Historic Record Player "Quick Fix".

[Edward Huggins]

Noting the many Threads regarding the issues surrounding the near unavailability of high-output crystal cartridges one remembers the time when they were cheap, readily available and still being made in quantity by BSR, Ronette, Acos et al.
I can certainly remember during the 1980s many Service Engineers installing these to give a quick fix to a two-stage record player amplifier suffering low gain, probably due to changing component values or low emissions.
In 5 minutes one could perk up a weak output player. And where an original, old Mono cartridge was orignally used, one could offer a new found stereo-compatiblilty!
I must say that over recent years I have been able to harvest many such cartridges when restoring an amplifier to its original performance and fitting in a more readily available medium output cartridge. Needless to say, these salvaged cartridges have really come in handy when re-working single-stage record players. Trouble is there are all now used up now, hence the need to (expensively) import them. And when a Customer has only paid £25.00 for his "bargain" record player, the cost of fitting these certainly does comes as quite a shock. Many have refused to let me fix them saying they will get it all done cheaper elsewhere....

[Richard_FM]

Back when I was a cash-strapped student I replaced the Shure M55E cartridge on my Pioneer PL-12D in the late 1990s, as the replacement styli were more than the price of a Shure R25XT, complete with new stylus.

Luckily I kept the M55E & found it recently in a sort out.

[jamesperrett]

Interesting you bring up the M55E - in the spirit of Edward's original post, I found it to have a higher output than most other magnetic cartridges. I tried replacing the one fitted to my Dynatron HFC101 and found that the replacement was much quieter than any other source though it worked fine in other systems.

[music-centre]

Yes, I wished I had stocked up on a few of those crystal cartridges when they were so cheap, I used to earn a bit of pocket money in the early/mid 1970s while still at school fitting them to the old 50's radiograms belonging to my friend's parents and our relations.

I used to order them out of the Practical Wireless magazine adverts, should have bought in bulk, I could certainly do with a few now!

Steve.

[Herald1360]

Originally Posted by Edward Huggins

Trouble is there are all now used up now, hence the need to (expensively) import them. And when a Customer has only paid £25.00 for his "bargain" record player, the cost of fitting these certainly does comes as quite a shock. Many have refused to let me fix them saying they will get it all done cheaper elsewhere....

You probably could- using a Chinese cheapy and an opamp powered from the O/P valve cathode or an HT dropper circuit.

[Vintage Engr]

I agree with Edward,

I have the same problem trying to persuade customers to part with cash for a new, & often inferior (compared to the 60's) cartridge.

Had an interesting one last week, not a cheap cartridge, but a Shure M75EJ.
Purchased a new stylus from a reputable supplier, whom I have known for 50 years.
True the deck was not ideal, a Garrard 4HF, which doesn't lend itself to low tracking weights, but this one fooled me for a moment.
Having serviced the deck, & checked the cartridge before ordering the new stylus, ( with a known genuine stylus) I confidently fitted the new one, checked the tracking weight at 2 grammes & put on my favourite test record...

It sort of played, with an annoying secondary mechanical playback, which turned out to be the plastic pip on the stylus integral mount, just skimming the suface of the record.In fact when I looked closer, the front of the headshell was almost touching the record.

After a few more checks I phoned the supplier to say that this stylus had an exceptional amount of vertical compliance!

I sent the original back, which was so floppy as to be unbelieveable.
The replacement did the trick. Just as well, as it wasn't cheap.

I don't remember having this sort of trouble in the 60's.

David.

[dseymo1]

The reality is that consumer electronics are a fraction of the price of their ertstwhile equivalents. Even a basic record player was a significant investment, unlike a generic MP3 player, for example. Naturally, spare parts have always been priced pro rata.

[Edward Huggins]

Originally Posted by Herald1360

You probably could- using a Chinese cheapy and an opamp powered from the O/P valve cathode or an HT dropper circuit.

