A new toy - PL-71..... [Archive] - The Art of Sound Forum

NRG

02-07-2009, 10:48

.....all the way from the US of A I'm now in possesion of a mid 70's PL-71. Having read the good reports from Richard on these I managed to snag one for a fair £97 quid....the shipping charges where something else though and then there was import duty :doh:

The deck seems in fine condition, I've cleaned it and checked the arm for any issues and all seems OK...I've recapped the power supply boards and cleaned 'n' oiled the main bearing.

It came with a Shure v15HR-P cart but I haven't tried it....instead I fitted a Sumiko headshell and a DL103R.

I thought the speed stablity was OK but its turned out that its a bit variable and it seems to be a problem with the speed select micro switches... who's contact resistance changes when you gently tap the top of the speed select buttons! New items are on order.

When the speed does settle down it sounds OK...but...I'm not sure the 103r is a good match for the arm...the sound is not coherent and its a bit vague. It could need more mass but I've tried adding some temporary mass and it's not improved.

So I've currently switched over to a Reson Reca and it's much better...

I intend to rewire the arm and replace the phono sockets on the back with a captured lead...

I've also got another DD on the way....I hope...and will post when it / if it arrives...

http://i94.photobucket.com/albums/l82/_NRG_/other/DSCF4339.jpg

http://i94.photobucket.com/albums/l82/_NRG_/other/DSCF4333.jpg

http://i94.photobucket.com/albums/l82/_NRG_/other/DSCF4337.jpg

http://i94.photobucket.com/albums/l82/_NRG_/other/DSCF4328.jpg

http://i94.photobucket.com/albums/l82/_NRG_/other/DSCF4329.jpg

Magna Audio

02-07-2009, 15:44

Looks very good. Nice LP-12 beater:). I had a good listen to an SP-10 + SMEV the other evening and on coming home and firing up the PL-71 I was not dissappointed.

Same switch prob as I had... £3 sorted.

I have not rewired the arm or changed caps - it's working so nicely I've left it original. Let us know what the re-wire does.

Did you move the voltage in wire to set it up for 230V?

DSJR

02-07-2009, 17:03

I've been racking my brains to remember if we ever sold these. I do remember the twenty or so PL12D's we sold ON EACH SATURDAY (can't remember how many we sold mid-week...) and I know we had a few of the others, but this was when I was being blown away (literally) by big IMF's and JBL L200's, not to mention Tannoy Berkely's and "Ard'Ons" and the huge and expensive (£1200 in 1974) Crown hybrid Electrostatics. Compared to the pretty and totally ineffective Era deck, the Techie range and the good old (?) Yamaha YP800, the PL71 looded, well, boring and slipped under the radar.....

I know it's been said that the arm bares more than a passing resemblance to the Rega R200, but looking at them closely, the differences are greater than the similarities to be honest. They were probably made in the same factory though, as apparently a very few companies churned out all the product for all the manufacturers back then.

I'm sure it's a great old deck and the substantial wood-block plinth (compared to the internally hollow Techies of the period) must help here I'd have thought).

This is guessing, but I suspect a top end AT cart might be the best thing, such as an AT33 varient (the PTG is the UK popular one, although there are others at higher prices) or an OC9ML.

I bet the seller in the US couldn't believe how much you paid for this deck. I bet he was looking for $50, not $140 or so.......:)

bigmoog

02-07-2009, 17:31

very nice set up :)

but will it better the reference Limp LP12?

you know the reference system:

LP12, ittok, karma, exposure super duper something or other, kans...

Im off to the 80's to confirm:lolsign:

exits nodding and a foot tappin'

Marco

02-07-2009, 18:26

Hi Neal,

When the speed does settle down it sounds OK...but...I'm not sure the 103r is a good match for the arm...the sound is not coherent and its a bit vague. It could need more mass but I've tried adding some temporary mass and it's not improved.

So I've currently switched over to a Reson Reca and it's much better...

Most interesting - and great pics as usual!

The bit in bold is intriguing because it flies completely in the face of what's been reported by, IMO, people who know a good sound when they hear it, such as Gromit, RD, and others who've reported superb results with the PL-71 and 103. You're observations of course are equally as valid, but it just goes to show how people judge things differently! :)

As far as I'm concerned, experience suggests that the arm on the PL-71 *should* suit a 103 very well, but that's obviously not what you're hearing, so it's doubly puzzling... Perhaps you could expand a little on what you mean by "not coherent and a bit vague"? What phono stage are you using, and how is the cartridge being loaded?

As I haven't yet heard the PL-71 for myself, the jury's still out, so I'll be following with interest how your journey develops :cool:

Marco.

Ali Tait

02-07-2009, 18:47

Nice looking deck! Can't help thinking how nice it would look with a slate plinth though...

scoobs

02-07-2009, 19:10

As far as I'm concerned, experience suggests that the arm on the PL-71 *should* suit a 103 very well, but that's obviously not what you're hearing, so it's doubly puzzling...

Remember though that both Gromit and RD were using additional mass on both the counterweight and the headshell, I guess the stock arm is middling in mass terms and probably a bit on light side for the 103.

Marco

02-07-2009, 19:29

Yep, but Neal has already said:

It could need more mass but I've tried adding some temporary mass and it's not improved.

:scratch:

Maybe he hasn't added enough... However, I suspect something more fundamental is wrong.

