[sdiy] TR-909 undersized DC blocking caps

[stew]

Hi Richie,

That still doesn't make sense to me. I'll give it a try in LTSpice or on the breadboard when I get home.

Regards,
Stewart.



> Richie Burnett <rburnett at richieburnett.co.uk> wrote:
> 
> > Again, I disagree...
> > 
> > Are you saying that if you do a sim of a summing op amp with Rf of 20k 
> 
> > (I cant read the value on the schematic), a common 1uF coupling cap, a 
> 
> > 13k input resistor going to your signal source and 9 other 13k 
> resistors 
> > going to ground that you get a HPF cutoff of 120Hz?
> 
> Yes!  PSpice simulation shows this, as does the actual TR-909 I tested,
> 
> -Richie,