PhonoII 3.18µS correction mod - resistor values
A I'm in the process of building-up a new PhonoII pcb I looked at the details of the PhonoII 3.18µS correction in the FAQ - Upgrades and Tweaks section of this forum....
To introduce this correction simply insert an additional resistor between C16/17 and the junction of R31/32 and V4b/a connection 7/2. See diagram. The easiest way to do this is to lift one leg of C16/C17, the leg connected to R31/32 and solder the new resistors into position on the top side of the PCB between the lifted leg and the solder pad of R31/32.
The required value is 14K454 Ohm, absolute accuracy is not necessary or achievable so parallel either a 51K resistor with a 20K resistor to give 14K366 or an 18K resistor with a 75K to give 14K516. All resistors should be .6W 1%.
... and having been given a link to the resistor calculator on Pete Millett's site by Steve (aka The Shadow) I decided to plug in the 14k454 and see what values it threw back to get close to this required value... It came up with 16k and 150k in parallel giving a value of 14k458 where as the sepecified parallelled 18k and 75k give 14k516. Probably not great shakes but just thought I'd share...
Steve
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