[Taika-Kim]

Hey, I bought an used Sammich without chips. The previous owner had a pair of 6852s, whereas I have dumpstered(!) 6581s. So do the filter caps need to be changed? I tried searching the forum and the net, but didn't find really anything concrete... I'm aware though of the jumper change to accommodate for the different power requirements of the filters.
Do the same instructions about the caps apply than for the usual Midibox SID?

[ilmenator]

Taika-Kim, on 22 January 2012 - 16:22, said:

Do the same instructions about the caps apply than for the usual Midibox SID?

Yes!

[Taika-Kim]

But with topics like this:
http://midibox.org/f...cap-comparison/

It seems it's possible to change the sound with the caps, and it's not dangerous to try different ones? (how much can the values deviate from the ideal 470pf?)

And also, there are ceramic condensators, styroflex, and some others? What is the best to use?

This post has been edited by Taika-Kim: 22 January 2012 - 17:08

[ilmenator]

The thread you link to provides sound demos for different filter caps on a 6582. You say you have 6581s, so you'll have to check which are the standard caps for this chip. I would interpret the sentence you quote in the way that the 22nF belong to 6582s, whereas 470pF go with 6581s.

[Taika-Kim]

Yeah 6581 uses 470pf, but what I am now wondering is the difference between different types of caps? I don't really know that much about electronics, made a few PCBs and projects, but that was just following instructions so don't really get the facts behind the numbers...

[Imp]

Styroflex are what's in smashTV's kits. If you can't get those, you can try any non-polar kind, but soundquality might decrease a little bit.

[Janis1279]

Hi,

For the filter part the preferred choice are capacitors with the low temperature coefficient
http://www.gqrp.com/na5n.pdf

the 6581are powered from +12VDC supply instead of +9VDC for the 6582.

Regards,
Janis

This post has been edited by Janis1279: 22 January 2012 - 22:56

[Gilesjuk]

The 6582 is much the same as the 8580, so you need to change them. I believe the capacitors are used by the filter and every chip has a slightly different sounding filter so you can try to get the sound you like by altering the capacitor values slightly.

If you find the filter too muffled then you should change them from the default values for the 6581.

[Taika-Kim]

So I go for low tolerance, low temp coefficient styroflex? Well, they seem easy enough to change, now I just want to get this working, and get what they'll have at the shop...

[rosch]

i'd say you can try different types of about the same value and then decide what you like best. styroflex are the most expensive and with the best performance (small tolerances also).
but i found the sound of the ceramic and mylar interesting too. after all it's a matter of taste. and they're just a few cents so no big loss to try some different types.

[Taika-Kim]

Do they only affect the cutoff action, or is it possible also to steepen the resonance of my 6581s? I read that the 6581 has weaker resonance than later models... Today finally got the parts, but don't have time to test yet. Yaiii, waiting for tomorrow now wildly