Busking sound system questions
January 8, 2018 11:43 AM Subscribe
About a year ago I got a cigar box amp for busking. I also recently acquired a Shure 55S mic at a yard sale, and I'd like to use this for busking. Because I'm getting a very low signal with the mic, amp, and an impedence transformer, and I'd like to do something to make the sound a little louder. I'd looked into a preamp--which does boost the signal--but I would need a battery-powered preamp and have only found preamps that require external power.
My questions are:
- Is there a way I can make the volume louder on my amp, and
- If I were to make my own amp (or hire someone to make one for me), is there a way I could get them to make one that would recognize the signal in the mic?
Quick note: I have a Vox Mini3, but the amp is heavy and sounds ugly. I gravitated towards the cigar box amp because the sound was warmer and more pleasant (and the amp is easier to carry), but it hasn't worked out the way I'd hoped. The Cube is also heavy and out of my price range. Please do not come in and tell me that I should buy a Vox product! Thanks.
My questions are:
- Is there a way I can make the volume louder on my amp, and
- If I were to make my own amp (or hire someone to make one for me), is there a way I could get them to make one that would recognize the signal in the mic?
Quick note: I have a Vox Mini3, but the amp is heavy and sounds ugly. I gravitated towards the cigar box amp because the sound was warmer and more pleasant (and the amp is easier to carry), but it hasn't worked out the way I'd hoped. The Cube is also heavy and out of my price range. Please do not come in and tell me that I should buy a Vox product! Thanks.
Response by poster: Hey candleman! I'm trying to use the amp just for the mic.
posted by pxe2000 at 12:05 PM on January 8, 2018
posted by pxe2000 at 12:05 PM on January 8, 2018
If you or someone you know is handy with soldering, the $5 option is worth trying. But bad solder joints will make you miserable if you're not good with it, especially with something that you're carrying around. Failing that, I'd probably give the Nady a try and just try to be gentle with it.
posted by Candleman at 2:11 PM on January 8, 2018 [1 favorite]
posted by Candleman at 2:11 PM on January 8, 2018 [1 favorite]
That $5 preamp is a cool design, but needs _four_ 9V batteries to operate and is more for the recording studio than PA use. I'm assuming the mic transformer you have is going from an XLR connection to a 1/4" plug? If so, you can probably use any one of a number of inexpensive battery powered "clean boost" guitar effects pedals, or a guitar effects EQ pedal... just crank up the output gain. The eq settings might also be helpful to cut feedback. Or, if you want to DIY, build one of the many jfet mini-booster circuits out there on the net.
posted by Larry David Syndrome at 3:00 PM on January 8, 2018
posted by Larry David Syndrome at 3:00 PM on January 8, 2018
The INA417 chip at the heart of the $5 preamp will run on lower voltage: the datasheet says the minimum voltage is +/- 4.5V. Might be worth trying to run an INA417 from two 9V batteries. I don't believe the mic you have needs phantom power.
You might also try a cmoy or other headphone amp if you or someone you know has one around, though they might not provide enough gain in their default configuration.
posted by exogenous at 5:27 PM on January 8, 2018
You might also try a cmoy or other headphone amp if you or someone you know has one around, though they might not provide enough gain in their default configuration.
posted by exogenous at 5:27 PM on January 8, 2018
The thing is, that impedance transformer should really get your mic to the same level as if you plugged your guitar into the little amp. When plugging a mic into a guitar amplifier, the impedance mismatch is primarily what kills the sound, and you've taken care of that. Yes, people talk about mic preamps, and gain, and all mixing boards have a gain stage preamp, but you already have "gain stage" in your cigar box amp, and then an additional volume control.
This, of course, is assuming the mic is a relatively modern version of the 55, and it works properly, and your xlr cable is wired & working properly. If you haven't done this yet, considering yard sale, you might want to touch base with other musician/soundperson friends or acquaintances and test everything into a different amp and/or actual PA system.
