Tracking problem with new SPU Synergy GM

[kor952]

Since a few days I have a new SPU Synergy GM.
First hour it had a very closed in sound, by now, after about 16 hours, the sound is good. But...
On every record with a sudden loud passage I get a short distorted sound as if the VTF is to low.
Tried 2.5g - 4g adviced VTF is 3 g (2.5 - 3.5g), this distortion does not get less above 3g but worsen below 3g.
Played my test records to find out about trackability, used the tracks with 315 Hz 40-80 um.
Above 50 um the needle jumps out of the groove and skips to the next track. The Synergy should track up to 70um.
Is there something wrong with the cart? Or is this due to the fact that it still is breaking in. (Never had this before with my other cartridges).

My TT is a Scheu Premier, arm is a 12" Jelco SA-750LB with the extra heavy counter weight, VTF is checked with a digital scale.
Tried damping oil too but that did not change anything concerning the tracking problems.

Other SPU owners did you have similar problems? Thanks in advance for sharing your thoughts.

Ronald.

[Audio Al]

Hi

Have you set it up with a cartridge Turntable Alignment Gauge ?

See the link

http://www.soundfountain.com/amb/ttadjust.html

:)

[Marco]

Hi Ronald,

First of all, have you set your tonearm/armboard to Baerwald or Stevenson alignment? I can tell you that the Jelco, as indeed other Japanese tonearms do, will prefer Stevenson, and so the SPU will sound much better aligned that way. I had these issues with my own SPU, and resolved them that way.

Also, SPUs are massively fussy about VTA, and so the arm MUST be 100% parallel with the record surface. If it's out by even the tiniest of margins, you'll hear it! Azimuth must also be similarly spot on. Use a small headshell spirit level to get both absolutely right.

As for VTF, set it to the recommended level (3g?) and get that spot on, too. Then set anti-skating to around 2.8-2.9, which should be optimal.

If you can achieve all of the above, your SPU should rock! Let me know how you get on :cool:

Marco.

[kor952]

@ Marco and Audio Al....
I cannot do much adjustments/alignments. Due to the fixed SPU GM headshell offset angle is fixed, so no Stevenson alignment for the Jelco arm.
I did stick to the Jelco allignment, 15 mm overhang and that's it. Azimuth also cannot be changed. OK you may be able to minimal twist the headshell but that's all.
Normally I use a small spirit level to adjust VTA and azimuth but as the SPU does not have a single stright side it is very difficult to say if my arm is 100% level (and the VTA is right).

[Barry]

Ronald,

Have you tried using a mirror to set up the azimuth? Even though the SPU frustratingly does not have straight sides, the image in the mirror should be symmetric with the bottom of the cartridge. You may have to 'switch off' the anti-skating bias whilst you do this otherwise the cartridge will skate across the surface of the mirror.

I haven't found any problem with my SPU (a lower grade version than yours) and get perfect tracking at 4g.

Marco is right about VTA and that many Japanese arms seem to be designed to be set up according to Stevenson's approach.

However I have a sneaking feeling that your cartridge sample is not up to performance. Suggest you have a word with Ortofon themselves.

Regards

[Rare Bird]

I usually bypass threads about SPU's as ive never had any intrest in them..However i had a quick look & noticed the mention of 3/4g tracking :eek: that scares me, i wouldnt be able to sleep.. i simply find it more of a relief using a cartridge that tracks nice at under 1g.
:thumbsup:

[kor952]

Ronald,

However I have a sneaking feeling that your cartridge sample is not up to performance. Suggest you have a word with Ortofon themselves.

Regards

I share your fealing, did send Ortofon an email last Thursday but they take their time to answer....
I fear the compliance is way to low although the cart is brand new.

I checked the azimuth both with the spirit level and mirror and I think it's OK.

Ronald.

[John Gordon]

Hi Ronald
Have you checked the mounting distance? This is the only adjustable parameter you have, so if it isn't exactly set for the actual effective length which is governed by the SPU mount, then it could make a big difference. If you use a two point protractor, and adjust the mounting distance to optimise the error using nulls at 66 and 121. The offset angle is the unknown here, although I see it mentioned as 19 degrees in various places. However this may simply be because that is the figure that emerges for Lofgren A IEC when the effective length and overhang are used in the spreadsheets. If the angle is different then that may mean a different mounting distance.

