ALFA RPAR AS3340 VCO Chips?

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Katherine Alicia
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ALFA RPAR AS3340 VCO Chips?

Post by Katherine Alicia » Fri Apr 02, 2021 5:05 am

Are these as good as CEM 3340 chips? and are they pin for pin compatible?
I was considering buying the PCBs and building my own VCOs using these chips because they`re affordable (more so than the CEM versions) would they be OK?

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ixtern
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Re: ALFA RPAR AS3340 VCO Chips?

Post by ixtern » Fri Apr 02, 2021 5:45 am

I am using AS3340 and CEM3340 chips in some different VCOs. CEM3340 seems to work OK in every design, AS3340 in most but not in all. Although they are pin-to-pin compatible, AS3340 needs 2 different resistors than CEM3340. Try newer version - AS3340A. Read datasheets.
Last edited by ixtern on Fri Apr 02, 2021 5:51 am, edited 1 time in total.

ixtern
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Re: ALFA RPAR AS3340 VCO Chips?

Post by ixtern » Fri Apr 02, 2021 5:47 am

Double post.

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Katherine Alicia
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Re: ALFA RPAR AS3340 VCO Chips?

Post by Katherine Alicia » Fri Apr 02, 2021 6:10 am

Thanks, I did read about the PW needing a 50K rather than a 10K resistor on the output (a trivial change really), I wonder if that`s why the Sqr wave on the Neutron is so hot going into the mixer, Hmmm...
Good to know that other than a few simple things it`s pin for pin, I think I`ll buy a couple and try it out ;)
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Re: ALFA RPAR AS3340 VCO Chips?

Post by papz » Fri Apr 02, 2021 12:25 pm

The Neutron uses the Coolaudio V3340, a CEM3340 clone made by B., not the AS3340.
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Katherine Alicia
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Re: ALFA RPAR AS3340 VCO Chips?

Post by Katherine Alicia » Fri Apr 02, 2021 12:58 pm

Thanks :)
Certainly seems to be a lot to choose from, I`v bought a pair of the AS3340`s and a couple of VCO PCBs and face plates for them, I socket all ICs anyway so it wouldn`t be a problem to swap them out later if I wanted to.
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