Mpp

[RCruz]

Originally Posted by Joachim Gerhard

Everybody will tell you that his solution is the best and so it should be. Have fun !!!!

I am far from stating mine is the best solution but using a simple hexfred bridge before 15000u smoothing Nichicon caps allready makes it sing.

I believe some coils would improve on this thou.

[RCruz]

Now a different story... I am using an old Micro TT that I found in the house I am now living in... It needed some work ... cleaning, new belt, bearing tightening and motor refurbishing. Now it works and sounds very good indeed. It is a very well built machine but an entry level with a very torquy motor that produces some vibration and noise.

Today I decided to experiment it connected to my Ricgeddon (a 220 to 110v 500VA toroid followed by some resistors to lower mains from 220 to around 80vac).

Now the platter takes some more time to reach full speed but does not need a hand start. The good news are: I do not hear or feel any more motor noise.

Results are incredible... micro detail much more aparent, bass more pronounced and a sense of ease on the presentation.

Those who have ac motors should try this simple trick... it is incredibly effective.

[Joachim Gerhard]

You found the turntable in the house ????? That is incredible !!!!!
Of cause a silent motor is a night and day experience. Thanks for sharing your simple and effective trick.
The common mode coils in Frans schematic i posted are the Talemas from Reichelt.

[RCruz]

I also found a violin hehe

It seems no one cares about turntables around here and this is really a rare find.

PS: I believe the idea to reduce AC voltage came from Naim for the Linn.

It works perfectly with Rega TT also.

It is incredibly effective.

PS: thank you for for the talema tip. I will try it and report the results.

[Nick77]

Cant find the Talemas, is this a suitable replacement?

B82733F2701B001 EPCOS | Mouser

[Joachim Gerhard]

That Epcos is a good find. Seems to be even better in quality.

[as-audio]

Originally Posted by RCruz

I also found a violin hehe

Please post a picture of the violin (and the TT).
Thanks

[phi]

Digikey version

http://www.digikey.com/product-searc...82733F2701B001

[Holger Barske]

Had another thought on this common mode choke thing and talked to a good friend of mine, someone who knows a lot more about chokes than me.

To put it short: Forget it. You can't use common mode chokes in the DC section of the PSU (aka behind the rectifier).

The reason for this is simple: common mode chokes are for filtering common mode components. The ripple currents on the plus and the minus lines of a PSU aren't common mode - they are just the opposite (given an identical load in both lines). So you might have the brillant idea to reverse one of the coils to have common mode ripple.
The problem is: if you do so, you also reverse one of the DC currents through the core. So both DC components won't compensate any more, they will add up.
Which leads to massive saturation of that tiny core. Result: Your inductance is gone. Your common mode choke won't do any harm, but it won't have any effect on the signal at all.

Forget about common mode chokes, use seperate chokes for each of the two power lines.

[Joachim Gerhard]

Amen.