Flanger electro harmonix Reticon SAD 1024 problem ?

[fjgaston]

Hi
I have an old Electro Harmonix Electric Mistress Flanger, it doesn't flange anymore.
It had bad wiring, so I soldered everything back as the original but it doesn't work anymore.
When I plug Input and output and push the footswitch the signal is lowered a little but no effect can be heard.
I measured with my multimeter (ac voltage), signal is present at the BBD's input (SAD 1024) when I play the guitar but no signal at the output.
Does it mean my SAD1024 is dead ???
How can I check if my SAD1024 is still alive ?
Reticon SAD 1024 seems to be expensive today ...

[Mark Hammer]

Malheureusement, des SAD1024 ne sont pas disponible. Ils existent,mais en forme de 2 ici ou 3 la-bas. Heureusement, un flanger peut être en panne à cause des nombreuses autres facteurs qui sont façile a réparer.

There are several trimpots inside. One of them sets the bias voltage. Each BBD needs a DC voltage at its input. If the DC voltage is too high or too low, you hear no sound from the BBD, and get no flanging. If the DC bias is un petit petit peu trop haut ou trop bas, you hear a distorted delay sound. You can adjust the trimpot by ear without damaging the BBD.

Lisez l'article trouvé ici: http://hammer.ampage.org/files/Device1-5.PDF

[fjgaston]

Thank you for the reply
I tried to adjust the trimpots the flange did not came back.
when adjusting the bias trim pots there is a position in which I have no sound at all.
but higher and lower I still have only the dry sound.

How can I easily see if my SAD1024 is still ok ??

[Mark Hammer]

Tout d'abord, let us identify WHICH model it is, because there are so many of them.

Does it use batteries, or does it have a power cord and transformer?

Does it use an LM339 chip?

[fjgaston]

It has a power cord and a transformer inside.
There is no LM339 chip
but LM311, LM324, UA741, RC4558, CD4013 and SAD 1024.
I think it has been made in the 70s

[Mark Hammer]

Okay, thanks. That information will help me to track down the appropriate schematic, and provide useful advice. Stay tuned!

[oc disorder]

Deluxe Electric Mistress project at General Guitar Gadgets
These schematics and parts layout use the same chips.

http://www.generalguitargadgets.com/...ms/dmistsc.gif
http://www.generalguitargadgets.com/...ms/dmistlo.gif

[fjgaston]

I gave up my flanger after a few try to repair it.
But now I have some time for another try.
I think the chip SAD1024 is down. I measured the voltage before and after the SAD1024 there is some signal in the inputs but nothing in the outputs.
Do you know how I can check if the chip SAD1024 is still "alive" ????
And if it's dead I'll try to buy another one.

[Jilka]

You can also use two SAD512, just rewire them.
I found SAD1024 on ebay, i spend 50$ for it.

[fjgaston]

Before I buy a SAD1024 (or 2 SAD512) on ebay does anyone know how I can check if mine still works ?????

[Mark Hammer]

In almost every case I've seen, whatever BBD-chip is used will likely be socketed. If you can find somebody else that has a pedal which uses an SAD-1024, you can open up that pedal, temporarily remove the one in there and insert your chip to test out.

If you want some idea of what pedals are possible "test units", go to modezero.com and look at the pictures there. Many of the chorus, flanger, and delay pedals will show a picture of the circuit board and identify the BBD chip used (MN3007, MN3205, SAD512D, SAD4096, SAD1024, etc.).

Be sure to discharge any static electricity from your body, and place the chip in conductive foam for safety when you are removing them.

[Jilka]

fjgaston, you also can replace all the IC's except SAD1024 and theck it out.
I found all other chips without any problem in Moscow. Just try!

[fjgaston]

I didn't try so much debugging I finally bought a SAD1024 on Ebay for $55.
There is a seller who seems to sell only SAD1024.
If this is not the problem in my Electric mistress, I'll just just keep it as a spare part anyway.
The only test I did was to send a signal in the input jack and measure with a multimetre (AC) at the input and outputs of the SAD. The signal is present at the input, but nothing at the output.
Everything seems to be wired the good way, I really think the SAD is sadly dead.
I hope I won't kill the one I just bought
I'll tell you as soon as I'll receive it.
Thanks for the advices.

[Jilka]

fjgaston, that sounds exactly like my story, i just replaced SAD1024 on my standard electric mistress and it started flanging!!!!
you should just tune the trimpot for the BBD chip. Anyway, I replaced all the IC's befory installing new SAD1024,
I was pretty scared to damage a new Reticon...