In Reply to: phono noise floor posted by David Smith on February 23, 2015 at 20:15:19:
So I had a look inside today. Voltage off of the last filament cap was 18.6V, high but within tube spec. I had a pair of 3.3ohm 2W resistors off of the bridge, a little higher than the 2.7 specified in the schematic. I tried clipping one out, it only brought the last filament cap down to 17.5V, so I clipped the second one out and replaced it with a pair of Mills 12W 3 ohm in series, which measured 6.4 ohm. This brought the voltage at the last cap down to 15.4V, pretty close to the 15V called for, so I left it that way.
I also cleaned all of the switches again, with extra attention to the Mag 1/2 switch.
The bad news is the white noise is unchanged...So I think the next step will be to try 5751s and LPSs.
I appreciate all of the help and suggestions.
Dave
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Follow Ups
- Followup - David Smith 13:14:39 02/25/15 (1)
- ..and one more.. - David Smith 19:21:54 02/25/15 (0)