Fishman Powerbridge Installation

[idsnowdog]

Fishman's website advertise the Powerbridge but yet they don't have a link anywhere to a recent schematic. I was able to find this older schematic but it doesn't make a lot of sense to me. Specifically why they are using a stereo jack? Why an on/off/on instead of on/on/on switch? What's going on with the caps and resistors in the second schematic?

I can understand running the positive terminal for each type of pickup to either the tip or sleeve of a stereo jack and using the ring for a common ground. But if you use a mono cable with a stereo jack the piezo just ends up getting grounded. Do they expect someone to run a stereo cable to a splitter? With an on/off/on switch is the middle really the two combined? What also makes no sense is the capacitors and resistors in the second diagram they say it helps "equalize" the output of the two sources magnetic/piezo. However, I doubt a piezo pickup is louder than a magnetic pickup and Fishman sells a preamp to equalize and mix the two sources. So how do these passive components equalize output between the two?

Are there any users who can shine a light on how they are wired?

[ArtieToo]

This is actually along the same lines as I'm doing with my new P-Rails wiring. They assume you'll use a stereo output cable. I just got one that terminates into two mono ends. That way, you can send each signal through a different chain, or two inputs of a mixer. The switch is on-off-on because its acting as a Mag/Piezo "kill" switch. Either side shorts the corresponding system. Remember, the contacts underneath, move opposite the handle above. So, switch handle to the right, shorts the terminals on the left. The "piezo" position, kills the "mag" position.

I'm going to assume that the cap and resistor are used to provide proper loading for the piezo system. That's a guess. I'll have to study it more. The top and bottom are two different ways to do it. You wouldn't do both.

[idsnowdog]

This is actually along the same lines as I'm doing with my new P-Rails wiring. They assume you'll use a stereo output cable. I just got one that terminates into two mono ends. That way, you can send each signal through a different chain, or two inputs of a mixer. The switch is on-off-on because its acting as a Mag/Piezo "kill" switch. Either side shorts the corresponding system. Remember, the contacts underneath, move opposite the handle above. So, switch handle to the right, shorts the terminals on the left. The "piezo" position, kills the "mag" position.

I'm going to assume that the cap and resistor are used to provide proper loading for the piezo system. That's a guess. I'll have to study it more. The top and bottom are two different ways to do it. You wouldn't do both.

So with the on/off/on switch in the middle I would still get the combined output of the two? Because I'm thinking of running each pickup to it's own volume control.

[PFDarkside]

Basically if you use a mono cable you just get magnetic pickups. Do you need an on board preamp to get them to blend with a mono cable? Maybe the Fishman Powerchip?

[ArtieToo]

So with the on/off/on switch in the middle I would still get the combined output of the two? Because I'm thinking of running each pickup to it's own volume control.

Yes. In other words, no kill. The switch contacts are "open."

[ArtieToo]

Basically if you use a mono cable you just get magnetic pickups. Do you need an on board preamp to get them to blend with a mono cable?

Yes, and yes. There are various ways to accomplish this. I recently purchased the EMG ABC control to experiment with. It's basically a 2-ch mixer, on a pot. The only potential problem is that both channels are 200k input impedance. But that's only one solution. I'll have to look up that Fishman Powerchip.

[idsnowdog]

Basically if you use a mono cable you just get magnetic pickups. Do you need an on board preamp to get them to blend with a mono cable? Maybe the Fishman Powerchip?

Here's the installation instructions. Their documentation is poor. https://media.americanmusical.com/It...stallation.pdf

First they talk about Powerchip being used to mix signals. "Powerchip active onboard blending An active onboard preamp, such as the Fishman Powerchip (available separately) may be used in order to combine the magnetic and Powerbridge signals to a single mono output on board the instrument. If you are installing the Powerbridge with the Powerchip, refer to the Powerchip installation."

Then they talk about this passive filter attenuating output by 14db to "match" a magnetic pickup. "This network will attenuate the Powerbridge so that it better matches levels between magnetic and piezo pickups. You can expect a 14dB (nominal) decrease in Powerbridge output with this circuit." I doubt lowering a piezo output will match a magnetic pickup.

[ArtieToo]

I hope this info will be helpful. I'm doing a similar thing with one of my guitars. But both my outputs are mag. No piezo, but the concept is the same. The idea here, is that we're making a guitar output 2-ch, and therefore need a practical way to mix the signals. I'm experimenting with two different paths. (No pun intended.)

First, is the Mackie 402VLZ4 mixer. This thing is cool for several reasons. It's only slightly larger than a Duncan Palladium pedal, and both of its 1/4" inputs have a switch to make them guitar-centric. (And it's less money than the Fishman Powerchip.) https://www.sweetwater.com/store/det...-channel-mixer
It also gives you separate Gain/Bass/Treble/Volume for both channels, plus the benefits that come naturally to a mixer. Such as, plug in an MP3 player to play along with for practice sessions.

Next, is my EHX Tri-Parallel Mixer. https://www.sweetwater.com/store/det...parallel-mixer
This is a bit more money, but not unreasonable. And it's exactly the same size as the Palladium. Similar capabilities but with the added benefit of now switching your pickup systems with your foot.

I don't want to get too long-winded, but there are some cool solutions to doing dual-channel guitar outputs. Mixing active with passive was never easier, and affordable.

[idsnowdog]

This is the piezo that I'm thinking about getting:
https://www.ebay.com/itm/KAISH-Tune-...0AAOSw4kNeeXB7

https://www.youtube.com/watch?v=vA0BIWKreE8

Here is a LR Baggs piezo when mixed with a magnetic neck pickup at 4:40:

https://www.youtube.com/watch?v=xCNkp4WHlN0

[Securb]

The Fishman has a "smart jack" it recognizes when you plug in a mono or stereo jack and adjusts automatically for the connection When you use the SmartChip. I have two Fishman piezos and strongly suggest this addition to your wiring scheme.

https://www.fishman.com/portfolio/powerchip/

[ArtieToo]

That thing does look interesting, but I wish they'd list the input impedance of both channels.

Edit: Dang! Now you guys have me GAS'ing for a Powerbridge. Looks cool. Could add a variety of tonal options.

[idsnowdog]

The majority of demos I have heard on youtube say they wired the piezo as a passive component. However, there's a simple preamp which I could mount under the edge of the pickguard with thumb wheels for volume and tone. I think I should be able to wire it to a stereo jack so I can power it with my phantom power box like my active pickups.

[Securb]

I only have one piezo that is wired as a passive component and it sounds subpar. It is distorted and not all that articulate. It does work for some applications, funky fuzzy stuff but it sounds nothing like the Fishman PowerBridge in my Iceman or the Fishman in my Parker. The Fishman pickups are crystal clean and also sound great with gain. This passive piezo came with a budget Chinese made axe.

[idsnowdog]

I probably wont spring for the Fishmann systems because the guitar it would be going into only cost $165. I thought the Kaish unit sounded ok for the price and if I could get better performance by adding a cheap preamp without needlessly complicating the wiring I would.

[idsnowdog]

I got the Kaish piezo bridge in the mail this morning and this thing is LOOOUUUUDD! I was laboring under the assumption that the piezo wouldn't be able to keep up with the magnetic pickup but it's actually louder. I haven't had a lot of time to try it but it doesn't sound plinky or that fuzzy zzzt sound you hear from piezo's. It is bright but not excessive. I question whether I will need the preamp now? I might end up needing the preamp to bring up the magnetic pickup's level.