In Reply to: RE: PAS 2, Lost high freq w/ mod posted by paulcblais on March 14, 2011 at 09:49:23:
So i've been through every component on the PC-6 board and verified their values. the 10k resistor has been changed to 24ohm as per Joe's pic of component values. the sound is still muffled. the highs are lacking. From that point i had to change the cap between the triodes back to the stock .05 because it started motorboating with the .1 in there. the output coupling cap sounded bad with the .1uf so i dropped it to .058uf then .03 and the sound improved but not enough. Somewhere in the circuit the highs are getting clamped down.
Where do i go from here? I'm sure it's something simple but i cannot seem to figure it out.
I'm doing a direct A/B comparison through a DIYTube ST-35 with a set of Zigmahornet speakers and a Dennon direct drive turntable with a Shure M91 cartridge. the other Phono preamp i'm comparing it to is a $30 MCM cheapie box that sounds really clear and clean.
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Follow Ups
- RE: PAS 2, Lost high freq w/ mod - paulcblais 09:46:52 03/15/11 (2)
- RE: PAS 2, Lost high freq w/ mod - Corndog71 14:07:45 03/16/11 (1)
- RE: PAS 2, Lost high freq w/ mod - paulcblais 16:06:37 03/16/11 (0)