Has anyone experienced an increase in noise from the line stage of their SL-10? It must be the output stage since it does not change with the level control. The power supply voltages are spot on. One channel is a little worse than the other. It is definately audible through a Threshold SA 3.9 driving WATT 5/Puppies.
Thanks,
Also, are there any good quality schematics of the SL-10 online? The only one I found is hard to read and the link to the one on the Pass Labs site is broken.
Thanks,
Also, are there any good quality schematics of the SL-10 online? The only one I found is hard to read and the link to the one on the Pass Labs site is broken.
Hi Nelson,
The noise is kind of a gritty white noise in the right channel (brown noise?) and the left channel is a lower level white noise. Relative to 700mV output signal, with the volume at 10:00, it is about 78db down in the left channel and 72-70db down in the right channel. With the volume pot all the way down it doesn't change. The phono stage (MC) is almost quieter than the line stage. Its those silly WATT/Puppies. Their just too efficient.
Thanks,
Doug
The noise is kind of a gritty white noise in the right channel (brown noise?) and the left channel is a lower level white noise. Relative to 700mV output signal, with the volume at 10:00, it is about 78db down in the left channel and 72-70db down in the right channel. With the volume pot all the way down it doesn't change. The phono stage (MC) is almost quieter than the line stage. Its those silly WATT/Puppies. Their just too efficient.
Thanks,
Doug
Swapping the input transistor on the High Level gain Stage did the trick so that now both channels have the same noise measurement. Unfortunately the noise in both channels is still fairly audible in our system. It is real quiet out where we live and the SA 3.9 has beau coup gain when paired up with the WATT 5s. I measured the SL-10 using 1v-out as a reference to compare it with some SL-10 specs that are on the web. Of course 1v out would blow the windows out of the house with the 3.9! On the RIAA stage with 24mV in and 1v on Tape out I measured -74db S/N unweighted and -82db Wtd. On the Line stage with 1v on Tuner In and Volume Pot set for 1v on Main Outputs I measured -82db S/N unweighted and -89db weighted. Since I can blow the windows out with the volume at 9:00 I may just build an attenuator to plug into the input of the SA3.9. That will give me a little more range on my preamp volume control and knock the noise down also. I guess I’m just an old fart now and I don’t listen at the levels that I used to!
Thanks for the advice. And happy listening!!!
Thanks for the advice. And happy listening!!!
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