diy sustainer pickup conversion

Started by benfox, April 07, 2010, 07:24:33 AM

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benfox

Hi
I've been working on the sustainer project based on a ruby schematic. My problem is the driver part. I have been searching and find info about the amplifier but not much about the driver.
I've tried with an old P90 pickup whitch is 8ohm and it did'nt wotk. I don't understand why ? What is the big difference between the drvier and a standard pickup with the right impedance ?
Do you know place where it's well explained ?
thanx
Sorry for my bad english !!

zhx

I'd say it has something to do with size or mass and its ability to resonate (don't really know - just a guess). I built my driver around a piece of steele cut from a PC-network card and around 200 rounds of copper wire. Works great!

I on the other hand have problems with the electronix part. My fetzer ruby tends to oscillate really easily.

suregork

Successfully built: Mosfet Boost, Red Llama, Crunch Box, SHO, RM Voodoo Vibe, Fuzz Face, Ross Comp, 9V Electric Mistress, Modded Crybaby

Paul Marossy

Quote from: suregork on April 07, 2010, 07:51:29 AM
I think the pickup was probably closer to 8K ohms

That sounds more like it.

Quote from: suregork on April 07, 2010, 07:51:29 AM
Try these threads:
http://projectguitar.ibforums.com/index.php?showtopic=24211
http://projectguitar.ibforums.com/index.php?showtopic=7512

Unfortunately, "The Great Sustainer" thread the www.projectguitar.com forum has been deleted, apparently due to people getting stupid, but I do remember that "psw" had worked on it extensively. There are some things that you have to get right or it simply won't work.

space_ryerson

Quote from: Paul Marossy on April 07, 2010, 12:10:12 PM
Unfortunately, "The Great Sustainer" thread the www.projectguitar.com forum has been deleted, apparently due to people getting stupid, but I do remember that "psw" had worked on it extensively. There are some things that you have to get right or it simply won't work.
Actually, it's back, but in locked and edited form :)

Quackzed

 i think its a question  of wire guage and current. i think a pickup has more windings of a very thin wire to arrive at 8ish ohms whereas a string 'driver' used after a 386 amp has thicker wire and less windings to arrive at 8ohms. i seem to remember someone managed to wind the extra driver winding around a regular'already wound' guitar pickup, without disturbing it. i'd search the sustainer thread for "wire guage"  and see about the guage wire and how many turns etc... otherwise a pickup and a driver coil are essentially the same thing right?
oi' is there a pdf or something on that sustainer?!? seems like an awful big thread to have to wade through. :icon_eek:
nothing says forever like a solid block of liquid nails!!!

BRingoC

Mmm... the diy sustainer. I was in awe of the sustainer forum, so much so that I bought a cheap guitar just for the purpose of building the sustainer into it.  I spent an hour building the amp for it, not really that difficult for the standard model that was floating around at the time I started doing it.  Then I spent hours and hours trying to put the driver together.  Essentially I used the neck pickup from the Squire Tele I had bought to make the driver, I used the correct wire gauge, depth and measurements, ohms etc, and nothing would come out.  Although with the incorrect wire size I could get some sustaining.  Eventually I put the guitar in playable form without the sustainer and chalked it up to something inherently wrong with the design. The guy that ran that design could talk your ear off without being able to answer a question on the design.  I just gave up thinking someone would come up with the answer so I wouldn't waste any more time on the thing.  Well, I'm still waiting.
Since when is 3/4 of the way up "cranked"?

Quackzed

yeah, thats the impression i got. that there was no difinitive 'final design'. perhaps due to the driver being a handmade part. to many variables there... ??? if it COULD be made to work with an off the shelf pickup, that would be a big step forward

nothing says forever like a solid block of liquid nails!!!