Marco.

WikiBoy

02-07-2009, 21:36

Yep, but Neal has already said:

:scratch:

Maybe he hasn't added enough... However, I suspect something more fundamental is wrong.

Marco.

Could be loose arm bearings chattering. The two knob like things either side of the arm bearing are screw caps, undo them and underneath each you will find a screw. Tighten to sort of finger tight with a screwdriver and try again.

My three cartridges with my PL-71s (I have three of them now) are DL103, M3D, SPU. They all sing but SPU is magic.

NRG

02-07-2009, 22:27

Whoa! loads of replies...

Steve: Yes moved the wire over to 240v

DSJR: I had to persuade the seller to ship to the UK! :lolsign:

Bigmoog (Jonathan): Already been there...got the T shirt and moved on...no Linn for me...;)

Marco: yes its a bit confusing, I used a Sumiko head shell and also added some extra mass during my fiddling...but the 103r just didn't seem to 'gel' as I know it can...maybe there's something else wrong like Richard suggests. I've tried both the phono input to a Linn Pretek at 100R and also into a Rotel 970 at 100R and....well it just doesnt seem to work.

Ali: Waaaay too much work and expense! :doh:

Scoobs: Probably...but I think there's something else wrong...

Richard: Now that's interesting...there is noticeable play in the yoke with lateral rotation of the arm...I can feel some play when slightly twisting the arm tube...I'll investigate more tomorrow.

DSJR

03-07-2009, 06:52

Take great care with bearing adjustments. If my 701 is anything to go by, MC carts take no prisoners and chatter can ruin an otherwise good sound. I had no "rock" but there was the tiniest bit of vertical play if the horizontal gimbal was held and firmly rocked up and down. Adjusting this out and adding a tiny drop of fine clock oil cured this completely (and improved arm friction too..) but I'd hesitate in your case as spares will be impossible to obtain for the PL71 (there's tons of Dual bits around and I have a spare "bitser" from Shane - thanks again sir! :)).

NRG

03-07-2009, 08:22

I've checked again, a bit more closely this time and there's no play in the vertical pivots...but there is slight play in the horizontal arm bearing. Not sure if there is any way of adjusting it...

NRG

03-07-2009, 10:52

I've reinstalled the 103R and gone back over everything with a fine tooth comb...careful attention to setup up pays dividends...its sounding much better now and as Richard said the 103 does match this arm very well. I did find though that the VTF dial on the arm is not very accurate and think this was the main cause of my previous dissatisfaction, on my deck it under reads by about .4gram so I was previously tracking near 2.9gram.... :doh:

Magna Audio

03-07-2009, 12:17

That's good.
I've got a 33 PTG but a 103 is a consideration for the future.

I've always use a Shure VTF balance so not bothered with the build in guide thing.

Have you noticed any RPM accuracy issues when playing / you touch the on/off buttons. Mine needed two new micro switches from Maplin for £3 - sorted.

speakers-1989

03-07-2009, 13:20

Has the PL-71 ever been compared to a Roksan Xerxes?

NRG

03-07-2009, 13:51

I've never compared it so can't comment...

Steve, I'm looking at two new micro switches at this very moment... ;)

WikiBoy

03-07-2009, 16:01

I've never compared it so can't comment...

Steve, I'm looking at two new micro switches at this very moment... ;)

I have - belt drive warble v DD stability is the main change, but the Roksan is one of the better belt drives, far better than a Linn.

I should get a couple of those switches for one of my units as those on it are a bit intermittent. Give me a heads up on the part number / URL / what have you. Save me looking for it.

NRG

04-07-2009, 07:54

I bought Maplin GW71N...these are different to the ones I removed. The old one has all three terminals on one end of the switch with the center terminal being the common one. http://www.maplin.co.uk/Module.aspx?ModuleNo=6453

With the GW71 the common terminal is the lower one (belly)...because of this I had to modify the mounting bracket so they would fit...also the normally open and normally closed terminals are opposite on the GW71.

Dave Cawley

04-07-2009, 09:47

If you scan on at 1:1 (on a chepo flat bed scanner) and let me know the functionality I will get some for you. I had to do the same thing for the SP-10. You would not believe how many versions there are..............

Regards

Dave

NRG

04-07-2009, 10:22

Will do Dave, later today.

Shuggies 1210 thread has got me thinking of a DIY PSU for the PL-71...based around a 317 pretracking cct and external TX...should be straight forward to do.

NRG

04-07-2009, 17:06

http://i94.photobucket.com/albums/l82/_NRG_/other/Micro_switch.jpg

Magna Audio

04-07-2009, 21:33

I used the same
http://www.maplin.co.uk/Module.aspx?ModuleNo=6453

Std-Microsw GW71N £1.49

I did not need to modify anything?!

Need to observe the contacts are in different places from the originals though.

Dave Cawley

05-07-2009, 09:53

NRG

05-07-2009, 11:07

Well, you have me flummoxed! The nearest I can find is here (http://panasonic-denko.co.jp/ac/e/control/switch/micro/tarcoiz-v/index.jsp), but it's a sealed one and not really the same. So use the Maplin one and re-wire it?

Yes an external PSU would be beneficial. But the mistake would be just to wire it in without analysing what is happening. I can't find a circuit; that would really help?

