The Technics SL-1200 GAE/G/GR general questions thread

the 50hz noise isn't louder than the groove noise, but when I lift the needle from a record at normal listening volume I can hear a bit of hiss. It was pointed out that the 50hz is about 15db above the noise floor on recordings, so it's technically there.

 

What happens in that case is just slite hiss, no hum.

 

I use the stock GR phono interconnects, so far I thought all was quiet but I noticed a (probably similar) hiss in the background when the volume gain is turned up to about 9 o'clock. Beyond the 9 o'clock point it does get louder.
It is also present with the GR completely unplugged.
This is through a Channel Islands PEQ.1 MKII phono with the upgrade power supply, on one hand this is no big deal as I never listen at that volume and basically at any point the source would make detecting the hiss impossible.
On another input I have a Lehmann Black Cube SEII which has a huge power supply tethered to a small circuit box and it makes zero noise period (with everything connected through to cart).
At some point I was going to experiment with grounding the CI phono to the outlet ground and/or the amp (Belles Aria integrated) phono ground, because although a benign hiss the fact that the other rig is silent makes me want this one to be as well.
When I had a MH MMF7.1 hooked up to the CI a few months ago I was using Anticables 'phono' cables and there came a point where I was actually hearing FM radio through that setup (I'm located 3 tall floors up), I recognized the station!
I swapped the Blue Jean cables in and no more radio, I think it was quieter after that than it is now but can't be sure.
I also plan on doing a lot of vinyl recording so even though the hiss probably isn't an actual issue I would like to see it go away.
I did do some recording with the FM bleeding in earlier this year and even that is something you have to crank in the blank (no music playing) parts to hear.

 

You will get hiss on phono inputs if you turn volume up loud enough. It's the phono stage and it's not there when a record is being played. You aren't going to hear anything when making recordings.

 

That does reflect what my experience has been in the past, I suppose I could put the needle on a lead in or trail off area and crank the volume to test whether hiss is still present.
The Black Cube makes the most minor hiss if at all when cranked WAY up, so making the CI phono just as quiet just seems like something to add to the to do list I guess.

BTW, has anyone figured out what the capacitance of the stock cable is?

 

Yup / if you do a search in this thread for capacitance you’ll find some posts of users that measured it.

 

You won't get it as quiet without modifying the design. I wouldn't expect a better PS to make a difference to hiss. If it is better sounding amount of hiss within reasonable limits is not an issue. Just the design compromises made. As for cables I don't know but I replaced them with a low capacitance dedicated phono design. I think you would gain in a smoother more detailed sound against the generic cable they supply as stock which seems close to the Chinese cable (Primewire from Amazon) I used initially as it had nicer plugs. In fact changing to Audioquest cable sounded like a serious cartridge upgrade.

 

That's a very interesting post,
if you want to hear what I'm getting here's the file again
http://oldgramophonerecords.co.uk/techntest10.wav
Since you're going to be making recordings I wonder if you could make a similar file and compare to see how bad or otherwise the stock cables are...
Interesting that the black cube totally got rid of noise for you!

 

Hiss can also be part of the phono stage noisefloor itself, so you have to rule that out.
It's likely that the source of the hiss is different from the source of the hum.

 

It's unusual to see kit which is intended to be connected to a protective ground.
Have you had need to lift the signal ground?

 

Nope, Blue Jeans LC-1 are shielded end-to-end. You can read on their site how they achieve that with a low capacitance.

 

For the money you really can not beat the Blue Jeans.

 

If you lift the ground completely you get hum in my setup. Not unusual for equipment to be grounded, at least not UK designs. Soft ground made little difference but haven't tried it since I had the Technics. This was something Project (who now own MF) added late on because it's only covered in the revised online manual and not the original that came with the phono stage.

 

Just looked it up, about 40 bucks for a 3 feet cable and the specs seem to be quite good; 12pF/ft
I didn't know that they're all shielded.
I think KAB also has their own low capacitance phono cables, might be worth looking into as well.

 

The funny thing about cables at this price is that I have 3 sets stored away somewhere, I only ever bought one set online and the others I have found in thrift stores.
All of them are nice and well worth purchase, I even found one of their 3.5 meter video cables (and it works excellent as a long run digital cable) at a thrift store.
Right now I have been using Analysis Plus interconnects for everything else as I did notice an excellent improvement with them, but their phono cables are fairly expensive, so although I'm sure I would love a set of those I just ordered the Audioquest Wildcat cable as this fits the current economic climate that I am navigating now.

 

Yes, cables lose most of their value on the second hand market, in contrast to things like good amps, speakers and turntables that retain value.
But I don't really get why?

 

I more or less got my money back on some Kimber PBJ cables after nearly 20 years possibly due to price rises on new models.

 

Well, the only audio thread in the world where we can talk about experience with cables without being marked with the classic "audio fool" label.

Celebrate that ...

The tiny signals we're using with cartridges are more sensible than the standard line sources and also the high gain (40dB and over) on phono preamp always generates some background hiss.

A decent quality cable (not talking about price, talking about quality) are usually a good benefit ... the stock cable can be enough under certain circumstances, but in a high resolutive system usually is better to replace it.

 

That would be different with powercables or digital signal cables

 

Just occured to me to check,
with no headshell/cartridge on the arm, is it normal to get hum that is much louder than when there's a headshell/cart on the arm? I just always thought this was normal but thought I'd check
that hum is a lot quieter when the power to the deck is unplugged but it's still there.

 

Connecting a spare headshell without cartridge shouldn't make a difference, because it's still an open end.
With the cartridge installed, the coils in the cartridge basically "short out" the + and -.

 

So a headshell with no cart should still hum and it's just a cartridge stopping the hum by shorting the wires?

 

More or less, it won't stop hum, but it should get less.
Unless the cartridge actually picks up hum.

 

Thanks for conferming this is normal. All the things that change the amount of that 50hz stuff I get with a normal headshell and cart eg touching the ground lug/screw and powering off the deck massively effect the amount of hum when there's no headshell on the arm, but somehow I don't use the turntable with no cartridge very often! Until I get my new mixer and then possibly new cables I will leave it alone as I have it the best it can be at the moment and it's liveable, as you pointed out -60db or so is alright really.

 

I understand that the estratosferic and crazy prices we can see it's a mess, but, i see the same on amplifiers / sources / ... everything else.

You know a good amplifier is better than a ... not so good, but, i believe in the right contexts to see that. The difference between a super duper amplifier can be reduced to zero compared to a intermediate level amplifier in the right context. And you can say "omg ... they sell amplifiers in that price!"

For me, it's more or less the same. There are honest and valuable products and ... others.