Re: 6569 vs. 8565

From: Gerrit Heitsch <>
Date: Sun, 25 Nov 2012 07:01:45 +0100
Message-ID: <>
On 11/24/2012 09:36 PM, wrote:
> On 2012-11-24, at 20:25, Gerrit Heitsch wrote:
>> If you use a 6569R5 on a 250466 board and replace the modulator with a just a driver circuit for S-video, you get a very clear picture.
> I tried this (BTW - some modulators introduce a lot of blur to the picture, other not so much) and I get a good luminance sharpness after replacing modulator with the Y/C amp, yet with (small but still) chroma artefacts. 250469 with 8565 delivers both sharp luma and clean chroma. Also on a scope the chroma off 6569 seem to be more noisy on the amplitude while 8565 board has it noticeably more clean output where amplitude doesn't fluctuate as much as with 250425 and 6569.

Did you try different revisions of the 6569? If yes which ones?

> If I place 8565 in the 250425 board (yeah, I know..) then it also delivers less artefacts, although the overall quality is poor for other reasons.

Well, if you take care of the different voltages on pin 13, you can run 
a 8565 in a 250425 board without problems.

>> As for lower power, the 6569 is NMOS, there's not much you can do about it if you want it to work.
> There is only some buffer (we discussed this, didn't we?) for supplying it with somewhat lower voltage in hope it may boil a bit less.

I did try that. Didn't make much of a difference with the 6569R5 I 
tested. Still worked, still ran hot with 10V instead of 12V.


       Message was sent through the cbm-hackers mailing list
Received on 2012-11-25 07:00:43

Archive generated by hypermail 2.2.0.