Regards

:bag:

Dave

Yep! Hence the Maplin one!

Mr Pure Sound very kindly posted the PL71 SVM here, second from the bottom...

http://www.mediafire.com/?sharekey=4d91587e02cfe0f75bf1f12f1ff3f30ae04e75f6 e8ebb871

Dave Cawley

05-07-2009, 11:16

Well done Guy! :kiss:

Yes an external 18V DC PSU should work well. I would like to see the actual motor control circuit though first?

Regards

:bag:

Dave

NRG

05-07-2009, 11:49

That I don't have Dave...I'll go-ahead with the supply I have in mind...

Many thanks!

NRG

07-07-2009, 09:41

Parts for the tone arm rewire have been orderd, gone with the Geo Cardas arm wire from Partsconnexion and some low cap cable from Maplins.

NRG

08-07-2009, 11:42

'scoped the 18v line of the PSU today and found the rail to be noisy and the DC level bouncing around...I've recapped the supply already so either there is a problem with my unit or it works this way.

So I knocked up a simple 317 regulator and fitted that using the rectified o/p of the existing board, bingo...2.5mv of ripple and rock steady.

I'm going to push on with my regulator cct idea and tweak the psu a little....PL-71 PSU 'NRG' anyone...£199 inc delivery ;) :eyebrows:

Marco

16-07-2009, 12:03

NRG

16-07-2009, 20:35

Sounds good, Neal. I'm sure that there would be a market for it! :eyebrows:

Interesting on pfm that Mr Dunn seems to think that you've got a duff PL-71, simply because he considers the stock PSU (and overall design) as being "just so sorted as is", and therefore unable to be improved, rather than the other obvious *possibility* that you've simply been able to implement more effective modifications to it than him! ;)

And he accuses me of having a superiority complex... :doh:

Marco.

That's interesting Marco, could you direct me to the thread?

I've now got the pretracking regulator cct running along with some Sckottky diodes and the speed stability seems way better than before. Sure there could be an issue with mine but I belive the changes I've made would improve on the original anyway....

The arm cable has arrived and I hope to re-wire the arm some time soon....also got my eys on a Uwe wood body for the DL103r but I've seen the admin over on LencoHeaven has an aluminium version that may offer a completely different presentation to the Uwe body....hmmmm...decisions.... :scratch:

Marco

16-07-2009, 21:21

Hi Neal,

Observe post #253:

http://www.pinkfishmedia.net/forum/showthread.php?p=867387#post867387

:)

I'll get to the rest of your post later - bit busy just now.

Marco.

NRG

16-07-2009, 21:42

No problem, replied to RD, thanks!

Marco

16-07-2009, 21:57

I've noticed... Btw, I'm not "stirring" anything; just making valid observations ;)

He always backtracks when you expose the hypocrisy and his ever-present double standards! :eyebrows:

Anyway, keep us all posted on the results of your mods.

Marco.

DSJR

18-07-2009, 11:55

I thought Richard had already tried an external supply and couldn't really justify it..

Don't always assume that the original designers didn't know what they're doing. They might just have done and worked the compromises just right without fully being aware of it. I doubt the PL71 has as tetchy a servo system as the current quartz locked technics system - it's probably a far gentler system as my SL150 has, little to no slowing under load and little to no overshoot on correction as a result.

Marco

18-07-2009, 12:38

Hi Dave,

That wasn't my point. He hears what he hears, but he makes the mistake (exactly as he accuses me of doing) of presenting his experiences as fact, or attempting to discredit/demean the contrary findings of others to satisfy his ego...i.e, Richard always knows best.

It was the presumption that just because *he* couldn't detect any benefit from upgrading the PSU in the PL-71, even though Neal could, that it therefore seemed likely Neal had a 'duff' one, rather than the possibility Neal had successfully implemented an improvement where he couldn't.

It's the irony/double standards that get me, and the fact he refuses to see that he acts in precisely the same way as he accuses others of doing. Blinkered doesn't even begin to explain it! :mental:

Marco.

DSJR

18-07-2009, 21:34

NRG

18-07-2009, 23:53

Well Marco, this is where measurements could help see if Neil's preference for an external supply helps the motor unit to do its job better, as Dave Cawley has shown with the regulating upgrade to the SL1200. As I understand it, the upgrade smooths the servo operation and this is audible.

Many of us in the industry probably come across as opinionated in the extreme. All of us have different rooms and different systems tuned to them, and the lack of objective testing means that we're all experts in our lunchbox sized lounges........

Just my tuppence worth.....

...but I did measure it. I found the DC level was pulsing and there was a lot of noise...now it could be faulty and I'll have another look at it this week sometime....the original supply has been recapped and it sports new Schottky diodes...there maybe other issues, however, the regulator cct its now running from dosen't exhibit these issues and it sounds damm fine. Also I'll add a switch to change between the two supplys so as I can A/B test between the two.

Dave Cawley

19-07-2009, 07:52

There is a fundamental problem with the SL-1200 that is easily fixed by a new PSU that is; properly designed, properly implemented and properly fitted. The problem is that we cannot measure a new PL-71 as they don't exist. To be pedantic one could re-build the power supply using new but original value/type components, and then measure it on and off load.

