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Wirer up stereo needle

Gregory

Member
I am fitting a new stereo needle to my Garda turn tablet There are 4 wires coming from the turntable how do I determine what wires goes we’re on the needle.
 

rjenkinsgb

Well-Known Member
Most Helpful Member
I cannot find a "Garda turntable" via google.

The simplest way to find the wiring is touch each wire in turn with a screwdriver tip while listening to the audio, at low volume.
Two wires should give a definite click or buzz - they are the preamp inputs, try them on the top two pins on the cartridge.
Put the others on the lower two pins.

See what it sound like, then try swapping the lower two wires and see if that makes any difference at all to the background noise or hum. It probably will not, but if it does, use whichever way around works best.

That only leaves left and right - listen to a piece of music that has something distinctive on one channel & compare to online versions.
If left and right are backwards, swap the top two wires (and swap the lower two, if they had any effect on the sound).
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
Arrgh!!!!

Couple of problems here:
1. When you fit a needle, the cartridge stays.
2. Some turntables have a headshell. This is by far the easiest to work with.
3. There are three main cartridge types: ceramic, moving magnet and moving coil.
They are way way different.

There are going to be some standards and possibly some markings. The colors should definately be standard.


I have a moving coil cartridge that requires a special pre-amp with a removeable headshell . Ceramic is for stupid stereos.
The headshell is removeable and there is an overhang guage to set where the needle goes.
Then you have tracking/ anti-skating and tone-arm weight to set.
My tone arm is "S-shaped".

This https://www.genuinereplacementparts.com/tpbga003-oem is a headshell. it's a real pain to replace cartridges without one.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
Usually the turntable does not, but the pre-amp does. There is this thing called RIAA equlization that's done on phono inputs.
Ceramic cartridges use regular line inputs, I think.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Usually the turntable does not, but the pre-amp does. There is this thing called RIAA equlization that's done on phono inputs.
Ceramic cartridges use regular line inputs, I think.
Presumably you're too young to actually remember record players? :D

There were four types of cartridge - ceramic, crystal, moving coil and moving magnet - moving coil were always extremely rare, and not supported by many preamps or amplifiers. My Trio/Kenwood amp is switchable, not that I've used a record deck for decades, but I've never had (or indeed even seen) a moving coil cartridge.

NONE of them will connect to a line input - ceramic and crystal require a flat input, but of a MUCH higher impedance - I commonly used a simple 2n3819 FET buffer stage with 2.2Meg input impedance for discos, and they always sounded great. Using too low an impedance, such as a line input or guitar input results in a huge loss of bass. You can plug a ceramic cartridge in to a moving magnet input though, as the RIAA equalisation and much higher gain compensates for the low input impedance somewhat.

You're perfectly correct though that if he's only changing the stylus (NOT a needle) there's no need to touch any wires.

Assuming he means changing the cartridge?, I changed hundreds and hundreds 'back in the day', they were a very common failure - and very simple to do. Just four wires, with two of them a common earth. Your buzzing technique is fine, as is simply going though the options two by two.

If there's a removable headshell, this makes it MUCH easier.

One possible issue is weight - if you change to a lighter cartridge you might not be in the adjustment range. We used to have a tin of lead seals (used for electricity meters) and I commonly glued one of those in the headshell if required.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
Well, we (mom and I) have a 1950's Magnavox that had a 78 only turntable. Dad upgraded the turntable thingy to play 16 33 45 and 78s..
The Magnavox thing AM/SW and record player needs to be rebuilt. 6l6 outputs, large speakers. I bouht the FM option off of ebay without tubes and tube shields. It has to be rebuilt too. Not something I have time for.

Aside: I need to get mom a radio, so I'm persueing tryimg to play audio through the TV. I haven;t completed that test yet. I have a VGA test generator and an HDMI scaler/cross converter and a tone generator. If I'm lucky, I can get audio to play through the TV's HDMI input.

Then, I'm off to the races. I have a dual AM/FM tuner that can be controlled by IR and RS-232. It uses an active antenna,. I have 2 extra coac cables heading to the attic and I need one for the active antenna.

I'm too far away from FM stations and AM picks up way to much interference from a phase angle fired light dimmer. let's hope I can find a good location for the antenna.

Now, I have another problem: get audio to the TV from the basement or I could stream it over IP. I could play it through the TV or a powered speaker. Two streamers would give one tuner for me and one for mom. Some options: Me use the laptop and/or stream to the basement. Mom would listen via a powered speaker or the TV (TV preferred). One station would be fine for mom initially.

Then I have to repeat IR. That can be done over Ethernet or RF, I have an RF repeater for the antenna rotor. The remotes could operate blind and/or with presets.

Finally, the plan is to replace the signal generator with a "computer terminal" that is vt100 compatible and has a VGA output. If I just usse that I would end up with a cursur. I could turn the cursur off until the next power failure. At this point audio with black screen, hopefully.

The next phase is to add a Rasberry PI. Through a virtual COM port, it would communicate to the tuner and locally to the "vt100".
It will gather station info and RDX info and put it on the TV screen in various places. That program would be LabView runtime.
It's easy to turn a Labview program into a webpage. I'll then have tuner control via a web page.

Other options open up like HDMI-CEC control of muting the TV and a real-time TV antenna position indicator.

==

I had a 45 changer as a kid and the "record player" in the suitcase.

So, mom bought me an "Electrophonic stereo" in the 70's and it came with speakers and a turntable with a ceramic cartrideg. it had a phone input, but I never dug further.

I started to buy my stereo in the late 70's early 80's. My first piece was a Tecnics SL-1700 turntable because I didn't want to ruin the LP's I owned. Got the discwasher system. I think that's what it was called.

1st cartridge was moving magnet. then I upgraded to Moving coil. My pre-amp supported both.
 

Gregory

Member
I have tried to down load the file on my I pad but with no luck.
can you post it in a format that I can down load. Thank you
 

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