Parker Retrofit

[Blitz-d]

First off: GLAD I FOUND THIS PLACE!

1998 Fly Deluxe, original owner. Bought it at East Coast Music When Ed Roman owned the joint. My Fly had developed this kind of oscillating/whistle when plugged in. I noticed it when I went direct into the mixer to do some acoustic tracks. No matter whether it was just the Dimarzios, or the piezo's, same thing. Stereo switching made no difference.

I reseated the ribbon cables (yes, original ribbon cable wiring) and noticed the input jack was kind of loose. I was taken aback at the "epoxied" on switch, thinking "what a kluge that was.

Long story short, I gutted the guitar, put in the Ghost saddles, will install the Acoustiphonic system. I am waiting on some parts from Stew Macs. My question is when seating the tremolo bridge, do you tighten the screws all the way? It seemed they were about 1 to 1 1/2 turns away from tight. I suspect this was for setting the action, as posted here in the forums.

Any insight would be awesome. I've been repairing guitars and their electronics for over 40 years, so pretty much a tech guy.

Glad to be aboard. I also found a way to keep all the ghost saddle wiring in the trem cavity, all nice and neat!

Blitz

[vjmanzo]

Glad you’re here, @Blitz-d! Welcome!

Yeah, the Piezo functionality was really pushing the envelope back in the Fly early days, and they did some “experimental“ things to get it to work

You’re referring to the screws that adjust the bridge height, correct? If so, what you’re describing sounds normal, though I would just be mindful that the bushings inserts are not coming loose—they are press fitted into the body.

[Blitz-d]

Yes, it is the POSTS. Remove the circlip, unscrew the hex bolt and out comes the bridge. The bushings seem fine. I was just playing around with the amount of tightening and noticed it makes difference on how much up tuning you get on the tremolo. I don't use the tremolo, so no big deal for me, just want to "do it right". I love my Parker and have played the dickens out of it. Had to "glue" a couple of frets back on, but that is it. I own a 1988 Strat Plus, one of the original Corona CA models, graffiti yellow with rosewood fingerboard, kind of a ""rare" combo, all original. I switch back and forth depending on the tune.

[Blitz-d]

And just as an note: I also owned one of the B5 basses, curly maple top. That thing had teeth! Had a growl to it when I played it. I ended up selling it when I was unemployed just to keep my house.

Kicking myself now.

[Blitz-d]

Well, got the retrofit done, guitar sounds great except for one problem. The output is now too hot for my AMT SS-20 tube pre-amp on my pedal board. It compresses heavily them swells as the initial strike dies down. My Strat, Gretch and Epiphone acoustic, don't exhibit this behaviour. I play straight into my mixing board or amp, or bypass the SS-20, I don't have any issues. I'm going to try bypassing the Acoustiphonic board with the DiMarzios to make sure it is the electronics causing the issue.

Bummer.

Blitz-d

[Patzag]

Check this thread. I posted the schematic to bypass the preamp for mags. Best mod I ever did on a guitar.

viewtopic.php?f=23&t=161&p=860&hilit=bypass#p860

[Blitz-d]

Wired up another jack directly to the DiMarzios. The output from the Acoustiphonic is definitely HOTTER than direct connection. I believe there is an impedance mismatch between the Acoustiphonic and the SS-20. The Acoustiphonic is overdriving the SS-20 and turning down the volume on the guitar and/or the SS-20 doesn't make a difference.

Time to reach out to Graph Tech and see if they'll give up the output impedance specs on the Acoustiphonic, as I can't find that info anywhere.

Too bad, as I like the SS-20 tonal selections.

[mmmguitar]

Have you not adjusted the piezo gain trimpot on the acoustiphonic board?

[Blitz-d]

My understanding is that the pot is ONLY to adjust the piezo output to match the passives. The board is supposed to pass the passive signal as a unity gain.

Obviously, that is NOT what is happening. When I get time, maybe I'll try turning the pot and see what happens. In the meantime, I'll reach out to Graph Tech.