This would be an interesting but potentially fruitless exercise................ :kiss:

As I said earlier, a well designed external power supply is bound to help the PL-71, but like the SL-1200 it has to be done properly and measured. One cannot arbitrarily attach a power supply any old how, it could make it worse. I keep a file on everything I do, the original measurements, comments, thoughts and paper/digital copies of scope traces with values. Then when improvements are made they can be quantified. I learnt this philosophy whist working as a senior design engineer for Philips in the 80's.

Regards

:bag:

Dave

Marco

19-07-2009, 10:33

Exactly, Dave.

I'm sure that the PL-71 is a reasonably 'well sorted' design, as this is what reports appear to indicate, however I'm also sure that just like every other deck on the planet, it can be improved by someone with the right equipment and know-how.

The problem is that we cannot measure a new PL-71 as they don't exist.

This is the problem I have with vintage T/Ts - one can never know if examples bought from Ebay, and the like, are functioning at 100% of their original capacity because, as you've pointed out above, there is no true 'benchmark' from which to judge.

It's what in the past has put me off buying an SP10, as unless I could guarantee that what I was buying was functioning 100% optimally (as if new) I wouldn't be interested in using it. Fortunately, with regard to SP10s, you're in a position to rectify that situation ;)

Quite clearly though, the PL-71 is not as "sorted" as Mr Dunn thinks it is, and the results of the bake-off yesterday at Flatpopely's (as reported on pfm) have thrown up some interesting observations. EMTs are clearly very special beasts. They're not new to me though; I've been a long-time admirer, so when I do move from my Techy I'll have to weigh up very carefully which way to go between obtaining an EMT or going for one of Dave's fully refurbished SP10s... That'll be a very interesting one when it comes!

In the meantime, I simply must get to hear a PL-71 for myself (probably Neal's at the forthcoming Owston fest) so I can form my own opinion and see how the Techy stacks up against it. It's also unfortunate that neither of the recent bake-offs featured a modified SL-1210 of any description, least of all one which I would consider as 'fully sorted', such as the likes of Martin T's or my own. Hopefully this situation can be rectified at Shuggie's forthcoming bake-off, if a mutually suitable date can be arranged, and that someone with a PL-71 is able to attend, too :cool:

Marco.

Marco

19-07-2009, 11:53

One other point I'd like to make regarding the bake-off results is that it should now be obvious to everyone how little genuine progress (if any) has been made in terms of turntable design since the days when SP10s, Garrards and EMTs were produced, as all three came at the top of the listening tests when put head-to-head with their modern counterparts. This confirms what I've known for a long time.

I believe that Andrew (Flatpopely's) LP12 sounded very good (in its own way), but then so it should considering that it had £2k+ Keels, and goodness knows what else, fitted to it. It would be interesting to know how much money the respective T/Ts cost between Andrew's LP12 and Lindsay's used EMT, which just goes to show how good a sound one can obtain for not massive amounts of money*, and a little lateral thinking (which I keep banging on about)! ;)

The other interesting point to note between the two recent T/T bake-offs is how well and how different the DL-103 performed, once on a Garrard/Rega and then on an EMT combo. On the former, the 103 was reported to have performed well, but at the same time was considered to have been rather "raucous" in comparison to other much more expensive designs.

However, on the latter, (which I would consider as a much more optimal combination, due to the high-mass EMT arm being a much better match), the 103 appears to have transcended its humble origins and competed admirably with its more illustrious competitors, allowing the EMT to win the bake-off even when arguably 'hobbled' by such a 'lowly' cartridge. Quite simply there is no way that the EMT would've won had the 103 sounded "raucous" or markedly inferior to the other cartridges used.

This proves, as I've always said, that it's the sum of the parts, not the individual components, and synergy, that matter most when assembling a vinyl replay system, just as it is in any other area of hi-fi. It also shows that when the 103 is set-up and partnered properly it can easily compete with the best in the areas where it excels - and one should remember that this was a stock model, not even an 'SA' or one of the other 'pimped' versions!

Hopefully all this will have sunk in and provided a few learning experiences, not only for those who attended both bake-offs, but also everyone reading the reports on pfm.

Marco.

* {Edit: I've just noticed that Lindsay paid £2000 for his EMT on Ebay, which is effectively less than Andrew paid alone for his Keel!!!} I think this puts things rather succinctly into perspective............. :eek:

NRG

19-07-2009, 14:10

Exactly, Dave.

I'm sure that the PL-71 is a reasonably 'well sorted' design, as this is what reports appear to indicate, however I'm also sure that just like every other deck on the planet, it can be improved by someone with the right equipment and know-how....................

.............In the meantime, I simply must get to hear a PL-71 for myself (probably Neal's at the forthcoming Owston fest) so I can form my own opinion and see how the Techy stacks up against it. It's also unfortunate that neither of the recent bake-offs featured a modified SL-1210 of any description, least of all one which I would consider as 'fully sorted', such as the likes of Martin T's or my own. Hopefully this situation can be rectified at Shuggie's forthcoming bake-off, if a mutually suitable date can be arranged, and that someone with a PL-71 is able to attend, too :cool:

Marco.

Agreed Marco. I'd also like to point out my PL71 sounds nothing like the description on PFM, they could be describing a deck from Mars as far as I'm concerned because it bares no resemblance to mine... pre or post tweeks.

I'll bring it to Owston and try to make Shuggies event if invited.

