DIY active electronics or inline preamp for Banjo

My dad plays banjo and he's an amateur luthiere. Tonight he was telling me how he can never get a decent sound running his banjo into an amp or PA system. Naturally, I offered to find him something or even build.

Trouble is, he's using a crappy piezo pickup taped inside the body of the banjo behind the head. As he describes it, the sound is very harsh and high frequency dominated. I suggested a preamp with RIAA equalization as a possible band-aid for the diminshed lowend. Ideally it would be something that could run off a 9V battery and fit in an Altoid box or something equally small. Otherwise, I'm just going to give him this old Shure phono/tape preamp I have and see how that works.

Any suggestions for a proper solution?

Thanks in advance,

Brian

I have been having pretty good luck with an internal mic setup useing a transound capsule. I removed the washers from two of the lugs on the inside of the pot and make a couple mounting brackets to hold the preamp/battery. The mic is mounted here on a piece of thick copper wire so I can easily reposition it. I find I get the best sound by placing the mic about halfway between the bridge and the neck just above the cordinator rod and aimed slightly back towards the bridge. It is the best I have found for the banjo short of a plain ol mic. I am not sure how well this would work on a resonator banjo though, I stick with open back.

adam

Dammit, do we need banjo players here? What next... violas?

> he's using a crappy piezo pickup

Well, that's a lot of the problem right there. A Piezo can "sparkle", or it can "screech".

> preamp with RIAA equalization

If it did what you thought, that would be far too much EQ.

But in fact, the typical Phono input impedance is low compared to the bass of a piezo. I'm guessing you won't get much below 500Hz. Which is already the problem.

The quick fix is to put the SM58 in front and move it around. Sure it will feedback, but the banjo body is so lively that feedback is inevitable. Strum harder.

Put an electret, either inside the body or on a stiff wire to face the bridge. You might even try a compact cardioid under the tailpiece, looking over the body along the string to the bridge.

Add a few wool socks inside the body. It makes a terrible acoustic instrument but will ease your feedback woes in PA use. Of course the extreme would be to stuff the body with solid maple and use a magnetic pickup: a round-body 5-string StratoCaster. Now he needs an amp: load it with some of those nasty poly cone speakers from the 1980s (you can probably still find them) to get that banjo-skin tone.

There must be a forum where the Banjo players go; there's several for Harmonica.

I am not scoreing to good here, I play banjo and viola is my favorite of the classical strings. Not only that but I play an open backed tenor banjo so I am an outcast amoung banjo players as well.

adam

What is the difference between a Violin and Viola?














The Viola burns longer :green:

Violas make you the butt of all orchestra jokes...

I've always wondered why :?

I have yet to hear a piezo pickup sound like anything but total crap on a banjo. A miniature condenser mic, inside the pot, will do way better. There are several from Audio Technica; your dad can get his feet wet by trying out a Radio Shack mini lavaliere mic, but that has the disadvantage of being unbalanced output. Maybe find him a nice 1:1 tranny for it, and build a box with 1/8" in and XLR out.

Anyway, the orchestra was on tour in Europe when the orchestra manager called a meeting and said, "Folks, we're gonna have to cancel most of the tour; the conductor just got rushed to the hospital with appendicitis, he'll be out of action for three weeks, and there's no one available to substitute."

After some mumbling in the ranks one of the viola players got up and said, "You know, when I was at the conservatory I did a minor in conducting. I don't claim to be any Georg Solti, but I think I can do a workmanlike job and at least get us through the tour okay."

Well, what else were they to do? The orchestra stood to lose half a million bucks if they blew the tour. So the viola player took the podium, and the tour continued. He did a decent job, too; they got okay reviews in Paris and Vienna, and even a couple of enthusiastic ones in Stockholm.

Three weeks went by, and the conductor, reasonably recovered, flew in and met the orchestra in Zurich. Before the first rehearsal, he met privately with the viola player and thanked him for his efforts and his success in keeping the orchestra going. When the rehearsal began, the conductor mounted the podium while the viola player, deeply moved and relieved, took his regular seat.

His stand-partner looked at him and said, "Hey, where you been?"

Peace,
Paul

Yikes. Sounds like my conducting class in college. My first time in front of an orchestra was the First Movement of the First Beethoven Symphony. We ran through it once and it actually sounded pretty good. Then my teacher, the concertmaster, said, "OK, this time we're going to follow you..."

What's the solid-body electric banjo that Bela Fleck plays?

Thanks for the responses everybody!

I have a bunch of Panasonic WM-61A capsules. I could whip up a 9V omni to clip inside. I was thinking of something really similar to what Adam described. The thick copper wire for positioning is a great idea, I was trying figure out where I could find a tiny gooseneck! :green:

I'm really excited about being able to help out my Dad. He was my inspiration to get into music and stay with it.
:sam: :sam: :sam:

I had good luck with one of those mini, stick on mics (I think it was the AKG 411) on my mandolin. I'd think something like that would be great on the banjo if it was placed in the right spot.

