Voltage mode vs current mode phono stages

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 , IMHO the Grails are horrendously over priced. Looking at the internals the construction quality is not up to modern standards. As an example the boards are through hole not surface mount which is considered to be better. 

The Seta L Plus has significantly better construction, a better power supply and comes in at $10K. It's only down sides are it is not very versatile having only one input and switching between current and voltage mode requires going into the unit and removing or replacing a jumper. You would have no problem with that and I greatly prefer the simplicity.

Without ever having heard or even seen any current drive phono stage, my current favorite just based on tech and reviews and cost, plus balanced operation, would be BMC MCCI.

I suppose some aspects of SMD construction are beneficial, especially in a device centered around an op amp, but not all, and not when repair is needed.

I suppose some aspects of SMD construction are beneficial, especially in a device centered around an op amp, but not all, and not when repair is needed.

This is very true - the proper equipment required to work on SMD boards is around $100k. Most tech's can't afford this investment, and if a manufacturer using SMD technology goes bust - then your precious unit, when it develops a problem will be toast. Even with most manufacturers that use SMD technology, if there is a fault - the "repair" is a new board.

Personally I would never buy a piece of audio kit using SMD technology - seen too many disasters. If you do buy an SMD based unit you have to assume it will need replacing within 5 years.

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.