You are absolutely right of course and more such mods will need to happen as cartridges become completely unavailable

But consider here what's involved:

The parts and getting them (usually with P&P), dismantling, making up a suitable sub-chassis/board, wiring it into the original circuit, possibly making component substitutions to achieve correct loading, re-assembly and testing - maybe 2/3 hours of time. What does one charge £25/30 or more?

[AC/HL]

With our technical knowledge fair enough, although commercial hourly rates are much more than that. However, advising the archetypal "vinyl" newbie to do this will likely go straight over their head. Fitting a replacement cartridge is quite a feat for most, rebuilding the amplifier (safely!) is much more problematic.

[lazythread]

It comes down to managing perceptions and using a vintage car analogy with your customer may be useful. You find a car that's been stored in a barn and buy it cheaply. But before you can drive it on the road it has to be got running and be capable of passing the MOT safety inspection, as well as being insurable. There are several distinct systems that are each crucial to the functioning of the car, engine, transmission, brakes, suspension, electrics and fuel delivery.

A record player is similar - the systems are cartridge, turntable, amplifier and speaker. Many old cars used leaded petrol, and as it is not easily available except from specialists (I think), the engine has to be adapted - sometimes expensively. With a record player, the type of cartridge originally fitted may no longer function, there is no drop in replacement and if there were it will ruin modern records. So it has to be adapted - possibly at some cost.

Record players were never really plug and play like today's technology, and like old cars they need some adapting to modern conditions, including an MOT - that PAT test if it's for a customer. Especially live chassis ones

My tuppence worth.

[kalee20]

Yes, a reworked record player, for someone else, done as a favour, should have some sort of safety due diligence, and PAT testing is probable appropriate. And bearing in mind the shortage of high-output cartridges, a medium-output one (or even a magnetic one!) with a preamplifier is the way to go. It need not be complex for the AF frequencies involved, a couple of transistors or a modern op-amp in an 8-pin DIP package. As others have said, it might be powerable from the output valve cathode.

Obviously, in such a case, the peak-peak output voltage can never exceed the cathode bias (which you can measure with a digital DVM meter, just look at the LCD display), so depending on the amplifier sensitivity, you may need to power from the heater supply instead.

I do recall a series of articles in Practical Wireless, late 1975, where the author bought a fairly cheap music centre and upgraded it with a magnetic cartridge, preamp, etc. Obviously this was solid-state from the beginning.

Whether it is cost-effective is another matter of course, and the answer, then as now, is probably not! So it's the sort of thing to be done for pleasure, or as a favour.

[Station X]

An article in the November 1966 issue of Practical Wireless describes an "Input Booster" circuit for use with valved record players. It uses two silicon transistors and is fed from the HT supply.

Whether this would allow the use of low or medium output crystal cartridges in place of high output ones I don't know.

[Ed_Dinning]

Hi Gents, the TAA320 chip from Philips (obsolete but still available from the usual sources) works well when run from the HT line of a valve amp. suitable circuits are in the Mullard FET app book.
It is also physically small.

Ed

[kalee20]

That's a device I didn't know about! Thanks Ed!

[Edward Huggins]

I always thought the operation voltage for these was 20V.

[Alistair D]

Talk about coincidence. I have just seen an article in an old issue of PTV that uses the TAA320. The schematic even shows the internal circuit of the device.

http://www.americanradiohistory.com/...on-1969-06.pdf Page 390.

Al

[Herald1360]

Originally Posted by Edward Huggins

I always thought the operation voltage for these was 20V.

It is. But a simple resistor from HT and 18V zener diode and a capacitor would give a suitable supply for it.

Still easier to use a FET input opamp, though.

[turretslug]

The TAA320 is an intriguing device, and a new one on me too! Seems like another take on the "the FET is a little like a thermionic triode, let's develop the basic device a little and make it more so..." theme that was buzzing in the thermionic/semiconductor transition but not quite to the plug-in transparency of the likes of the Fetron.

Seems like a good excuse to use one and see, if nothing else.

[AC/HL]

They do give an alternative circuit with a bootstrapped BC107 as an alternative if you can't find a TAA320 IC.