I'm surprised at the amount to gain needed. I thought strain gauge pickups were high output.
FWIW, I've only heard one, I think it was the Soundsmith cart. The entire system was quite good, remarkable on orchestral works. Don't know how much of a role the strain gauge played, but it certainly didn't hold back the system.
FWIW, I've only heard one, I think it was the Soundsmith cart. The entire system was quite good, remarkable on orchestral works. Don't know how much of a role the strain gauge played, but it certainly didn't hold back the system.
Not sure exactly where you got that impression, the Panasonic 460C and 465C are 3mVrms out into 4.7K with 4mA of excitation current at a lateral recorded velocity of 5cm/sec @ 1kHz.
Currently I have between 6dB and 10dB more gain than I actually need in my system. I may address this in a redesigned second stage. I need to find a tube with decent performance with about half the mu of the 6S3P-EV, unfortunately my experience with 6N23P and its somewhat whimpier western cousin the 6DJ8 convinces me to stay away from them in the future - in theory this would be the best match gain wise.
Currently I have between 6dB and 10dB more gain than I actually need in my system. I may address this in a redesigned second stage. I need to find a tube with decent performance with about half the mu of the 6S3P-EV, unfortunately my experience with 6N23P and its somewhat whimpier western cousin the 6DJ8 convinces me to stay away from them in the future - in theory this would be the best match gain wise.
There is a remarkable amount of tracing noise with the NOS Shibata stylus, even at the ideal VTA it is not exactly quiet. Away from the ideal it is both noisier and some odd colorations/distortions come to the fore. The conical is slightly quieter...
They were not kidding about the high recommended tracking forces either with the 465C tracking much below 4gms results in noticeable tracking distress in the HF particularly on female vocals and sibilant sounds. I started at 3.5gms and was unpleasantly surprised on some material, at 4gms the issue went away.
They were not kidding about the high recommended tracking forces either with the 465C tracking much below 4gms results in noticeable tracking distress in the HF particularly on female vocals and sibilant sounds. I started at 3.5gms and was unpleasantly surprised on some material, at 4gms the issue went away.
You are adjusting your fore and aft tracing line tracking when adjusting the VTA for optimunm tracking, meaning you pull behind perfect tangency on raising for VTA and the opposite when lowering?
I,m faily certain you know about this hassle
With so short of a pivot distance and high tracking force, these might make more of a sonic difference than being off on say a 10" normal pivoting arm that is slightly off for example.
Just trying to cover any possibilities
Regards
David
I,m faily certain you know about this hassle
With so short of a pivot distance and high tracking force, these might make more of a sonic difference than being off on say a 10" normal pivoting arm that is slightly off for example.
Just trying to cover any possibilities
Regards
David
Another design consideration of these is the replacement stylus integrity being a push on affair AND high tracking force__ this might be a recipe for added movement you don't want leading to possible colorations. super glue the dam thing��
No proof of this of cource, but there are incredible forces going on down there
No proof of this of cource, but there are incredible forces going on down there
Scott and I did a couple of quick measurements today on the strain gauge, bearing in mind that we could not do synchronized frequency sweeps we elected to use the pink noise bands off of one of his STR test disks.
Bearing in mind that the pink noise amplitude falls at a 10dB per decade rate here is a response graph showing the equalized response of the cartridge, considering what we knew about the response of the pre-amplifier we decided this was sufficient.
The equalized response is not flat but is a significant improvement over what the unequalized response would have been. (The equalizer reduces HF response by 4.5dB relative to 1kHz at 10kHz and almost 10dB at 20kHz.
It appears that some additional reduction below 100Hz might be worth considering.
We both agreed that it fell short of the Windfeld's performance to a significant degree which was no real surprise.
Bearing in mind that the pink noise amplitude falls at a 10dB per decade rate here is a response graph showing the equalized response of the cartridge, considering what we knew about the response of the pre-amplifier we decided this was sufficient.
The equalized response is not flat but is a significant improvement over what the unequalized response would have been. (The equalizer reduces HF response by 4.5dB relative to 1kHz at 10kHz and almost 10dB at 20kHz.
It appears that some additional reduction below 100Hz might be worth considering.
We both agreed that it fell short of the Windfeld's performance to a significant degree which was no real surprise.
Attachments
Very good, Kevin!You didn't happen to record those, did you?
Also, in what ways did the Panasonic fall short?
Unfortunately the QA400 cannot record and we did not do anything else. I could actually record it at some point with a little bit of work.
It just really can't compete on any level against one Ortofon's best MC cartridges, the Windfeld better in every way you can imagine, but it costs a great deal more. The SG is probably better than anything close to the price however.
I am working on an improved pre-amplifier design which maybe pushes things a bit further or not.
Can definitely run a sweep, but there is no common hardware between the two set ups. Would be an interesting, informative and potentially disturbing experiment to perform.. LOL (i.e. Does the Windfeld measure as well as I think it should? And how good is the conformance of my other phono stage to RIAA)
Makes sense to do it once I've got another SG cartridge on hand to evaluate.
The pre-amp has been widely discussed and measured too in the Muscovite thread. (but not with a cartridge)
The cartridge is a known quantity from a reputable maker, but I don't have any graphs of the response.
My old Benz Ebony had a strip chart included from a BK analyzer showing the frequency response and matching between the channels. It measured very well, but was somewhat lacking in dynamics. (It just went to a new home a couple of weeks ago.)
The cartridge is a known quantity from a reputable maker, but I don't have any graphs of the response.
My old Benz Ebony had a strip chart included from a BK analyzer showing the frequency response and matching between the channels. It measured very well, but was somewhat lacking in dynamics. (It just went to a new home a couple of weeks ago.)
