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ALWSR for DD turntable psu

mega lord

Centre tapped
I was wondering if an ALWSR could supply the necessary current to power a Pioneer PL-71 turntable. I believe the standard regulator in there outputs 18V.

I don't know what the TT pulls current wise but on the back the label says power consumed is 5.2W.
Using I=P/V that means current is 5.2/18 = 0.29A or 290mA. Looking at the ALWSR manual it suggests it is good up to 500mA.

Have I worked this out right or is there something glaringly wrong with this assumption ?

Thanks in advance.
 
Cheers Dowser. It's just that I have four of them looking for something to do. 18V @ 290mA max seemed like a perfect job for one of them.
 
There’s a few posts here and elsewhere on modifying drive to the PL-51 & 71 motors. Well worth a read before you start.
 
thats just a Jez “bold statement” - don’t discard the thought at all, try for yourself. For what it’s worth, adding PSU capacitance to the motor drive circuits on my old PL-51 made a difference - if I’d kept it I would have played more.

Absolute arse gravy. It's the facts as I always provide.

OP Ignore dowser he doesn't know what he's talking about.
 
Absolute arse gravy. It's the facts as I always provide.

OP Ignore dowser he doesn't know what he's talking about.

LOL - OK, I’m lying Jez...or I simply imagine the improvements I hear, because why would doing some work on something ever make it sound worse... :D

Also note I never claim to be right, I only share what I perceive to be. You on the other hand, of course, know everything from your years of engineering experience, such that you can comment on things from a purely theoretical view... Sorry, that’s bollocks :)
 
There's no reason why better regulated voltage rails couldnt deliver an improvement in speed, they certainly won't make it worse.

In most cases the limit to speed accuracy in any TT setup is the precision of the drive system, belts, pulleys, motor poles, balance of physical parts and the accuracy of the maths of the control system.


In the case of the pl71 replacing those 3 lytic caps is probably a smart move.
 
There's no reason why better regulated voltage rails couldnt deliver an improvement in speed, they certainly won't make it worse.

In most cases the limit to speed accuracy in any TT setup is the precision of the drive system, belts, pulleys, motor poles, balance of physical parts and the accuracy of the maths of the control system.


In the case of the pl71 replacing those 3 lytic caps is probably a smart move.

Replacing old electrolytics is worthwhile but the unit will already have regulated rails and the rest is down to the servo. This is not a MC phono stage where uV's of noise can make all the difference!
 
Agreed, the motor swamps almost everything. Looking at the pcb I fail to see any oscillator, looks more like simple servo rather than a pll.
 
Caps and micro switches were already on my list to replace if I can find suitable switches. The reg is a very basic one from what i remember. The deck is pre quartz lock.
 
Looking at it it seems to be very simple indeed. I'm hoping there's an opamp hidden away somewhere in there.
 


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