phantom powered belt preamp

[swarfrat]

Its all popular these days to carve huge holes for complex preamps with a lot of knobs, but I'm looking for a phantom powered,XLR to 1/4" , piezo preamp (>1g input impedance). There was a $80 inline unit called the "Bigamp" from Triton Audio, but it doesnt seem to be in stock anywhere and the ebay unit i found was about 4x list MSRP.

I've seen someone in UK selling an Alex Rice derived board, but I'm in a bit of a hurry and don't want to start a project, especially if international shipping is involved.

I see floor units, but apparently $200 is the new entry level switch in a box price,and I'd really rather get to buffered and balanced as close to the guitar jack as I can.

LR Baggs gig pro is neither XLR nor phantom powered. (And i see no need for a battery in a device which could and should be phantom powered.)

Does anyone make a readily available sub $100 phantom powered high impedance belt pack preamp?

[philjs]

How about a Dee-Eye in a strap-mounted holder? Or just use a short pedalboard-type interconnect jack to have it mounted on the guitar jack?

Phil

[swarfrat]

Thanks - that's very close. It fits everything except the input impedance. I'd like something a bit higher than 1M - I'll consider it if I can't find something closer.

[Pnewsom]

Originally Posted by swarfrat

Thanks - that's very close. It fits everything except the input impedance. I'd like something a bit higher than 1M - I'll consider it if I can't find something closer.

What pickup has an impedance of higher than 1M?

[swarfrat]

Hmmm actually I see now the JJB site says 1M is ideal, and you might get excessive bass response with extremly high input impedance.

[Cuki79]

Fishman platinum stage has 10 Mohm impedance input and can be powered via XLR phantom power

[ManyMartinMan]

Originally Posted by swarfrat

Its all popular these days to carve huge holes for complex preamps with a lot of knobs, but I'm looking for a phantom powered,XLR to 1/4" , piezo preamp ...

First I had to look to see if this was a phantom thread from the 90's as my observation is that there is probably the least amount of barn-door preamps, and the type since onboard guitar preamps began. I see almost no guitars cutting holes and installing visible knobs.

However, I understand the desire for the ability to shape their tone. I prefer to have all my equipment on my pedal-board to minimize the weight I bear on my shoulders but the Fishman Platinum Stage Acoustic Guitar Preamp might be what you desire. Setting a price of $99, to me, is a formula for just missing the mark. If quality sound is what you're after, examine a couple of units (like the afore mentioned) from $150-$250 would yield far better end results.

[swarfrat]

Oh there's still PLENTY to be had, even from the big names. And it still seems to be the norm in guitars with built in pickups.

[ManyMartinMan]

Originally Posted by swarfrat

Oh there's still PLENTY to be had, even from the big names. And it still seems to be the norm in guitars with built in pickups.

Luckily, no one has to buy them. You can just focus on getting a great sound. Good luck.

[swarfrat]

Radial SB-4 enroute. The AC Driver was interesting but neither phantom nor battery powered. My Guild OM-240CE has a UST (which I hate, and intend to replace with a JJB 330 some day), and I've got a JJB 330 on the way for my Alvarez ABT-60.

[jonfields45]

Originally Posted by swarfrat

Radial SB-4 enroute. The AC Driver was interesting but neither phantom nor battery powered. My Guild OM-240CE has a UST (which I hate, and intend to replace with a JJB 330 some day), and I've got a JJB 330 on the way for my Alvarez ABT-60.

The 10M ohm input impedance of the SB-4 might be a problem. I've found some very high input impedance devices don't sound quite right with a K&K (or JJB); one sounded really bad, one sounded a little off, and another sounded fine. It might depend on the input impedance being dominated by resistance or capacitance, if they over shot the spec, maybe even your cable, etc. I made these two 1M ohm shunt resisters to fix it, which in your case might help but make the strap mounted result a bit ugly.

https://drive.google.com/open?id=0B_...2xJQnA1Y0VZdFk

https://drive.google.com/open?id=0B_...ll0WnlldTBBblk

This one with a volume control (it has a male 1/4" jack that plugs into the guitar strap jack):

https://drive.google.com/open?id=1cU...vsBbrwQnjkLM1w

Here's a 500K volume control you can buy which is close enough to the 1M target:

http://www.bluestarmusic.com/Schatte...ol_p_1016.html

[swarfrat]

So I've done some more reading about the expected input impedance for the JJB's. The higher the input impedance, the less peaky/quaky it will be. You might get more bass than you want, but there's a HPF. Some folks are saying that the "official story line" from the folks at JJB is suggesting a lower than optimal impedance (for the peakiness) in order to tame the bass response.

I don't think for a minute that these things are "designed" in the traditional engineering sense. There's precious little actual engineering work that goes into Musical Instrument products aside from the biggest of companies. ALL piezo pickups are assemblies of off the shelf commercial components.

[Methos1979]

The Headway EDM-1 looks promising with belt clip, phantom power, variable 3-way impedance input switch, notch, three band EQ and battery operation. Supposedly uses really high-end components. I have no experience - yet. More than you're looking to pay though at just over $200 new. I just found a used one for $99 so I scooped that up as I was looking for something like the K&K belt clip amp (battery powered) but that also had a notch. Just ordered today so will give a review in a week or so when I get it.

[steelvibe]

Jon, that is a very cool and doable solution on the cheap!

Also, since we are talking about amplification, the fix could be as easy as using a buffer at the front end of your signal chain. Since I will be in the market a stage tuner soon, something like the Boss TU-3 might be just the ticket. A pedal tuner a 1Mohm input to buffer the signal of the SBT before the quality pre of choice?

just thinking.....hmmm?

[jonfields45]

Originally Posted by swarfrat

So I've done some more reading about the expected input impedance for the JJB's. The higher the input impedance, the less peaky/quaky it will be. You might get more bass than you want, but there's a HPF. Some folks are saying that the "official story line" from the folks at JJB is suggesting a lower than optimal impedance (for the peakiness) in order to tame the bass response.

I don't think for a minute that these things are "designed" in the traditional engineering sense. There's precious little actual engineering work that goes into Musical Instrument products aside from the biggest of companies. ALL piezo pickups are assemblies of off the shelf commercial components.

Agreed. The equivalent model for these piezos is a voltage source (the signal) in series with a capacitor. If the input impedance is too low, then you get a high pass filter corner in the audio range of your guitar. Plug a JJB or K&K into a mixer 10K line input to demonstrate. With two or more heads in parallel, and only for where the heads are not in phase with the same signal (if they were then single head pickups would be viable and the head placement would be none critical...), the heads compete as loads with your amp/pedal/mixer. Since not all high frequencies will be out of phase between heads, this is one strange sounding low pass filter. Other details of the input impedance's capacitive reactance also play in this model. I suspect this is really only an issue for 10M input specs where the actual device overshoots the spec significantly (I've got no measuring equipment to test this theory).