Parts Help For My Pioneer PL-L1000A

I am new to this forum. I see there are lots of posts on my Pioneer Linear Tracking Turntable PL-L1000A. So I have to assume there may be some members here who are very knowledgeable on this turntable. I am the original owner of this fine turntable. I have had it in storage for at least 20 years. Now that the kids are gone it is time to bring it out and dust off the vinyl. It is near mint (my opinion). But age does take its toll. Rubber just does not last. The EV belt was gone. I found a replacement online. The “Rubber Cushion” (part number PEB-102) on the Stabilization Foot is cracking and falling apart. I have not found a replacement online. Can anyone tell me a source for a replacement or a suitable work-around? Is this rubber boot even needed? It looks like it is the spring that really provides the support and isolation. Any help will be appreciated!

Very common problem with the series. Dunno specifically what subs for the rubber part.

You can just leave them alone, since the bottom part is usually OK. Or, you can cut away the boot part, and replace it with a finger from a rubber glove. Or, throw the whole rubber part away and replace it with a suitably sized rubber o-ring or neoprene washer and glove finger.

I used electric tape and wrapped them just to keep them from tearing any more much when I take the TT apart service.

There is a resilient liquid coating for tool handles, dunno if a coat of that would do it but I don't see how it would hurt anything that isn't already in trouble.

dennismiller said:

I am new to this forum. I see there are lots of posts on my Pioneer Linear Tracking Turntable PL-L1000A. So I have to assume there may be some members here who are very knowledgeable on this turntable. I am the original owner of this fine turntable. I have had it in storage for at least 20 years. Now that the kids are gone it is time to bring it out and dust off the vinyl. It is near mint (my opinion). But age does take its toll. Rubber just does not last. The EV belt was gone. I found a replacement online. The “Rubber Cushion” (part number PEB-102) on the Stabilization Foot is cracking and falling apart. I have not found a replacement online. Can anyone tell me a source for a replacement or a suitable work-around? Is this rubber boot even needed? It looks like it is the spring that really provides the support and isolation. Any help will be appreciated!

Click to expand...

I went to the hardware store and bought neoprene O-rings for the top and bottom contact points.

As mentioned earlier, you may be able to use the bottom of the boots. The belt for the little motor should be around $5 or so. Replace it while you're rejuvenating your PL-L-1000.

Love mine, along with a Yamaha PX-3 and Mitsubishi LT-20.

Pioneer PL-L series & Phase Linear 8000 series suspension "Boots".

Hello all,

It's been awhile since I last posted. I've been very busy with turntable repairs.

What you are all referring to is officially known as a "Rubber cushion A" in the Pioneer service manual. The part number is 942-8040.

I have discussed this part already in another AK thread, so I'll try to add information instead of saying the same thing.

The function of the Rubber cushion A "boot" is threefold:
FIRST, (and most importantly), it provides a positively centered, geometrically stable, compliant seat for the spring.
SECOND, it provides a thin rubber sleeve that fits snugly over the spring to help damp spring coil resonances.
THIRD, the sleeve (when new only!) assists the spring by slightly increasing the spring rate. The effect of this is that the lower plinth will reside at a slightly higher position with a new boot as opposed to an old torn boot, and the fundamental suspension frequency will be slightly higher.

Since the amount of spring rate assist a new boot provides is probably quite low (you would have to do an analysis of the design to determine the actual percentage of this), it is probably safe to say we can ignore this factor especially since we can make up for the theoretical increase in downward displacement of the lower plinth with a higher pre-load in the form of a slightly thicker spring seat. The lower suspension frequency due to the lower spring rate of a dried out torn boot will be a welcome outcome anyway.

I hate to say it, but most of the Audio Karma advice I have seen (including the advice posted here in this thread) demonstrates a lack of understanding of this part. Remember, when it comes to these turntables (and the Yamaha PX series, and the Sony PS-X SLT series), I do not proclaim my opinions from the arm-chair, my advice comes from actually working on these repeatedly and carefully studying their idiosyncrasies and special needs.

