One pair of S55's cooking up

A tip I got from a long time restorer and collector of records - He use to take his records to places that had the best machines, but found in the end, that the best method, was to make a mixture of Isopropyl and small amount of washing up liquid, and use a high quality, fine bristled decorators brush to apply the mixture 1/3 disk at a time, rinse with tap, then final rinse with RO. I can say his vinyl is spotless and noiseless, so have started using the same process myself now!

Step1 wrote:

A tip I got from a long time restorer and collector of records - He use to take his records to places that had the best machines, but found in the end, that the best method, was to make a mixture of Isopropyl and small amount of washing up liquid, and use a high quality, fine bristled decorators brush to apply the mixture 1/3 disk at a time, rinse with tap, then final rinse with RO. I can say his vinyl is spotless and noiseless, so have started using the same process myself now!

What is RO ?

I have cleaned all my records about one year ago, used the record cleaner hand piece from Audio Technica (flanel fabric) , and my destilled water, IPA and a drop of dish washer mix. I made a 2 liter mix, and wetted the cleaning piece thoroughly, cleaned each record all around more times and then dried off with a micro fiber rag. Yesterday I wanted to test my own cleaning pad (spongy underlay covered with microfiber fabric), just to be sure the glue and materials were resistant to the cleaning liquid. Using my own liquid I cleaned a new record, before that the record has been cleaned with Audio Tecnica´s cleaning liquid and their hand piece. My cleaning pad, only moistened,  came out slightly dirty, I then found a record that has been cleaned one year ago, cleaned with the same pad, it came out even more dirty, I now found a record that has been cleaned and played frequently within the last year, my pad came out even more dirty. Remember my pad was only moistened with my own cleaning liquid.

Here the compare pics, one new unused and the dirty one after cleaning 3 records, I wonder I wonder

Today I finished the shaft with label protectors, and will continue with the basin/box

Soren I am sorry I meant distilled - RO is similar but not as pure in many respects!

Not sure what you are saying, your not happy with your current method? I think with the paint brush the bristles really get into the grooves so all dirt is lift out, with no damage to the vinyl surface. I guess the convenience of a semi automatic or assisted system would be ideal, I just wonder if it can ever be quite as thorough?

I´m NOT happy with the Audio Tecnica system, but I´m surprised of how much dirt I got on my homemade pad, and that from records I thought clean.

I´m now more than convinced that microfiber is the way to go, microfiber threads are far thinner than any bristles.

Ah I see now. You could argue that bristles are easily small enough to get into the depths of any groove though! (Just playing devils advocate!)

Step1 wrote:

Ah I see now. You could argue that bristles are easily small enough to get into the depths of any groove though! (Just playing devils advocate!)

Oh yes just took a look at the grooves vith a 10X thread counter, and they are big enough for camel hair bristles to get in there.

ABRs replaced with BRPs
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Just occasionally (actually quite rare) you find that the servo motors in Beogram 400x players has a short, and has taken out the H bridge, as I have found with the latest example on my bench.

The Leaf brushes are very delicate and anything up to 40 years of use is starting to take its tole on the brushes.

One temporary solution is to pull the back off the motor, and break away the offending leaf. It is not by any means a great solution, as the motor is now relying on just two leafs, but it will give a little bit more life to these amazing motors! Test the motor on a bench power supply and make sure they start up at about 0.5V, and very smoothly too. I have a video showing how amazing these little things are they generally start at about 250mV !!!!! and I have kept one spinning down to 50mV!!!!!!! I will upload it :-)

until I have tested a replacement for these motors, and if there are no alternatives available, it might give a little more life to the original motor! I replace the original transistors with ZTX transistors, and if this solution is considered (and I repeat is only temporary!) it is worth considering a small inline fuse to protect the H bridge should any more of the fingers fail, which I think will be fairly inevitable!

There were some near identical coreless motors made by the same company on ebay some time ago, and rather stupidly I did not buy one to try (in my defense they are not cheap, but half the amount than buying direct from the company!) :-( So waiting for more to appear, which I have no doubt they will!

I just want to clarify why the motor presents a dead short when a brush fails - The brushes on these motors consist of three simple bronze fingers, leafs or whatever you want to call them. There are 2 lots of 3 leafs, sitting 180 degree apart, with a very fine commutator between - This commutator is much finer than you would find in a regular motor. When the motors approach end of life, the brush leafs have largely worn through, and because the commutator is so small, a very small area becomes weak, and eventually breaks. This leaves a short leaf sitting at the apex of the commutator, which might be ok whilst the motor continues running in the same direction - However, reverse the motor, and this is where the problem now arises! The leaf jams in one of the commutator gaps, and is flipped over to the other side, contacts one of the opposite leafs and bam, dead short - transistors release their magic smoke!

Yes, I've got a beautiful motor here, but with bad leaves, and there's nothing to be done.

I use the ZTX450 NPN and ZTX550 PNP, but I end up having a lot left over after cherry-picking for matching hFe. At least they're cheap.

Menahem