Rega RP10 VTA shims

I am sure this applies to the RP8 as well. But I have an RP10 and bought two of the 2mm shims to accommodate the VTA of a Kleos cartridge. My dilemma is that the single shim does tighten the bass to where i prefer but the highs and mids drift from what I prefer. With both shims the highs and mids are, in my opinion, exactly what I want, but the bass control starts to slip away. Does any one know of a 3mm shim? I think that would bring everything into line. I will experiment with tracking force, but am reluctant to drift to far from 1.75 which was ideal on my old LP12. I looked at Acoustic Signature but this are drilled for the RP6 which uses a smaller screw. Also I am considering the Groove Tracer counterweight, but I really don't see that as the correct solution for this issue, but rather a tweak once the VTA is corrected. So my question is, anyone have an RP8 or 10 that has come across this issue and have you found a different supplier of shims for the Rega. I have thought about filing my extra 2mm down but realize I cannot maintain a perfectly flat surface.
Try these guys:

If they don't have it, maybe they can make you one.
Try adding a mat?
Even making a paper mat or mats to adjust the height difference to lock it in.
Then you could either look for the exact shim, or have one of your shims cut down to the exact thickness by a machine shop.
Or you might even like the mat.
Dear Theo: The Kleos was designed to have a vertical height (headshell underside to stylus tip) of 17.377~17.48mm with VTF applied. Let's say 17.4mm. I believe that the Rega cartridges are 14mm high, and Rega's tonearms and shims are designed accordingly.

IOW, you probably need to bring the base of the Rega tonearm up by 3.4mm to make the Kleos level.

If Rega cannot provide a custom shim for you, I would bring one of your shims to a machine shop. Ask them to caliper the inner and outer diameter, then have them make up a custom shim of 3.4mm thickness (if the machinist can make 3.43mm thickness, even better).

If you have a range of tonearm shims made to varying thicknesses, say 0.3mm apart (or even 0.1mm if the pricing allows you to make 10 or a dozen), you have a fairly predictable method of experimenting with SRA. Shims of more than 3.4mm thickness will result in tail-up SRA with the Kleos, and shims with less than 3.4mm thickness should result in tail-down SRA.

Or as Elizabeth said, you could install the two Rega-supplied 2mm shims, then add an LP mat of 0.6mm thickness to take up the difference.

hth, jonathan carr

PS. When changing the tonearm bearing height, recheck the VTF and overhang, and correct them if they have shifted.
Jonathan, Thank you so much for your response. I have found some shims that are available in .5MM increments.
I am planning to order those and set it to 3.5MM I realize that is just .1MM to high. But if I fand that the performace is "dialing-in" to an optimum sound, then I can
approach a machine shop and have a custom 3.4MM machined so I have a solid shim rather than a stack. I had thought about Elizibeths suggestion, but felt (no pun) that a thicker mat might effect the sound or benefits of the ceramic platter.
But this explains why I get better performance at 4MM than I do at 2MM, although at 4MM the bass was to muddled although deep. I am excited to try the 3.5MM and then narrow it to the 3.4 as budget permits.

Mr.Carr, your help and advice is greatly appreciated and invaluable to me and I am sure all Rega owners owning or seeking Lyra. Thank you very very much.

PS. I do have a question, what is your advice on de-magging
a Lyra, I see small metal filings, I have no idea how they get there playing vinyl, but I see them in my magnifing glass?
Theo -- can you tell us about those 0.5mm shims?
Drubin, here is the link;


I ordered today but upon further investigation, Gene Rubin appears to provide 4 shims whereas NeedleDoctor provides only 3 for only 4.00 more.
I am going to re-order once I get a confirmation from Needle Doctor. Unfortuneatley they are closed till Monday.

Also these are for a RP 6 and the RP8/RP10 use a larger screw, so I will need to drill the hole a little larger
but that shouldn't be much of an issue.
Dear Theo: Your idea to get as close as possible with the ready-made 0.5mm incremented shims to validate the SRA trend, then follow up with a custom job, sounds like an excellent plan to me. Good thinking!

I still recommend that when you have the custom shims made, you make a number of them in varying thickness, since not all LPs are of the same thickness.

>what is your advice on de-magging Lyra cartridges? I see small metal filings, I have no idea how they get there playing vinyl, but I see them in my magnifing glass?

"Demagging" or fluxbusting a ferrous-core MC cartridge is a low-level process intended to "reset" the magnetic alignment of the ferrous core (over which the signal coils are wound) to the magnetic field. Doing so will not exert any significant effect on the magnets or magnet yokes (unless the magnet is vintage Alnico or a similarly weak material), and will therefore not be effective in removing ferrous particles that have collected on the magnets or magnet yokes.