First let's look at the advice for using an O-ring for the spring seat. Like I have already stated here "most importantly it provides a positively centered compliant seat for the spring". A typical round cross-section O-ring from the hardware store will not provide adequate lateral positive centering. The O-ring will tend to slip between the coils of the suspension spring and now the plinth looses its necessary centering. Of course, there is always the possibility that an O-ring will work in your particular situation (unlike me, you might have been born under a lucky star), but this is not the correct, thorough, and proper way to effect a repair that you can be confident and proud of.

Second is the less important issue of spring coil damping. Energy of all frequencies is doing its level best to ingress into your turntable from the feet and any other surface it can (nature abhors a vacuum). Frequencies higher than the fundamental resonance of the suspension spring/plinth mass combination will try to set the spring coil into a harmonic resonance condition. In addition, the primary fundamental resonance of the suspension will need to be tamed with some damping as well. This is what the sleeve portion of the Rubber cushion A does.

Now, if we take into account the fact that there is a substantial amount of wiring connecting the upper plinth to the suspended lower plastic pan plinth on a PL-L1000, we will understand that adequate fundamental resonance damping is already present. If we now look at the function of the sleeve at higher harmonic frequencies, we will see that a sleeve will indeed provide damping of the spring coils. How important is harmonic damping? This is a good question. If we assume that an attenuation of this harmonic energy will occur across the only path that this energy can take into the critical lower plastic pan plinth (the compliant and hopefully lossy spring seat), we can assume that the sleeve should be mostly unnecessary.

So the bottom line is:
1- Don't use a round or X cross-section spring seat. Use a square cross-section seat of suitable durometer and material.
2- If you must use a sleeve, use a sensible, stable, and compliant material/device that will not impede the free movement of the spring such as a finger from a thin rubber glove or even a condom. Keep in mind that latex is not going to give you eons of stable longevity. Again you can use a spring sleeve, but I don't think it is necessary.

Finally, what I would like to convey here is how important it is for audio forum posters to have their facts straight and to make the effort to thoroughly and properly understand the physics of whatever they are volunteering advice on.

There are countless cases where an innocent reader of a given thread implements forum advice only to break something or compromise the performance of whatever device he or she is involved with. Of course there are also many cases where forum advice was very helpful and my guess is the good advice is more prevalent than the bad. Let's strive to improve this ratio as much as possible.


Best wishes, Professor Bizzt

Professor, perhaps you can make a specific recommendation for replacements spring seats for the PL-L1000.

Pioneer PL-L series & Phase Linear 8000 series suspension "Boots".

Aerobat said:

Professor, perhaps you can make a specific recommendation for replacements spring seats for the PL-L1000.

Click to expand...

Hello Aerobat,

I have spent many hours researching potential part substitutes and sources for these substitutes. I volunteer much of my experience and time composing posts here on AK and I also occasionally reveal actual part numbers for substitute parts that are no longer available like the photointerrupters for the Yamaha PX-2 and PX-3 Sensor C. Boards. I have a personal and practical limit to this however.

After investing a fair amount of time with a certain manufacturer, I have a source for spring seats that work properly. I will be introducing it on eBay soon for no more than about 50% over my total cost for these items. So keep watching there.

There are some sellers on eBay selling audio parts at a massive markup, I am not one of those. It is more important for me to have quick access to the parts I need for repairs. There is a large minimum purchase for these seats and that has delayed this purchase. Hopefully (if I can stop giving people such good deals on my work!) I will soon have enough capital to make a purchase.

Back to the original question from Dennis Miller...
Dennis, from what I can see of your spring seat/boots, it looks like the seats are in OK condition and there is still life left on them. I would just cut off the cracked sleeve portion with a scissors and reuse the seats as long as the seats are not torn anywhere.

This advice also applies to anyone else (and most people are or will be having problems with their boots) as well. Just look at the pictures Dennis has provided on this thread, and if your boots look as good as his, just do what I have recommended here.



Best wishes, Professor Bizzt

Thanks everyone for all your advise and possible solutions. This is exactly why I joined this forum. A problem presented, a solution returned.

Professor, do you think a section of butyl bicycle inner tube would work as a substitute spring damping shroud in the meantime for those in immediate need?

