distorion without germanium diodes (or transistors used as cliping elements) ?

[gasmask]

hi,
as the topic says, is it technically possible to produce distortion sound using only opamps and substitution of germanium parts?
I'm from Poland and it is really really hard to find all germanium based parts here.
Thanks in advance
gasmask

[PRR]

> Poland ...it is really really hard to find all germanium

You should have stayed friends with Russia, because they were the world's biggest producer of Germanium stuff for many decades.

(True, the Russian economy in those decades was very bad at *distribution*, getting tractors and grain and diodes to the people who wanted/needed them.)

Geo-politics aside....

YES you can distort with about anything.

The distortion tone has less to do with the device material and more to do with circuit design.

The Silicon FuzzFace is a simple, well-known, thoroughly proven guitar distortion effect, and can be built about any place you can buy resistors. Recent thread:
http://www.diystompboxes.com/smfforum/index.php?topic=111539.0

[mcknib]

Depends what circuit you want to use them in but yes you can use op amps for distortion as well as silicon diodes, transistors, mosfets and LED's etc


You can make versions of tube screamers for example with no transistors using silicon diodes (1N914) and an op amp (JRC4558)

and versions of the RAT in fact most modern NPN distorters use mainly silicon versions with the odd 1N34A germanium diode thrown in here and there you should be able to get plenty of D series germanium diodes and transistors from Russia on e-bay D9E's etc

http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.Xrussian+germanium+diodes.TRS0&_nkw=russian+germanium+diodes&_sacat=0

[Maroslav]

Przecież na Allegro i Amptone są tranzystory germanowe

[Brisance]

I'll leave this here, in case you still want germanium diodes(when in doubt, China)

http://www.aliexpress.com/item/Free-Shipping-100-pcs-Germanium-Diode-1N60-Glass/2035497325.html

[aron]

You can always order from the STORE link above.

[LightSoundGeometry]

You can always order from the STORE link above.

I will probably buy a tee shirt before the fall semester

[ashcat_lt]

IDK about any of the mojo or leakage or whatever, but the big difference you get if you sub a standard silicon diode for a germanium is the diode drop almost doubles.  That means you need more gain to get the same amount of clipping, and the output will be overall louder.  If that is not  acceptable an/or you can't or won't compensate for it elsewhere, you can usually get away with using a Shottky diode instead.  They are pretty close to germanium for most things.

Opamps can be used to distort, but they usually clip pretty close to the supply rails.  With a standard 9V supply, it takes an absurd amount of gain to get it to clip at the same point in the wave swing as a diode might.  I mean, 0.3V (for germ) vs like 3V...  Sure, an opamp has plenty of gain available, but then the output is 6V or more peak to peak!  That's too much for about anything you plug it into to deal with gracefully.  So attenuate it back down?...

...Or use a lower voltage supply.  Except that there are very few common opamps that will do anything at all much below 9V supply.  The LM324 will operate with 3V rails.  It swings all the way to 0, but can only get to about 0.8V of the top rail.  At 3V, that means the maximum signal swing is 2.2 V, and (if biased to 1.5V) is very much like an assymetrical clipper with a Si up and an LED down.