeats trying to solve the problem...errrggghhh. The drummer, too. WTF!? I seldom need to signal with hand motions, to turn down. And they turn down a bit for me. I stress the need to relax and maintain the dynamics throughout the night. I simply loose my concentration, my energy, and tire too quickly. Having played with these guys over a long period of time...they now get it. Seeing me exerting myself unnecessarily, that is. We have become pros now, and I'm lucky most of the time..Every body has their moods...sometimes they don't give a shit about me....ha! Anyhow..the extra 1/4 is there for those moments, when they don't listen to me. I hate going there, because it turns the whole band into a WALL OF SOUND...no dynamics and the crowd doesn't like it either. Yes, much to our amazement! We play to a crowd...and it's really fun! three cents actually... ----------
Why is it that we all just can't get along?<
Last Edited by Mojokane on Apr 10, 2015 2:14 PM
Hi SuperBee-- I'll leave the electronic analysis to someone else; not my area of expertise.
My ears tell me, though, that there's a definite change in an amp's sound when you make the power tubes work harder. I like it.
The best I can do to describe the sound is to repeat what I said when I started this post-- it gives the sound a sizzle; an edginess; a presence. The notes leap out of the amp. It's almost as if they're quivering to be let out. (I know this description is neither objective nor measurable.) There's also a bit more distortion.
So... while we puzzle over the electronics, let's perform an easy experiment. If you've got a tube amp, and a volume controlled mic, why don't you try it? If your amp is usually set at 3, set it at 6 or 7, and turn your mic down accordingly. Listen for the change in the sound. You should be able to hear it. There is a definite change.
I noticed it first when playing through my '62 Fender Concert Amp in the 70s-- if the room was big enough to require turning the amp quite high (5 or 6 instead of 3), the amp just sang.
Greg Heumann said in 2012,"Depends what you want to hear". I agree. The sound I find so attractive may be an ugly sound to someone else. It's worth playing around with volume control on your amp though, to see if you can find the sweet spot that pleases your ears.
G'day Wolf. It kinda is the theoretical part that interests me, because I think it should be feasible to set up the amp to do what you want and not have to worry so much about bumping the VC on the mic. However, you make a good point that first I should test the scenario you described. I just did some testing with my 5F1-style amp. I tried mic in both inputs, mic on full and amp up to where it started to ring, then I tried setting the amp first and bringing up the mic volume. I tried amp at 9, and at 12 (full). It's only one amp, and the first stage is low gain, and I'm running a lower gain preamp tube in it. 12ay7 or 5751, I've forgotten which I settled on. Anyway, I couldn't really detect much difference in tone at the point immediately prior to feedback. Not anything I could say wasn't my imagination. But it was only a quick test. I'll try it at lower volume and see if it sounds different. I'll try some different amps, providing my daughter doesn't become homicidal.
@SuperBee - The place where I hear "power tube" distortion the most (and that's why's happening when we turn the amp up all the way and leave the VC way down" is "edge distortion" - the amp's response to the attack of a note.) The easiest way to hear it is by doing a head shake. The nature of the distortion between the notes (i.e., the "edges") is different.
I suggest to hear it at first you turn the amp all the way up (and of course leave the VC down so it isn't feeding back) - then compare that the VC all the way up and amp down.
Thanks Greg, I'll try that. i'm not sure it was quite the sound as described but i did at least find a setting i like for my champ. i've not played with this much since i built it and i really need to mess with it some more. its not very complicated, dunno why i didn't think to run it a little quieter. maybe been trained too long to get the amp as loud as possible
Video description: --------------------------------- This video compares two scenarios: In the first segment the volume on the amp is all the way up and the volume on the harp microphone is barely cracked. In the second segment the amp volume is on 4 and the microphone volume is all the way up.
My phone is in the foreground running the RTA app to show the relative loudness. The amp is a Mission Chicago 32-20 and the mic is a 1959 Shure 440SL with 99B86 CM element.
The two segments sound similar. To my ear the segment with the amp all the way up was less lively and not as full sounding. The amp tipped into screaming feedback if I turned the mic up the slightest bit, so this is about as loud as I could get in this scenario. That was my benchmark volume for the comparison.
In the second scenario the amp is on 4 with lots of room for more volume, and a greater range of tonal inflections.
I'd heard about the "amp all the way up" thing over the years and decided to test it after hearing a jammer do it at Ziggies the other night. I think there is a good reason it is not very common. The traditional way sounds better.
Please pardon my noodly playing.... ----------------------------------- ---------- Sorry for any misspell, english is not my first language.
The thread about that video: http://www.modernbluesharmonica.com/board/board_topic/5560960/4857901.htm ---------- Sorry for any misspell, english is not my first language.
Thanks Rogonzab. It's strange; I couldn't see video on my iMac but it's ok on the phone. And the thread, I remember seeing it at the time. The effect here is similar to the effect I noticed with my champ. But I think somewhere in between may be best.
