[sdiy] ALFA clone chips?

[cheater cheater]

>> On 27 Mar 2021, at 18:19, cheater cheater <cheater00social at gmail.com> wrote:
>>
>> Thanks. was the original CEM3320 equally easy to damage? Did the other
>> chips have similar problems in their original versions?
>>


On Sat, Mar 27, 2021 at 7:48 PM Tom Wiltshire <tom at electricdruid.net> wrote:
>
> Yes, the early CEMs were just the same, and the early SSMs were worse, since Dave Smith had to move the Prophet 5 from one chipset to the other to get it to stay in tune.
>
> The current CEM3340 is Rev.G. My understanding is that Rev.G was only a datasheet change and an acknowledgement that some of the claimed figures for Rev.F weren’t likely in practice, but that still means there were five versions fixing earlier problems. I think that’s worth bearing in mind when we compare chips from Coolaudio and Alfa with the originals. We’re comparing later versions with early versions in most cases. CEM took a decade to get the chips to the final state that we’re judging against.

I thought what these companies did (CoolAudio aka Uli Behringer, ALFA,
SSI) was take photos of the old chips and re-issue them based off
that?

> BTW, there’s a good application note now for the PWM problem:
>
> https://www.alfarzpp.lv/eng/sc/AS3340%20tip%20VCO%20_%20PWM%20.pdf
>
> I’m sure it’s not the only solution. I’d like to see something like this integrated onto the silicon and an AS3340 Rev.B get released. Fixing things is not a failure, but a success. No-one expects everything to be perfect first time. It’s what you do next that counts.

(...which may or may not mean reissues are impossible)