Raquel, assuming you have the original Frog (.65 mV output, 21 ohm coil resistance) 400 ohms would be well within the calculated load range (260 - 790 ohms). |
No negative! What cartridge maker in their right mind would have you tilt their cartridge backwards to get the correct SRA? (Read the vdH website as well.)
I've discovered it's only when folks have their cartridges loaded way too high that (they think) they get better sound that way.
If you have the .55 mV copper coil Condor, your optimum loading will be 2400 ohms +/_ 50%. (In other words, start at 1200 ohms and work your way up until the bass is tight and full and the highs are smooth but not shrill.) Your VTA (actually SRA) for a van den Hul will just about right (1-2 degrees) by raising the tonearm post about 4-6mm above the point where the cartridge/tonearm is parallel to the record. |
Hi Dgad. The .35mV Condor has an internal coil resistance of 36 ohms. Using the standard 25x multiplier, that puts the (theoretically) optimum load at 900 ohms. And the overall range in which you should find your best setting (+/_ 50%) 450 ohms to 1350 ohms.
So you're probably close to perfect at 1Kohm. If it were me, I'd start raising it in 100 ohm increments until the bass started thinning out and the mid/highs started getting bright, glarey, grainy and/or shrill, and then back off.
The best way to set the SRA (stylus rake angle) for any cartridge is as follows:
Tape the platter so it can't spin.
Get a small first surface mirror (from an old SLR camera. They have lots of 'em at camera repair shops now.) and put it on the platter (without a record) near the outside where the stylus sets down.
Take off anti-skate, but make sure VTF is correct.
Lower the stylus to the mirror (get some good light too) and viewing the stylus from the side with a 50x pocket microscope, raise/lower the tonearm until the stylus is perfectly vertical, ie it lines up with its own reflection in the mirror (for a vdH stylus, this will be a perfect hourglass shape.)
To add 1.5 degrees of SRA using a standard 9" (23cm) tonearm, raise the tonearm post approx. 6mm. This is an excellent starting point, and by raising or lowering the arm 1mm at a time from this point, and listening carefully, you may improve over this setting or you may not :~) |
Unless any of you taildraggers would like to explain to me why it makes rational sense NOT to have your micro-ridge stylus fit the groove as the cutting head did when it cut the groove, you've got a lot of happy surprises in store once you accept the mechanical realities of the stylus/record interface. |
Bob (and others as well), with all due respect, this is beginning to sound like the debate between evolution and "intelligent design."
Has it occurred to you, VPI, etc., that maybe the "good" results you are reporting are due to a happy collision of errors? And that if you'd just ONCE! take the time to find out where your stylus is REALLY VERTICAL, and then with proper VTF and load, set the correct SRA, who knows what incredibly better results might await you -- I know this is what sirspeedy (a veteran ass dragger) reported once he took my advice.
If you want to read the whole thread, it's at:
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1111189002&openfrom&1&4#1
or the following excerpts:
1.) 04-16-05: sirspeedy70680@earthlink.net
Nsgarsh,my instruction manual(that came with my cartridge)indicates this stylus angle as preferred. (MY COMMENT: He means negative rake, but he had mis-interpreted the instructions) I,in the beginning, had the BODY fairly parallel,but found myself tilting backwards,as I played more and more records,over numerous listening sessions.I fully understand your trepidation with this,as I never would have thought the body needed this degree of back tilt.However,as time went on it became obvious to me.What I find hardest to obtain,in analog,is TRUE timbre in instruments.Too many hobbyists get off on bass.To me,dialing in the cartridge using various records,showing off timbre, results in ALL ELSE falling into place.I have a friend with the exact cartridge(vintage of about 18 months old),and his tilt back,is virtually identical.Once done,when one looks at the stylus tip from the side,the diamond seems to be about vertical in the groove.Obviously this is not written in stone,and some slight variation can be preferred.But,all in all,close to vertical is close to correct,in my set-up.As for the "W" I don't know.
Please understand,I'm not trying to get into any kind of an arguement.It's just that on my set-up,what my instructions(coming with my Temper-V)state,is in fact what my results came to be.I will admit that I overlooked the instruction recommended angle,for a long time,since I set up by ear.The only reason I went back,and took a hard look at the instructions,was because I,myself,could not believe that I had to go back on the arm,as I did.A paralel body,or even close to parallel,will be off sonically.When I noticed that the instruction manual said to check for stylus tip vertical,I did so,and found that my ears were not far off.The tip was,just about vertical,as stated.As for cutter rake,etc.,I could care less.I'm only concerned as to what sounds best,to me.
Excerpt 2.)
