Collaro RC49

[RojDW48]

Something I couldn't resist at auction today! A Collaro RC49 autochanger - just the TT I think - not an RP. Can anyone date this for me? And any hints about checking it out - before I start any kind of ham-fisted investigation?

[Edward Huggins]

I think there was also a version where the arm was chromed. I'd date this as at 1948. Beautifuly crafted.

[peter_sol]

The deck number Will give you a clue.

[PaulR]

What a nice looking turntable. There is a detailed service manual available free at The Vinyl Engine.

[RojDW48]

Originally Posted by peter_sol

The deck number Will give you a clue.

As in 1949!? Well I never !!

And thank you Paul - just what I needed.

[Records]

I know they are over engineered and not easy to service but i do love the
style and thought they put into them.

[Heatercathodeshort]

Two adverts from the Wireless World for 1949.J.

[RojDW48]

Tried it out for the first time this morning - dropped the record, landed in the right place. then had a bit of a head fit! Very promising.

[PaulR]

What sort of pickup does it have? It looks a bit less industrial than the usual magnetic ones from the period,

[Edward Huggins]

I always assumed this was an early piezo type which used a sapphire stylus.

[RojDW48]

Just getting back to fiddling with this. I have bashed my way through the mind-numbing service data and got it to complete a few cycles. I am just looking at the pickup - seems reminiscent of the old Decca magnetic pickups, but that looks like an old gramophone needle to me - would it just pull out for replacement? Also, the head pulls out but does not detach. Does anyone know if it is supposed to? The manual has thousands of words about the operation of the TT, but next to nothing about the pickup.

[PaulR]

It does look like one of those Decca pickups doesn't it? What can you see if you remove the two shiny screws at the front. They take the XMS stylus which is unobtainable now. I think they can be re-tipped at a price.

Alternatively it might just be a Columbia 99 type where the needle is just held in by the magnetism of the pickup. They do come up on Ebay occasionally.

[Techman]

It does look like one of those 'special' gramophone needles that HMV/EMI used in their early 50s single speed decks. These were held in by both magnetism and the rubber damping, so the Collaro one could be the same idea.

Edit: just noticed 4,000 posts - WOW!

[PaulR]

Is there any sound if you rub the needle?

[RojDW48]

Originally Posted by PaulR

Is there any sound if you rub the needle?

I haven't got that far yet - just trying to get the mechanics going - so far so good.

I shall try dismantling the pickup - happily I have 2 or 3 xms styli, which I bought many years ago on spec. Wouldn't it be nice if they fitted?

[PaulR]

Yes it would be brilliant if they fitted. It just goes to show ...

[RojDW48]

Getting better! After discovering a dead short in the mute switch, I connected direct and it sprang to life. And it sounds very nice considering its great age and the old gramophone type needle. A bit of stiffness here and there in the mechanics to address, but a real pleasure to watch and listen.

I tried both magnetic and line inputs. Both worked - the line input sounded better, but rather skewed towards the top end. What are the characteristics of this kind of pickup? Are there any simple ways of improving equalization?

[PaulR]

If you are using a solid state amp with a low impedance input I wonder whether there is a mis-match as the pickup will be expecting a high impedance valve amp.

I have had problems with too much top end with ordinary magnetic pickups if the rubber has begun to go hard. Some, particularly Garrard ones, seem to go hard but HMV types are better.

[Phonosandradios]

wouldn't these sapphire tipped miniature needles from musonic fit? The 78rpm version that is rather than the mono version which is for mono LP's.

https://www.musonic.co.uk/?s=hmv+min...&type_aws=true

[Hartley118]

Your pickup restoration project looks similar to one that I undertook a while ago on the Garrard 'High Fidelity' 78 pickup on my RC60 autochanger, dating from the late 1940s. The pickup was branded RGD, reflecting the radiogram that it came from.

The internals of the Garrard head look very similar to your Collaro. I guess that these designs represented the state of the art in the 1940s, as of course does the Decca type C which led to the rather good XMS plugin heads by 1950. Unlike the Collaro steel needle design, the Garrard had a 'permanent' sapphire stylus. Very optimistically, it was expected to wear so slowly that replacement required returning the head to the factory!

For stylus replacement, I used one of those straight miniature sapphires pictured in post 19. That needed some ingenuity because the needle/stylus is part of the magnetic circuit and the replacement has an aluminium shaft, so the replacement involved a joining job. I used a short length of brass tubing and Araldite. The Araldite needs a week or so to set the the necessary degree of hardness.

The Garrard head had (of course) also a mess of hardened rubber inside around the armature which is suspended between the magnet polepieces. After many experiments, I found that a couple of tiny O-rings round the armature provided about the right degree of compliance. Your Collaro head may have similar internals unless the steel needle is the only armature.

I find that the resulting head plays well into an RIAA equalized input. Though I had doubts about the mass of my 'hybrid' stylus, the resulting frequency response is decently flat to 8kHz (the upper limit of my HMV frequency test disc).

Hopefully the attached photos show what I did and may be helpful as you restore your Collaro head. I guess that you may need to cut short a steel needle to act as the basis of your own hybrid stylus.