So tell me about the SL-1210, paleeze

[Deleted]

I'd like to know more about the Technics SL-1210 turntable, please. Would it be wise to buy a used one? Would DJ work kill it, beyond, consideration for an in home buy?

Just wondering,
Johnsan

[fanboi]

John,
seeing you are in the US of A check out www.kabusa.com/frameset.htm?/index.htm
The man is a Technics 1200 specialist, also have a look at Werners review of the SL1200 on tnt-audio.
I think you would find a new 1200 from Kev at Kabusa with his special pre-delivery checks and detailing well worth the price.

[gns]

johnsan said:

I'd like to know more about the Technics SL-1210 turntable, please. Would it be wise to buy a used one? Would DJ work kill it, beyond, consideration for an in home buy?

Just wondering,
Johnsan

I've used all sorts of turntables in my listening tests. I use them to enable me to optimise my phono preamp designs. The SL1210/1200 is one of the best, but far cheaper! It has one drawback in that hum radiation is worse than a hi-fi deck, but that simply means using a sensible high output cartridge like a moving magnet or high output moving coil, instead of the ill conceived standard moving coils everybody raves on about in complete ignorance of the simple facts nobody ever explains (ask me...)

The SL's are cheap enough to buy brand new. The platter forms one part of the motor and needs to be fitted with care, so as some DJ's are also good engineers and some are just idiots, you may find it hard to tell from an e-bay ad if it's been treated OK, or damaged.

[fanboi]

~ snip ~ instead of the ill conceived standard moving coils everybody raves on about in complete ignorance of the simple facts nobody ever explains (ask me...)
~ snip ~
.

Consider yourself asked

[gns]

fanboi said:

~ snip ~ instead of the ill conceived standard moving coils everybody raves on about in complete ignorance of the simple facts nobody ever explains (ask me...)
~ snip ~
.

Consider yourself asked

Consider a really low output moving coil.

0.15mV?

Seems common enough - lots of people buying this sort of thing at big bucks prices.

That's 0.15mV at the 1kHz reference frequency.

A preamp should be able to do that, shouldn't it?

I mean, take a professional dynamic studio mic - same sort of output, yes?

True, so end of story...

Not so fast!

Ever heard of RIAA?

The recording curve used to squeeze the frequency range of an LP into a groove of uniform size.

What happens to the bass?

It's made smaller.

How much smaller?

Well, the constant velocity of the RIAA curve puts it at very nearly -20dB compared to its 1kHz output.

So that's 0.015mV!

Yes 15 micro-volts!

And with a source impedance of a few Ohms, you can have great fun finding anything that can amplify it with the low noise demanded. In otherwords, quite impossible.

Go on, give it a try - look up some low noise transistor tables (if you can find them these days).

Or try finding an op-amp whose equivalent input noise voltage is 60dB below 15 micro-volts with a source impedance of a few Ohms. You want 15 nano-volts. Yes, many state 15 nano volts per square root of hertz, but at 20Hz that's 67 nano volts. So you need something around 3nV/root Hz. Yes, there is one or two, but not for that source impedance - higher yes, so let's put in a series resistor!

Wrong!

Johnson's noise - that's what you get from a resistor - swamping the op-amp's noise performance!

So what about valves (tubes)?

Get away!

You'd not hear anything for the noise from a valve.

So what about transformers?

Ever heard of magnetising current?

Almost pure class B distortion if it were not for transformers rounding things off with their poor frequency response. Plodding bass results that can't keep up with the tempo.

So, go on, join the millions of gullible people forking out 800 quid-plus on a dream - a promise that isn't worth all the garbage written by all the chummy boy reviewers!

But if you increase the output to around 0.5mV you may just stand a chance.

Moving coil? High output yes! Conventional? Hi-Fi-Fo-Fum, I smell the blood of a bullshit man!

[Deleted]

Thank you, fanboi. I'm studying the site now. There's a lot to read!

I have no problem buying a direct drive table, as the website alludes to, they are way over engineered for the purpose of home listening. The history of quadraphonics reminds me of the history of my Subaru WRX, and how the engine is basically 2/3's of a Porsche 956, one of the best, and very well engineered for the road, any road.

Thank you for the site. I'll get a lot out of it.

Thanks also, Graham, I'll stay away from any table I don't personally know the history of. New is good.

On the cartridge side of preference, the AT; Has that model been around a while? I seem to remember it along time ago. I liked it then, and the price was always right.

Thanks,
John

[fanboi]

Thank you for that explanation Graham.
In the context of the original post with reference to the hum radiation of the SL1200:
this then would be EMI radiation from the motor unit forming a greater proportion of the signal from the cartridge?
Reading between the lines suggests to me that in order to obtain benefit from using the Exp stepup with an MC cartridge, it is necessary that the cartridge operate with an electrically quieter background/turntable.
I found your observation re transformers interesting and will keep it in mind for future listening when I can afford an Exp to replace my current cheapo transformer. It may well explain the slightly reduced attack and dynamics I have observed with the DL103 v the DL110.
I doubt that I will ever be likely to consider a cartridge dearer than $500 - so that sees me stopped at around a DL304 or AT OC9.
If I correctly understand your explanation, the lower the cartridge output, the more difficult it is to separate bass frequencies from background noise. (or even to extract and amplify those frequencies)
Perhaps I have it all a..e about too

[Deleted]

Graham's reply , as usual is very informative. Years ago. there were even MC preamp designs using big output transistors at the input in an effort to meet the requirements. There are other designs that also use several dual transistors such as the SSM2220 in parallel ,in an effort to reduce noise. But as Graham has demonstrated, it just isn't worth all the trouble . It is far better to have a higher output design to start with. , particularly these days with all the radiated crap from those energy saver globes etc.
SandyK