Steve

I got a mini goose neck from a laptop web cam. I think it was 15 bucks but
there are those book reading lamps etc that might be found at a dollar store.
I put an electret capsule on one end with heat shrink tubing. This one is for a violin

[quote author="josan"]there are those book reading lamps etc that might be found at a dollar store.[/quote]

Ingenious!!!! :thumb:

[quote author="PRR"]Dammit, do we need banjo players here? What next... violas?

There must be a forum where the Banjo players go; there's several for Harmonica.[/quote]
And what´s wrong with banjo players (I´m not one) no difference at all with folks who fiddle with Valves :grin: :grin: :grin: :grin: :grin:
But of course you are joking!!!
Stephen

The banjo player in my band uses a piezo pickup by LR Baggs into an Avalon U5 DI. He sends Baggs the bridge that he likes, and they put it on for him. Sounds great...

[quote author="Grubbalot"]The banjo player in my band uses a piezo pickup by LR Baggs into an Avalon U5 DI. He sends Baggs the bridge that he likes, and they put it on for him. Sounds great...[/quote]

So the piezo is actually mounted on the bridge? That sounds a whole lot better than taped inside the rim, like my Dad has been doing. This got me thinking that I've seen upright bass players use a piezo attached to the bridge.

I will check out the Baggs piezo.

> the conductor... met privately with the viola player and thanked him for his efforts and his success

That would never happen. I think it is against union rules.

> That sounds a whole lot better than taped inside the rim,.... I've seen upright bass players use a piezo attached to the bridge.

Taped-on is so very wrong that I didn't want to mention it.

A piezo is a stiff transducer and needs to be placed between a high-leverage vibrating part and a fairly solid part. And some need direct pressure, some need to be bent, and some twist. I don't see what taped-on can do except slap against the side and make spike-waves.

On bass, the bridge has vibrations and leverage, one end bears on a bar inside the body, the other is near enough to the bar to be pretty stiff. This is the high-impedance zone of a transformer that couples the limp strings to the floppy sounding board through a quasi-concentrated area. A piezo, correctly oriented, can make strong output here.

My impression of banjo is that there is no really stiff reference to lever the bridge against. But Grubbalot says it works, so I'm sure it can. Note that the coupling to the bridge is so critical that they don't want you to DIY: they can do it better. You could do it, eventually, after a lot of trial and error; unless you plan to go into the banjo pickup business, it probably isn't worth it.

The banjo does produce a respectable amount of sound in a concentrated area, so conventional air microphones should give good acoustic gain. The sound heard at a distance is the sum of many different sounds from different areas; you'll need to play around to find a happy balance. At least with air-mikes you don't have to leave tape-residue or piezo-holes all over.

The copper or steel wire is the simple "gooseneck". Disadvantage is that in 10 or 100 good adjustments, the wire breaks. But a scrap of house-wire gives a dozen replacements. If you don't plan on fiddling the placement every song, the wire is maybe the way to go. For a universal adjustable rig, such as I have for various ad-hoc uses, the mini-gooseneck on A-T mikes or webcams/readinglites will live longer and look neater.

I have seen two versions of the piezo banjo bridge pickup, One where they sandwhich the piezo between the bridges main body, usualy maple, and the ebony cap, and one where they attach it to the the feet of the bridge. Both versions sounded like piezos pickups, in other words like crap and nothing like a banjo. Although if you do do this you need to make sure the bridge has already been fitted to the banjo before you mail it off to LR Baggs. If your dad is one of those players that switches between multipul bridges or prefers bridges made of softer woods or without the ebony cap, this probably is not a good way to go, unless he also likes to spend money.

adam

[quote author="adamasd"]unless he also likes to spend money.[/quote]

That he certainly does not. If there's one thing I inherited from him it's a thriftiness that borders on being downright cheap, especially in areas where it would actually make sense to splurge, like instruments. I think he built his first banjo as much to save money as anything else, then realized he liked the process.

I think at this point, it's best to ditch the piezo since it's most likely a poor quality specimen and I obviously know nothing about it's proper usage. I'm going to whip up a microphone and pay a visit to the dollar discount store for a gooseneck to re-purpose.

I will report back with results. Thanks again!

Dammit, do we need banjo players here? What next... violas?

Click to expand...

If you think that's bad, wait'll you hear "Hot for Teacher" on an accordion! :twisted:

...try B-band ( www.b-band.com ) they have a line of condenser/electret mics in an under sadle package, to sit where you usualy place the piezo, but since it's not a piezo but a condenser mic, it sounds completely different..its the only system I've tried so far that at least do a decent jobb on 12-string guitars...( both piezo and magnetic pickips make the octave strings sound like out-of-tune sinewaves..)

johan