I re-measured the supply again and I've not changed my thoughts, the OEM supply has a 20mV 'bounce' and a lot of noise...the new regulator is clean with some 'ripple' under load but it looks like dropout...I'll try and post a'scope pic later for Dave to have a look at.

I've also fitted a switch to change between the two, can't really get any time to listen today but a very quick A/B indicates the new cct is bringing out more detail and depth than the original...

Ammonite Audio

19-07-2009, 15:43

.....I'll bring it to Owston and try to make Shuggies event if invited....

I've proposed a few dates on my SL-1210 Blog thread for the DD 'table bake-off, and you'd be very welcome to come along. As an aside, my Paul Hynes SR3 PSU can be adjusted down to 18v, so it's something that you can try with your PL-71 if you wish.

Cheers

Marco

19-07-2009, 17:08

Hi Neal,

Agreed Marco. I'd also like to point out my PL71 sounds nothing like the description on PFM, they could be describing a deck from Mars as far as I'm concerned because it bares no resemblance to mine... pre or post tweeks.

I know exactly how you feel. It's the same for me when I read people describing the Techy (even when modified) as 'unmusical', 'grey-sounding', 'tuneless', etc! :lol: :eyebrows: ;)

It just goes to show how significant the all-important synergy thing is!

Anyway, it'll be most interesting finding out more about each other's decks either at Owston and/or Shuggie's bake-off :)

Marco.

NRG

20-07-2009, 20:51

I've now had a good listen between the original and my new regulator. The new is clearly better, it makes the music come more alive, everything has greater clarity and seperation...dynamics seem to be slightly better as well. Not bad for a few £'s worth of components.

NRG

09-10-2009, 10:15

How time flies!

I've been looking for a replacement or close replacement for the knackered OEM mat my PL-71 came with. Found something very similar on Ebay, don't know what deck it came off or who made it but its similar in layout style as the OEM, about as thick and a bit more floppy than the one I've been using. The OEM one is like a bit of old stiff cardboard with cracks all over it. :( so can't compare directly...$18....

Used it with my crockery anti-slip top mat and re-adjusted the VTA to suit, ah! A small step forward, the groove factor has increased....can't put my finger on exactly why but this is better and more enjoyable than before.

This is really turning into an excellent deck, it may not be the best in Hi-Fi terms but its very engaging, I use it far more than the SP10. Only got the arm to rewire now and I think it's 'done'!

:gig:

Magna Audio

15-10-2009, 20:31

Good stuff.
I have tried other mats and prefer the PL-71 one. That is both on the PL-71 and the SL-1210.
I am using the SL-1210 now but will PL-71 arm and mat and it just works well for me...

I'd be interested in your arm re-wiring as that is one area I have not done yet. Do let us know how it goes.
I was thinking of using Litz tonearm wire as used on the Terminator series of arms.

Did you guys ever get together for a DD bake off?

Marco

15-10-2009, 21:40

Hi Steve,

Neal and I compared his PL-71 to my modded Techy at Owston, and had great fun doing so :)

I think that Neal would agree with me in saying that the Techy was overall better (I can go into a bit more detail here if you wish), but for me the real eye-opener was just how bloody good the PL-71 was as standard!

I can quite easily understand now how some people would prefer it to a stock or even (in some ways modified) Techy. It took my completely maxed-out and 'holistically' modified 1210 to beat it - and even then the difference wasn't huge.

Who knows how good Neal's PL-71 would be with, say a Jelco SA-750D fitted, or some other high quality aftermarket arm, instead of the stock Pioneer one (which is actually pretty good in its own right)?

Marco.

NRG

16-10-2009, 07:48

Marco

16-10-2009, 07:56

Indeed, Neal. If you can find one, the PL-71 is an astonishing bargain.

I wonder though how influential the regulator mods you've done to it are compared to how the deck performs as stock?

Have you abandoned plans then for a new arm? As much as I rate the Pioneer arm (and I do, quite highly, actually), I'm very confident that the Jelco 750 would eke out even more performance from your superb wood-bodied 103 :)

Btw, that was something else I was very impressed with at Owston. The difference between your wood-bodied 103 and my 103SA was I thought fairly subtle.

Was the original donor cartridge a standard 103 or a 103R?

Marco.

NRG

16-10-2009, 08:07

The regulator mods help Marco, we didn't try this at Owston, I had fitted a switch to flick between standard PSU and my regulated one....using the standard supply would have made the gap wider between decks...we where listening to my supply.

Jelco...hmmmm....yes! I'm still eying them up but would probably get one for the SP10....I like the '71 the way it is with its 'low rent' look but solid performance :)

I liked the SA, thought it sounded very 'together' with no obvious problems....is it a rebodied 103R but from Denon? My donor cart was a 103R.

Marco

16-10-2009, 09:21

That's interesting, Neal, especially in respect of the regulator mods. That gives me a better idea now of how much the PL-71 has to offer as standard.

I take your point about the SP10... It’s probably best to leave the Pioneer 'as is' and put the Jelco on your better T/T. I suspect that fitting a 750D and your wood-bodied 103 to the SP10 would pay some serious dividends ;)

I'm glad that you liked the 103SA. It sounds very "together" I think because it's ideally partnered, and also because the plastic body-shell of the standard model has been discarded.