The ferrous metal particles that you saw with your magnifier exist in the environment (including the LPs and their sleeves), and are attracted to the very powerful magnetic field that energizes the signal coils. Any cartridge with powerful magnets (not only Lyras) will suffer from this to a greater or lesser extent.

The existence of these tiny ferrous particles is why we cover our private parts (aka gap and coils) with a pressed-paper "washi" dustcover. Other companies use a thin rubber skin (white, gray, black are typical colors), and so have we on occasion. But in our experience, the washi does a better job in allowing pressure waves inside the gap to dissipate, and sounds better.

That said, the cantilever moves in a big way when VTF is applied and removed, requiring that the hole in the front magnet (front yoke for other cartridge manufacturers) is clearly larger than the cantilever diameter. This leaves a ring-shaped space between the two. Over time, the aforementioned ferrous particles will find their way into this space and collect there, also within the gap.

So the washi (or rubber) dust cover slows down the ingress of the tiny ferrous particles, but does not prevent it completely.

When the amount of collected particles becomes excessive, it can hamper the movement of the cantilever, thereby impairing performance. We see these all the time on cartridges that are returned to us for servicing. Since the particles' ferrous composition causes them to adhere securely to the magnet (or yoke), they won't always come off easily. The best way to get rid of them is to clean them off carefully and thoroughly by hand.

We clean off this ferrous buildup, along with other grime that may have collected where it shouldn't be, as an integral part of our inspection and servicing program for any of our cartridges that is returned to us (caveat - the cartridge must not have been retipped or rebuilt by any other company). We don't charge for doing this.

OTOH, given the painstaking nature of the particle removal process, I can easily understand why companies such as Soundsmith or Andy Kim would perhaps want to ask payment for this.

In many cases, a thorough cleaning of the stylus, and / or the magnetic gap surrounding the cantilever, is all that a cartridge needs to sound pristine again. Of the cartridges are returned to us nominally because the owner feels that the stylus or suspension is worn or damaged, frequently the problem is stylus buildup that prevents the stylus from touching the LP groove properly, or accumulated ferrous particles that clog up the cantilever's freedom of movement.

BTW, if you have the opportunity, please read the following thread, from page 3 to the end.

It talks about the factors that affect cartridge loading, but unlike similar threads here on Audiogon, or the Kleos' user manual, there are frequency charts and test schematics which should give you a better visualization of what happens.

kind regards, jonathan carr
Mr.Carr, thank you once again for your insightfull response to my question. What an education, you have provided me and the readers of this thread. I had no idea all this was taking place inside the cartridge and that the process or service from Lyra was available to restore the cartridge's performance by the cleaning. I guess my next question(s)is, how long does this take and where do I send it? I wouldn't do this for a few months as the summer time seems to my lowest listening time of year. And I want to get the table fine tuned with the shims I have on order and enjoy it for a time before it takes a leave of absense.
Is this something I should do thru my dealer or can I send it direct, that latter being my preference?
Again thank you, you have provided a wealth of information of not only Lyra but cartridges in general.

Thank You
As a follow up, first off, a sincere expression of gratitude to Mr.Carr for his advice. I received and installed my 3.5mm shims and readjusted everthing accordingly last night. I was a little hard to get out of bed this morning as I couldn't stop listening last night.
This brought everything into focus, the bass is deep and controlled, the mids and highs have a very natural presentation. The sound stage opened up and lifted off the floor. I could go on and on, but the jest of this is, if you own a RP8 or RP10 and a Lyra Kleos, get the Acoustic Signature shims referenced above or have a custom 3.4MM shim made. I just wanted share my success story. By the way after years with an LP12 that was in perfect tune from the dealer, I am not looking back with any remorse. This RP10 equals and may exceed performance of that table. I am very happy and am picking up my new custom dustcover later today, as I am using this in the "skeletal" mode and have the plinth and dustcover packed away. Rega has realy outdone themselves.
Dear Theo: Lyra doesn't nominally provide a separate cleaning service, and heaven forbid were this the case! We are heavily backlogged in our production, and the single person who builds all Lyra cartridges is the same one who takes care of all servicing issues, including inspection and cleaning. If we were to provide a standalone cleaning service, we'd be even farther behind in delivering cartridges than we already are.

Usually what happens is that we get a cartridge back because it doesn't track properly, doesn't sound right, is a low-rider, or whatever. We will look at the cartridge, test it, listen to it, and take care of whatever is wrong with the cartridge, and that automatically includes cleaning. Unless the user specifically requests us to do so, we prefer not to perform any more deep surgery than is necessary to bring the cartridge back to good health, since doing so would take more time (thereby eating into our limited production time), and cost the user money.