Professor Bizzt said:

Hello all,
The function of the rubber cushion A "boot" is twofold. Most importantly it provides a positively centered compliant seat for the spring, and second, it provides a thin rubber sleeve that fits snugly over the spring to help damp spring coil resonances.

I hate to say it, but most of the Audio Karma advice I have seen (including the advice posted here in this thread) demonstrates a lack of understanding of this part. Remember, when it comes to these turntables (and the Yamaha PX series, and the Sony PS-X SLT series), I do not proclaim my opinions from the arm-chair, my advice comes from actually working on these repeatedly and carefully studying their idiosyncrasies and special needs.<<

>>>First let's look at the advice for using an O-ring for the spring seat. Like I have already stated here "most importantly it provides a positively centered compliant seat for the spring". A typical round cross-section O-ring from the hardware store will not provide adequate lateral positive centering. The O-ring will tend to slip between the coils of the suspension spring and now the plinth looses its necessary centering. Of course, there is always the possibility that an O-ring will work in your particular situation (unlike me, you might have been born under a lucky star), but this is not the correct, thorough, and proper way to effect a repair that you can be confident and proud of.

Second is the less important issue of spring coil damping. Energy of all frequencies is doing its level best to ingress into your turntable from the feet and any other surface it can (nature abhors a vacuum). Frequencies higher than the fundamental resonance of the suspension spring/plinth mass combination will try to set the spring coil into a harmonic resonance condition. In addition, the primary fundamental resonance of the suspension will need to be tamed with some damping as well. This is what the sleeve portion of the Rubber cushion A does.


So the bottom line is:
1- Don't use a round or X cross-section spring seat. Use a square cross-section seat of suitable durometer and material.
2- If you must use a sleeve, use a sensible, stable, and compliant material/device that will not impede the free movement of the spring such as a finger from a thin rubber glove or even a condom. Again you can use a spring sleeve, but I don't think it is necessary.

Finally, what I would like to convey here is how important it is for audio forum posters to have their facts straight and to make the effort to thoroughly and properly understand the physics of whatever they are volunteering advice on.

There are countless cases where an innocent reader of a given thread implements forum advice only to break something or compromise the performance of whatever device he is involved with. Of course there are also many cases where forum advice was very helpful and my guess is the good advice is more prevalent than the bad. Let's strive to improve this ratio as much as possible.


Best wishes, Professor Bizzt

Click to expand...

Hi Perfessor...

When bought my PL-L1000 4+ years ago, the boots had disintegrated in the Nevada desert air of it's former home...it also carried some of the desert with it to Georgia.

Alas...I never came across your PL-L1000 thread, but I was a newbie then. (still am). My research here, and the service manual, told of the function of the boot over the coil. another AKer suggested the rubber glove fingers/condom over the spring, and the neoprene rings. Ultimately, I elected to use the O-rings, as I was afraid that the rubber fingers wouldn't last very long, and I was unwilling to disassemble the TT every year or two to replace them.

Round rings were used, and one at the top has slipped once. I'll have to inspect the bottom rings that I used, but things "seem" stable for now.

I'll try locating a source of flat rings/washers, but a better idea seems to be to search fore the (direct??) replacements that you're getting ready to offer (soon, I hope) on E-Bay.

Regards,

Pioneer PL-L series & Phase Linear 8000 series suspension "Boots".

Pio1980 said:

Professor, do you think a section of butyl bicycle inner tube would work as a substitute spring damping shroud in the meantime for those in immediate need?

Click to expand...

Hi Pio1980,

You and I have discussed much on AK regarding turntables and I'm sure I don't need to convince you of how practical I try to be regarding these devices. If something needs to be changed or improved from factory spec, I will support that. If the evidence suggests an aspect to the design is unimportant and can be left alone or even deleted, I will lobby for that too.

Again, I maintain the sleeve portion of the Rubber cushion A (boot) is unimportant and can be deleted if it has decayed (and as you know, almost all these boots do). You just have to make sure the seat portion of the boot is intact. Eventually that will rot away too, but why worry about it if it is perfectly fine now?

There are so many other aspects of the PL-L and 8000 series that are more deserving of our attention, and I see no good reason to dwell on this one. I mean, don't you think it would be more fun to talk about the pros and cons of the Wankel engine compared to the reciprocating piston engine or something?