04-17-05: Nsgarch
RE: cartridge loading and stylus rake angle:
Groove undulations not only wiggle from side to side, they also angle forward, because a cutter head has to point backward (at 1 degree) like a chisel, so that the wax cuttings will fly away as it's making the goove. If you have a spherical or elliptical stylus, it doesn't matter a lot if the stylus is vertical, or leaning a little forward or backward, because it fits in the groove more or less the same (inaccurate) way in all three cases. BUT, with the new generation of micro-ridge styli, vdH being one of the first in the early 1990's, (if not THE first) it's a whole 'nother matter. These styli are chisel or "spade" shaped, almost like the cutter head itself. If they sit vertically in the groove (or -yikes!- tilted backward) then their sharp side edges actually scrape over, or "clip" the tops of the forward-slanting groove undulations! Paradoxically, even "mis-set" that way, they still sound better than conventional (old-type) styli because their very tip (at the bottom of the groove) can still "see" information that elliptical styli miss.
To extract all the information in the groove, these new styli must "see" the groove from top to bottom, and the only way they can do that is if they can lock into the groove by leaning forward at exactly the same angle as the cutter head.
Now, one can go on and on expounding on the vagaries of different systems and components and tubes and rooms ad nauseum -- however, there are certain scientifically proven mechanical and electronic rules that must apply "across the board" regardless of the equipment or the room. I have just described a couple of them.
Excerpt 3.)
04-18-05: sirspeedy70680@earthlink.net
Nsgarch,are you tellig Transfiguration owners that,when the cartridge instructions indicate one should view the stylus tip as "leaning slightly back",when viewed from the side,that the stylus is actually leaning forward,with the tip angling towards the rear?Wouldn't the instructions have said,"tip raked back",as this would then more closely follow your choice.I'm asking,not questioning.In my case I have the arm leaning back(cart. body too),because I understood the instructions to mean tip backward slightly,as lowering the body towards rear!
Excerpt 4.)
04-19-05: sirspeedy70680@earthlink.net
Nsgarch,just had a really great breakfast,with the EGG THAT I PEELED OFF MY FACE.You are correct in your description/advice,and(well the instructions were a bit ambiguous to me)the tip now rests as you describe it,with better sound,obviously.Too bad I already named my kids,or I'd be obligated to name one after you!Thanks!!
sirspeedy70680@earthlink.net
------------------------------------------------------------
You might want to write speedy and have him relate his experiences as he discovered the beauty of correct SRA. |
Here's a little reading for you ZYX owners by Hisayoshi Nakatsuka san himself (translated into English)
http://www.sibatech.co.jp/ZYX/ZYXTalks.htm
in which he describes the complex windings of the ZYX cartridge coils, and particularly the importance of their axes being correctly oriented to the groove modulations to achieve what he calls "original stereo sound."
Why don't you write to him at:
sales@sibatech.co.jp
and ask him about the advisability of tilting his cartridges backwards. I'm sure he'll be politely horrified.
Two other points:
1.) ZYX styli have the sharpest edged micro-ridge diamonds of all. If they don't exactly lock into the forward slanting groove modulations, they will wear off the delicate high frequency undulations in the groove and
2.) Most tonearms are designed so that their geometry is most stable (center of gravity below the bearings) when the arm slopes slightly down toward the record. This configuration provides the most resonance-free platform for the cartridge. So if you insisted on tilting your cartridge backward, it would be best to shim it at the headshell and let the tonearm assume its natural downward slope.
Are you sure you still want to do this?
. |
Dgad: First regarding your cartridge loading. Most cartridge makers simply state a minimum input impedance (load) for their cartridges. Below that number, the phono preamp input will (and I'm oversimplifying) begin to look like a short to the cartridge and shunt it's output. But that doesn't mean that that is the optimum load for the cartridge-and-phono preamp electronics which will give you the most effective output and flattest response in your system. The figure of 25 times the internal coil resistance of the cartridge is a good place to mark as the center of a range that goes from 50% less than that figure to 50% more than that figure. I've found the best way to dial in the optimum setting (for your system) is to begin near the lower end of that range and work up, keeping the midpoint in mind for reference. As you begin, you will probably experience muddy or undefined bass which will tighten and tighten as you move up the range. But at some point, if you continue to add load, the (amount of) bass will begin to drop off and the balance will begin to shift toward the mid/high end. You then need to reduce the load a little at a time until the top to bottom frequency balance is restored.
If instead you continue to add load, the mid/highs will continue to predominate, and may even become glarey or grainy. If you now tilt the cartridge backward, you will be mechanically reducing the high frequency response of the cartridge, because the stylus will be "skimming" across some of those delicate groove modulations, and the frequency balance will (only) appear to be restored.
As for the advice of Lloyd Walker and others, I have no problem with it except to ask, "What is neutral?" If it means with the stylus perpendicular to the record, that would be OK, but my suggestion of first setting up the stylus perpendicular, and then adding an average Stylus Rake Angle of about 1-1/2 degrees, gets you a lot closer to the starting line.
