Which stylus is which?

[Panrock]

Hi. I'm new to working on gram decks and the like. This question is about my own Dynatron Ether Conqueror, which needs a new cartridge and stylus.

As far as I'm aware the deck may not be original on this 1948 set, since it has a speed selector. This is raised atop a column. The deck appears to bear no maker's marking but looks to be of good quality. A photo can be posted if requested.

I have to hand a new/old stock BSR SC12H cartridge, which I understand is stereo compatible. To this I have fitted a new turn-over stylus set.

My question is about the styli. There is a stylus 'point' on either side: one a little further back along the shaft than the other. Under a low power microscope the two of them look identical.

Which one is for LPs and which for 78s? I am guessing the one further in might be for 78s since I would imagine the 'needle' excursion is more. Am I right?

Thanks!

Steve

['LIVEWIRE?']

It's possible that what you have is a Dual LP Stylus, rather than an LP/78 one. There are normally markings on each side of the T/O lever. If it is an LP/78 one, one side will/should be clearly marked '78'.

[Panrock]

In this case, I made up the stylus assembly from a loose stylus (pair) found in the stores bin, a spare unmarked turnover lever c/w its little rubber tube, and the tiniest spot of superglue! The result fits well and flips over correctly. I've made sure the stylus always sits perpendicular.

So - no markings!

[Edward Huggins]

The BSR SC12H cartridge is not just stereo-compatible, it is a full stereo cartridge. To use this in your (mono) Dynatron you will need to bridge the LH ad RH channels. Without a photo of your record deck which will not be the original, from your description this might be a late model Collaro "Studio" autochanger. As regards the stylus, it should be perpendicular when viewed from the front and -15 degrees from the vertical when viewed from the side. Whilst I appreciate you have made up a stylus assembly, this must track as well as a factory made one or your records may be scoured. The BSR cartridge should track at 4/5 grams.

[Panrock]

Thanks Edward. I attach a picture of the deck and of the cartridge from the side, with the stylus as I've installed it, under no tracking load of course. Does minus 15 deg mean 15 deg anticlockwise or clockwise as shown here?

Yes, I intend to check the tracking weight. Since I haven't got a proper gauge, I'll be giving the 'lolly stick-and coin' method a try. This is described on a Sticky elsewhere in this section.

As you imply, there are two separate leads going to this cartridge. These are paired up (to mono) further down the line. I presume it doesn't matter which way round the 'prongs' on the cartridge are connected, so long as the two sides match (?).

Your advice is appreciated. I'm a beginner at this game.

Steve

[peter_sol]

The deck is a Magnavox made Cy collaro. 4 grammes should suit that nicely.

[Edward Huggins]

Yes it is, and a very nice deck too. It comes from c. 1961, possibly as late as 1962.
From the photos provided by the OP, the side view of the stylus does look correctly inclined. Make sure the autochanger is floating properly on its mounts given the acoustic feedback there will be on that lightweight tone arm. That big Dynatron will create quite some turbulence!

[Panrock]

Some basic stuff. Is the screw at the top of the rear end of the arm the tracking weight adjustment? Given the low tracking weight by historical standards, will it be OK to dedicate one of these styli to playing 78s?

[Edward Huggins]

As you have made up the stylus assembly yourself, you may not know the provenance of those stylus tips. They could be for Mono, Stereo or 78s. Ideally you really need a legitimate stylus that is designed for Stereo LPs and 78s - they are certainly cheap enough!
You should see that a 78 tip is more rounded, but much more difficult to tell a Mono LP tip form a Stereo LP tip. Unless you are not that bothered about damaging the records you intend to play, I would not use it.

[Panrock]

I found the tracking weight adjustment screw, and the lollipop stick method proved surprisingly sensitive, since I could slide the 20p piece along to get less than 5g.

Now to put it back in the set.

[Techman]

That's certainly an unusual deck. I've also got the same Dynatron radiogram and it originally from factory had a Garrard RC70 fitted, but many years ago I pulled it out and fitted a Philips semi automatic deck. A while after that, I replaced this with a Garrard SP25. A good while after that I wanted to fit a more original type deck, but not one that played 78s only, so went for a nice brown Garrard RC80. Fortunately there was enough of the original motor board left un-cut to mount this deck, as the motor board can't be removed as it's part of the original cabinet assembly. I'd previously fitted replacement boards on top of the original board with certain parts of it trimmed off, but I needed to get the height down to original with the fitting of the RC80, so needed to use the original motor board, even if that meant adding wood to it!

You're as bad as me using what you've already got in the spare parts box, but in your case I would probably draw the line at that unknown stylus and just buy the proper one for it, as they're cheap enough.

