Question about loading with an SUT

I use five different carts and use one SUT currently wired at 1:10.

Perhaps a Hagerman Piccolo is in my future but I think from this discussion, I’m going to rule out a different SUT since it seems they need to be tailored very specifically to the cart/tonearm cable and I don’t want to have a different SUT for every cart.

It doesn’t need to be tailored, really. Any SUT in the range of 10x - 24x can be a pretty good general-purpose SUT for most low-ish to low-medium-ish MC cartridges (0.2mV - 0.6mV). Many SUTs also offer 2 taps, which is usually enough to cover "most" needs in an MC cartridge collection. Some even offer 3 or more taps - like the EAR MC-3 and MC-4 - these SUTs are extremely flexible, and sound great with almost any cartridge (excluding the high-output MCs, which are weird anyways).

If you do purchase a Piccolo (I’m a big fan of Hagerman phono gear in general), take note there are 2 versions: the Piccolo MC and Piccolo ZERO. The MC is a more traditional JFET-based "voltage mode" amplifier, with multiple gain levels and load settings. The ZERO is a "current mode" amplifier (a.k.a. transimpedance) that has "some" of the same considerations as a SUT - it won’t work well with cartridges that have high coil DC ohms. However, the Zero is spectacular on cartridges with very low DC ohms paired to efficient magnetic generators - like Ortofon SPUs.The Zero also offers 4 sensitivity levels (internal jumpers) for matching to a specific cartridge. I have a collection of SUTs, phono stages, and cartridges - and I love my Zero! It’s a big middle finger to the rest of the industry that Jim H. sells this for $270.

The Piccolo MC is also quite good by the way - I find Jim's JFET head-amps to be more "musical" than other JFET stages, at the expense of higher noise floor - a tradeoff that is acceptable to me. He does use very cheap SMPS units, in order to hit such low price points. There may be some gain in 3rd party linear PSU's. 

Adam, I’ve got two oscilloscopes, an audio signal generator, and etc. I’ve built and modified my own equipment, which includes Atmasphere amps and preamp. Even I would find Atmosphere’s suggested procedure daunting. There’s nothing wrong with following the few simple rules of impedance matching ( if you know and understand them and can do the simple math) and then using your ears. Down the road you might compare the results to the various kinds of active gain stages and see what you like best.

I use five different carts and use one SUT currently wired at 1:10.

@theflattire If you hear differences between the cartridges its likely got more to do with loading the transformer correctly than anything else.

@adam8179 That method I mentioned is daunting! Jensen Transformers did a lot of this work and so they have a pdf file you have to ask about that shows the loading their transformers are expecting, depending on the cartridge  used.

Plan B: place a 100K variable resistance across the output of the transformer while its plugged into your phono section. Find an LP of which you also have a CD or digital source. Play the CD or file. Compare to the LP and vary the control until the two sound very similar. Its likely that the LP won't sound as bright... At any rate disconnect the potentiometer and measure its value using a Digital Voltmeter on the Ohms scale and find a fixed resistor of the same value or very close.

Right here is actually the biggest weakness of LP reproduction as opposed to digital; not noise floor, dynamic range, distortion or any of that. Its setup and that is likely a huge part of why digiphiles prefer digital; they just really haven't heard an LP set up properly and no shame in that.