The importance of VTA, SRA and Azimuth - pics

[andromedaaudio]

Bblue , ever tried a decca , ive tried vd hul condor , zyx r100 fs and koetsu urushi , i could nt see myself using a mc again , no comparisson in my opinion

 

[bblue]

Hi Bill, sorry to hear about your tribulations. I came from the xx2 and the A90 is leagues above it. I've been meaning to follow up here, as I have done extensive A/B between the A90 and the same tracks on CD, and basically where sibilance is excessive in the recording the A90's rendition is slightly more distorted but that could also mean the CD mastering is different. Where the material is crystal clear, e.g. RR, it is simply trouncing the CD all across the spectrum. But - it HAS to be set up at +2 SRA. It's a tough beast to tame but I think I have it as optimally set up as possible.

That's disappointing (Dynavector not being in the same league).

When you have your SRA at +2, how tails-up is your arm? What are you tracking at?

I vaguely recall you(?) telling me once that Ortofon was claiming that the facet that is most vertical at the leading edge toward the oncoming groove, was supposed to be at exactly 90 degrees? Prior to now I've always tried to get the A90 to close to +2, but now in this setup it is not possible without actually tilting the cartridge forward at the mount. Are you doing anything that radical?

It's really hard to imagine that I've had two new A90's with problems, and the same problems at that.

--Bill

 

[bblue]

Bblue , ever tried a decca , ive tried vd hul condor , zyx r100 fs and koetsu urushi , i could nt see myself using a mc again , no comparisson in my opinion

Hmm. No, never had a Decca. So many mixed opinions there. Which Decca are you referring to?

--Bill

 

[audioarcher]

Bill, You can put a small shim between the A90 and the head shell to angle the cart some more. 1 to 2 mm thick in the front of the cartridge before the head shell screws should do it. Maybe a small piece of non corigated cardboard. That will give you more SRA to work with.

Sean

 

[andromedaaudio]

The Supergold does the trick , on another level dynamic wise , ..in my opinion

 

[bblue]

The Supergold does the trick , on another level dynamic wise , ..in my opinion

Interesting. I never took the Decca carts very seriously because of their crude appearance and reported quirkiness. But further research shows quite a number of folks with pretty high opinions of them (Supergold, Jubilee and latest Reference).

I'm not looking for sensational or overly dramatic, but accurate to the master and extreme trackability and tracing.

Thanks for the suggestion.

--Bill

 

[andromedaaudio]

I never have had tracking problems , they are very sensitive though and dont hide anything , yet very neutral which i like , i wrote something about them here .

http://www.whatsbestforum.com/showthread.php?p=97665#post97665

 

[ack]

Prior to now I've always tried to get the A90 to close to +2, but now in this setup it is not possible without actually tilting the cartridge forward at the mount. Are you doing anything that radical?

Nothing special other than starting with a tracking force of 2.3g (since when is weight really a force, anyway???). This, or lower, will give you a final SRA higher than what you have. The shim approach others suggested may also work if the resulting resonant frequencies are still within range.

I think you will be better off trying Lyras for similar sound, but the Atlas at least apparently has the same stylus?

 

[MylesBAstor]

Nothing special other than starting with a tracking force of 2.3g (since when is weight really a force, anyway???). This, or lower, will give you a final SRA higher than what you have. The shim approach others suggested may also work if the resulting resonant frequencies are still within range.

I think you will be better off trying Lyras for similar sound, but the Atlas at least apparently has the same stylus?

All they say is variable radius line contact stylus. Tell you when mine arrives.

 

[bblue]

All they say is variable radius line contact stylus. Tell you when mine arrives.

They also say it's a "Lyra designed" stylus. That would *seem* to eliminate the Gyger type unless they just tweaked it a bit.

And I wonder exactly what 'variable radius' line contact actually means?

--Bill

 

[bblue]

Nothing special other than starting with a tracking force of 2.3g (since when is weight really a force, anyway???). This, or lower, will give you a final SRA higher than what you have. The shim approach others suggested may also work if the resulting resonant frequencies are still within range.

I think you will be better off trying Lyras for similar sound, but the Atlas at least apparently has the same stylus?

I have a shim that is expressly designed for exactly this, but it fits only between the headshell and cartridge body at the screw holes. The reason I haven't used it is that the A90 appears to want three points of direct contact with the headshell -- two in the rear and one in front. These would all be negated, leaving the only point of contact for energy drain to be at the screw holes, through the shim. I guess it wouldn't hurt to try it and see if it really improves the tracking. Never has before, but this is a different setup.

The Atlas is a bit rich for my pocket, though its description certainly sounds promising. As per andromedaaudio's Decca suggestion, have any of you had experience with the Decca Jubilee or Reference compared to these we've been talking about?

--Bill

 

[audioarcher]

Bill, I have an A90 and I'm aware of the little nubs on the top. In that case just put a couple of shims on both sides of the front nub. The shims have to be in front of the headshell screws to angle the cart the right way. Its worth a try if only to see if the tracking improves. I doubt if the shims will effect the sound that much.

Sean

 

[bblue]

Bill, I have an A90 and I'm aware of the little nubs on the top. In that case just put a couple of shims on both sides of the front nub. The shims have to be in front of the headshell screws to angle the cart the right way. Its worth a try if only to see if the tracking improves. I doubt if the shims will effect the sound that much.