In your case, the best plan would be to keep listening to your Kleos, and looking at it periodically through the magnifying glass. If the cartridge starts to sound decidedly "off", or if looking through the magnifying glass makes it appear that the magnet area is encrusted in black pepper or rare spices (smile), then send us back the cartridge.

Lyra handles any and all service issues through the dealer that you originally bought the cartridge from (or the national distributor). It makes life much easier for us when we can deal with bulk returns of a dozen or 20 cartridges at a time, rather than needing to write paperwork or visit the shipping depot for each and every cartridge.

With our present backlog in production and servicing, frankly it could take 8-10 weeks before we can turn an order around.

Normally we take care of service cartridges in the chronological order that we receive them, but it always helps us if the owner can write a memo describing what he thinks is wrong with the cartridge, and sticks the memo to the cartridge box (so that we can read the memo without opening the contents).

BTW, I strongly recommend preventative maintenance. While it may not be advisable to attempt any action about the ferrous particle issue, the stylus should be cleaned frequently. I can hear the buildup on the stylus after one LP side, and therefore I normally clean the stylus after each side. If I am feeling lazy, I may only clean the stylus after one LP.

Preventative maintenance will definitely extend the useful playing life of the cartridge, which we certainly welcome (as it lessens our workload), and I am sure that you do, too (smile).

As an aside, do you feel that the material of the shim affects the sound above and beyond the revised VTA? I wouldn't be surprised if a duralumin shim, brass shim, stainless steel shim all affect the sound in somewhat different ways.

kind regards and hth, jonathan
Hello Jonathan,
I completely understand that the servicing could become a problem of attracting "cartridge hypochondriacs" (grin), and further your production backlog.
As far as the shims metallurgy contributing to the performance, I don't know. The Rega shims are stainless steel and the Acoustic Signature look to be but have a slight magnetic attraction. I am wondering if magnesium would be a good choice since the top brace is magnesium. I do think once I get a solid 3.4mm shim fabricated it will be better than the 2 shims I am using now. Plus the fact that they are in 4 pieces due to the design. Although it makes it quicker and easier to add and remove, I question just how solid of a foundation they provide. Any thoughts you could share would be welcome.
On the demag or degaussing concern, what is your thought on the method of shorting the leads by touching the RCA connectors? I would like your direction on this before I risk ruining a perfectly good cartridge.

Again my gratitude abounds for all your help. It has increased the value and pride of my Kleos ownership.
Best Regards
Of the cartridges are returned to us nominally because the owner feels that the stylus or suspension is worn or damaged, frequently the problem is stylus buildup that prevents the stylus from touching the LP groove properly...
Bingo! This mirrors my (much smaller) experience exactly. I've "saved" over a dozen supposedly worn out ZYX cartridges sent to me for a quick look just by cleaning the stylus properly. That's all they needed to sound as good as new. If you aren't cleaning your stylus after every side (Jcarr's recommendation to me, many years ago) you aren't hearing all it's capable of.
I have observed that the Rega Tonearm + Rega cartridge have a positive VTA (a pivot end raised slightly ) . So, we can not consider only the cartridge height to determine how many shims we should use to adjust the VTA in a Rega Turntable when using a cartridge from other brand. It will vary from cartridge to cartridge. Actually, the measure we should be worried about is the SRA. Much more important than the VTA which at the end is one of the ways we will utilize to try to achieve the optimum SRA adjustment.

can you comment (similar to the kleos) on the height of the delos cartridge? is it 17.43mm as well? i'm trying to dial in the vta for mine on a rp10 as well.

- j
Hi Vinylkid: These days I try to keep the height and stylus-to-mounting-screws distance as similar as possible across all of our cartridges.

I just looked at my CAD drawings, and according to those, the height range of the Delos should fall between 17.377 and 17.48mm.

hope this helps!

kind regards, jonathan carr
Vinylkid, I took Mr. Carr's advice to the first step and bought 3.5mm in shims but yet to have had one made at the 3.43 as suggested due to time and budget. But I have been very pleased with the VTA setting for my Kleos. I wonder as well if the .57mm will make enough difference since vinyl thickness varies as well. It is unfortunate that Rega doesn't accommodate a more practical method of VTA adjustment, but I believe their cartridges provide optimum performance. So offering easy adjustment may be viewed as contradiction. Just my opinion of course.
One observation with my setup, I would pass along is, that this table is sensitive to the surface. My cabinet is an older hollow body cabinet and I realized a "guitar body" resonance in the upper bass/lower mid range. I am using the Aurio's with an MDF cored platform from my LP12 and this has eliminated that issue. However I am going to use a maple cutting board once I get it completed and hope to further the progress.
I would be curious what you are finding with your table.
Hi Theo: I seem to have overlooked this question from you:

>On the demag or degaussing concern, what is your thought on the method of shorting the leads by touching the RCA connectors?