The other thing is that you need to know if there is more or less distortion on one or other channel, as there may be an issue of excess anti-skate.
John

[Barry]

Hi Ronald
Have you checked the mounting distance? This is the only adjustable parameter you have, so if it isn't exactly set for the actual effective length which is governed by the SPU mount, then it could make a big difference. If you use a two point protractor, and adjust the mounting distance to optimise the error using nulls at 66 and 121. The offset angle is the unknown here, although I see it mentioned as 19 degrees in various places. However this may simply be because that is the figure that emerges for Lofgren A IEC when the effective length and overhang are used in the spreadsheets. If the angle is different then that may mean a different mounting distance.

The other thing is that you need to know if there is more or less distortion on one or other channel, as there may be an issue of excess anti-skate.
John

Vinylengine quotes an effective length of 305mm, an overhang of 15mm and an offset angle of 19 degrees for the Jelco SA-750LB.

None of these figures correspond to either Loefgren A (= Baerwald) or B, or to Stevenson. It would seem Jelco (like a lot of Japanese arm manufacturers) have done 'their own thing'.

Accepting these figures, the null points are at 68.7mm and at 129.9mm.

[kor952]

I solved the problem...

Marco was/is right....The arm was to high, I lowered it at least 5 mm, now the nastie crackling sound has gone. When raising the VTF to 3.5g it also tracks 70 micron.

Art Dudley wrote in his (Stereofile) review of the Synergy (A) that it sounded better at 3.5g as with the recommended 3.0g. A Polish reviewer also had the same experience.

I think that if the bottom line of the headshell (not the bottom cover) is in parallel with the record surface you are more or less ensured that the cart is in horizontal position.

Thanks for all your suggestions and help.

Ronald.

[DSJR]

5mm at the bearing end is a heck of a lot of VTA to adjust you know... Does the arm tube now look fairly parallel to the record when playing? I bet it wasn't before. Glad you got it sorted though :)

And I thought my eyes were bad at doing this (they were, until I discovered that too far down at the rear to my eyes was actually parallel in truth - ahem - )

[kor952]

If I use my 103R I level it with a spirit level on top of the headshell. If the headshell is level my arm looks raised at the bearing point. I assumed this to be right. That's why I more or less mounted the SPU with the same arm angle.
What I did today was taking the same spirit level sticked it with very thin double sided tape to the arm tube and leveled the arm. The arm now looks 100% parallel to the platter/record surface.
Indeed the sound is complete different as before.

Ronald.

[Marco]

Hi Ronald,


Marco was/is right....The arm was to high, I lowered it at least 5 mm, now the nastie crackling sound has gone.

Nice one - glad you got it sorted out. I thought that might be the main problem, as from experience, I know how critical achieving optimal VTA is with an SPU.

Incidentally, regarding alignment, what I meant earlier about aligning your arm to Stevenson measurements, was to have a new armboard made, and drilled, using the relevant geometry, as I know that there is no facility for making adjustments at the headshell.

I'm pretty confident that, if you did that, you'd obtain even better results than you're getting now :cool:

Marco.

[kor952]

There is no possibility to change the geometry of the arm. The offset angle is fixed at 19 deg. and the eff. lenght is fixed at 305 mm.
If I want a Stevenson (or any other) geometry I have to change either the offset angle or the eff. lenght.
So I have to deal with the arm as provided by Jelco.

Ronald.

[kor952]

At last, after all possible test were done, I decided to return the SPU Synergy for warranty. That was 14 November last year. Last week I received the Synergy back, a new motor, cantilever and diamond were installed. And I am happy to say that it tracks OK now and NO distortion is heard.
It took quite a while but I am happy with the sound in my Jelco SA 750 LB.

Ronald.

[Marco]

Hi Ronald,

Nice one. Thanks for the update - glad you got there in the end! It's a superb cartridge. I love my Royal GM MKII - it just thrills and stuns me everytime I listen to it!

Enjoy your SPU :)

Marco.

[FFL]

With my new SPU Classic N E happened exactly the same ( as described in the first post ) , after 50 hours of working. It is under warranty and I will send it back today to the factory for repair.