This is a great post. Thanks to Pbnaudio for coming to the forum to ask.
Above and beyond everything is sound. Not too long ago I switched to a 30yr old headamp and phono stage where the mfr moved heaven and earth to reduce EMI within the circuitry with exotic materials and manufacturing techniques used (call it super-tweaking). The results are blatantly obvious. That is what I want in a stage. The rest is something I'll deal with somehow. But, as that stage/headamp combo has 1, 2, 3, 4 on the list, the only one I am missing is multiple inputs. I wish I had that.
My commentary would be as follows:
1. Mute/Operate/Mono
Mono good, but then it begs the question if it is real mono or faked mono of a stereo cart. If real mono, it might be better placed in #5 (i.e. Input1, Input2, InputMono). I don't need a mute on a phono stage. If it is 'fake mono', this could be a button/switch next to your input selector (out/in (or up/down) = stereo/mono).
2. Impedance. Lots of choice is great but with so many choices, you'd need a bigger knob. Don't ignore the low end of impedance. I have a couple of carts with <2ohm internal impedance and one cart I lust after has internal impedance below 1ohm.
3. Capacitive Load
My gut is you don't need that granularity but if it costs nothing to get it, go for it.
4. Gain
Everyone will have a volume knob so no need to go overboard. I would think 2 should be fine, 3 would be a luxury, 6 choices is overboard.
5. Input 1 / 2
My preference would be for 3 inputs plus a mono input (real mono).
6/7 If you do real mono, I would suggest doing turnover/rolloff points to provide equalization curves. Maybe that is a special version with a different faceplate and you charge an extra amount for real mono with different equalization curves - if layout was designed right, it would not be a difficult add-in I expect so could be upgraded later, or be added in as a 'module' when building it, tacking on a different, more expensive faceplate. Some would want it, some would not. Those who would want it don't have many commercially available choices at the high end.
The real problem with all of this is that it means lots of switches/connections in the circuit. An input switch is probably the worst offender so has to be the best quality.
As to price... as long as it is the quietest thing on the road, there would be plenty of buyers at that price.
Above and beyond everything is sound. Not too long ago I switched to a 30yr old headamp and phono stage where the mfr moved heaven and earth to reduce EMI within the circuitry with exotic materials and manufacturing techniques used (call it super-tweaking). The results are blatantly obvious. That is what I want in a stage. The rest is something I'll deal with somehow. But, as that stage/headamp combo has 1, 2, 3, 4 on the list, the only one I am missing is multiple inputs. I wish I had that.
My commentary would be as follows:
1. Mute/Operate/Mono
Mono good, but then it begs the question if it is real mono or faked mono of a stereo cart. If real mono, it might be better placed in #5 (i.e. Input1, Input2, InputMono). I don't need a mute on a phono stage. If it is 'fake mono', this could be a button/switch next to your input selector (out/in (or up/down) = stereo/mono).
2. Impedance. Lots of choice is great but with so many choices, you'd need a bigger knob. Don't ignore the low end of impedance. I have a couple of carts with <2ohm internal impedance and one cart I lust after has internal impedance below 1ohm.
3. Capacitive Load
My gut is you don't need that granularity but if it costs nothing to get it, go for it.
4. Gain
Everyone will have a volume knob so no need to go overboard. I would think 2 should be fine, 3 would be a luxury, 6 choices is overboard.
5. Input 1 / 2
My preference would be for 3 inputs plus a mono input (real mono).
6/7 If you do real mono, I would suggest doing turnover/rolloff points to provide equalization curves. Maybe that is a special version with a different faceplate and you charge an extra amount for real mono with different equalization curves - if layout was designed right, it would not be a difficult add-in I expect so could be upgraded later, or be added in as a 'module' when building it, tacking on a different, more expensive faceplate. Some would want it, some would not. Those who would want it don't have many commercially available choices at the high end.
The real problem with all of this is that it means lots of switches/connections in the circuit. An input switch is probably the worst offender so has to be the best quality.
As to price... as long as it is the quietest thing on the road, there would be plenty of buyers at that price.