[HAM] Wax caps measured and then placed in four pans....

[OF]

At 02:34 PM 11/22/2006, Don Erickson wrote:

>On Wed, 22 Nov 2006, Harold wrote:
>
> > So if you put in new caps you have a likelihood of needing to recalibrate
> > because the original caps *were not as uniform as your replacements*.
>
>Ah HA!  This has to be correct, because if the inductors were calibrated
>to the caps

They weren't!

>  AND the caps were all the "same" value,

They weren't.

>  then wholesale cap
>replacement of the "same" value caps would have to approach restoration of
>the original sound. [snip]
>
>There's no record on the organ as to which of the four pans values the
>original caps came from, but dammit, ALL CAPS WERE HAND MATCHED _before_
>the organ was calibrated,

That hasn't been established, and as was pointed out, wouldn't make sense. 
Calibration would likely have to have been done after the caps were installed.

>  and so getting a matched set of caps with values
>close to the original cap values HAS to approach getting back to the
>original sound...
>
>So assuming "hand matched" means the same four tolerances of value ranges
>that Hammond used originally, then you've got a 1 in 4 chance of getting
>the same range value of caps.  The probablility of being on the edges of
>the tolerance scale is what, one in 16, but it might account for the
>occasional horrid sounding recap job, especially if the donor organ was
>originally capped from the "high" value pan and then gets recapped from
>values corresponding to the "low" value pan, which of course WOULD be too
>harsh & shrill & out of balance because the inductors were calibrated for
>high value caps.

You don't seem to "get" that each filter had a cap specifically picked to 
get the best resonance for each filter. There would be no such thing as an 
organ "originally capped from the 'high' value pan." Each organ would have 
had caps picked from all four pans.

--Quickdraw McGraw