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dancelwerk
Joined: Aug 28, 2009 Posts: 93 Location: berlin
Audio files: 2
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Posted: Mon Nov 06, 2017 7:58 am Post subject:
CEM chips Clones, Can somebody confirm if this is true? |
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I found this website and they have pin to pin compatible CEM CLONES.
Have somebody heard about this company?
http://www.alfarzpp.lv/eng/sc/application.php
I hope your answers.
Fernando.
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wackelpeter
Joined: May 05, 2013 Posts: 461 Location: germany
Audio files: 10
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sneakthief
Joined: Jul 24, 2006 Posts: 569 Location: Berlin
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Posted: Wed Nov 08, 2017 3:21 am Post subject:
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Onchip have the original intellectual property and sell a new CEM3340.
Coolaudio (behringer/ music group) have a V3340 vco clone and a V3320 vcf clone.
I've seen confirmation that this Latvian company also has a 3320 clone.
So yes, it seems legit. _________________ Sneak-Thief - raw electrofunk |
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krainov
Joined: Feb 26, 2015 Posts: 20 Location: Nowhereland
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Posted: Tue Jul 03, 2018 1:22 am Post subject:
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I confirm the chips from Alfa are 100% clones and works good! |
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blakeAlbion
Joined: Jun 16, 2020 Posts: 23 Location: Boston, Massachusetts, USA
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Posted: Tue Jun 16, 2020 6:24 am Post subject:
Tried the 3320 and the 3330 Subject description: DIY struggles |
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I purchased some VCA and VCF alfa chips. I had built an effects processor 15 years ago using the CEM 3320, 3330, and 3340 chips, and I remember they were all shockingly easy to set up.
The as3320 VCF was easy to build and I love the result. It's a very close clone of the CEM3320.
The as3330 does not deliver. I can't get it to give me at least unity gain and it generates a lot (as in a swish on the speakers) of white-ish noise as attenuation increases. When it's about to completely fade out the noise abruptly stops. It sounds like I had a bunch of cheap guitar pedals with a noise gate on the end. Granted, I am using it at +/- 12V, not 15 as shown. But I do remember using the CEM3330 at 12 volts and the Paia EKX boards used 12V.
I saw on twitter Alfa has an evaluation board, and I looked at the schematics. It's very different from the old CEM 3330 in implementation. I noted the absence of diodes at the inputs. The reference board is loaded with trimpots and feedback-dampening capacitors, and it only makes me doubt the return-on-investment of using this chip.
Just about every circuit schematic I have seen using the original CEM3330 does not deviate from the reference design. Down to the resistor values, nobody is taking liberty with a customized use of the 3330.
But I also noticed that almost nobody is using this chip except for production of nostalgia synths.
I think it's time for me to consider using another VCA chip. I have an envelope of old CA3080 OTAs and honestly they seem to work better. |
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wackelpeter
Joined: May 05, 2013 Posts: 461 Location: germany
Audio files: 10
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Posted: Tue Jun 16, 2020 11:39 am Post subject:
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I think i would save the CA3080 and use the LM13700 instead... unless there is something powered on a single supply or to use the W.Jung trick or in an case of a 1 to 1 replacement i think their are too expensive today.
There are certainly many folks desperately looking for CA3080 chips.
Even leaving one side of the LM13700 unused is from the economical and financial factor more benefitting and when this chips breaks it's easier to find a replacement and one can avoid to be the one being forced in the long line of people searching for CA3080 chips... _________________ https://soundcloud.com/bastian-j |
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blakeAlbion
Joined: Jun 16, 2020 Posts: 23 Location: Boston, Massachusetts, USA
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Posted: Tue Jun 16, 2020 12:31 pm Post subject:
Mea culpa. |
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Garbage in, garbage out. I did all the things I should have done with my as3330 chip, and now it's responding nicely. I had a 100K resistor going in directly from the op amp buffering the output of the VCF. 1 capacitor on the input eliminated all the noise, and without the noise, the response is very linear.
Hm... I have not thought about capturing this as a diagram.
But yes, this CEM3330 clone is okay. |
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