Trans-Fi Terminator Tonearm: 2019 Update

@qwin I am happy that there is improvement in SQ. The pump I used before, Eheim 400, is similar to yours in power output, I believe. I recall going up to maybe 60L so there should be plenty of reserve in the pump to experiment.

on a different note, I visited a local audio store over the weekend operated by a hardcore two channel vinyl proprietor. He carries interesting brands mostly from Eastern Europe, J. Sikora, Reed, Holbo…etc. He showed me a Polish TT with an integrated LT arm by Pre Audio. The arm had an even shorter wand than the Terminator and an integrated pump located underneath the arm. In terms of design, it solved many of the problems we are dealing with the Terminator, dressing the phono leads, getting the arm out of the way to remove records,….etc and not very expensive. I was excited to see another humble LT arm. Didn’t get to hear it play though. 

Interesting about the LT arm, I will try and find details of that.
I'm still experimenting with the filter material in the 3L chamber of my twin tank.
I emptied out the small Polystyrene balls, which are very light and even static off your arm moves them around. I put 1.5L of ceramic baking beads in the bottom of the tank. The kind used for blind baking, about 10/11mm diameter. This will be topped off with 1.5L of 6mm "Airsoft" BB gun plastic pellets. The ceramic beads are slightly irregular and form a course filter, the BB pellets are perfect polished spheres. The smaller diameter of the pellets and precise spherical form will create much smaller passage ways between them.

I have an intermittent problem with my arm.
Occasionally in use, when I come to move the wand back at the end of a record, the slider has great resistance, almost as though it is being sucked down on to the manifold. I'm wondering if there is some form of vacuum effect, where the air is exiting from the holes either side of the slider and there is a venturi effect from the holes under the slider sucking it down. It becomes so stiff, it is easier to move it with the pump off and no air at all. Just repositioning the slider or lifting one end of it while the air is on, seems to rectify this for a while.
I was wondering if anyone else had come across this issue?

@qwin Have you found the source of your problem? It’s a very weird condition. I have never had a suction problem as you described. 

@qwin

Here are a few tips for your air supply -

For surge tank Bruce ( ET ) recommends loose cotton stuffing - I would use upholstery wadding.

The surge tank should be closer to the pump and far away from the arm.

A long line of air hose ( 10ft or 3m ) to the arm will further smooth the air flow.

I also found that with small air pumps using an isolation transformer ( large ) made a significant improvement in sound quality.

when I come to move the wand back at the end of a record, the slider has great resistance,

I feel sorry for your cartridge suspension. It's probably not going to last very long.

Perhaps you should try cleaning out the capilliaries. You should also regularly clean the bearing surfaces with alcohol to make sure they are clean.

@dover I cleaned the manifold and checked each hole was clear, fairly early on.
It only sucked down at the beginning or end of an album, after I had manually moved the slider a reasonable distance and even then it was an intermittent fault.

As mentioned above, in my 3L pre tank, I have changed the filter material to half filled with 11mm ceramic beads, with 6mm BB gun plastic pellets on top. This seems to reduce pulsing a lot.

I don't like the idea of using cotton stuffing as this will have loose fibres that will need a very fine filter to prevent them getting through to the manifold and potentially blocking its fine holes.

Since using the new filter material, the slider has not stuck once, which is strange.
All working well and sounding great at present, the only thing I might try is a longer air tube from tank to Terminator. I have the Pump 5 inches (125mm) from the Tank as in the picture above. This allows me to unplug the figure 8 lead from the pump and the single 4mm outlet tube from the tank and move the whole set up as one. Handy for transporting to HiFi meetings.