Here is a post of the direction I am currently going. This eliminates the battery biased DN2540 hybrid mu-follower circuit and replaces it with a standard cascode CCS/follower.
Note that the simulations with improved DN2540 VDMOS model indicate there is some potential for oscillation in the cascode CCS hence the 10K gate resistors. This may or may not be real. Given the signal levels the SNR impact of those resistors is minimal. I have not tested this variant yet, currently designing a PCB that will have it.
Note those who need less gain could sub a lower mu triode for the 6S3P and adjust the bias voltage accordingly. Also 6SN7 can be used directly for first stage, and 6J5 for second stage if desired.. (Adjust bias in second stage to about -6V)
Note that the simulations with improved DN2540 VDMOS model indicate there is some potential for oscillation in the cascode CCS hence the 10K gate resistors. This may or may not be real. Given the signal levels the SNR impact of those resistors is minimal. I have not tested this variant yet, currently designing a PCB that will have it.
Note those who need less gain could sub a lower mu triode for the 6S3P and adjust the bias voltage accordingly. Also 6SN7 can be used directly for first stage, and 6J5 for second stage if desired.. (Adjust bias in second stage to about -6V)
Attachments
Unfortunately I was outbid at the last minute and did not snag the 451C. I'm not planning to try again, and will wrap up this experiment in the next couple of weeks.
I have a few further ideas to evaluate. I've designed a PCB with some interesting features which I will share here when I am ready.
I have a few further ideas to evaluate. I've designed a PCB with some interesting features which I will share here when I am ready.
Strain gauge cartridges definitely have some sort of sex appeal.. LOL Running one definitely puts you in the hippest of the hip crowd, getting really good performance out of one sets you apart from the crowd..
The first strain gauge I've heard that actually sounded good to me was the Panasonic I heard at a friend's house in Dallas, up to that point I'd not heard many, and none that I could bear to listen to for more than a couple of minutes.
They need very carefully considered electronics and are best employed by people who really love to experiment and build an understanding of how to use them effectively, for anyone else there will be cheaper and better performing alternatives particularly when you consider the cost of the dedicated and decidedly oddball pre-amp required to make them sing. In a sense part of the problem is that they will still work with quite crappy electronics, but you get nowhere close to what they may be capable of.
In most modern arms given the low cartridge mass they are going to need very heavy head shells if you go with one of the late heavy trackers like the 460 or 465. They will need spacers in many cases as well.
They do not track well IMVLE much below the maximum rated tracking force on either of the arms I've tried them on.
The Shibata is NOISY, and rather sensitive to VTA. Long high mass arms certainly don't hurt in terms of performance.
I have an old conical stylus here and on stereo records it acquits itself well. It also has less tracing noise and is less sensitive to VTA.
They apparently have a warm up time like the electronics I use, I don't think it is my imagination when they seem to sound better after several hours of use.
I have not decided how I feel about the loaner JICO sonically speaking, need to listen to it more, however it does not fit the cartridge as snugly as the OEM replacements do which may be a concern.
Running them on LTA tone arms as I am is probably going to create as many issues and questions as it resolves. I've compared the 460C on the Schick with the 465C on the Souther and the shortcomings I hear were not mitigated on the Schick. Since in my instance there is no other choice the 460C will remain on the Souther.
You may have figured out that I have very mixed feelings about these cartridges, and that is possibly the consequence of the excessive hype surrounding them, they're good, but maybe not great. I keep wanting to be wowed, but I am not, OTOH on this particular set up nothing has really sounded better either - so there is that. They might potentially be one of the best cartridges to come out of the 1970s and I can't argue with that, but there are some awfully good cartridges available today, perhaps some of the best ever, and some of those won't cost much more than one of these.
The first strain gauge I've heard that actually sounded good to me was the Panasonic I heard at a friend's house in Dallas, up to that point I'd not heard many, and none that I could bear to listen to for more than a couple of minutes.
They need very carefully considered electronics and are best employed by people who really love to experiment and build an understanding of how to use them effectively, for anyone else there will be cheaper and better performing alternatives particularly when you consider the cost of the dedicated and decidedly oddball pre-amp required to make them sing. In a sense part of the problem is that they will still work with quite crappy electronics, but you get nowhere close to what they may be capable of.
In most modern arms given the low cartridge mass they are going to need very heavy head shells if you go with one of the late heavy trackers like the 460 or 465. They will need spacers in many cases as well.
They do not track well IMVLE much below the maximum rated tracking force on either of the arms I've tried them on.
The Shibata is NOISY, and rather sensitive to VTA. Long high mass arms certainly don't hurt in terms of performance.
I have an old conical stylus here and on stereo records it acquits itself well. It also has less tracing noise and is less sensitive to VTA.
They apparently have a warm up time like the electronics I use, I don't think it is my imagination when they seem to sound better after several hours of use.
I have not decided how I feel about the loaner JICO sonically speaking, need to listen to it more, however it does not fit the cartridge as snugly as the OEM replacements do which may be a concern.
Running them on LTA tone arms as I am is probably going to create as many issues and questions as it resolves. I've compared the 460C on the Schick with the 465C on the Souther and the shortcomings I hear were not mitigated on the Schick. Since in my instance there is no other choice the 460C will remain on the Souther.
You may have figured out that I have very mixed feelings about these cartridges, and that is possibly the consequence of the excessive hype surrounding them, they're good, but maybe not great. I keep wanting to be wowed, but I am not, OTOH on this particular set up nothing has really sounded better either - so there is that. They might potentially be one of the best cartridges to come out of the 1970s and I can't argue with that, but there are some awfully good cartridges available today, perhaps some of the best ever, and some of those won't cost much more than one of these.