This, in my experience, is the main drawback of the stock model much more so than the effect of its 'old fashioned' conical stylus, which when partnered with the right high-mass arm and headshell is ameliorated significantly and thus reduced to the status of negligible importance. The plastic body-shell of the stock model is simply much too resonant, and this severely sullies the signal it gives to the SUT and/or phonostage downstream.

I suspected that your donor cartridge was a 103R because I could hear the effect of the OFC internal wiring, which lends it a clearer, more precise, sound. However, different materials of body-shell impart their own sonic signature, and for that reason there was a slight difference in character between your cartridge and mine (the respective body-shells are essentially the only difference). Koetsu have cleverly utilised this effect for years with their designs using various different exotic materials.

You've heard a standard 103, and you've now heard what your wood-bodied version and my 'SA' sound like, so it just shows what the serious potential of this cartridge is when suitably fettled and partnered sympathetically :)

I'm not sure if you'll agree, but I much preferred both Denons to your Kontrapunkt (B?) - and look at the difference in price! I reckon that the way I have my 103SA set-up (with the A23, Jelco, etc) it's as good as any cartridge up to £2k - certainly in the areas that matter most to me.

Marco.

P.S I thought that the M3D was none too shabby either!

Hypnotoad

21-10-2009, 03:13

:) Yes that's a fair comment Marco. The PL-71 got close but the techie was better. Bear in mind the price difference though! £120 for the PL-71 vs ? My new unidentified rubber mat (URM) has improved the '71 since then and I've finally banished a slight tendancy for siblance using it along with some tweaks to the wood bodied 103R.

Yamaha's are very good also in this regard.

I had a friend with a HiFi boutique and he always said put a good Denon cart in a good Yamaha table and you have a first rate source for a fraction of the cost of the big boys.

I listened to one connected to a Denon step up transformer, a Harman Kardon pre/amp and a pair of Janszen electrostatics.

It gave you goosebumps it was that good.

NRG

12-04-2012, 22:01

Appologies for resurecting an old thread but I wanted to bring it up to date.

I’ve been using the PL-71 on and off for the last few years and its been wonderful with my improvised PSU.

I’ve had a nagging doubt though that I could do better so over Easter I’ve been tweaking and refining the PSU.

Firstly I wanted to improve the stock supply and then use it to power an improved version of the pre-tracking regulator supply I’ve used up until now.

The stock suppy is below:

http://i94.photobucket.com/albums/l82/_NRG_/other/PL-71_PSU.jpg

It provides a rough 18v to the motor with about 30mV of ripple under load. I wanted to improve it as a stand alone supply even though I don’t use it as such. The first improvement I made a few years back was to fit some 1A Schottky diodes and recap the supply. The diodes have stayed but I’ve replaced the caps with Panasonic FC types, C101 is now 2200uF and fed from a 10R resistor (I cut the PCB trace and installed the resistor under the PCB. This adds a low pass filter at about 10Hz. 2200uF was all I had to hand a higher value may work better.

The resistor drops no more than 2v. Next C102 was replaced with a 100uF Panasonic as was C103. The Zener D105 sets the output voltage and to get better regulation I replace this with a TL431 precision shunt regulator in the following config:

http://i94.photobucket.com/albums/l82/_NRG_/other/PL-71_TL431_Zener.jpg

To give the following pre-tracking regulator enough head room for 18v I set the output volts at 25v by setting the top resistor R1 to 90K and R2 the lower to 10K, the formula being ((R1/R2)+1)x2.5. In reality it worked out at 24v under load. If there where no pre-tracking circuit then a 62K/10K pair could be used to get 18v out. I built the resistor network up on the top side of the PCB.

The result was a very steady output with no more than 2.5mV peak of noise…a huge improvement from standard.

For the pre-tracking regulator I refined what I was using by followed the suggestions on Acoustica.org… IE: using ordinary ‘lytics , adding a 1R damping resistor to C2 and replacing R4 with a 16.2v Zener and series Schottky diode to give a spot on 18v under load. I had already been using a green LED to set voltage for the first regulator.

http://www.acoustica.org.uk/t/images/mc-tpr.jpg

The beauty of this cct is in its simplicity...the first regulator deals with ripple rejection from the power supply and the second benefits from a clean feed and deals with regulating the load.

The result is a rock steady output with very low noise all from off the shelf cheap regulator parts. It may be possible to improve things further by using some LDO regulators...the next step would be an expensive jump to an all out discrete design.

How does it sound? Well it’s a shame we can no longer post needle drops as a listen would explain it better than I can. It’s simply better in every respect, timing, Bass extension and clarity, greater depth, midrange detailing, more air around vocals and better separation etc. etc. It’s moved the deck on to a whole new level, well worth the effort. :)

oceanobsession

13-04-2012, 23:13

NRG

14-04-2012, 08:55

Hello neal, is the psu still part of the turntable or now a seperate item, did you rewire the arm and has it improved things,you talk about ripple do you
have to have a scope to test for this, ive also got a pl71 so im interested in
any improvments, cheers phil.

