Tír Na HiFi

Hi All.
Help needed ...
I have an Acoustic Signature Final TT motor that runs fast.
Was fine when I last ran it, but having been idle for several months it now runs at an estimated 40 r.p.m. when switched to 33. [estimate by ear here].

I bought it as a stand alone unit hardwired to a simple box containing 2 toggle switches, 1 for 33 or 45 and 1 for on/off which in turn is wired ti a large wall wart type power supply.

Is there an aftermarket speed controller that would allow variable speed setting ?
Is there such a thing that works on any brand of motor. Don't really want to lash out on, specifically, an Acoustic signature branded yoke.

Thanks in advance.
Gerry

Gerry D wrote:Hi All.
Help needed ...
I have an Acoustic Signature Final TT motor that runs fast.
Was fine when I last ran it, but having been idle for several months it now runs at an estimated 40 r.p.m. when switched to 33. [estimate by ear here].

I bought it as a stand alone unit hardwired to a simple box containing 2 toggle switches, 1 for 33 or 45 and 1 for on/off which in turn is wired ti a large wall wart type power supply.

Is there an aftermarket speed controller that would allow variable speed setting ?
Is there such a thing that works on any brand of motor. Don't really want to lash out on, specifically, an Acoustic signature branded yoke.

Thanks in advance.
Gerry

http://www.decoaudio.com/deco_audio_ttpsu_ac.html.html - Hope this helps...

Excellent Dermot.
Thanks a million.
Gerry

Gerry - I think those acoustic signature decks use DC motors - and undoubtedly its only a matter of adjusting the controller to bring it back right.... probably no need for $$ at all... if you go to an AC motor the pulley size is critical


Fran

Fran wrote:Gerry - I think those acoustic signature decks use DC motors - and undoubtedly its only a matter of adjusting the controller to bring it back right.... probably no need for $$ at all... if you go to an AC motor the pulley size is critical


Fran

Thank You Fran.
I had a look and the motor pod has a label that just states 230 V and 50 Htz.

The 'switch box" [on/off and speed] has a PCB asssembly inside but I cant see any adjustable elements in there ?
Any ideas ?

Cheers,
Gerry

I'll look up some stuff alter Gerry. In the meantime it would be good to get a firm number on it.

I suggest you stick a small bit of tape to the platter so that it hangs over the edge (make sure it doesn't hit the stylus). Set the table running and rest your finger n the deck so the bit of tape hits it. Start counting at "1" and hit go on a stopwatch (phone app?) at the same time. Look at the time to reach 100 revolutions - should be exactly 3 minutes. You can work out the exact RPm from that.

If its DC, then there should be some means of adjustment. If its AC then its probably more complicated, a phase issue, crystal oscillator etc.

Is it a deck that changes from 33 to 45 by shifting a belt to a different pulley or by a switch?

Fran

I'll have another look later Fran.

It switches via a toggle to 33 or 45. The pulley is a fixed single diametre. Speed of pulley revs changes.

The motor and control box is a unit that I bought from David Mc to use with my DIY turntable.

Will also try the tape for 100 revs trick. The kids will deffo believe I've gone to the far side now !

Am I right in thinking that the number of revs on the motor pulley is exactly the same as the turntable driven by it ? No matter what distance/length the thread is from one to another.
I guess it is but the more I think about it .... :-[

Nope, the motor will do several turns for every platter revolution - its the ratio of their circumferences that is the key......


Fran