Not wishing to disagree with Edward, but I don't believe that there's any such thing as a stereo only stylus, I think it's just the compatibility of the cartridge that governs this. The two versions of the BSR TC8 is a very good example of this. I've seen both a stereo and mono stylus advertised for the two versions of this cartridge in the past and when I've investigated this, I've found that they both have the same manufacturers part number, so they're both exactly the same stylus. I also think that the stereo compatibility of the TC8 'S' cartridge is dubious to say the least, but that's probably a topic for another discussion on its own.

[Restoration73]

The difference is marked if you use a stylus microscope, with at least X50 magnification.

On all the turnover styli I 've seen, the LP stylus is always mounted at the end of the
cantilever bar, with the 78 stylus further back.

The Vaco Luxor stylus/cartridge is stereo, and is very similar to the TC8S in construction.

[Panrock]

That's how I'm using the two styli.

It's all back in and playing well now.

[Techman]

Originally Posted by Restoration73

The Vaco Luxor stylus/cartridge is stereo, and is very similar to the TC8S in construction.

I should probably just clarify that it's down to that very non-flexible metal stylus arm the causes the TC8 'S' to be so no non-compatible, rather than the cartridge itself.

I may have encountered the cartridge you mention above, possibly in a GEC music centre. If this was the one you mention, it had a VERY similar stylus to the ones fitted to BSR TC8, but which had the metal shank split with a flexible sort rubber type coupling, thereby making it very compatible for stereo pressings. I remember thinking at the time that it would be interesting to see if this particular stylus would fit a TC8 cartridge, although in theory it's not supposed to. When I was working on this particular GEC unit, I did take some close up pictures for comparison at the time, which I may still have on file.

[Techman]

Originally Posted by Panrock

That's how I'm using the two styli.

It's all back in and playing well now.

If you do the microscope check as suggested by Restoration, then you will be able to determine whether the 'other' stylus tip is the larger 78 type - I suspect it may not be. If it's not, you will be unlikely to damage 78s at that tracking weight, but the smaller stylus tip will tend to rattle around in the mucky bottom of the groove and not contact the side walls properly. This may make the records not sound as good as they should, but if you're happy with it, then that's all good.

[Panrock]

The styli out of the bin are brand new, so they should be OK. I've just played a '50s 78 on the inner stylus... there's a quiet background and it generally sounds fine.

It's a big beast though, this Dynatron, and I daren't turn it up too much! I still enjoy good relations with the neighbour.

[Hartley118]

That'll be fine. The groove profile of '50s 78s has a pretty well-defined V-shape with a sharp bottom. A microgroove stylus will normally track them OK. There may even be some advantage on a worn disc that the smaller stylus misses the groove distortion caused by wear. Older pre-war 78s though may be less satisfactory, with an increase in surface noise from the stylus wandering in their less well-defined groove bottom.

As long as styli are unworn and not chipped, I know of no evidence that playing a disc with the 'wrong' size of stylus causes damage to either stylus or disc so long as no serious groove jumping results. The latter can sometimes happen if playing a microgroove disc with a 78 stylus.

Martin

['LIVEWIRE?']

Many years ago I accidentally played one side of a new Buddy Holly 45 with the 78 stylus selected. The record did, and still does, play alright after that, but with increased surface noise, so, whilst playing a 78 with a stylus designed for LPs/45s may be OK, the reverse, INHO, is not true.

[Techman]

Yes, I think you may well get away with using a 78 stylus on a vinyl LP or 45 at very low tracking weight, but suspect that certainly anything over 5 grams will cause at least some damage and probably damage that may not be particularly noticed at less than that.

Of course, the question I need to ask is what modification has been done to the Dynatron to be able to take a ceramic cartridge? The original magnetic 78 head that took steel gramophone needles ran into an impedance of 50K, whereas the ceramic BSR cartridge will need around 2M. I certainly had to modify mine at the time.

[Hartley118]

Originally Posted by 'LIVEWIRE?'

Many years ago I accidentally played one side of a new Buddy Holly 45 with the 78 stylus selected. The record did, and still does, play alright after that, but with increased surface noise, so, whilst playing a 78 with a stylus designed for LPs/45s may be OK, the reverse, INHO, is not true.

Interesting. Can you think of a reason for the audible wear created by the 78 stylus? A normal spherical 2.5 mil 78 stylus profile would just ride high in the groove, well out of the way of the microgroove stylus tracking path. The main risk would be groove jumping.

Maybe your 78 stylus was chipped or badly worn, in which case all bets are off!

Martin