1 Reply by dendy

(7 replies, posted in Commodore Computers)

ok, now it all ended with totally umexpected result :-))

I ordered ARMSID chip - just to be 100% sure that my test midibox sid, which i used for testing those chips, is 100% ok.

Now, it turned out that with ARMSID sound is almost exactly same (just a bit less noise but that is normal) than all my 6582A chips !!!! Looks like they are all actually 100% ok and original, all features which i tested are workimg exactly same on them like they are working on ARMSID chip (including almost no resonance on filter)

I think this is very important, looks like this serie of chips (at least mine 8 pieces), even through they originates from seller with history of some fake chips, they are genuime and totally OK !!

I'm really glad that it is just some bug in my test board, not it those chips...

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2 Reply by dendy

(7 replies, posted in Commodore Computers)

hm at least printing looks like it is original, definitely not rebranded, tried acetone and nothing ...

i will probably simply rexord various sound examples, so potential buyer can decide if it is interesting for him... with additional info about source and not working resonance.. i think that would be fair

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3 Reply by dendy

(7 replies, posted in Commodore Computers)

hm rebranded 6581 - that would make sense because as i know resonance on 6581 filter is almost none... except of resonance i really didn't found any other issue, and as you can hear in example i attached, they are basically sounding not bad.. basic filters (cutoff) works very nice, it's just that damn resonance what doesn't work

will try acetone ;-)

but in case they are actually 6581 - how it is possible
they're working powered by just 9 Volts ? 6581 needs 12 Volts, only 8580/6582A have lower voltage... I have 9V stabiliser in my test midibox board, and they're working just fine

Or it is that even 6581 can work at 9V, just they are less stable or something like that ?

Anyway if they are really just rebranded 6581´s, that's ok - some people even like more 6581 because of more raw oldschool sound :-) Will think what to do next, for sure this is good information for potential buyer...

Thanks for all advices !

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4 Topic by dendy

(7 replies, posted in Commodore Computers)

Hello,

i found this nice community and i would kindly ask for help/advice. In case i'm here at wrong place with my qustion then sory and feel free to delete my post or
move it to proper section.

I have for years (probably 15 years) 8 6582A chips. I bought them with intention to build Wilba 6582A midibox SID synth -  but it never happened.

I decided to sell tem - mainly because it's a pity they are unused, and they may serve well to somebody. I almost dit, but weirdo who wanted to buy was not able for 3 weeks to get them at the post so i asked for returning them (which is not important for my question but just want to draw complere story)

Now, after all that, i decided i give a shot to them an try them. So i quickly finished my single chip test-board with midibox SID and tried all chips in it. At first round everything looked OK, they all were playing, all
parameters pf synth engine (oscillator types, modulations, everything just fine)

But then i notices strange thing - the resonnance on filter was almost none. Even with maximum setting, resonance is very subtle, almost not noticeable.

This surprised me a lot, because i readed that 6582A chips (9V ones) should aound exactly like 8580R5, and from demos on YT i heard noticeable resonance on filter in many demos.

So now i'm not sure - may it be that my chips are fakes ? Almost everything (at least to my ears) sounds OK, just that almost no-resonnance (on otherwise fully functional filter) is boggling me.

Is there anything i can do to sure that those chips are no fakes ? Because i don't want to sell
something which is not 100% ok :-((

Here i recorded some random
loop with some tweaking - in some parts i was tweaking resonance of filter to max but as you can hear it's almost no noticeable...

https://www.dropbox.com/s/64214cqy08u1g … A.wav?dl=0

and here are photos of my chips from both sides
https://www.dropbox.com/sh/hvc69972qa4e … NxVGa?dl=0


Thanks for any advice !

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