sustainer pickup design which is the best one?

[numpty]

I have read a number posts about building a pickup sustainer similar to a fernades or sustainiac, but which transducer design is the most effective. some use magnets a with an 8ohm impedance winding but it has be suggested that a laminated single pole piece is best i assume this isn't magnetised but relies on a higher output amplifier source. As many people have done a lot of ground work on this rather than try to reinvent the wheel i would like to know if there is an overall clear winner in terms of the best design to follow.As far as the amplifier part is concerned I'm sure experimenting with a compressor and graphic equaliser an small bench amp would yield a decent result an efficient transducer is constructed .

[soggybag]

I haven't used the Fernandez, but i have two Sustainiacs and they both work great. I installed them myself. It was not an easy task. Not overly difficult but not a beginner project. There's a lot of wires and wiring the switch is a bit confusing. I took one of my guitars to a shop and had them route a battery cavity. On the other guitar I put the battery under the pick guard.

[numpty]

I would like to build one from scratch as others have done, but I'm confused about what design to follow. I dont want to buy a manufactured version.

[Electric_Death]

I would like to build one from scratch as others have done, but I'm confused about what design to follow. I dont want to buy a manufactured version.

Here's a nice basic one that's been passed around online for a while now:


Really simple concept I'm sure many people thought up long before seeing this diagram
You could surely fine tune it a couple ways though. For one, the piezo you use will determine how well it will perform. You could also probably fine tune it with a cap and resistor in parallel on the input of the piezo.

[numpty]

I don't think that would work, you would just end up with "howl back" due to the proximity of output signal to input

[ambulancevoice]

http://www.storm-software.co.yu/diy/index.php?project=sustainer
there is this

[DDD]

Sustainiac drivers seem to be the best ones, plus they have special "compensating" steel tab to reduce unwilling crosstalk.

[Dave_B]

psw has done a lot of work on his sustaining device.  He's posted his efforts here several times as well the project guitar forum.

[numpty]

I have read some of the posts in that long thread.  it seems that a lot of key info is missing as i understand some of the more advanced project developers believe their attempts have commercial potential. Given that there are at least three products out there all with patents and that these kits involve drastic surgery and the loss of the all important neck pickup, I'm not so sure about that. As a diy experiment with a cheap but OK guitar it could be fun though.
I would like to know if anybody has recorded the waveform that comes out of the sustainic transducer and compared it to the original on a scope, I'm sure the key to success lies there, once a decent transducer has been built.

[Electric_Death]

I don't think that would work, you would just end up with "howl back" due to the proximity of output signal to input

According to project guitar and a handful of posts I've read, it's tried and true numpty. All a sustainer is doing is creating a feedback loop which keeps the string vibrating. I also looked at the sustainer kit circuit, it's nothing more than an op amp driven preamp so I would bet the sustainer pickup uses a similar resonation device to the piezo and lm386 technique.

For about 5 bucks, it's worth the effort instead of spending a few hundred and if it does work, you can really fine tune it with your own preamp circuit using a transistor or op amp.

[stumper1]

All a sustainer is doing is creating a feedback loop which keeps the string vibrating

[numpty]

 ;DClearly there's a lot more to it than that (and it uses a magnetic transducer! ) i wouldn't have started this thread if it was that simple, there is a huge amount of R and D that has gone into this sort of thing, tnat is why nobody is giving any secrets away it seems.

[Electric_Death]

I don't think that would work, you would just end up with "howl back" due to the proximity of output signal to input

The piezo isn't loud enough to "howl back" and will be dampened by gluing it to your pickup. I'm not the expert here but yes, you're just creating a feedback loop. Your strings vibrating at say 1,000 hz at the fret you're fingering it on so, you loop back that 1,000 hz to your pickup to hit the string with and keep it vibrating.
Surely you've gotten this effect from your amp before?
Sometimes if I dial everything in just right, I can get feedback sustain on every string and fret, past the 7th-8th fret. Whether you use a coil or a piezo as your resonator, they're still doing the same thing.

One final note- if you ever wondered how Dime had such wild dive bombs and pitch bends, I have always assumed this was his secret weapon.

[frankclarke]

Speaker on the headstock still works.

[Electric_Death]

Speaker on the headstock still works.

lol, that surely opens up the doors of possibility. I've got several ideas for the piezo technique I'm going to incorporate. I'll be willing to share them based on success level but with the cost of sustainer kits, you better believe I'm going to copyright them first!

[Electric_Death]

Strike one, the technique I applied today didn't work. I'll invoke a few other tricks and if it still doesn't work, on to the next idea..and the next and the next until it works!
I vow to engineer a sustainer that is cheap and simple to build or my name isn't Sylvester Elowishiss McGuilicutty the 3rd!!

[numpty]

I don't think that would work, you would just end up with "howl back" due to the proximity of output signal to input

The piezo isn't loud enough to "howl back" and will be dampened by gluing it to your pickup. I'm not the expert here but yes, you're just creating a feedback loop. Your strings vibrating at say 1,000 hz at the fret you're fingering it on so, you loop back that 1,000 hz to your pickup to hit the string with and keep it vibrating.
Surely you've gotten this effect from your amp before?

I didn't mean acoustic feedback: It was the proximity of the output signal going to the the piezo next to the pick up wires which could cause oscillation, like poor lead dress in  a tube amplifier

[Electric_Death]

I don't think that would work, you would just end up with "howl back" due to the proximity of output signal to input

I didn't mean acoustic feedback: It was the proximity of the output signal going to the the piezo next to the pick up wires which could cause oscillation, like poor lead dress in  a tube amplifier

Well if it's not some form of acoustic feedback it's still some type of physical feedback oscillating the string. With the coil method it's magnetic, my understanding is that the piezo is to vibrate the pickups field which will be that of the feedback frequency. The strings vibrating at 1,000 hz, you loop it back to the pickup by means of the piezo and capitalize on it's field.

I have to admit I haven't gotten around to building the one in the diagram I posted, I was taking it on faith that it worked due to the claims of others and the reputation of the sites I found it on. Honestly, I suspect an LM386 doesn't have enough juice to get the piezo oscillating intensely enough. I've experimented with piezos here and there, I can see how it should definitely work but not without at least 2-3 watts of RMS power driving it.
Maybe a dual op amp with one stage cascading into the other, both with a gain of 1000 and a +9- power supply?

I guess I'll get around to it over the next week and check back in so I'm not just blowing my own horn.