Best wishes, Professor Bizzt

Pioneer PL-L series & Phase Linear 8000 series suspension "Boots".

Harvey/ Ga said:

Hi Perfessor...
I'll try locating a source of flat rings/washers, but a better idea seems to be to search fore the (direct??) replacements that you're getting ready to offer (soon, I hope) on E-Bay.

Regards,

Click to expand...

Hello Harvey,

I don't think the original boots are available anymore. If they were, they would probably be listed on the Parts Store's website. I am not going to define or name the spring seats I plan on making available a "direct replacement". They will do the job well, but they will simply be a proper fitting and long life seat. I don't want anyone to think I will be introducing something that looks just like the original, because I am not. Again, please see my earlier posts to understand why I do not feel an identical "direct replacement" is necessary.

Of course it is inevitable that someone, somewhere, is paying attention to all this chat about needing spring boots and that person is going to play on the concerns of those who don't agree with me, and this person is going to find a way to produce these boots in Asia and sell them for a substantial markup to those nervous about this whole affair.

Oh well, it wouldn't be the first time audiophiles have spent too much on a whole lot of nothing....


Best wishes, Professor Bizzt

Professor Bizzt said:

..I maintain the sleeve portion of the Rubber cushion A (boot) is unimportant and can be deleted if it has decayed (and as you know, almost all these boots do). You just have to make sure the seat portion of the boot is intact....

Click to expand...

That's what I concluded too. My two 'tables have the rubber part on the ends of the springs as seats but the sleeve is gone, rotted away into pieces. Thinking about it, when those sleeves are intact, and the suspension springs are compressed slightly, those rubber sleeves are likely bowed out away from the springs, and not contributing much if any spring damping. I certainly haven't noticed any performance issues.

Replacement Pioneer spring seats are on the way!!

Hello everyone,

I have some good news!

I was finally able to place an order for replacement spring seats for the PL-L1000, PL-L1000A, PL-L5, Phase Linear 8000 Series II, and Phase Linear 8000A.

These seats may also fit other Pioneer turntables that utilize their coaxial suspension design, such as the PL-L800, PL-4, PL-5, etc.

Anyway, I expect to have these by 5/30/11, and I plan on putting them on eBay and perhaps the turntable classified section here on Audio Karma.


Best wishes, Professor Bizzt

Professor Bizzt said:

Hi Pio1980,
There are so many other aspects of the PL-L and 8000 series that are more deserving of our attention, and I see no good reason to dwell on this one. I mean, don't you think it would be more fun to talk about the pros and cons of the Wankel engine compared to the reciprocating piston engine or something?
Best wishes, Professor Bizzt

Click to expand...

Hmmmmm...just re-read this post, and...as an aside...we CAN discuss the merits of the Wankel vs the recip. piston engine. I have both in my model airplanes :thmbsp:

The Wankel that ate New York (and this thread).

Hi Harvey,

That would be great to know what you have to say about Wankels, but I have to admit that I find it mind bending when threads go off-topic.

But what the heck, aren't Mazda 787B race cars the coolest things ever?! And what about that Diasio D962R Turbo? Please, someone leave me one of these in their will.

Bad Professor for corrupting a perfectly good thread.


Best wishes, Professor Bizzt

To the "purists" out there or anyone interested in replacing the dry-rotted rubber boots in their Pioneer PL-630, PL-L1000, etc. turntables, I have created a small 2 cavity mold to reproduce the boots, including the groove where the spring gets enclosed. The parts are made from a 2-part silicone material that feels very much like the original boot. This boot isolates the spring from any other hard surface, dampens spring vibration as the original did, and as mentioned in this thread, provides the necessary centering of the spring in its seat. I have replaced the boots in my PL-630 and they work beautifully. If anyone would like a set of these boots, you can do a search on ebay for PEB-102 or PL-630, or PL-L1000 in either active or completed auctions and send me a note. I will make them to order or as time permits and post an auction when a set of 4 is ready to send.

Welcome to AK!

Nice to see a member with a skill he is willing to share.
.