Essentialaudio, the Fozgometer may not be the problem. Read what Stringreen is saying; it may be the Ortofon cartridge.
Until the cartridge is replaced and the Fozgometer is used to align azimuth with the new cartridge, it's all speculation.
I've been using a Fozgometer for more than five years now and have been quite satisfied with it's ability to consistently get cartridge alignment very close to ideal. Fine-tuning by ear is the final step if needed. The price is still reasonable when you consider the alternatives.
Regards,
Tom |
Sdcampbell, that's great information. I used the Musical Surroundings test tones to calibrate my Fozgometer and it went smoothly and the Foz works well for azimuth adjustment. But if the unit ever seems to be "out of whack" and the test tone recalibration method doesn't work I'll know to just send it in for service. It's nice to know that the unit is so easily restored.
Regards,
Tom |
Sdcampbell, thanks for the clarification. I have been wondering about some of the problemss people have posted on using and calibrating the Fozgometer. As Mike Fajin mentioned to you, the unit is sensitive to extraneous signal noise so you have to use good quality connectors and a clean signal. I found this out while using one of my phono preamps and a LOMC cartridge; the preamp had developed some signal noise in one channel that was affecting the Fozgometer and making it difficult to set azimuth. So I used the tonearm cables directly into the Foz. That's the preferred method but when you have a cartridge with low output, the range of signal output is reduced so it reduces the sensitivity of the adjustments in azimuth.
Your mention of the Fozgometer being recalibrated to a 30dB sensitivity got me to thinking that I could do the same in order to have a wider range of sensitivity for LOMC cartridges. I'm assuming that's how it would work. I'll have to experiment to see. Or have you already seen that effect?
I know it would cost more to implement but it would be handy to have two signal level settings on the Fozgometer, one for high output cartridges and one for low output cartridges. But that'd make the Fozgometer more expensive for everyone just to make it more convenient for a limited number of users.
Thanks again for posting the information. Helps to understand how these things work. |
Onhwy61, on the contrary, it points out that you need to pay attention to how you use the Fozgometer and what the signal readings mean. As I said in my recent post, I think some of the difficulties in using the Fozgometer are the result of user error or misunderstanding, or faulty cartridges and/or phono preamps. The owners manual is fairly complete but it could be improved by providing more background information on how the Foz works, what the signal readings mean, and how to troubleshoot (and correct) for odd readings or behavior. That would also help users know when the device is actually deffective or needs to be recalibrated by Musical Surroundings. (And to expect that every single Fozgometer manufactured will work perfectly, forever, is unrealistic.)
The Fozgometer is a very handy device to aid in setting azimuth but it's not a purely "plug-and-play" device; you need to use it properly, use a fresh battery, have good connectors, and normally functioning cartridges and phono preamps. Playing vinyl can be very simple if you want it to be. But if you're wanting to get the highest level of playback that's reasonably possible, you have to take the time and trouble to make that happen. I don't consider it a hassle, it's just part of the enjoyment of a lifelong hobby.
Regards,
Tom |
Well, Don, I guess your expectations are far higher than mine when it comes to consumer electronic gear. I suppose that for some things, like MRI, EKG, and X-ray machines I expect perfect manufacturing and they'll last almost indefinitely. Same for car ABS systems and airplane avionics. But for consumer stereo gear and accessories, not so much. I expect that every so often one of the units will have a defect, and that they won't work perfectly forever and will need some maintenance.
If that's total bullsh!t then I guess you're right.
Regards,
Tom |
Lew, you're right, a new battery is not a panacea in preventing all the potential pitfalls in using a sensitive electronic device like the Fozgometer. And no, I don't put a fresh battery in my Fozgometer each and every time I use it. I made the suggestion because it helps to at least establish a baseline if anyone is unsure about the condition or quality of a battery. Do I recalibrate my Fozgometer every time I use it? No, but I do swap out the battery every year and I recalibrate after doing so. It's not difficult. It doesn't take much time. Not really a burden.
Now, setting azimuth by eye and ear, that's a burden. '-)
Regards,
Tom |
Onhwy61, it all depends on who you ask as to whether or not the Fozgometer indicates the optimal azimuth. Opinions on the merits of the Fozgometer are all over the map, with a wide gap between camps. Not surprising for a device that's attempting to measure weak signals from a limited frequency range based on an imperfect source. Just do a search on how (im)perfect many of the test LPs are. Compounding that is the level of exactitude that is used during the alignment process.
In my opinion, based on setting azimuth for five different cartridges (4 LOMC and 1 MM) with three different turntables, is that the Fozgometer makes it very easy to set azimuth that is darn close to optimal. Sometimes the azimuth is probably perfect, but I wouldn't know because I don't have a way to test for perfection and I don't spend the extra time necessary to validate perfection by ear.
