Weight lifting Expert

Discussions on Talking Machines of British or European Manufacture
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emgcr
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Re: Weight lifting Expert

Post by emgcr »

My experience, for what it is worth, is as follows:

Quinke tube. I too have never detected any audible change to sound output wherever the adjustment is made. As Andy has suggested, it does appear to have been a marketing gimmic but, on the Expert tonearm, affords a useful anchor-point for the counterweight pivot.

Counterweight. I do agree that the four-spring Expert soundbox is very heavy---probably needlessly so. I have had to employ the lighter two-spring on some records containing highly modulated passages to avoid disaster---particularly towards the end of the disc. However, I have also found that the most important aspect of achieving a long-lasting fibre or thorn needle point is to ensure that the sideways bias on the tonearm is virtually nil. This may be an obvious fact to mention but carefully adjusting the level of the base unit and employing a blank-sided record to demonstrate no needle/soundbox movement either way, makes the biggest difference of all. This is a very subtle adjustment (even use of another blank record can give a different result), most easily achieved by fine opposing wedges under the feet of the case, and will often allow the playing of up to five records without needle sharpening. The actual number that can be played successfully does, of course, also depend upon the extent of modulation on the disc. Other factors involved are correct overlap/tracking, a vertical needle, length of needle and a free-running tonearm bearing.

I agree that finding a counterweight is probably very unlikely (I have never seen one for sale) but I do have some photos and drawings on file but am away at present so will be unable to post for a while. I also have a couple of actual examples, one of which is identical to the one in the photos attached to the Expert goose-neck tonearm.

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Orchorsol
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Re: Weight lifting Expert

Post by Orchorsol »

Here is a counterweight design taken from an issue of Talking Machine Review - I'm unsure of the date. Apologies for low resolution.
Attachments
Counterweight - Talking Machine Review.jpg
Counterweight - Talking Machine Review.jpg (26.84 KiB) Viewed 1291 times
BCN thorn needles made to the original 1920s specifications: http://www.burmesecolourneedles.com

Youtube channel: https://www.youtube.com/channel/UCe4DNb ... TPE-zTAJGg?

snallast
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Re: Weight lifting Expert

Post by snallast »

Thanks Orchorsol for the drawing, every piece of this puzzle helps! Especially if I´m going to have to build it myself in the end!
emgcr wrote: Counterweight. I do agree that the four-spring Expert soundbox is very heavy---probably needlessly so. I have had to employ the lighter two-spring on some records containing highly modulated passages to avoid disaster---particularly towards the end of the disc. However, I have also found that the most important aspect of achieving a long-lasting fibre or thorn needle point is to ensure that the sideways bias on the tonearm is virtually nil. This may be an obvious fact to mention but carefully adjusting the level of the base unit and employing a blank-sided record to demonstrate no needle/soundbox movement either way, makes the biggest difference of all. This is a very subtle adjustment (even use of another blank record can give a different result), most easily achieved by fine opposing wedges under the feet of the case, and will often allow the playing of up to five records without needle sharpening. The actual number that can be played successfully does, of course, also depend upon the extent of modulation on the disc. Other factors involved are correct overlap/tracking, a vertical needle, length of needle and a free-running tonearm bearing.

I agree that finding a counterweight is probably very unlikely (I have never seen one for sale) but I do have some photos and drawings on file but am away at present so will be unable to post for a while. I also have a couple of actual examples, one of which is identical to the one in the photos attached to the Expert goose-neck tonearm.
Yes I agree - I worked on that part first, and it IS something that takes it´s time, hadn´t thought of the blank-record test, very good idea!

Today I did som weighing: the 4-spring soundbox weighs 215g whereas with my primitive counterweight, needlepressure is down to approximately 79g - which gives very good results.

The Meltrope soundbox weighs 135g which seems ok - it is only fitted for steel needles but does not seem to wear records at that pressure.

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emgcr
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Re: Weight lifting Expert

Post by emgcr »

Here are some photos showing different design ideas. They are really only suitable for goose-neck tonearms (the Expert range). The EMG swan-neck requires more thought and more complex design to achieve a similar, cosmetically appealing, result.
Attachments
pic 2.jpg
DSC04891.JPG
DSC04890.JPG
Expert tonearm counterweight.jpg
Counterweights. Seymour.JPG
Counterweights. Seymour.JPG (72.89 KiB) Viewed 1026 times

Frankia
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Re: Weight lifting Expert

Post by Frankia »

Excellent Graham, and so interesting. This is an area that I almost delved into a few years ago but got halted by financial matters. I notice that my 2 spring soundboxes are all easier on bamboos and thorns than the 4 spring ones. That's why I'm interested in the whole area.
The fact that some people have contradictory experiences only serves to heighten interest!
Anyway, if ever someone decided to manufacture some, I'm in the market for several! (At least presently until finances plummet again!) Not really a nudge or hint by the way - I'm well aware how busy you can be!
Thanks very much for the upload though!

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