Audio

Special parts in stock

Parts for Braun PS-500

Renovation kit for the hydraulic (oil) dampers in Braun PS-500 turntables.

(Ersatz Öldämpfer, Ölhydraulische Dämpfung)

A kit of three silicone rubber dampers, to be inserted inside the original oil dampers. No other hardware included or needed.

The classic Braun PS-500 turntables have often badly aged plastic and rubber parts, which have been unobtainable for decades. They have three typical problems:

  1. The plastic cam wheel under the platter, controlling the tonearm mechanism and power switches, is made in a subpar quality of plastic. I can't offer any replacements for those, but fortunately the plastic in them can often be repaired and armored applying super glue and epoxy in the right places. This is the only upside of Braun not making that part in nylon as one would have expected. To spare this part in the future, I would recommend to always turn the auto-stop switch on the tonearm off. A malfunctioning auto-stop mechanism is a main reason for the broken cam wheels.
  2. The rubber mounts on the top and bottom sides of the motor are often hardened or disintegrated, increasing the rumble. For replacement parts, see further down on this page.
  3. The main problem on these machines is broken oil dampers under the springs in the suspended chassis. They break down in two ways: Dried out rubber in the topmost caps, and cracked plastic in the bottom cups. Both lead to the damping oil leaking out, ruining both the suspension of the machine, and the piece of furniture it is placed on. None of these parts can be easily replaced or repaired, apart by finding not-yet-broken ones from other machines.

The parts I offer are not intended to repair the original dampers, but to replace the damping oil within them with a very soft silicone rubber plug. This way one doesn't need to modify or replace any leaky original parts, should they be fixable later - all you need is to empty and clean up the oil cups, remove a stopper cup from within the damper, put in the silicone plug and readjust the action of the suspension. (OK, that´s actually quite a lot, but still an easier job than replacing the oil, and can be done keeping the broken cups).

Damper taken apart and cleaned.

Damper with rubber cup, step 1.

Damper with rubber cup, step 2.

Three dampers with mounted silicone parts.

Damper in situ.

These parts should not be considered as an upgrade or a totally equivalent replacement of the original construction. Replacing a viscous damping oil with a soft silicone is bound to modify the properties of the damper. Íf possible, you should instead restore the dampers with ca 3500 cst silicone oil, about 27 g per cup, removing any captured air within them.

But if your dampers are leaking, using silicone rubber is much better than scrapping the entire turntable. Mechanically the modification is in fact not as dramatic as it would seem. The original damper is a two-stage mechanical vibration isolator combining a spring with a plastic container with a flexible rubber top, filled with a thick oil.

According to mechanical impedance theory, a spring has most of its effect on the lowest frequencies, while a viscous (oil) damper has more of an even effect over the entire frequency range.

Replacing the oil with a silicone rubber will only affect the viscous part of the isolation, into more of a "springy" mode. This leaves the effect of the isolators unharmed, or slightly increased, in the lower range, and slightly reduced for the higher.

This does not imply that a rubber damper must be audibly inferior to the original design, only that it will be slightly different. One way to describe the difference is that you may lose a bit of the damping of the higher frequencies from motor, floor, and airborn vibrations. But on the other hand you may gain a bit of speed stability, since the stiffened isolatator will reduce vibrations in the belt from a moving inner chassis. Whether these differences are in fact audible depends on your setup and musical choises.

[The above description of these parts was revised in july 2024 after further reading in mechanical impedances. The total effect is the more or less the same as before, but the mechanisms were incorrectly described. Sorry for that!].

If your dampers have damaged rubber or plastic cups that can't be mounted any more we could perhaps have a chat. I've prepared methods for combining these silicone rubber dampers with additional replacement parts, casting the top cup in a harder type of silicone, and/or the bottom cup in an epoxy plastic. I wouldn't dare to use these cups filled with oil - they are only meant for use with the rubber dampers. These parts are still experimental, since I'm quite out of broken PS-500s.

Price: 550 Sek / set.

Motor mounts in silicone rubber for Braun PS-500

A pair of motor mounts (rubber bushings) in silicone rubber for Braun PS-500.

Hand cast copies of original parts with better vibration damping and expected lifetime than the originals.

Price: 330 Sek / set.

 

Most of the parts we sell can be bought through Tradera, a Swedish auction site. Unfortunately, Tradera can be pretty hostile against buyers outside EU, and not always very helpful for those inside too. We've heard some nasty stuff about requirements for copies of passports. Also, since 2024 Tradera adds a "buyer protection fee" to all non-swedish orders, which we of course do not.

All parts we sell can be ordered directly by contact via e-mail: audio@collegit.se.

We ship worldwide, and accept payment through PayPal or bank transfer. Customers in Sweden can also pay by Swish or Plusgiro.

Shipping fees are of course dependent on the weight of the parts, and on the receiving country. Typically, the fee for sets of motor mounts within EU, USA, Australia, and many other regions is 36 SEK for a plain letter, or 114 SEK for a trackable one. (Within Sweden, 18 SEK or 58 SEK). The fee for other regions may be higher. Likewise for heavier parts, like sets of Sonab feet or Braun dampers.

Since the parts are hand made in very small batches, we don't have the margins to offer any notable discounts for larger orders, or to resellers. The best we can do is to not increase the postage fee for orders with multiple sets of parts, and for business buyers within EU we can arrange the usual VAT deduction. If this applies to your order, please add the correct name and the VAT identification number of your business to the e-mail with your request.

Normally all parts listed are in stock. Any parts that may have been recently sold out can be made in one day or two.