BRingoC

The www.uspto.gov website has the patent for the fernandes sustainer.  use the patent 'search', 'quick search', then 'guitar sustainer' in term 1, it's patent 5,585,588.  the fernandes problem is the same one the forum was having, the driver.  fernandes figured out how to make it work, the design the forum was working on didn't seem to address the issues that fernandes did, it seemed like the forum was using trial and error, fernandes was using science, obviously the forum was going to miss a lot before they got a working design.  I plan on sitting on it for a while then trying again having read through the patent grants.  Unless that forum employs science in their design they will never get it right.
Since when is 3/4 of the way up "cranked"?


andronico

I had problems with the Ruby and sustainers, I don´t like LM386 very much  :(
Try this links, it´s simple, has a video and an MP3 sample and uses other IC for the amp.

http://www15.brinkster.com/zakzub/susdriver009/

http://projectguitar.ibforums.com/index.php?showtopic=42876

Good luck.

Paul Marossy

Quote from: space_ryerson on April 07, 2010, 03:36:18 PM
Quote from: Paul Marossy on April 07, 2010, 12:10:12 PM
Unfortunately, "The Great Sustainer" thread the www.projectguitar.com forum has been deleted, apparently due to people getting stupid, but I do remember that "psw" had worked on it extensively. There are some things that you have to get right or it simply won't work.
Actually, it's back, but in locked and edited form :)

Huh, good to know that. Thanks.

benfox

#12
I'm following the same problems !!
Sorry for the ohm instead of khoms.

I've tried with a 0.5 wire with about 150 turns. The string just oscillate a bit with a big distort behind.

I'll try :

- 0.2mm wire

- lm386 n4 instead of lm386n1 !!

- i am looking over this chip interesting lm4250 (up to 30W !! ?)
http://www.alldatasheet.com/datasheet-pdf/pdf/8911/NSC/LM4250CN.html

- maybe look also the magnets !!I've seen many differences.

My personal thought of the day (maybe a piece of crap) :
In my past experiment with mini speaker coils i'v notice that the fact the coil moves gives more strength to the string...
Let's make a moving coil ??!!
Sorry for my bad english !!

BRingoC

If you read through the patent description on the uspto site, it will tell you exactly how to make the thing. It has nothing to do with the amp, you can use any amp design, the problem with the design is the magnetic driver.  Fernandes figured out you cannot make just any old driver work, ie, 'the forum' says use a certain mm wire wrapped about 150-170 turns to make  an 8 ohm coil, but that is an extremely simplistic design and will not create a driver that will work like the Fernandes sustainer.  Fernandes describes that you need a rail pickup, not individual pole pieces like a typical Strat pickup.  The rail is then cut partially, in a fan shape, creating 6 variable width 'poles', each 'pole' is a different size for each string.  They later refined this to have three rail pieces of varying thickness for each string, all in parallel.   Fernandes figured out that each string needs a certain amount of magnetic flux to get that string working, and no single pole size works optimally for all strings.  Look over the patent description, read through the thing, and it will tell you exactly how to make the driver correctly, the simplistic 'forum' driver has not addressed any of the problems that the patent describes.
Since when is 3/4 of the way up "cranked"?

BRingoC

Since when is 3/4 of the way up "cranked"?

BRingoC

Figure 18(b) shows the bar magnet that is fanned out to give the strings their own sized 'pole'.  Figure 21 shows the three magnets that make up the driver.
Since when is 3/4 of the way up "cranked"?

benfox

#16
wow
that's very interesting !
i'm impressed !! there is a lot to learn !!
That's funny because
I was wondering about pole pieces and that each string will react differently too...
Maybe the pole piece standard strat pickup could be wind differently
My idea is (tell me if it's crappy) :
winding each polepieces differently

witch would mean find the turns needed for each pole piece / string

But as you said and as show the picture 18(b) the pole pieces have different surfaces.
Sorry for my bad english !!

psw

While mechanically they might seem similar, a driver is different from a pickup...they are not interchangeable. Pickups as stated are far more likely to be 8K or 8,000 ohms than anything like 8 ohms.