Hi Phil, I've still not rewired the arm :doh: I really must get around to it. The PSU is still in the deck, I suspect moving the transformer out may improve things further. Yes I have a 'scope plus other test gear...would be lost with out it! No other way to see whats really going on.

walpurgis

19-04-2012, 18:15

Looks very nice Neal. I think you know what the problem is as you've already stated your intention to re-wire throughout! (from cartridge to phono input?)That's what's holding back the sound. The 103R is familiar to me and should work fine in the PL-71 arm without extra mass. The plinth would benefit from extra internal bracing/damping, as its a bit resonant. I've got the PL-61, similar, but belt drive with a wopping great Hall Effect motor instead. It appealed to me as a maybe belt drive 401 beater. Cheers, Walpurgis (Geoff).

NRG

25-04-2012, 16:43

Finally got around to doing the re-wire, been putting it of for years! ;) Now I know why..... its a PIA! I used the existing wires as a pull through but broke the first I tried until I worked out I needed to create a loop of wire at the arm gimbal and then tease the wire through, I suspect some sort of grommet in the arm.

Soldering the wires was fun, I got lucky the pins at the headshell end are sprung and the white plastic melts as soon as any heat gets near it :eek: so I used an old head shell to sink away heat from the pins but I still needed to be quick! Anyhow its done, I need to remount the arm and set VTA then before I can have listen...maybe tomorrow, I need a stiff drink first!

Its not possible to do this with the arm on the deck. Note small packing strip.
http://i94.photobucket.com/albums/l82/_NRG_/other/PL-71/IMG_0214.jpg

Loop of wire needed at the gimbal to get a better pull angle down the arm tube.
http://i94.photobucket.com/albums/l82/_NRG_/other/PL-71/IMG_0211.jpg

The original wires where very neatly soldered, by the time I got to the last I was as good as the original, 2% silver loaded solder used.
http://i94.photobucket.com/albums/l82/_NRG_/other/PL-71/IMG_0210.jpg

sq225917

25-04-2012, 17:30

Neal, do you not think you'd be better off with a different motor rather than refining a PSU where the accuracy is utterly swamped by the motor cogging? Maybe the addition of some drag would help smooth the PL71 out.

oceanobsession

25-04-2012, 17:51

Hello again neal, i have also thought about a few mod's , a paul hynes power
supply SR3-18 which is externally adjustable between 12-18vdc, i think the
drive motor is 18v dc, so this could be fitted as an external power supply.

The little piece of what looks like copper at the end of your tonearm tube is
that where the black earth wire connects and joins one of the earths from
the cartridge, did you replace this wire also, after you removed the screw
from the end did it come out ok. cheers phil.

NRG

25-04-2012, 19:06

Hi Simon, yes I think you're right but what motor? and how much would it cost and what sort of a headache would it be to fit? Tinkering with the PSU is cheap but I'm open to any suggestions....

Hi Phil, I'm sure a Paul Haynes supply would be fantastic but its not cheap! :eyebrows: I have a plan to relocate the mains TX outside the deck and maybe add a bit of magnetic shielding under the deck.

That little bit of copper or whatever was not attached to anything, theres no hole or solder connection or evidence of any wires connected to it. The black earth wire for the arm is connected at the bearing end somewhere. When the grub screw is undone a bit of force is needed to remove the plug, its a tight fit.

oceanobsession

25-04-2012, 19:26

Neal ive got plenty of thick silicon for the damper if you need any 300000cst
works a treat . cheers phil.

NRG

28-04-2012, 10:09

Cheers Phil, I'm away on business over the next few weeks so maybe drop you a PM when I get back, the damper on mine...well...doesn't!

So the arm is back on the deck but before I remounted it I decided to check the main horizontal arm bearing, there's always been a small amount of play and I thought there may be a way to reduce it.

Removing a couple of grub screws allows the arm to be separated like this:

http://i94.photobucket.com/albums/l82/_NRG_/other/PL-71/IMG_0218.jpg

A close up of the bearing assembly:

http://i94.photobucket.com/albums/l82/_NRG_/other/PL-71/IMG_0219.jpg

Theres a top and bottom ball race and cone running in a main cupped sleeve as can bee seen from the break down. Theres a brass collet on the bottom race thats threaded and secured by a grub screw allowing for adjustment of the play. The bearings are dry and mine where reasonably clean but some lint and dirt was present so an easy job to clean. I also very lightly oiled each ball of both races with some watchmakers D5 'grease'.

http://i94.photobucket.com/albums/l82/_NRG_/other/PL-71/IMG_0217.jpg

The cupped sleeve:

http://i94.photobucket.com/albums/l82/_NRG_/other/PL-71/IMG_0216.jpg

Oil was watchmakers D5 'grease', one small drop applied to each ball using a yellow oiler:

http://i94.photobucket.com/albums/l82/_NRG_/other/PL-71/IMG_0215.jpg

A view of the anti-skate adjustment:

http://i94.photobucket.com/albums/l82/_NRG_/other/PL-71/IMG_0220.jpg

Adjusting the bearing was straight forward, theres still a tiny amount of play but this ensured low friction movement of the arm. Balanced out the arm moves with the slightest puff of air or being brushed with a small bit of paper.

How does it sound, well the effort was worth it. Before there was always a slight hint of congestion when the music got complex with some loss of detail and separation now theres a sense of better separation and the presentation appears more relaxed and the music laid out more coherently...if that makes sense. Its definitely approaching my SP10/SME309/KontraB in terms of detailing but without that slightly detached analytical presentation.

