Dear all, time to wake up. No-one is contributing. I hope it is due to everyone enjoying music. And not the boring sheet of numbers I posted above.
Here are some points, from reading our thread.
- Cartridge output - Kcin, Oldvinyl, myself and others - we all agree that the Io "likes" higher output cartridges, like 0.4 and above, although some seem to get 0.2 carts to work OK without noise problems or the cart sounding too anemic or weak. - I am not fully convinced. Remains to be clarified.
- Tubes - most agreee, NOS sounds better, and all agree that the first gain stage (v1-2) is the most crucial regarding the sound. Some argue that stock new production sounds (almost) as good as NOS, and besides, you can stop worry about tube life, since these are cheap.
- Noise level - general agreement that new production 12ax7 tubes, or at least selected ones (e g by Aesthetix) can be very effective, reducing tube noise in the first gain stage (especially), thereby allowing lower output carts.
- Umbilicals - few have tried. Possibly a marked improvement.
- Balanced phono cable - relatively few have compared (?), but opinion seems to be: no great improvement. No wonder, maybe, since gain stage one is single ended (but then, why the XLR inputs?).
- Connect the Io direct to the amp(s), or use a preamp in between - opinions are divided, but it seems that, those who have tried a high quality preamp in between stick to that solution.
- Kcin mentioned, preamp or direct is "system dependent", and I agree. The speaker / room integration comes into it too. I my case, I traded the "very pure" sound of the Io direct to my amps, for the "more muscular" sound through the Einstein preamp, and this also had to do with my rather large room, which the preamp helped fill with music, to a better extent than the Io direct to the amps.
- It is some years since I tested. I did get an impression that "something" was better, even regardless of room size or gain, with the Io signal passing through a good preamp on its way to the amps. I felt that the Io alone was somewhat thin, or even "ghostly". But this was only after several years, using it as stand-alone preamp. At first I did not notice.
- Cart loading - unresolved. Different results. Main result: everyone finds some workable setting that sounds fairly good.
- Basics – start from good electricity and a stable foundation, and go on from there. The Io loves a dedicated line and a highly stable shelf. Next, you can explore power cables, feet, etc.
- Don’t overdamp the room – good advice from Audioquest4life. If something sounds harsh or glaring, check other possible errors, further up in the sound chain (like, cartridge alignment).