However, the only way you can do this, even using Lloyd's method, is to actually take the time (it can be tedious, but you only have to do it once for a given cartridge) to really find out where that "neutral" position is for your stylus. I inspected two vdH Frogs, a standard one and a Gold, and the Gold stylus was vertical (perpendicular to the record) when the cartidge body was parallel to the record. The other Frog had a rake (of unknown amount) on the stylus when the cartridge body was parallel to the record. Lowering the back of the tonearm brought the stylus of that cartridge perpendicular. From that point, the back of the tonearm was then raised 6 mm to apply the 1-1/2 degree SRA. And lo and behold, the tonearm was just about parallel!
So I can't stress enough, the importance of doing this preliminary determination. You'll be glad you did. After all, the "big breakthrough" in stylus design, after the elliptical styli (which were ground, like on a jeweler's wheel) was the "line-contact" stylus which is shaped and polished using lasers, and was developed so the stylus could more effectively approximate the cutter head and "lock" into the groove. I might be crazy, but it certainly seems to me counterproductive to risk defeating this capability by not taking care to insure that these sophisticated styli fit into the groove as their designers intended. |
The Shibata stylus was definitely a precursor to the line contact, but it was still crafted using standard grinding techniques. I thought it predated the SQ records, but my memory may be wrong. As I recall, it had slightly curved edges, which was as close as could be achieved by the standard shaping methods, without breaking the diamond. I think vdH was actually the first to develop a true line contact by (as I understand) using lasers.
I was unaware that vdH had these variations from cartridge to cartridge, but it doesn't surprise me, and highlights the need to make the initial determination of stylus position I recommend. Further, if you examine certain cartridges that have short cantilevers (notably Condor, Colibri, Allaerts) you'll notice the pole piece (behind the coil) or in the case of the Allaerts, the front pole piece, have been beveled to better clear the record. If you tilt them backwards, even a little, you could be in for a heap of trouble. |
Doug, thanks for your support. Your are right of course about various cutter settings and record thicknesses affecting the optimum SRA for any given record.
I only wish I had your arm (I mean your tonearm!) so I could make slight adjustments on the fly. Just try that with an SME V -- or better yet, don't! |
Raul, according to the vdH website, the recommended load for the .35mV Condor is 500 ohms, not 200 ohms, and 500 ohms is within the suggested range. In any case, the "optimal" value will not be exactly the same in each system because of the difference in tonearm cable impedance and the effective impedance of the circuitry of the phono preamp (or the impedance of the step-up transformer if you are using one.)
That is why it's important to have a mathematical method to determine a working range (a high load limit and a low load limit for each cartridge) and then to have a reliable way to hear when the load is a little too high or a little too low, or just right. |
Dgad, check your Condor box again. I betcha it says ">200 ohms" which means "greater than 200 ohms."
On the vdH website, in the "recommended load" column of the specs for your cartridge, it says "500 (>200)" which means that van den Hul recommends 500 ohms, but NO LESS than 200 ohms. |
Dgad, I find the discrepancy between the specs on your box and what's published on the vdH website very strange. I would call or email Andre at the USA vdH office in California, give him the serial no. of your cartridge and ask him to check it with the factory and get back to you.
On the other hand, if you use the standard multiple of 25x the (36 ohm) internal resistance, you could still wind up at 500 ohms be in the load range I suggested (although I would've guessed more like 900, but whatever....)
You are correct about the effective arm mass issue, but not to worry, the resonant frequency for the compliance of the Condor will still be well below 20Hz. There is an interactive graph at www.cartridgedb.com if you want to check it.
The anti skate dial of the SME V does indeed correspond to the vdH specs, except that the markings on the dial don't go low enough! Here's a better way to do it (you'll need good light, but it's very easy):
Set anti skate to zero. Viewing the cartridge from the front and just slightly above, note the position of the cantilever relative to the pole piece behind the coils. Then gently lower the tonearm to the record somewhere in the middle of the first band. Watch the cantilever carefully, just as the stylus goes into the groove. The cartridge body-and-headshell will tend to move toward the middle of the record, pulling inward slightly on the cantilever, and when you lift the stylus up out of the groove, the cantilever will return to center. Do this a few times until you see what I'm talking about. Then begin adding anti skating force a little (1/10 gram) at a time until there's no movement of the cartridge/headshell relative to the cantilever, whether the stylus is in or out of the groove. That's the correct setting. Soloist vocals should be solidly between the speakers. You can fine tune it by ear, but the visual adjustment is extremely accurate once you get the hang of watching for movement/no movement.
Regarding ground loops: they should produce a continuous 60 cycle hum in one or both channels. Is that the problem? or are you getting buzzing, and pops when you turn the lights on and off? The latter is usually due to radio frequency interference (RFI) produced in this case by arcing in the switches and fluorescent starters. This noise can picked up even by your dedicated lines or by phono unterconnects because it is sent out like a radio signal from those devices, and is best eliminated by stopping it at the device(s) rather than trying to filter it out afterward. Usually, you can replace the switches with noise-free ones that have a capacitor across the switch contacts. I think there's a remedy for the fluorescent lights too, but you'll have to ask an electrician. |