Next on the list will be some shielding under the platter, on the motor and around the TX oh and I've found a pair of Eichman bullets so they'll go on over the weekend....and I want to investigate thicker oil for the main bearing as Simon suggested.

oceanobsession

29-04-2012, 20:51

Neil pm me your address and ill send you some silicon, i also had play in the
vertical bearings, had to unsolder the wires from the tag board, to remove the arm, i set it up by feel, but after reading a bit on the net it would seem
you use a piece of paper to push the arm noting the bend keep taking the
play out the bearings until that paper bends more stop there and tighten,
i noticed a big increase in performance also loads more fluff on the needle.

Canetoad

13-05-2012, 10:57

Neal,

Thanks for the details for adjusting the tonearm bearings. :) I've found that my tonearm has exactly the same problem.

Is it important what lubricant is used on the bearings?

I'm also curious about your PSU mods but, being a novice, I'm not sure exactly how to implement the changes you have outlined. Is the regulator circuit a direct replacement for the diode in the original, or is it modified to suit?

I'd like to first improve the existing PSU performance before going any further. I've already replaced the caps in mine, which has improved speed stability. Any further details you could give would be greatly appreciated. :)

NRG

13-05-2012, 15:25

Hi Bernie,

I dont think the oil is critical as the amount I used was tiny, think pin head sized drop and from what I observed they looked to be assembly dry anyhow... Extremely thin oil may not be a good idea but anything that clings well and not 'migrate' would do. You still need a small amount of 'play' for the arm to swing freely.

My PSU is just a tweaked and optimised pre-tracking regulator circuit based around standard 3 pin adjustable regulators although I recently replaced them with LT Low drop out version which seem to perform better. This is bolted on to the output of the standard PSU, the output is tweaked to give approx 24v into my regulator cct.

You can tweak the standard PSU alone for better performance, I published the details further up thread...mine now has an additional RC stage (2 now) to lower ripple further and I use Schottky diodes in the PSU.

So the layout is Rectifier >> RC >> RC >> Series pass regulator with TL431 voltage reference. I may, if I can build up the enthusiasm, try a shunt regulator at some point but at this stage the I think there's other tweaks I'd like to try first.

NRG

21-06-2012, 07:43

I've now gone balanced into my SUT from the PL-71. Was running unbalanced previously and not give it a second thought.

The greatest tonearm cable thread got me thinking so I did a little bit of digging on Vinyl Engine and discovered this thread:

http://www.vinylengine.com/turntable_forum/viewtopic.php?p=374577&sid=42ea7091f4fac39832959a6033319d07

I've implemented option 5 which is the same configuration SME use on my 309. I tried some Maplin Shark cable I had spare and found and improvement, greater sense of ease, midrange clarity improved and everything sounding more cohesive, however, having used the Shark cable before I knew it can sit on dynamics and hold back treble extension which is what it did here.

So its been replaced with some VanDamme Silver plated LOFC cable and its made a vast improvement, its very natural sounding, good treble extension and a sense of more air and depth to recordings. A really good result.

Not much more I think I can squeeze out of the old girl, well, maybe one more thing I can do.... ;)

oceanobsession

02-09-2012, 08:19

Hi, i have just found this regulated 18v power supply

(http://www.amazon.co.uk/Adjustable-Regulated-Bench-Power-Supply/dp/B0056BHI9O)

would this do the trick.

I have also placed the turntable on four 30mm by 20mm sorbathane feet which has improved detail, the sprung feet on the pl 71 is of poor design, im
hoping to turn up four new aluminium blocks to mount the sorbathane on.

NRG

02-09-2012, 08:37

It would certainly work but it's a bit OTT if you ask me and not very small or domestically acceptable!

I'll post another update in awhile, made another change that seems to have improved SQ a bit more.

Marco

02-09-2012, 08:42

Your picture diary, above, Neil, shows the arm on the PL-71 to be remarkably well-engineered - much better than the stock Techy arm! :)

Marco.

DSJR

02-09-2012, 15:53

The distantly related Rega R200 uses similar horizontal bearing races I believe and Rega claimed the slight play was irrelevant since the races are gravity loaded, borne out on the PL71 arm by the cups which should prevent casual slop when in use.

NRG

07-09-2012, 09:41

So the latest mod to the deck was to replace the motor.

I've been experimenting with heavier spindle oils on the standard motor and there's been a small improvement in the polar plots (see the Turntable Speed Analysis thread on PFM)...listening tests revealed a slight improvement in sound quality...IE better separation and a touch more bass attack but the deck takes quite a while to stabilise from cold...the motor doesn't have much grunt and the oil in combination with a platter weight makes it struggle.

So I've been looking for a way to replace the OEM motor and came upon an Ebay advert selling a motor from a PL-55. It has better rumble and W&F specs than the standard unit and is a drop in replacement mechanically. Its also a hall effect speed controlled motor different to the pole detection original...still crude by SP-10 standards but better than the original.

It sits about 1mm lower so I've raised it on three washers to compensate. The fine speed adjustment wiring is different to standard so I've lashed up a speed change switch and two adjustment pots.

Using the same heavy oil it gets up to speed and settles within a few revolutions and stays there!

The polar plots show an improvement and listening test reveal quite a big change for the better. Bass attack and timing in particular stand out as does an improvement in separation and texture.

A good result, just one more mod to do and thats to move the mains TX outside of the deck...if I can stop myself listening to it!