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EXPERT AUDIO PLAYER

Posted: Sat Jan 11, 2014 10:30 am
by chunnybh
Here is the Expert Audio Player.
The pdf file is from The Gramophone magazine. An interesting technical report and the Expert ad.
The technical report says it all.
What surprised me was the tonearm. It is longer and wider than the one on my Expert Senior, as can be seen in the pictures.
The soundbox is a two spring with what I believe is a wrongly replaced mica diaphragm.
A youtube video at this link.
http://youtu.be/hCKyR2NQzp8

Re: EXPERT AUDIO PLAYER

Posted: Sat Jan 11, 2014 11:59 am
by emgcr
Absolutely fascinating Chunny and many thanks for posting. A rare machine indeed---excellent photos.

From the address, it would appear that the manufacturing date is 1936/39 but the difference in tonearm dimensions is particularly interesting. Are you able to say by how much they vary ? I have a spare Expert tonearm which, from memory, appears to be about half an inch longer than usual and I have always thought that it might originally have been part of an All Range. Your information is new (to me anyway) thus we may now be able to shed further light on such things ! I am away for a week now but will measure mine accurately upon return.

The case seems to be quite a bit wider than the external horn models.

As far as performance is concerned, do you agree with The Gramophone about the reproduction ? Listening via YouTube is misleading. It is hard to see that a small bifurcated horn could compete with a Senior in any way but the report 80 years ago would seem to confound such thoughts in some respects.

Re: EXPERT AUDIO PLAYER

Posted: Sun Jan 12, 2014 4:14 am
by Orchorsol
Fantastic to see this rare, fabled and slightly bizarre beast Chunny, many thanks!

Very strange indeed to see an Expert with a mica diaphragm - I wonder how and why that happened.

How does the instrument sound with other soundboxes? What is the bass extension like? The speaking length is so short compared with the other models!

Re: EXPERT AUDIO PLAYER

Posted: Sun Jan 12, 2014 8:52 am
by chunnybh
I tried it with another Expert 2-spring with a metal diaphragm and the difference was astounding. I suspect the mica was an easy replacement for a damaged diaphragm.
The bass is surprisingly forthright for something that breaks all the rules. The tonearm probably is it's best asset. I am tempted to try it on my Expert Senior.
It is approximately half an inch longer than the one on the Senior and is wider throughout it's length. Both bases are marked with the same patent.
It pales in comparison to any of the Expert and EMG range, but it still has a solid clear tone.

Re: EXPERT AUDIO PLAYER

Posted: Sun Jan 12, 2014 1:11 pm
by Joe_DS
chunnybh wrote:I tried it with another Expert 2-spring with a metal diaphragm and the difference was astounding. I suspect the mica was an easy replacement for a damaged diaphragm.
The bass is surprisingly forthright for something that breaks all the rules. ...
It pales in comparison to any of the Expert and EMG range, but it still has a solid clear tone.
Many thanks for posting about this! I agree, the design seems to break all the rules--especially those set down by the company that manufactured it. The two "squared-off conical horns" are particularly interesting, since they do not flare as one would expect.

When you have a chance, could you post a video showing the performance difference using the 2-spring Expert sound box with the metal diaphragm? That should make for a very interesting comparison.

Joe

Re: EXPERT AUDIO PLAYER

Posted: Thu Oct 18, 2018 8:20 pm
by chunnybh
An update to an old post.
On closer inspection the tonearm on the Audio Player turns out to be made from welded seamed tubing. It is a lot lighter than the usual cast Expert tonearm. The same tonearm is fitted to both of my incomplete Expert Minors. Being cheaper to manufacture this tonearm seems to have been used on budget models. The joins are obvious in the picture below. On the Audio Player, I can feel the joins below the chrome. It would be interesting to see if Graham's other longer Expert tonearm is cast or tubing.
I have also come across another Expert 2-spring soundbox with a mica diaphragm. Perhaps they were offering them with mica and aluminum.

Re: EXPERT AUDIO PLAYER

Posted: Fri Oct 19, 2018 2:36 am
by Marco Gilardetti
chunnybh wrote:On closer inspection the tonearm on the Audio Player turns out to be made from welded seamed tubing. It is a lot lighter than the usual cast Expert tonearm.
Well, it seems that the Cost Cutting Department hit hard also at EMG in the end...

Back to the size of the arm, of course what matters acoustically is the inner size of the duct, not its exterior appearance. However, since the horn is so shorter than usual, it would be logical for the arm to taper faster and be slightly larger especially at the outer end in respect to the soundbox.

Re: EXPERT AUDIO PLAYER

Posted: Fri Oct 19, 2018 4:24 am
by epigramophone
The bifurcated horn bears some similarities with the Columbia "Stereoscopic" design of 1926. Here is one which I recently salvaged from a worm eaten table model :

Re: EXPERT AUDIO PLAYER

Posted: Fri Oct 19, 2018 11:29 am
by emgcr
chunnybh wrote: It would be interesting to see if Graham's other longer Expert tonearm is cast or tubing.
Hello Chunny,

This is still a bit of a mystery as, at first glance, my itinerant Expert tonearm appears to be identical to all the others. However, it is actually ½" longer. This is particularly strange as the diameters of the tubing where it enters the Quincke tube at one end and the bearing at the other are identical ! The tubing has been stretched.

The manufacturing method is clearly not fabricated, evidenced by the attached photos.

There are opposing thoughts as to why the dimensions should vary in that, on the one hand, it might appear logical to increase the tonearm length for the All-Range with a final bell-mouth diameter of 36" but, on the other hand, it is not clear why all other models should have similar tonearm dimensions right down to the Minor with a final horn diameter of about 18". I know the internal conduit lengths and diameters are vastly different but there is an inconsistency here isn't there ?

Your discovery of the lighter tonearms on the cheaper models is very interesting. I have a Senior, Junior and Minor here all with identical non-fabricated tonearms.

I do not own a hyper-rare All-Range but it would be helpful to have actual measurements. I know of only one where the owner might allow such work and I shall endeavour to do the necessary next time the opportunity occurs.

Re: EXPERT AUDIO PLAYER

Posted: Sun Oct 21, 2018 4:21 am
by emgcr
Just as an afterthought, it might be worth recording that the threads securing the tonearms to the internal conduit on both EMG and Expert are identical---they are interchangeable.