lm386 amp

[reg-g innit]

i have started to build a sustainer using the available info on the net

why has the schematic that has been ' on show for the last 20 years ( on this site ) got pin 2/3 mixed up

no wonder most people couldnt get it to work

i am basing this observation on google searches not what might be resolved on this website

are pins 2/3  interchangeable on the lm386?
regards regi-g innit

[reg-g innit]

2 minutes ago, reg-g innit said:

i have started to build a sustainer using the available info on the net

why has the schematic that has been ' on show for the last 20 years ( on this site ) got pin 2/3 mixed up (lm386)

no wonder most people couldnt get it to work

i am basing this observation on google searches not what might be resolved on this website

are pins 2/3  interchangeable on the lm386?
regards regi-g innit

 

[curtisa]

What diagram are you referencing against?

Pins 2 and 3 are interchangeable, insofar as the output will be polarity-reversed if they are swapped. This is the same as toggling the sustainer between normal and harmonic modes by flipping the polarity of the driver leads at the output.

There were a lot of other underlying reasons why so many people struggled to get the DIY sustainer working, not the least because it was never a particularly reliable design to start with.

[reg-g innit]

thanks for the info..that explains the variations of i/p wiring of this ic
re your comments are there any links to better circuit / driver design

this is what i am building to at the moment 

regards
reg

[curtisa]

2 hours ago, reg-g innit said:

re your comments are there any links to better circuit / driver design

Not to the best of my knowledge. There's been some discussion here and there, but development of the DIY sustainer never really evolved past the loose tutorials and schematics that you've likely already found. I can think of better power amp and preamp topologies than the LM386 and Fetzer-Ruby solutions that get mentioned a lot, but they're not exactly user-friendly, easy-to-build solutions. For many weekend DIY-ers, it's hard to justify putting mountains of effort into beating Fernandes and Sustainiac at their own game..

Here's a thread that may offer some insights into future avenues to explore if an improved sustainer is something you want to investigate:

 

[reg-g innit]

for anyone who built the sustainer and got frustrated
with the lack of response try this

since the sustainer didn't work well enough using a stripped down pickup rewound with
32awg copper wire( 8 ohms ) i searched for the  fenandes design at the patents office

this is the template of the core ( for some reason the image wont upload
but will keep trying )

i made the core using a piece of 60mmx 9mmx 3mm  mild steel bar ( cut as the template 
instead of pole pieces ) and it works perfectly on all strings
my original circuit based on the lm386 is the the driver amp ( excluding the fet pre amp )

this part of the project now works as intended 
the electronics now need to be sorted for the harmonics mode etc

i am using a 2a 12vpsu instead of batteries at the moment
 

Edited April 22, 2017 by reg-g innit

[reg-g innit]

why cant i upload my images??

[curtisa]

Are you getting some kind of error message when you upload?

[reg-g innit]

this is the error message and it is still doing it
it does it with bmp or jpg... both files are less than 100kb

' There was a problem processing the
uploaded file.Please contact us for assistance '

will try again later

[reg-g innit]

fernades template2.bmp

[reg-g innit]

21 hours ago, reg-g innit said:

for anyone who built the sustainer and got frustrated
with the lack of response try this

since the sustainer didn't work well enough using a stripped down pickup rewound with
32awg copper wire( 8 ohms ) i searched for the  fenandes design at the patents office

this is the template of the core ( for some reason the image wont upload
but will keep trying )

i made the core using a piece of 60mmx 9mmx 3mm  mild steel bar ( cut as the template 
instead of pole pieces ) and it works perfectly on all strings
my original circuit based on the lm386 is the the driver amp ( excluding the fet pre amp )

this part of the project now works as intended 
the electronics now need to be sorted for the harmonics mode etc

i am using a 2a 12vpsu instead of batteries at the moment
 

 

fernades template2.bmp

[curtisa]

I can see no obvious reason in the forum software why your uploads are failing, sorry. Maybe some of our moderator staff will have an idea.

Can you try using a different browser? I've had issues in the past with certain versions of Internet Explorer or when using an Android phone.

If all else fails you can host the image on an external picture server like Photobucket or Flickr.

[Prostheta]

I've tested the uploader, checked group permissions and there's nothing going wrong on this end of things. BMP files are too large, so our software is set to reject them. The site will only accept the uploading of:

• jpg
• png
• gif
• rtf
• mp3
• zip
• pdf
• dxf
• dwg
• tcw
• wav

Site hosting is extremely expensive, so we only allow specific file formats that tend to be large like WAV. BMP is about as useful as PCX these days. 

[reg-g innit]

i tried to upload a jpg of the same image ..with the same results ( it uploaded the shortcut ) ..the jpg was 73kb ??

not to worry i'll try a different computer next time
reg-g