All I can say is that after setting a Baerwald alignment, getting VTF and SRA adjusted, and then quickly setting azimuth with the Fozgometer, I can put an album on the turntable, queue the tonearm, and sit back and enjoy some of the best sounding music I've ever heard in my home.
Man, that's optimal. :-)
Regards,
Tom |
Hans, the readings you're getting seem on the low side but perhaps you have a very low output cartridge. The channel separation indicated by the Fozgometer is not bad but I would try to adjust the azimuth so the channels are closer to being balanced (smaller difference).
If this is the first time you have used the Fozgometer I suggest experimenting with azimuth settings to see much stylus tilt affects channel separation. Try tilting the cartridge first one way and then another. Not too much but enough to see a difference in the readings. I check the amount of tilt with a small level. When you get the channel separation to be very close, stop and enjoy some music. :-)
Then, when you have some time, carefully listen to an LP with clean solo vocals and/or acoustic instruments to see if you can hear differences as you make fine adjustments. For example, listen to the LP before you make any adjustments using the Fozgometer and then listen to the same LP after you make adjustments. (Use an LP that you don't mind playing several times without resting it between plays.) Vocals and instruments should come into sharper focus when you're at or near optimum azimuth. As you become familiar with how the readings on the Fozgometer relate to the sound you hear, you'll know when you've got good azimuth alignment by the readings alone.
It's a learning process and takes time so don't be in a hurry and enjoy some music as you go.
Regards,
Tom
|
Stringreen, you shouldn't have to adjust VTF or VTA/SRA or alignment when adjusting azimuth. All of those parameters should be been set and locked in before you adjust azimuth.
If you have a tonearm that uses a set screw to adjust azimuth then yes, you could be affecting tonearm length if the arm tube is somehow pushed or pulled in or out of the tube sleeve. But all you have to do is put a very small drop of "White Out" on the arm tube right at the edge of the sleeve. That provides a reference marking to make sure you aren't moving the arm tube in/out as you tilt it to adjust for azimuth.
Regards,
Tom |
Stringreen, you're description of setting azimuth on a VPI uni-pivot doesn't motivate me to try one out. If VTF is directly coupled with azimuth adjustments and is that fidgety, I think I'll stay with gimbal-pivot tonearms. :-)
So to clarify that there shouldn't be a need to adjust VTA/SRA and VTF when setting azimuth: IF arm length and VTF are stable while adjusting azimuth, having to tilt the cartridge even 1 to 2 degrees will only change height by ~0.05mm to ~0.10mm from a reference vertical stylus setting. I've measured record thickness differences greater than that on a single LP, let alone the differences in thickness between LPs.
Enjoy the music!
Tom |
Ooops, that's "your" description. I had started with a different train of thought and then changed everything but "you're". 8-) |
Lew, the manual states that channel separation is what's being measured. Also: "The readings are virtually independent of overall signal levels, and can be made with a wide range of input signals without effecting accuracy."
So your comment about what correct azimuth entails is consistent with using the Fozgometer for alignment. Try to get both the best balance between channels and the highest separation in each channel. As you also mention, the two are probably synonymous in a perfect world, but I've found that sometimes it's a compromise between the best separation and the best balance. But which should have priority is not clear to me and I've biased the alignment in favor of trying to get channel separation in better balance while maintaining the best separation value in the lower of the two channels. Does that seem reasonable? (Reasonable or not, it sounds mighty fine. :-)
It would be helpful if Mr. Fosgate and Musical Surroundings were a bit more thorough in describing what the goals are and how to get there.
Regards,
Tom |
Stingreen, I may try a uni-pivot tonearm some day. But for now, it's gimbals, man.
Best,
Tom |
Doug, thank you for the clarification regarding channel separation as a surrogate (derivative statistic) for crosstalk. I had used the term crosstalk in the past when describing the Fozgometer but wanted to be consistent with the manual. If you read the manual it does not discuss crosstalk, probably to avoid confusion.
Lew, the test record recommended by Musical Surroundings is produced by Analogue Productions and utilizes a 1kHz tone for the two channels. (They also state that any 1kHz test tone track, one for each channel, can be used.) I have to assume that the two tracks are accurate and equal in output. I have read suggestions to purchase as many as three versions of test LPs to compare tracks and ensure consistency.
I have been curious to use other test tone frequencies to see how the optimum alignment for the 1kHz frequency compares to lower and higher frequencies.
And yes, when I said balanced I was talking about trying to equalize channel separation (crosstalk) between channels. The Fozgometer does have a test for channel output balance as well.
Regards,
Tom |
Lew, no, they do not imply that channel imbalances can be fixed by adjusting azimuth. However, the manual would be much more useful if it included information on how to deal with channel imbalances when adjusting azimuth for optimum channel separation (crosstalk). There are discussions on this topic at several forums but no clear answers as how to best handle it.
Regards,
Tom |
