In part 1, we laid out a strategy for auditioning multiple tonearms and cartridges on both a Galibier Eiger prototype and our customer’s turntable (from another manufacturer).
In this post, we finalize how we adapted the customer’s existing armboard to work correctly with his mis-specified Reed 2A tonearm. Mis-specified tonearm? Strong words, I know.
Our customer came to us asking for help in aligning his Reed 2A/Lyra Atlas tonearm/cartridge combination on his turntable.
Upon inspection, we found the armboard had been drilled twice.
Trying both arm mounting hole sets, the closest we could get to the specified Baerwaald alignment point resulted in a pivot to spindle error of 5.6mm – this, with a pivoting armboard!
A design exercise …
We started by mounting the arm with one screw which allowed us to rotate the tonearm to achieve the specified mounting location.
Mounted at the specified Baerwaald pivot to spindle distance of 251.6mm, we ran out of headshell slot adjustment range. We needed to establish “new” geometry in order to align the cartridge.
Using our Feickert alignment gauge we settled on a pivot to spindle distance increase of 2.4mm (adjusting the effective length as well). This new set of Baerwaald parameters allowed for positioning his Lyra cartridge’s mounting bolts in the approximate center of the headshell slots.
If the Reed tonearm did not have such exceptionally short adjustment slots, this re-specification wouldn’t have been necessary (Whiskey Tango Foxtrot Reed???).
How tall ARE you (with apologies to Monty Python)?
This was not the fault of the turntable.
The Reed is specified for a platter to armboard “drop” of about .8″. Statistically, the majority of the tonearms we’ve encountered expect to see a drop in the 1.2 to 1.5″ range ( about 30 to 40mm – we specify 35mm for Galibier turntables).
We fabricated spacers out of acrylic, and this informed us of the final armboard height. The sound was dreadful (no surprise, due to the materials interface), but we now had our height.
… but luck is frequently the result of doing diligence.
Looking at how best to work with the required .500″ height increase, we fabricated a sandwich using two, .250″ thick plates of aluminum.
This reinforced the armboard and we achieved a constrained layer armboard in the process! Not bad for a day’s work.
The photo shows the board before bonding the layers and polishing.
Come on tonearm manufacturers!
I continue to be appalled at the utter disregard for standards in this industry.
In the absence of standards, can’t we at least accept some statistical norms and design with this in mind?
Note: a special shout out goes to the designers who get it – fellows whose products play “nice” with other products. Frank Schröder and Franc Kuzma immediately come to mind as individuals who get it. Unfortunately, they are in the minority.