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KLM367A clone: Another parts error?

KLM367A clone: Another parts error?

2010-12-04 by Malte Rogacki

Hello;

I've noticed that I needed to use a very high level to load sounds "From
Tape", much higher than with the original boards.

C4 is given a 0.047uF ceramic in the parts list; on the original boards it
is 470pF. Exchanging this cap made loading "From Tape" much easier.

The mistake may stem from the service manual which has two caps marked C4;
the "real" C4 (470pF ceramic) is the one parallel to R5; while the one in
series with R28 is C5 (0.047uF plastic film).

Re: [PolySix] KLM367A clone: Another parts error?

2010-12-04 by Andrew Jury

Well spotted! I am just sitting here in front of an original and the ceramic
disk is marked Œ471¹ (470pF), so yes, you are right. Jed: Can you change the
parts list on your site? I am imagining that the wrong value capacitor would
quite severely change the shape of the input waveform and this is why you
have to drive it very hard in order to get a tape load. And I just though my
laptop and the input had an impedance mismatch!

Cheers,
Andy


On 04/12/2010 10:01, "Malte Rogacki" <gacki@gacki.sax.de> wrote:

>  
>  
>  
>    
> 
> Hello;
> 
> I've noticed that I needed to use a very high level to load sounds "From
> Tape", much higher than with the original boards.
> 
> C4 is given a 0.047uF ceramic in the parts list; on the original boards it
> is 470pF. Exchanging this cap made loading "From Tape" much easier.
> 
> The mistake may stem from the service manual which has two caps marked C4;
> the "real" C4 (470pF ceramic) is the one parallel to R5; while the one in
> series with R28 is C5 (0.047uF plastic film).
> 
>  
>    
> 
> 



[Non-text portions of this message have been removed]

Re: [PolySix] KLM367A clone: Another parts error?

2010-12-04 by Jed Jorgensen

Yes, thanks! Good catch!

I've updated both the Mouser and Farnell parts lists accordingly.

On Sat, Dec 4, 2010 at 2:26 AM, Andrew Jury <andy@networkjabber.com> wrote:

>
>
> Well spotted! I am just sitting here in front of an original and the
> ceramic
> disk is marked �471� (470pF), so yes, you are right. Jed: Can you change
> the
> parts list on your site? I am imagining that the wrong value capacitor
> would
> quite severely change the shape of the input waveform and this is why you
> have to drive it very hard in order to get a tape load. And I just though
> my
> laptop and the input had an impedance mismatch!
>
> Cheers,
> Andy
>
>
> On 04/12/2010 10:01, "Malte Rogacki" <gacki@gacki.sax.de<gacki%40gacki.sax.de>>
> wrote:
>
> >
> >
> >
> >
> >
> > Hello;
> >
> > I've noticed that I needed to use a very high level to load sounds "From
> > Tape", much higher than with the original boards.
> >
> > C4 is given a 0.047uF ceramic in the parts list; on the original boards
> it
> > is 470pF. Exchanging this cap made loading "From Tape" much easier.
> >
> > The mistake may stem from the service manual which has two caps marked
> C4;
> > the "real" C4 (470pF ceramic) is the one parallel to R5; while the one in
> > series with R28 is C5 (0.047uF plastic film).
> >
> >
> >
> >
> >
>
> [Non-text portions of this message have been removed]
>
>  
>


[Non-text portions of this message have been removed]

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