Voltage mode vs current mode phono stages

You been on a ride yet? My wife and I have new bikes this year. The drive trains are somewhere between New Hampshire and Italy.

This year's ride is leaving Banff on the 10th of June and hoping to arrive at Antelope Wells, NM in under 30 days (we'll see). https://www.youtube.com/watch?v=MW_z-z3tfxw In 2019 I made it to the Brush Mountain Lodge; Steven of this video passed me on Union Pass in Wyoming...

This is very true - the proper equipment required to work on SMD boards is around $100k.

@dover That depends on the type of SMDs used. The 0402s and the 0201s can be done with fairly simple equipment certainly costing maybe $500 if you stretch it! It can also be done by hand, which is how all of our class D stuff is done (locally). All you need is the right kind of solder station, proper magnification and a steady hand.

Hi Ralph, You wrote, "This suggests that as the impedance of the cartridge goes up, the gain of the circuit goes down, which is probably good since the output of the cartridge will be higher."  The linear relationship between voltage output and stylus velocity (higher at higher frequencies) is accounted for by the RIAA correction.  Would you want the cartridge to alter that relationship by virtue of an upgoing internal impedance?

@lewm I don't think I would employ any EQ on the transimpedance input (meaning the opamp). I would leave that for later in the circuit, such as a passive EQ network at the output of the opamp. In this case the constant velocity aspect of the cartridge really has nothing to do with it.

@lewm Since the cartridge functions as the input resistor to the opamp, the impedance of the cartridge affects the gain of the circuit (as you probably know, the gain of an opamp will be the ratio between the feedback resistor and the input resistor). This suggests that as the impedance of the cartridge goes up, the gain of the circuit goes down, which is probably good since the output of the cartridge will be higher.

I've not messed with this circuit to any great degree, so I don't know what constraints might exist, but I'm sure there are limitations- there always are. I just thought I'd point this first bit out.

 Isn't the difference between a 'warm' and 'lean' sounding system a shift in frequency responses? 

@ledoux1238 IME on a system level that is often caused by distortion. The ear assigns a tonality to all forms of distortion. Lower orders (2nd- 4th) add warmth and they can mask the presence of the higher orders. If the higher orders are not masked, even in tiny amounts they cause harshness and brightness. The ear is keenly sensitive to them as it uses them to sense sound pressure.

For example in a phono section to know whether its a frequency response error causing the tonality or distortion, you have to measure the phono section with an inverse RIAA network to see how accurate it is. If its has flat response but sounds bright, distortion is likely the cause.

whereas voltage mode is an endless pursuit of SUT’s and loading. I have admittedly rather entry level stuff, so not the final word. 

@ledoux1238 If you have the right voltage mode phono section, its also plug and play- no SUT and no worries about loading.