The design is fully detailed in Linear Audio Volume 4, so yes you can build it yourself.
BTW, I have the distinct impression that some comments here are from people who do not know what VinylTrak is...
Ja
I didnt find building my Ncores the easiest in the world and that was simple....
I understand this guy is similarly reliable? Should I consider something like this instead?
The Signal Transfer Company: RIAA balanced output
I understand this guy is similarly reliable? Should I consider something like this instead?
The Signal Transfer Company: RIAA balanced output
The VinylTrak is an advanced design. It will reward with a very transparent unit where you hear every detail on the disc and will allow you to adjust it to the load requirements of the cartridge.
But it is not a design for the faint of heart.
No offense intended, but if an nCore makes you sweat maybe a Pearl or similar might be better.
jan
But it is not a design for the faint of heart.
No offense intended, but if an nCore makes you sweat maybe a Pearl or similar might be better.
jan
The article is now made available for download, thx Jan.
Now that I look at it in detail, i see it was made using perf/proto board.
One day I might make the time to do a layout. If I do, it will be a mix of SM and TH devices to reduce the pcb footprint area to save $.
Best to is leave it partitioned, as Bob has done, doing a separate pcb for the MM and MC gain stages. Possible to combine the MM gain stage, relays, selectable gain stage and o/p stage on one pcb. Add MC pcb as required.
Now that I look at it in detail, i see it was made using perf/proto board.
One day I might make the time to do a layout. If I do, it will be a mix of SM and TH devices to reduce the pcb footprint area to save $.
Best to is leave it partitioned, as Bob has done, doing a separate pcb for the MM and MC gain stages. Possible to combine the MM gain stage, relays, selectable gain stage and o/p stage on one pcb. Add MC pcb as required.
The VINYL TRAK is an idea that deserves more attention.
Thanks, Mr. Cordell, for the article in LINEAR AUDIO. I got the issue for the Pass article and the regulator test but have found the most use in your phono stage article. I just "discovered" it a few months ago. I must admit for years I did not read it. I thought it was too complicated and did not bother to look into the details. My foolishness ...
The idea of using the cartridges inductance for the 75 uS constant seems so obvious as to make me wonder about the old admonition: if it is too good to be true it probably is.
Starting with Pete Millett's LR board; I wanted to hear what inductors do for correction. I know they are not perfect. Seems like that has to be said with any discussion about inductors!
Mr. Millett uses two inductors for the RIAA correction and then an additonal inductor to cure ringing at very high frequencies.
I had first tried the DAMPED approach with adding a resistor to the second choke to stop it like was done in the article. Then it seemed kind of silly to keep it there so i went with a very low load, 5K, for a Clearaudio Charisma cartridge. Now there is only a 520 mH choke working with the cartridge's choke for the RIAA correction )separated by the first gain stage). I am not using the gain stages given in the article. I'm using the OPA 627/637 for first and second stages, respectively. I used these since Peter Daniel liked what they did with his phonoclone. That stage, like the MILLETT was intended for use with moving coil cartridges.
I found I did need to add capacitance over and above the 45 pF of my tonearm cables. Obviously they are very short. About 150 pF total seems to work best. I use air trimmers at the input.
I do not hear a problem with noise so I am curious why you decided to go "half way" with your idea unless with your gain stage there was a noise problem. Or I am blissfully ignoring something that should be obvious?
I am very pleased with this thing. I had never used op amps in a phono stage before and was expecting to use them as a first step before trying something more exotic. But for the moment I like how it sounds, as is.
One strange anomaly that I suspect is a fault of the phono cartridge but wonder if there is some way this phono stage could be producing a 25 Hz spike? is that possible? Luckily, I can notch it out otherwise there is this very annoying rumble in the room. My table is very carefully set up and I cannot see how this is a form of rumble. I would think that would occur at a much lower frequency as well as being wider in frequency range.
I see this with the REW RTA running. It is consistent with all records. I have used really quiet recordings to identify where it is. But the noise is not subtle. this is a TALL spike!
I thought this could be some interaction because of the low resistance in parallel with the cartridge so I placed a 20K resistor across the inputs and it is still there.
I do not know if this is a valid test - but I placed a piece of ebony wood on the top plate (with the bearing bolted to it) and placed the cartridge atop the wood turned the volume up high and looked at the screen. The motor is running and the platter is spinning. Not having a piece of metal that was the right size still I would think something would be visible (if this test has any validity at all) on the screen and it is placid as my room's background noise. Which is not as placid as I would like but nothing I can do about that.
Is it possible for a cartridge to have a 25 Hz spike? I am going to get one an inexpensive MM cartridge. Maybe an AUDIO TECHNICA but I hear they supply the innards to CLEARAUDIO ...
Both op amps are in inverting mode. Could that make a difference? In every other way the thing sounds fine other than this bizarre spike.
I realize Mr. Cordell is probably never going to see this but anyone familiar with what he is doing with the VINYL TRAK I would enjoy hearing what you have to say if you find this worthy of a response!
Thanks,
Thanks, Mr. Cordell, for the article in LINEAR AUDIO. I got the issue for the Pass article and the regulator test but have found the most use in your phono stage article. I just "discovered" it a few months ago. I must admit for years I did not read it. I thought it was too complicated and did not bother to look into the details. My foolishness ...
The idea of using the cartridges inductance for the 75 uS constant seems so obvious as to make me wonder about the old admonition: if it is too good to be true it probably is.
Starting with Pete Millett's LR board; I wanted to hear what inductors do for correction. I know they are not perfect. Seems like that has to be said with any discussion about inductors!
Mr. Millett uses two inductors for the RIAA correction and then an additonal inductor to cure ringing at very high frequencies.
