Technics SL-1700 (MK1) Hum/Hiss Help

[Janotoro]

I got my Technics SL-1700 from one of my favorite record stores in Louisville KY as a gift when I asked about it. They told me it did not work, the speed change was stuck and the speed controls out of wack, it came without counterweight, headshell and mat. Before investing time and money on it, I borrow the headshell, mat and weight from my SL-1200 and rotated the Platter manually to hear the sound, sound came back from both channels (however it was a very superficial test). After cleaning it, taking some parts apart to deoxidize the controls and modifying the 33.33/45 control to work, I realized the right channel has significant hum/hiss/buzz (seems like a combo of the three). I checked and tested all the wires from the headshell to the RCA board and all seems to be fine, however the noise is still there. Have any of you experienced a similar situation? Any advice on what else to try? THANKS!

 

[Stanton681EEES]

My friend had one back in the 70's and he had the same problem with his. He upgraded the RCA cables and the noise went away. Also could be a bad headshell.

 

[Grommit]

My Aiwa TT tested ok on my multimeter , but I ended up replacing the RCA's completely ,and that solved my hum

 

[bigx5murf]

Did you check the ground wire? I've restored a few the SL-1x00 series, and I always swap out the RCA cables + ground wire. If they're not a problem now, they will be eventually. There was a monster cable, that I think was meant for car audio install. I got a few back in the day, and used them for RCA cable replacements, because they had a ground wire built in, in between the RCAs

 

[Janotoro]

Thanks for the advice all. @bidx5murf, I did check all the connections with the multimeter, including the ground... I even tried by adding an extra ground wire and connecting both in different pieces of equipment from different distances and sides of the amp. I just ordered the cables and will try that next week. I will keep you posted

 

[Montycat]

Another often overlooked area involves the pins inside the end of the tonearm. They are springloaded and can stick in the retracted position. Prod them with a small screwdriver and clean them with a pencil eraser or something. Also touch up the headshell pins.

 

[bigx5murf]

Another source for hum could be the cart itself, I've had carts that were causing a hum.