That 10dB improvement reflects the upper part of the SRPP contribution we should suppose? Because the lower part owes to be dominated by the K170 en?
The noise graph is for 2 MM units, so there is no 2SK170 involved there. The noise difference is only due to the two different types of FETs in M1 and M2 positions. As I've said earlier, the BSS139 has a noise voltage density about 15-20nV/sqrtHz at 1kHz, the "LE" type FET has less than half of that, about 6-7nV/sqrtHz at 1kHz. In the MC version the noise contribution of the input 2SK170 is dominating, however there is still some difference in the noise between the SE MC and the LE MC units, about 1.5-2dBA.
Yes, I was late with my answer, sorry!
Cheers
Alex
Sure Felix, I agree that's optimal. But it means you can't readily change cartridges.
Which (facility) is a good thing to have. Just like not having coupling caps is "optimal" ... but not that many components go this way. I have no doubt it will be better than your ESP phono stage ... but, once you've got your Kora up and running (with the soldered resistor of your choice installed
), I could send up my JFET phono stage for you to compare. (You have my email address.)Enjoy.
Regards,
Andy
Hi Ian,
I am not sure that I should authorise a group buy of an untested pcb. On one hand the Kora 3T circuit is so simple that it can be built on a strip-board in one evening, on another hand I may offer the original pcb (or even a kit) for DIY. The pcb would fit one of the Hammond aluminium enclosures perfectly and would at least guarantee that the performance of the circuit won't suffer from a bad layout. It won't be very cheap thought
.On the second question - I've described the differences in the post #18.
Cheers
Alex
G'day all, Well my ANT Kora 3T (SE) phono stage for moving magnet cartridges. http://www.ant-audio.co.uk/reviews/Kora_3T_SE.pdf arrived yesterday from the UK, and I've wasted no time in getting it connected and playing reconds via my Kenwood KP-3022 and Shure M97xE/SAS. By the way my unit looks brand new and the build quality is superb.
My impressions? This is a very fine and good sounding phono stage and deserves the accolades it has received in recent years. I am advised that this particular model is now no longer in production, but the 'LE' (Limited Edition) model is.
Its arrival is also interesting as I was keen to compare it to my existing DIY ESP P06 phono stage, and I am gratified to say that the two are essentially equivalent in quality and sonic performance. If anything the ESP P06 has a 'slightly' stronger lower bass end and slightly higher overall voltage gain (that is, it plays louder at the same volume setting), but in all other respects (noise floor, RIAA equalisation and soundstage), they are virtually equal and both outstanding.
Apart from revealing the general excellence of the ANT Kora 3T in itself, the comparison also shows the excellent performance afforded by the present crop of high quality DIY designs and I hope that this FET based phono stage is made available in some form of DIY guise! It will be truly excellent. Regards, Felix.
My impressions? This is a very fine and good sounding phono stage and deserves the accolades it has received in recent years. I am advised that this particular model is now no longer in production, but the 'LE' (Limited Edition) model is.
Its arrival is also interesting as I was keen to compare it to my existing DIY ESP P06 phono stage, and I am gratified to say that the two are essentially equivalent in quality and sonic performance. If anything the ESP P06 has a 'slightly' stronger lower bass end and slightly higher overall voltage gain (that is, it plays louder at the same volume setting), but in all other respects (noise floor, RIAA equalisation and soundstage), they are virtually equal and both outstanding.
Apart from revealing the general excellence of the ANT Kora 3T in itself, the comparison also shows the excellent performance afforded by the present crop of high quality DIY designs and I hope that this FET based phono stage is made available in some form of DIY guise! It will be truly excellent. Regards, Felix.
G'day mate, although I've seen 'mechanical' break in/warm up happen for myself, I've done enough audio DIY work to say that it basically doesn't happen with electronics to any marked degree.
Don't get me wrong, I love the ANT Kora 3T and I will give it plenty of use and yes I'm leaving it powered onm but my DIY ESP P06 is every bit as good. Regards, Felix.
Don't get me wrong, I love the ANT Kora 3T and I will give it plenty of use and yes I'm leaving it powered onm but my DIY ESP P06 is every bit as good. Regards, Felix.
Hi Felix,
1) The Kora 3T MM SE you've got is an ex-demo unit which was only used for 50-70 hours about 10 month ago so it does need a good run-in (few days at the very least).
2) There is no magic in the "running in" of an electronic audio device. Most of this process (IMHO) is due to the dielectric absorption in electrolytic capacitors - time constants involved extend to hundreds of hours. I did some measurements on that and the time it takes for an elcap to stop leaking additional current due to DA quite well coincides with the time for the circuit to reach its full sonic potential.
3) After a few days break-in period I would advise you to have a careful play with the biasing adjustment. The optimal biasing point could be quite sharp for some set-ups however only when biased correctly the Kora is capable of showing its true colours.
Cheers
Alex
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There is not quite enough space in the original board to put in good quality 10uF polypropylene caps and a good electrolytic is better than a polyester film cap IMHO. There is no special "synergistic voicing" in my design - I'm after the most transparent and natural sound, when you can hear more of the music, not more of nice distortions
. I've used ELNA StarGet on the output with good results but there are better options and if the casing allows you to use PP caps - good! It is also possible to increase the capacitance of the output cap to 22uF or 33uF, useful if the further load is less than 10-15kOhm. Cheers
Alex
G'day all, a bit of listening this afternoon in between numerous other tasks!
I was able to spin one side of the Jimi Hendrix Experience 'Electric Ladyland' album, and listening to 'The Burning of the Midnight Lamp' (a personal favourite), as Jimi sang the words, 'Loneliness is such a ...drag' the sense of sincerely in Jimi's voice was quite palpable.
Most impressive from a phono stage! The ANT Kora 3T is top notch! Regards, Felix.
I was able to spin one side of the Jimi Hendrix Experience 'Electric Ladyland' album, and listening to 'The Burning of the Midnight Lamp' (a personal favourite), as Jimi sang the words, 'Loneliness is such a ...drag' the sense of sincerely in Jimi's voice was quite palpable.
Most impressive from a phono stage! The ANT Kora 3T is top notch! Regards, Felix.
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