Pioneer PL-51A

[Dowser]

Argh - I've been after a sensibly priced Pioneer PL-71 for 10 years or more now, never got lucky. After recently purchasing another Lenco, and (hopefully) selling it pretty quickly, I just bought a Pioneer PL-51A - same base deck as the PL-71, just with a cheaper arm fitted (I think?).

Cosmetically bad, but cheap, and I always wanted to hear one - bearing clean and re-lube and I quickly mounted a low hours Ortofon Red. I am again shocked and stunned - within the limits of the cartridge and arm (same as on a PL12D I think! Cheap shit!) this thing sounds brilliant. Such a solid soundstage/image is presented - and this is with a budget arm and cart!

I keep this I think, and sell another of my Lenco's....and the HK ST8...and try fitting a decent arm and cartridge to it - pivot to spindle is 205-6mm....that must be close enough to be able to bodge a Rega into it

My first direct-drive (driving the platter, the ST8 uses a DD motor, but with a belt to the platter!) - definitely sounds different to belt and idler!

Piccies;

 

[Taff63]

Those Pioneers are great aren't they? I must admit I'm a bit smitten after reaquainting myself with my Pioneer PL-570 dd turntable. After suffering a stylus collapse on my Systemdek 3/Nima/Karat d2 it's been back in service and just sounds really good. Not as detailed as the main deck but music is soooo enjoyable and has real bounce and drive. Not missing the Systemdek as much as i thought i would

 

[crimsondonkey]

Nice turntable, congrats.

 

[Dowser]

I love the looks of these decks - although this one is a bit scruffy, I hope to be able to improve it somewhat by dying some of the veneer damage. The arm though looks as the same fitted to a Pioneer PL12d I had previously, and definitely budget. This seems the main difference between pl51 and 71.

 

[starbuck]

Hope you enjoy your purchase, not wishing to gloat but I have been enjoying my recently acquired PL-71 and agree with all said above, they are a lot of fun to listen to. Plus having push button speed change is very nice after coming from a belt drive with manual belt/pulley swapping for playing 45s. In case it is of interest/use, the following thread gives some excellent details and close up photos of the PL-71, inside and out:

http://www.diyaudio.com/forums/anal...ion-modification-pioneer-pl-71-turntable.html

How is the speed stability on your PL-51, is there much drift?

 

[Dowser]

Thanks - mine seems OK on the short listen I gave it the other night, but for sure I will look to replace the micro-switches...and improve the PSU drive rail. But first I want to see if an RB arm can be made to fit...otherwise I may just resell...I'm really not impressed with this arm. A full strip down beckons when I have time, to see what is possible.

Richard

 

[Dowser]

Having posted off the red Lenco to it's new owner tonight, I feel less bad about the PL-51 I recently bought, so decided to strip to stock (and crap) arm off it to see how likely mounting a Rega is.

Bottom cover off - immediately I see more differences from the PL-71 - while motor and PSU is the same, the transformer is mounted to the underside of the platter tray, making it more of a candidate for an offboard supply;

Arm cut out is also different I think (need to check PL-71 photos again), arm only mounts to the metal face plate on the 51, but also through the wooden base on the 71. Not a big problem I think, metal plate is 2 or 3mm anodised steel by the looks of it;

Stock arm off;

X marks the spot of a new 23mm hole required Will look a bit of a bodge, but I got this deck cheap enough to experiment and not feel guilty.

Rega RB250 will be a visual match I think;

Need to get some new small drill bits, drill and cut the hole out, then file it smooth (don't feel comfortable a hole cutter will do the job?

Cheers, Richard

 

[Dowser]

Off the the DIY store tonight to pick up some new 2mm drill bits, also found some beeswax - wow, this is just a single application;

It's motivated me to strip the whole damned thing, clean the old veneer (with turps?) and then do a decent beeswax job on it.

Hole marked out with a metal compass (I'm going to regret my first pivot to spindle scratch being so long I guess...);

Under-tray - question: will I do best by moving the transformer off this and onto the wooden plinth? All transformers hum, no? I'd rather at least have a chipboard interface between it and the platter? Think I'm going to move the transformer;

Stock arm and earth wiring - I have a DIN-R plug on the bottom of my modified RB250, so will wire direct to RCA's. I did consider swapping earth over to a 3 wire mains lead, but guess this may cause a loop as the RB250 mounting collar is also part of the arm's earth - I try as is first, and see how it goes;

 

[Dowser]

Some more progress;

2mm drill bit used to drill holes, then as a make-shift milling machine...it took a long time

Stripped plinth before clean;

And after turps clean and beeswax polish;

Rega arm test mount;

The hole for the Rega still needs opening out a little, and the plinth needs trimming to make space for the Rega nut to screw down...I will get there

Richard

 

[starbuck]

Looking good, the Rega matches nicely and no doubt will sound excellent too. In the unlikely event I ever disassemble mine to that degree, how easy was it to remove the platter/motor assembly from the plinth?

 

[Dowser]

Looking good, the Rega matches nicely and no doubt will sound excellent too. In the unlikely event I ever disassemble mine to that degree, how easy was it to remove the platter/motor assembly from the plinth?

Fairly straightforward - unsolder 8 wires, plus remove the captive mains cable, then remove screws from top and lift out. Another 3 wires if you want to remove arm board too. This is with the bottom metal cover removed already - about a billion screws in total

I post some more pictures later showing the wiring. There appears to be 2 variants of the 51A (& 71A), one with 2 micro switches and one with 3. Mine has 3, and only one 3 pole switch is used for switching speed. The other 2 are for mains on/off.

 

[starbuck]

Thanks for the info. My 71 is the 3 micro switch variant. I have the new/replacement micro switches though haven't gotten around to fitting them yet - something to add to my new year resolution list.

 

[Dowser]

Lovely;

VTA good (but note you need a spacer underneath as the Rega expects a thicker armboard!);

New arm wiring from RB250 to sockets (I fitted a DIN plug to my RB);

Motor control and PSU boards recapped - motor board is a PITA, everything too close together!

How does it sound - bloody good, rock solid imaging and great dynamics. I have no experience of the 2M Red though, and assume it is just a budget cart - I will put my Asaka on it once I've cleaned it, then I can really tell.

I replaced all electrolytics - for posterity, this is what is fitted originally;

Motor PCB;
4x 4.7uF 25v
2x 10uF 16v
1x 100uF 16v
1x 100uF 25v

PSU;
330uF 35v
100uF 25v
33uF 35v

I just chose replacements of similar size - ended up using 10uF instead of 4.7uF for the motor (across the winding I think) as I didn't have right value, but it is fine. 220uFs to replace to 100uFs on motor board, and hugely increased values on PSU.

To fully strip the motor assembly and arm board from the deck, you need to remove blue, green and brown wires from this board, and the brown/orange/yellow from this one. All easy, wires are wrapped on, heat with soldering iron and unwrap.

Richard

 

[Craig B]

Nice job Richard!

Looking at those pictures, one is reminded of that classic Pioneer woody electronics smell.

Craig