Shorting the cartridge while playing limits the amount of current pushed through the coils to whatever the cartridge can generate on its own. Ergo, it is the most gentle method of fluxbusting, and most likely can be used without qualms even on cartridges with magnets that are not so resistant to demagnetization (Alnico).

>I would like your direction on this before I risk ruining a perfectly good cartridge.

The present Lyra cartridges all use super-strong Neodymium 50 magnets (their powerful magnetic field is why metal particles from the turntable environment accumulate in the coil vicinity). In order to demagnetize these magnets, you would need to push so much current through the cartridge coils that they would vaporize first. Ergo, even if you use an active fluxbusting device, as long as the fluxbusting circuit is in proper working order, I don't believe that any of our present cartridges would suffer negative effects.

FWIW, an EE friend in Japan has built a re-magnetizing machine for MC cartridges. He reports that when used with Alnico-based MC cartridges from the 1960s and 1970s, the cartridge output voltage increased, indicating that magnet strength went up.

The later Alnico magnet formulas were engineered to better resist demagnetization, and should therefore benefit less from remagnetization. The rare-earth magnets (samarium cobalt, neodymium and whatnot) are inherently quite resistant to demagnetization, and probably would not benefit from remagnetization (although I doubt if remagnetization would hurt anything).

kind regards, jonathan
Mr. Carr, thank you for looking back at previous posts and responding to my question. I have read your response a couple times and must admit it is a little over my head. But if I understand your statements correctly, I could use a fluxbusting device, I should have favorable results. Any suggestions as to a brand or model with which you have had favorable results?
Thank you again for responding.
Thanks for the response, Jonathan. The Delos was really dialled in with a 3mm shim on my RP40/RB303 (and a 2mm Herbies Way Excellent Mat), but on the RP10/RB2000 it seems be doing well with a 1mm shim (and a 1.6mm Herbies Grungebuster mat).

I suspect that the RB2000 tonearm has a slightly higher pivot point (+2mm) then the RB303 tonearm.
On my Rega P9 with RB1000 arm I use 2 - 2mm spacers and a Herbie's Grungbuster mat for the P9. This was setup by my dealer.
Hi Theo: Fluxbusters can be divided into two types. The first type involve shorting the cartridge output into itself while playing, and therefore the amount of current pushed through the cartridge coils is limited to whatever the cartridge can produce by itself. This means that the fluxbusting process is completely safe for the cartridge, but the effectiveness of the fluxbusting process is limited.

The second type uses an active (powered) fluxbusting device (combining a sine wave signal source and power output stage) to forcibly inject current through the cartridge coils. Since the active fluxbusting device can force far more current through the cartridge coils than the cartridge can produce on its own, the effectiveness of the fluxbusting procedure is enhanced. However, since more current is forced through the cartridge coils than normal, there are those who fear that the current may reach dangerous levels for the coils, or may weaken the magnets that create the field that the coils operate in.

As long as the active fluxbuster designer did his job properly, the fluxbuster should be current-limited to not exceed a level that remains safe for most MC cartridges made (the finest wire used in cartridge production is 12 micrometers - smaller than that and the production failure rate becomes too high).

If any problems occur with an external fluxbuster, it will be when it is used in an application that falls outside of what the fluxbuster designer envisioned.

One such possibility would be when using MC cartridges that were built with early types of Alnico magnets (during the 1950s, 1960s, and possibly the early 1970s), that did not retain their magnetic strength very well. With these cartridges it may be safer to use passive fluxbusting (unless you have access to a magnet recharging service).

A second possibility would be when using MC cartridges with IC or printed-circuit (photo-etched) coils, as the resulting coils will have far smaller conducting cross-sections than any normal wire. Examples of such cartridges would include Yamaha's MC-1s and MC-1X, JVC's MC-1, MC-2E, MC-L10, and MC-1000. With these cartridges, again it may be safer to use passive fluxbusting.

A third possibility would be when the active fluxbuster has failing internal components. If you purchase an active fluxbuster second-hand or NOS, I strongly suggest that you test it out on a broken cartridge first before your prized reference MC!

Everyone should keep around at least one borked Denon DL-103 (which uses 14-micrometer wire in the coils).

>Any suggestions as to a brand or model with which you have had favorable results?

I don't think that too many models are available today, and I don't have any experience with any of them. I'd suggest going with a reputable brand - for example, Aesthetix's Benz ABCD-1 MC Cartridge Demagnetizer.

I hope that the above answered your questions and cleared up any opaque areas. If you have any more questions, please feel free to ask.

kind regards, jonathan carr