I had first tried the DAMPED approach with adding a resistor to the second choke to stop it like was done in the article. Then it seemed kind of silly to keep it there so i went with a very low load, 5K, for a Clearaudio Charisma cartridge. Now there is only a 520 mH choke working with the cartridge's choke for the RIAA correction )separated by the first gain stage). I am not using the gain stages given in the article. I'm using the OPA 627/637 for first and second stages, respectively. I used these since Peter Daniel liked what they did with his phonoclone. That stage, like the MILLETT was intended for use with moving coil cartridges.
I found I did need to add capacitance over and above the 45 pF of my tonearm cables. Obviously they are very short. About 150 pF total seems to work best. I use air trimmers at the input.
I do not hear a problem with noise so I am curious why you decided to go "half way" with your idea unless with your gain stage there was a noise problem. Or I am blissfully ignoring something that should be obvious?
I am very pleased with this thing. I had never used op amps in a phono stage before and was expecting to use them as a first step before trying something more exotic. But for the moment I like how it sounds, as is.
One strange anomaly that I suspect is a fault of the phono cartridge but wonder if there is some way this phono stage could be producing a 25 Hz spike? is that possible? Luckily, I can notch it out otherwise there is this very annoying rumble in the room. My table is very carefully set up and I cannot see how this is a form of rumble. I would think that would occur at a much lower frequency as well as being wider in frequency range.
I see this with the REW RTA running. It is consistent with all records. I have used really quiet recordings to identify where it is. But the noise is not subtle. this is a TALL spike!
I thought this could be some interaction because of the low resistance in parallel with the cartridge so I placed a 20K resistor across the inputs and it is still there.
I do not know if this is a valid test - but I placed a piece of ebony wood on the top plate (with the bearing bolted to it) and placed the cartridge atop the wood turned the volume up high and looked at the screen. The motor is running and the platter is spinning. Not having a piece of metal that was the right size still I would think something would be visible (if this test has any validity at all) on the screen and it is placid as my room's background noise. Which is not as placid as I would like but nothing I can do about that.
Is it possible for a cartridge to have a 25 Hz spike? I am going to get one an inexpensive MM cartridge. Maybe an AUDIO TECHNICA but I hear they supply the innards to CLEARAUDIO ...
Both op amps are in inverting mode. Could that make a difference? In every other way the thing sounds fine other than this bizarre spike.
I realize Mr. Cordell is probably never going to see this but anyone familiar with what he is doing with the VINYL TRAK I would enjoy hearing what you have to say if you find this worthy of a response!
Thanks,
I did look at this a bit before deciding on my current path for MM phono stages. The reason for not going the whole way is a potential 7dB noise penalty. Bob's chosen frequency saves you from most of that, but still gives potential benefits in rolling the cartridge off to bypass a lot of the loading problems with MM.
Why wasn't it picked up before? well basically maufacturers were playing safe and wanted to meet the 'spec' for a 47k input. Barney Oliver did something similar in 1972 for his amplifier Barney Oliver Amplifier and there were other attempts before that to use the cartridge as part of a low pass filter. but all fell by the wayside.
Why wasn't it picked up before? well basically maufacturers were playing safe and wanted to meet the 'spec' for a 47k input. Barney Oliver did something similar in 1972 for his amplifier Barney Oliver Amplifier and there were other attempts before that to use the cartridge as part of a low pass filter. but all fell by the wayside.
One figures the noise problem was a greater problem with vacuum tubes and that is when the die was set.
My speakers extend to 20kHz measured at my chair - not flat, though i could make it flat if I wanted to torture myself! But in my system noise is not a problem.
I certainly don't think this is something for the marketplace. There is something very interesting to be heard for the DIYer.
I had been an MC devotee until my TRANSFIGURATION Proteus lost a channel in its second year of use and the fellow who was the company had died a couple of weeks earlier. I have a useless expensive slug of aluminum.
So I thought , after getting advice from a good source, that the CLEARAUDIO MMs were very good. Much less expensive than another MC of the same class as the dead one. Has a boron cantilever so it has some lineage to the Proteus.
My previous TRANSFIGURATION cartridge had lasted for ten years. This has been very disappointing.
But the low loading really does good things for the high frequencies. They are there with a natural balance and greater extension. As well as my ears can detect them. Plus there is that "body" a MM gives to the sound. Seems you trade a little spaciousness for a fuller tone. I had used the cartridge in the MILLETT as he configured it and a SALAS FET before making the change to the highly damped mode.
Hope someone else gives low resistance loading a try in any configuration following the input they prefer. I would love to hear some other experiences with the idea.
My speakers extend to 20kHz measured at my chair - not flat, though i could make it flat if I wanted to torture myself! But in my system noise is not a problem.
I certainly don't think this is something for the marketplace. There is something very interesting to be heard for the DIYer.
I had been an MC devotee until my TRANSFIGURATION Proteus lost a channel in its second year of use and the fellow who was the company had died a couple of weeks earlier. I have a useless expensive slug of aluminum.
So I thought , after getting advice from a good source, that the CLEARAUDIO MMs were very good. Much less expensive than another MC of the same class as the dead one. Has a boron cantilever so it has some lineage to the Proteus.
My previous TRANSFIGURATION cartridge had lasted for ten years. This has been very disappointing.
But the low loading really does good things for the high frequencies. They are there with a natural balance and greater extension. As well as my ears can detect them. Plus there is that "body" a MM gives to the sound. Seems you trade a little spaciousness for a fuller tone. I had used the cartridge in the MILLETT as he configured it and a SALAS FET before making the change to the highly damped mode.
Hope someone else gives low resistance loading a try in any configuration following the input they prefer. I would love to hear some other experiences with the idea.
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