Air compressor for tangential tonearm

Hi all,

My good friend Karel, a very talented handyman, is building a tangential tonearm on a cushion of air (which I hope a copy will be used on one of my turntables) somewhat in the style of this one:
http: / / www.trans-fi.com/terminatortonearm.htm

So it seems we have to use an air compressor or something like that. Area in which I know nothing. Should we use an air pump or a compressor for fish tank or something else? What features should we consider? And of course, how much does it cost? Apparently, it is desirable that the airflow of the unit is adjustable according to the arm with which it is used.

For audiophile use, it is clear that an appliance as quiet as possible is desirable.

Thanks in advance for your help.

Regards,

Cristobal

 

The Trans-Fi uses a compressor intended for aerating a fish tank. If you have not already done so, you should look up the Poul Ladegaard arm, upon which the Trans-Fi is based:

http://www.aiko.com/airbearingarm.html

In general, air bearings are best used with an oil-less compressor and a smoothing tank must be used. The quietest ones are made for use by dentists and are priced accordingly - making a compressor genuinely quiet is not an easy task.

 

Having designed various facilities I'll just add that dental vacuum units while very nice in terms of oil/water-free air delivery are certainly not necessarily quiet - at all*.

Best answer will always be to site any compressor remotely if possible. Not only does it address noise, but the volume (and distributed resistance) of the line adds compliance additional to the smoothing tank YNMOAN recommends. It works exactly like RC filtering of an electrical supply.


* in one current project the pump room- 6 vacc / compressor units, about 18Kw total, will hit 94dB. A lot of money has been spent on dealing with this... the kit manufacturers just do not care, or even have good answers, since much of the racket is actually low frequency cyclic noise. Compliant mounts can only go so far!

 

Ah yes, I'm sorry if I gave the impression that they were genuinely quiet - I meant quieter than some other options - but still pretty noisy.

As you say, the smoothing tank adds compliance - life is never simple . One of the problems with air-bearing arms is that the solution seems elegantly simple (and in many ways it is), but the technical application needed to realise that 'simple' concept is actually very complex, and it is easy for new problems to be created during the solving of existing issues.

 

I had to house my fish tank pump in a MDF box insulated with foam and carpet tiles and just 4 x 6mm holes for air intake - that shut it up.