I've attempted that before, but unfortunately the 'head' of the ET2 arm wand stops abruptly about 1/4" forward of the cartridge mounting screws -- for reasons that make no sense to me. I had once tried shims there but it ends up contorting the head shell section of the wand.

I did just try my tilt shim which, when viewed from the side is trapezoidal in shape, producing an angular offset of whatever it is installed between. When in place it has very little height, but produces an angular tilt of between 4-5 degrees either direction depending on which way it was installed. So now at the top of my arm height range and the top of the VTA adjustment range which was just at 90 degrees stylus angle on the A90 is just under 95 degrees (+5), which at the bottom of the adjustable VTA range is about 91.5. That should be good enough to get on both sides of 92 degrees on both thin and thick records for eval. All three of the top mount nubs on the A90 are floating, not contacting the headshell at all.

Now for some listening.

--Bill

 

[ack]

Great! Let us know.

 

[Mike Lavigne]

I have a shim that is expressly designed for exactly this, but it fits only between the headshell and cartridge body at the screw holes. The reason I haven't used it is that the A90 appears to want three points of direct contact with the headshell -- two in the rear and one in front. These would all be negated, leaving the only point of contact for energy drain to be at the screw holes, through the shim. I guess it wouldn't hurt to try it and see if it really improves the tracking. Never has before, but this is a different setup.

The Atlas is a bit rich for my pocket, though its description certainly sounds promising. As per andromedaaudio's Decca suggestion, have any of you had experience with the Decca Jubilee or Reference compared to these we've been talking about?

--Bill

i would not mess with shims between the headshell<->cartridge as they will definitely color the sound (the A90 is a very high resolution device and will tell you everything about how your cart is mounted whether you like it or not) and you will not be able to separate the effect of the shims from the effect of the SRA change. a better solution might be to make a spacer between your arm and armboard to dial in the SRA. a little geometry ought to give you the thickness you need. stainless steel would be the best material, but you need to maintain the same rigidity of your current arm-armboard interface. if that is a choice and you have mounting screws long enough or you can easily find them, then that would be the method i would use.

i think sometimes we assume that the arm is mounted at the ideal height for every cartridge to give us the correct angle of approach. unfortunately that is not always the case.

 

[Mike Lavigne]

i'll repeat a point mentioned earlier by Jazdoc, and that is that it's great to have an SRA number to shoot at like 92 degrees for the A90, but if it turns out that another SRA sounds better then guess what; it's better!!

don't get hung up on the numbers, trust your ears.

i can tell you i owned 3 A90's and had 2 mounted for 2 years. i had other A90's in my system involved in tonearm development. lots and lots of A90 set-ups; and we never choose 92 degrees SRA as ideal sounding. i'm not saying there may not be technical reasons it's recommended, it just did not speciifically sound the best.

YMM definitely in this case V.

 

[bblue]

i would not mess with shims between the headshell<->cartridge as they will definitely color the sound (the A90 is a very high resolution device and will tell you everything about how your cart is mounted whether you like it or not) and you will not be able to separate the effect of the shims from the effect of the SRA change. a better solution might be to make a spacer between your arm and armboard to dial in the SRA. a little geometry ought to give you the thickness you need. stainless steel would be the best material, but you need to maintain the same rigidity of your current arm-armboard interface. if that is a choice and you have mounting screws long enough or you can easily find them, then that would be the method i would use.

As a matter of course I would agree. But this cartridge (both that I've had) is so out of calibration that I really don't want to make a special hardware mod just for it. It would become difficult to deal with a cartridge that is within spec.

At this point I'm willing to sacrifice a little color to find out if it can really track as well as some say. This is now my fourth complete setup of this cart (with varying changes) and throughout the SRA range, there was a clearly good angle but it didn't track/trace well -- ever. You can read more about this in earlier posts.

i think sometimes we assume that the arm is mounted at the ideal height for every cartridge to give us the correct angle of approach. unfortunately that is not always the case.

The ET2 can accommodate (adjust to) a wide range of different cartridge heights already, with the assumption that the cartridge and arm parallel to the record is a reasonable place to start. In this case the 90 degree point for this cart is with the arm significantly tails up, not anywhere close to published specs. I think the suspension is soft and allowing the stylus to shift upward too far. The only way to correct for that is raise the back of the arm or try to go extremely light on VTF, which you can't do on these (see picture posted a few messages back). Tracking *really* gets horrible with insufficient VTF on some records. On easy to play records it's pretty good even at low VTF.

--Bill

 

[ack]

Bill, what are your preliminary listening test results?

 

[bblue]

Great! Let us know.

So far there is a clear SRA sweet spot that only varies slightly from record to record. Maybe 50/1000's of a rear arm height range as shown on the 0 to .3" rear height gauge. Looking at it with the side microscope, it appears to be about +2.4 degrees. But I think that is showing higher than it really is during use since real stylus drag tends to pull it down somewhat. On typical records (references) there is very little mistracking, though a touch here and there. I'm trying some more difficult ones later on tonight (I hope).

--Bill

 

[audioarcher]

Cool. Sounds like your having better luck now. Let us know how it does on more challenging records.

Sean