TC8 type cartridge

[robert.copley1]

Anyone tried remaking with the repro types available?

[Edward Huggins]

Not quite sure what you mean by this. Do you mean rebuilding an original TC8 series mono cartridge - or - what is user's experience with the re-manufacturered 8TCH repro now available?

[robert.copley1]

hi Edward , replacing the internals with a modern cartridge , keeping the origional cartridge with modern internals , hope this makes sense bob

[Edward Huggins]

I think I understand you, but why ever would you do this? It makes no sense, as well as there being no guarantee that transplanting the crystal element will be successful....
Why not just buy a modern (copy) cartridge and leave it intact. There are TC8H and TC8M re-manufactured types, Ronette or BSR.

[leslie5555]

I have recently seen a guy on YouTube replace the inards of a tch with the inards of a BSR X5M or H?
Can't remember which , however it looks pretty straight forward and works very well.
May be worth searching you tube for that video.

[robert.copley1]

the price is £35 each and I need 3

[Edward Huggins]

That's the kind of price you will need to pay.
If you need as many as three, does this mean that you have three different record players to restore?
If so, you will need to ensure that each cartridge correctly matches the type of amplifier in each player.

[astro63]

its pretty easy once you've got the cartridge apart, the rivets removed, ive done it several times in the past using BSR / Ronette ,Acos crystal elements , never tried with the ceramic elements as they are skinny and thin.

as long as you clean all the original BSR TC8 internal rubbers etc you can carefully slip the donor crystal in BUT dont bend it as it will crack, and watch the foil stips they snap easy and drop of then the crystal is no good, the foil stips have to fold either side of the crystal at the back to be able to touch the metal connector part which the pick up wires will slip onto.

Main problem now is getting donor crystal aka BSR x5 etc as they are getting pricey.

[robert.copley1]

good man !

[astro63]

If you can get the donor crystal cartridge and the dead TC8's I'm willing to do it for you Bob, the hardest bit is getting both cartridges apart without damaging the good crystal, but out of all the restored ones I've done over many years the TC8's are the easiest, the worst was the garrard GC7-8 for the Cossors. LOL.

['LIVEWIRE?']

Personally, I agree with Edward. I would simply fit one of the modern TC8M or TC8H reproduction cartridges and fit that.

[astro63]

I've seen them on ebay and the brown Medium is 250mV and the orange High 930mV. I'm curious as I've never found online what makes the output of crystal cartridges different? Is it down to the hardness of the rubber where the stylus tip rests?

[leslie5555]

Funny you should ask that question,
I started a thread a couple of years ago asking the same question.
If you search BSR X5M and BSR X5H you will find my thread.

[Hartley118]

Originally Posted by astro63

ive seen them on ebay and the brown Medium is 250mV and the orange High 930mV im curious as ive never found online what makes the output of crystal cartridges different? is it down to the hardness of the rubber where the stylus tip rest?

The crystal/ceramic element itself is a very stiff strip of piezo-electric material which generates a voltage when it's bent or twisted. The greater the bending stress, the bigger the voltage across the contacts at the ends of the element. For example, the trigger of a gaslighter applies a big stress and results in a few kV to produce a spark.

In a pickup cartridge, the element is stressed by the deflection of the stylus in the record groove. If the stylus were directly connected to the element, we'd get a high voltage output, but the groove modulation would have too much work to do in bending the crystal. Consequently the stylus isn't mounted directly on the piezo element but has a flexible rubber or plastic connection. The stiffer the connection, the greater the electrical output, but the lower the compliance of the stylus as it meets the record groove.

So a high output cartridge has a pretty stiff connection to the crystal and will need a higher tracking weight to maintain good contact with the groove modulation. That's why record changers fitted with the the old TC8H high output cartridge had a reputation as 'groove grinders'. In practice though, records suffered more damage from too little tracking weight which allowed the stiff stylus to rattle around in the groove than from the 8 grams or so required to keep it in good contact.

Martin

[astro63]

Thanks for the in depth info really interesting.