[mmmguitar]

Ah. I misinterpreted your complaint as being that only the buffered piezo signal was too hot. Please keep us updated.

[Blitz-d]

I did some testing with the guitar plugged directly into my Mackie mixing console. I set the channel input gain to zero on the level meters. I then plugged the guitar in using the jack I directly wired to the DiMarzio's and got HALF the levels as the Acoustiphonic.

So, the Acoustiphonic is overdriving the SS-20 into saturation. There isn't a gain control on the input of the SS-20, those are after the input stage.

If I run the acoustiphonic into the Mackie, then out an AUX channel to the SS-20 and slowly increase the output of the AUX channel, I can drive the SS-20 WITHOUT going into saturation!

I'm taking the set up into work tomorrow and tossing it on an Oscilloscope just for the hell of it.

I emailed Graph tech and all I got was the output impedance (2.2 Kohm in series with a 4.7uf cap). I emailed them back with my test results and asked them if they could provide the OUTPUT levels of the system.

I'll keep ya posted. I made need that extra hole in the Parker for a pot between the output of the Acousticphonic and the jack!

[Patzag]

I happen to have a spare acoustaphonic preamp that I will never use.
If Graphtech does not replace yours, you can send me a shipping label to your address and I'll send it to you free.
I'm positive yours is defective because mine was absolutely unity gain on mag.
Cheers,

Patrick

[vjmanzo]

I happen to have a spare acoustaphonic preamp that I will never use.
If Graphtech does not replace yours, you can send me a shipping label to your address and I'll send it to you free.

You’re a legend, Patrick Love it!

[Blitz-d]

Did some testing today at work with an Oscilloscope. When I plug in the passive pickups only (NO ACOUSTIPHONIC), I get about a 250mv peak to peak waveform.

When I plug in the Acoustiphonic, the scope showed a -2V bias immediately. Still got a 250mv peak to peak, but it was around the -2V bias.

We checked this several times to verify. I will double check my wiring later to make sure there isn't anything bad.

I may need that free board after all!

I'll post the results later.

[Blitz-d]

Just measured the voltage on the output with a DMM, got -1.8V across the tip and sleeve.

Not good.

[Blitz-d]

I am a bit perplexed by something. According to the "Parker Electronics Technical Bulletin", the Fishman Endpin Switchjack can be used in place of the stereo jack supplied with the Acoustiphonic system.

The jack supplied with the system has a CLOSED contact that opens up when the jack is inserted.

The Fishman CLOSES the contact when the jack is inserted.

This operation should mean the Acoustiphonic shouldn't work when used with the Fishman, yet it does and I get -1.8VDC across the tip to sleeve.

I will verify that this is the case when I get home later.

Still no response from Graph Tech. Going to have to CALL them I suppose...

[Blitz-d]

The Fishman jack is the problem. I removed the switch wire from the Acoustiphonic (effectively turning it on) and my pedal board was a happy camper.

Going to slap a push button on/off switch in so I don't have to alter the electronics cavity in the Parker.

[vjmanzo]

This is great news, @Blitz-d! Congrats on getting back up and running and thanks for documenting your process—I’m sure it will save others a lot of heartache!

Way to persevere!

[Patzag]

The Fishman jack is the problem. I removed the switch wire from the Acoustiphonic (effectively turning it on) and my pedal board was a happy camper.

Going to slap a push button on/off switch in so I don't have to alter the electronics cavity in the Parker.

Great to hear!

[Blitz-d]

OK here is the "verdict".

The Fishman switchjack works exactly opposite of the switch included in the Acoustiphonic kit.

It will not work if you wire it in.

I put a switch in to simulate the jack in the kit, and the guitar works fine.

IF I switch the switch "closed", it distorts and puts -1.8VDC on the output cable. Switched "open" it works as advertised.

IF I remove the battery, NOTHING works.

So, moral of the story:

DO NOT USE THE FISHMAN ENDPIN SWITCHJACK WITH THE ACOUSTIPHONIC!

There. I feel better!

I left the jack that is wired direct to the DiMarzio's in case I need it.