Bad phono section on SX-950

[shacky]

Bought an SX-950 on EPRAY a few months ago. Unit is real nice haven't checked the DC offset yet but it sounds very nice.

Didn't get to hook up my tunrtable for a while and when I did ran into problems. Had to turn volume up past 12 o'clock to get good sound level - but sound was crappy. Hooked up my old Proton receiver using the Proton's phono section and tape out to SX-950. Viola! Wonderfull sound. :yes: So my SX-950 phono section is bad - prbably why the guy sold it on ebay.

What typically goes with phono sections and how difficult would fix be? I would like to use the Pioneer's phono if possible. :scratch2:

Thanks,

Jim

 

[agger]

Sounds like dirty switches. Didi you toggle them an hear a difference? If not , maybe the supply to the phono board is bad. There you need a manual to check the voltages.

 

[petervv]

phono section SX-950

hi Jim,

I had intermittent sound on the phono section of my 950, I solved it by changing a few transistors.
Try 'wobbling' the transistors while playing a record.

regards, Peter (NL)

 

[shacky]

I have toggled the switches on front - this unit has two phono inputs. At first I thought how could both be bad but then realized that there probably is only one real phono section with 2 inputs.

When you say "wobble" the transitors do you literally mean move them by hand or pliers?

Another AK'er is helping me with a schematic so I should be able to check voltages in a few weeks. Until then the phono section from my Proton receiver is doing duty - and quite well. I'll actually be interested to see if the Pioneer phono section is better (once it is working) than the Proton. The Proton has MM/MC Hi/Lo and 100P, 200P, 320P Capacitance settings so I'm thinking this is quite a good phono section.

Thanks,

Jim

 

[Pioneer727]

What type of cart are you using?

Ron

 

[shacky]

Cartridge is an ORIGINAL Ortofon FF 15 C MK II cartridge *NOS*. It works fine through the Proton receiver - then using tape out to Pioneer. I also tried my B&O with MMC4 cartridge with same results. Also tried my sons TT with Grado Blue. All no good throug the Pioneer - have to turn volume up past 12 o'clock. Sound is constant volume not scratchy at all but no punch.

Jim