Pye Achoic 1005. Pick Up problems. - UK Vintage Radio Repair and Restoration Discussion Forum

samjmann · 9th Sep 2016, 2:54 pm

This unit uses as I'm sure many of you know, the infamous butterfly cartridge!
There's two problems:

1. There is only 1.25grms of tracking weight. Should be 2.5grms approx.?
2. The spring that links the floating cartridge to the arm mount appears
stretched, so much so as it is never under any tension.

The tracking weight is fixed, there's no adjustment to the weight position on the UA15 autochanger. In addition to this the LHC of the PU is short to ground.
I can only think that there is a little extra weight that would be fixed to the cartridge end of the arm to give it a little more mass. The spring that allows the cartridge to float is now so stretched that it does nothing.

Does any one know what the spring looked like originally?

There's also two long wire springs that are fixed to the cartridge body that reach back to the fixed part of the PU mount. Are these for grounding?

Hope all this makes some sense, any advice would be appreciated.

Edward Huggins · 9th Sep 2016, 3:48 pm

It's designed to be non-adjustable and to track at 2.5 grams, thats why it has a different tone arm to a standard production BSR UA15. I suggest you add some blue tac and weigh it to 2.5 g. The springs are to allow the stylus mounting to be supported under tension when revolving from the knurled red control Mono LP to Stereo LP. Any other wires/thin plates will be for earthing. Edward

samjmann · 9th Sep 2016, 4:22 pm

Thanks Edward for the reply. I'll have to add some extra weight as you suggested, there seems nothing else for it. I'm not sure if there has been a different version of the tone arm; but I saw an adjustment procedure for the tracking weight on a download of the service manual, but on mine it's fixed.
What was the point of having the cartridge on the sprung mount?

Regards, SJM.

Edward Huggins · 9th Sep 2016, 10:12 pm

The spring mount was all to do with the "Butterfly" concept. It was (and still is) very unusual to have a cartridge tracking at as low a weight as 2.5 grams in an autochanger. More so especially in 1963! Unheard of. Edward

9th Sep 2016, 2:54 pm	#1
samjmann Heptode Join Date: Feb 2014 Location: Nottingham, UK. Posts: 653	Pye Achoic 1005. Pick Up problems. This unit uses as I'm sure many of you know, the infamous butterfly cartridge! There's two problems: 1. There is only 1.25grms of tracking weight. Should be 2.5grms approx.? 2. The spring that links the floating cartridge to the arm mount appears stretched, so much so as it is never under any tension. The tracking weight is fixed, there's no adjustment to the weight position on the UA15 autochanger. In addition to this the LHC of the PU is short to ground. I can only think that there is a little extra weight that would be fixed to the cartridge end of the arm to give it a little more mass. The spring that allows the cartridge to float is now so stretched that it does nothing. Does any one know what the spring looked like originally? There's also two long wire springs that are fixed to the cartridge body that reach back to the fixed part of the PU mount. Are these for grounding? Hope all this makes some sense, any advice would be appreciated.

9th Sep 2016, 3:48 pm	#2
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,345	Re: Pye Achoic 1005. PU problems. It's designed to be non-adjustable and to track at 2.5 grams, thats why it has a different tone arm to a standard production BSR UA15. I suggest you add some blue tac and weigh it to 2.5 g. The springs are to allow the stylus mounting to be supported under tension when revolving from the knurled red control Mono LP to Stereo LP. Any other wires/thin plates will be for earthing. Edward

9th Sep 2016, 4:22 pm	#3
samjmann Heptode Join Date: Feb 2014 Location: Nottingham, UK. Posts: 653	Re: Pye Achoic 1005. Pick Up problems. Thanks Edward for the reply. I'll have to add some extra weight as you suggested, there seems nothing else for it. I'm not sure if there has been a different version of the tone arm; but I saw an adjustment procedure for the tracking weight on a download of the service manual, but on mine it's fixed. What was the point of having the cartridge on the sprung mount? Regards, SJM.

9th Sep 2016, 10:12 pm	#4
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,345	Re: Pye Achoic 1005. Pick Up problems. The spring mount was all to do with the "Butterfly" concept. It was (and still is) very unusual to have a cartridge tracking at as low a weight as 2.5 grams in an autochanger. More so especially in 1963! Unheard of. Edward