I would suggest 24bit/96kHz FLAC as a minimum to get any reasonable comparison. MP3 has a brick wall at 16kHz, and it's generally obsolete. If you must use lossy compression, please use OPUS. It works much better, and it's FOSS.
Why would High Output Moving Coil (HOMC) cartridges be bothered by loading with a higher input capacitance? Their output impedance is much lower than MM carts. That puts the pole of the low pass filter formed by output Z and input C higher, and any resonance higher up as well. The Denon DL110 has a coil resistance of 160 ohms, which is much lower than the over 500 ohms from a Shure, etc.
It could be that the cartridge's coil inductance has more of a bearing on whether it will run well into a higher input capacitance. If so, can somebody explain why that is, and how that works?
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so you are saying 12AX7 is OK for MM but not for MC ? - an oversimplification if taken out of context, but taking into account the comments above.
Just pointing out that the Miller Cap of the average 12AX7 gain stage coincides with many MM manufacturers' recommended loading specs.
I should not have mentioned MC carts wrt capacitive loading. That was off the cuff and I didn't give it careful thought.
I should not have mentioned MC carts wrt capacitive loading. That was off the cuff and I didn't give it careful thought.
I listen to needledrops posted on other forums, and they are usually at least 16/44.1.
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Tells us what the system sound is but we can’t compare across systems- if you can post comparisons where everything is the same except for the phono amp ?
the idea is to have a reasonable file to test on your system against your existing phono system. this would allow the listener to determine which project to start.
ideally, the song is the same track
ideally, the song is the same track
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sounds interesting.
at the same time, I'm still curious about the Cmiller concerns raised before for phono stages based on high gain first tube (e.g. 12AX7) and why the all-tube cascode input stage isn't de rigueur around here ?
at the same time, I'm still curious about the Cmiller concerns raised before for phono stages based on high gain first tube (e.g. 12AX7) and why the all-tube cascode input stage isn't de rigueur around here ?
I'm planning a couple of cascode projects now and one will be a phono pre. I'd like to try the folded cascode style using a pnp as the "upper" pass device. Just ordered a bunch of 6S4p tubes for this project actually.
Russian 6S4 or European PC86 [at 170V 14mA] make very good RIAA eq stages in Shunt Cascode.
One refinement, that is missing from my previous 'serving suggestion' schematics is an anode stopper resistor: say 330-560Ω 3W wirewound. The tuner triodes can be very susceptible to oscillating without it.
The Shunt Cascode stage gives a current output to drive the EQ network: 2 capacitors, 2 resistors that can do their stuff with zero interference from the ra of the triode - quite an advantage.
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there are plenty of options to address that, one being Merlin's feed-forward (he claims -30dB), the other being a clean supply (yes, that's more complex, but not much). if one uses a clean supply would the cascode then be the preferred approach ?
if you have listened to both, how would you compare them, subjectively speaking ?
I did not listened Kevin stuff but he helped me a lot lowering the input capacitance of Valve Itch with great success so he knows what's doing.
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Kevin gently provided my a table and the way to do it, see the thread Valve Itch post 2699 Valve Itch phono
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One post doesn't illuminate too much for me but if I understand it they are not reducing the capacitance. They are changing the cartridge load resistance to change the Q of the cartridge-preamp-capacitance circuit, cutting down the 'hump' in the treble response at the expense of an earlier roll-off in the treble. Hence, at the end, a lower capacitance will give a more extended frequency response no ?
12AX7 should be a great RIAA tube. however I would do a SS front end > 12AX7 RIAA> SS buffer that should be able to take on any hi end phono preamp and have lower noise as well. The 12AX7 should also have DC heaters.
currently using a single 2SC1815 as an input stage gain of 10 ( noise lower then JFET )
distortion < .01% into op amp RIAA. I used this setup with excellent results as a tape head amp for car stereo back in 1986. the transistor 2N5410 has a gain of 45 and a LF353 performed the NAB eq. s/n 63 db no dolby
currently using a single 2SC1815 as an input stage gain of 10 ( noise lower then JFET )
distortion < .01% into op amp RIAA. I used this setup with excellent results as a tape head amp for car stereo back in 1986. the transistor 2N5410 has a gain of 45 and a LF353 performed the NAB eq. s/n 63 db no dolby
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This describes a technique for measuring input capacitance in the front end of a phono stage. I then suggested how to minimize the strays. (Miller capacitance is a different matter of course)
I use cascodes in the front end of many of my phono stage designs but I am also one of a small cadre of people who like regulated B+ for tube circuits.
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