Earth hum Bad Sherwood DEK-7U

diyAudio Member
Joined 2007
I just got this cheap [ $50-] turntable for the shed and plugging it into my little party mixer I have the worst earth hum.
There is no wire connector with this TT for earth connection to the amp or pre-amp/mixer and the instructions on-line are no help.
Is there a workaround or does simply using the inbuilt preamp and treating it as a line level input work best?
I haven't yet tried using line inpiut as it means taking everything apart and it's almost time for me to start cooking dinner
 
OK Dinners over and I went out and swapped from phono input to line level and no hum.
I've no idea what was happening there as i followed the usual rules regarding using only one power line [ it's a dedicated 15Ampere circuit] and not paralleling leads with power cords etc.
I may wind up using the record to USB dongle feature on a few albums; even if quality won't be so great but it seems so convenient.
A great many of my old vinyl isn't on Spotify or reduced to CD
 
I suppose you could have a faulty or badly wired phono/line selector switch.

Or perhaps you were so distracted by hunger that you simply didn't insert the RCA cable fully. 🙂

The gain of the China sourced built-in preamps on these turntables is low, x60 (36dB) compared to the x 100 (40 dB) standard.

It simply means you'll have to turn the volume up a little. However, their RIAA equalisation is accurate.
 
The little party mixer is getting on for 50 years old so most probably it is dicky wiring in the phono inputs; but I've had it looked at and I've touched up a couple of old dry solderings and it's not getting any better.
I'd happily buy a new replacement if I could find one, I use if for the volume control mainly but being able to use it for Karaoke can be fun when the mood hits us [ I have some old Tandy gear here for mixing mikes etc:] and having echo and a built in Graphic EQ is handy and I do have a DJ turntable spare in the lounge I can swap over if I want
Thanx for that info on RIAA boost, that is something I was ignorant about, why is that ??
 
why is that ??

Don't know why design wise. It's just the way they are. It appears the same preamp board goes into all these China-sourced decks.

I've got a Tandy stereo mic mixer languishing in the loft, as well as a (Soundlab?) disco mixer with MM inputs. Given the extremes of temperatures they have experienced in the loft over the years, they probably don't work anymore! I've also got a Tandy reverb unit that I used to have a lot of fun with on both mic and guitar in my younger, more experimental days!
 

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Ditto but my old reverb unit is Sony/Pioneer or somesuch. I should drag it out and insert it somewhere in the chain. My Tandy Mike mixer unit is even older than that and tales 12V DC from a wall wart. Old gear can be fun, if it still works