I'd like to do something to make the sound a little louder.
Those little cigar box amps look cool, and they sound surprisingly good (from checking out the company's videos), but they've only got a little 2.5 watt amp in them, running to a little 4 watt speaker. That's just . . . . . not very much power. Even in their demo video (this one) with acoustic guitar about half the sound is the mic on the camera picking up the acoustic sound of the guitar in the room - when they turn the amp on it changes the tone, and gets a little louder, but not a LOT louder.
And in that video you'll notice that in the last part when the guy turns the "gain" up, the tone gets boxier and the sound of the guitar starts to distort. IOW, getting a booster or a preamp and sending a hotter louder signal from the mic to the amp even before the gain knob part of the circuit is just going to overload the amplifier and/or speaker even faster.
In short, I think mostly you just don't have enough amp for good vocal reinforcement. I know you're busking, not trying to blow away an audience of thousands, but I don't know that I would go with less than about 15 or 20 watts if I wanted my voice to be heard above the noise of the subway/traffic/people blabbing on their cell phones. I would try googling "portable PA systems", seeing which retailers offer which brands - here's the search results for Sweetwater refined by a $200 max price, and I know that's not all the different models out there, so check several retailers' websites. Plus I believe you're in or near a fairly major city, so you should be able to try a bunch out in person.
Weight could be an issue - if the 6 and 1/2 pound Vox Mini is too much, I don't know that any portable PA is going to be any lighter, most will probably be over ten pounds. You might want to think about something like a folding hand truck to help with transportation.
posted by soundguy99 at 6:26 PM on January 8, 2018 [1 favorite]
This, of course, is assuming the mic is a relatively modern version of the 55, and it works properly, and your xlr cable is wired & working properly. If you haven't done this yet, considering yard sale, you might want to touch base with other musician/soundperson friends or acquaintances and test everything into a different amp and/or actual PA system.
I'd like to do something to make the sound a little louder.
Those little cigar box amps look cool, and they sound surprisingly good (from checking out the company's videos), but they've only got a little 2.5 watt amp in them, running to a little 4 watt speaker. That's just . . . . . not very much power. Even in their demo video (this one) with acoustic guitar about half the sound is the mic on the camera picking up the acoustic sound of the guitar in the room - when they turn the amp on it changes the tone, and gets a little louder, but not a LOT louder.
And in that video you'll notice that in the last part when the guy turns the "gain" up, the tone gets boxier and the sound of the guitar starts to distort. IOW, getting a booster or a preamp and sending a hotter louder signal from the mic to the amp even before the gain knob part of the circuit is just going to overload the amplifier and/or speaker even faster.
In short, I think mostly you just don't have enough amp for good vocal reinforcement. I know you're busking, not trying to blow away an audience of thousands, but I don't know that I would go with less than about 15 or 20 watts if I wanted my voice to be heard above the noise of the subway/traffic/people blabbing on their cell phones. I would try googling "portable PA systems", seeing which retailers offer which brands - here's the search results for Sweetwater refined by a $200 max price, and I know that's not all the different models out there, so check several retailers' websites. Plus I believe you're in or near a fairly major city, so you should be able to try a bunch out in person.
Weight could be an issue - if the 6 and 1/2 pound Vox Mini is too much, I don't know that any portable PA is going to be any lighter, most will probably be over ten pounds. You might want to think about something like a folding hand truck to help with transportation.
posted by soundguy99 at 6:26 PM on January 8, 2018 [1 favorite]
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There are a variety of battery powered mic preamps out there - many cater to the broadcasting field where you need to be working away from reliable power. They tend to be a little pricey as a result. The Nady DMP-2 is battery powered but is from a pretty cheap brand so who knows how long it will last.
Here's a few more options at increasing price points.
If you want to go DIY, here's a $5 of parts battery powered mic preamp that might work for your purposes.
posted by Candleman at 11:57 AM on January 8, 2018