The design for a basic sustainer is quite clear...0.2 ohms wound to 8ohms with a thin profile. There are mods to the Fetzer/ruby circuit that make it more stable, that was not my suggestiong, but any number of non-loading (buffered or preamped) small amplifier circuits (typically LM386 based) will work. The secret is in the driver IMHO...

here's the shorter tutorial...

http://projectguitar.ibforums.com/index.php?showtopic=16984

Here's a pictorial of actually winding a driver, this is built onot a pickup, but the procedure is identical for this desing...I don't see where the mystery is...

http://projectguitar.ibforums.com/index.php?showtopic=24211

You do not need excessive power, more power generally causes more problems. The specs for a driver that will work are based on a many tests and verified by many, many people who have successfully replicated the design. There are all kinds of inductance and resonat issues behind why it work with these specs...but 0.5mm wire is so far out of the ballpark, it makes no sense. Also, 150 turns of 0.2mm usually gets you to about 8 ohms...so something seems wrong there as well.

The other issue that people often neglect is the potting...it will not work properly if the coil is not potted solid with glue...this is not a pickup!

Also...on LM386 circuits, I have consistently suggested a 100uF output capacitor to bias the circuit with these drivers to get a more even response and better high string response to it.

...

The Sustainer thread itself was an open thread for a lot of ideas and exploration...it is hardly fair to suggest the project did not have many successes from me and others in it, but it is not the thread on the design, it is the thread from which this and other designs emerged.

My design does work, is fully verified and duplicated over many years and extremely well publicized. What happens though is that people do not find the basic tutorials or follow the instructions given, make naive judgments or fail to understand what is required from the device and the requirements on it...IMHO.

I'm happy to attempt to answer questions if the tutorials are not clear...but if results are not forthcoming, blaming the design is not going to cut it because so many have been successfully made with the correct procedures and specs with complete success.

It's like saying that a stompbox design doesn't work because you thought it would be ok to use any 8pin chip or transistor that "looked" like the one specified, but had completely different pin outs or functions...or decided that glue would be a better option than solder to make it up...it really is nonsense. 0.2mm wire is quite specific enough, this will yield a driver that is efficient enough at the frequencies of the guitar and the power from a small battery power amp and not cause all kinds of EMI problems if built right (potting, care with winding, etc).

I've read most patents and discussed them over the years....for a basic working DIY sustainer, I'd not get to caught up in them. My design is quite different from the commercial versions in many ways anyway. The standard basic driver has been wound onto strat and even half HB pickups with complete success, added to passive strat pickups, or built as stand alone designs by myself and many others. Different pole pieces or a single blade has little effect on the performance of the device.

I spent a year on Hex sustainers (six separate drivers)...there are significant problems and hurdles...it really is not necessary. One thing to consider with such designs, how would you isolate one pole from another? Magnets that close to gether will be attracted to each other and therefore effectively linked. Your coil/s are also electromagnets working on this static field...how will you separate the influence of one on another. In the end, they tend to at least work as one.

This is of course only a necessary  solution if there is indeed a problem. The fact is you can get a pretty ggod response from a DIY device or a commercial version without going to such extremes.

benfox

thanx for this usefull reply,
i've been looking over the links you've post already. I'm waiting now for the wire i've order.

I'll test different stuff and let you know.
I've made the driver (without the bobine) with 2 pieces of epoxy and with a ferrite bar. Does ferrite is a good metal for this ?

I've seen over the tutorials that the bobine has to be thin. I did quite catch how wide it must be. Is it 3mm large ?
How does that affect the response of the driver ?
Sorry for my bad english !!

petemoore

   I know that explained a lot because now I have many new curiosities.
   Magnitude of thanks to psw for sharing valuable information filtered and compiled, apparently from many hours of experimentation, study and good experience.
Convention creates following, following creates convention.