Do I need a phono preamp?

[billyz]

This is all VERY helpful to me and has cleared up a lot. Thanks for all of the responses, everyone! Even the ribbers. For the record: I am not a thief. I bought a VPI turntable with the Koetsu Rosewood Signature attached for only $350 at an estate sale in Boston several years ago. It was probably the best thing I will ever find second hand. So that’s how I have such a high-end cartridge without knowing all of what’s recommended for getting the most out of it. But I’ve really been trying to understand more about the gear that I have so I can update and outfit my setup accordingly. Also, I posted my question on my lunch break at work and I haven’t had time to check back in until now.

My budget is about $500, but of course I would rather spend less than that. Thanks billyz. The Denon DU 320 seems like it might be the one for me. The price is right! The Parks Audio Budgie looks beautiful, but there aren't any on eBay.

What is the difference between a SUT and a Head Amp?

A SUT is a passive “Step Up Transformer “ .
There is a ratio of windings on one side to the other side. Typically 1:10 or 1:20 or other like 1:14 etc. I have read it also described as transforming the current of the cartridge into voltage . You don’t get something for nothing.
A Head Amp or Pre-preamp is an active circuit just like the regular pre amp . It’s just an added amplification stage. The SUT usually needs to be located in a position that is least susceptible to picking up hum. Like not in close proximity to a motor or power transformer, which radiate a field .
I have never had trouble locating the SUT for quiet operation . I have experienced hum when placed in a less ideal location . Sometimes just a inch or two one way or the other makes a world of difference. Grounding can be an issue as well just like with any cartridge.

Here is a link to a more in depth article.
https://theanalogdept.com/sut.htm

 

[MisterDK]

Some SUT’s are better shielded than others. My favorite one uses a Mu-metal internal casing and I haven’t noticed any hum through it.

 

[sachu888]

You can build this one https://audiokarma.org/forums/index.php?threads/ad797-phono-stage-build-and-help-desk-thread.501186/

Regards
Sachin

 

[sqlsavior]

A transformer is a device that has two wires wound around a common core. One wire, the input, is called the primary winding, and creates a varying magnetic field when a signal is passed through it. The output wire, called the secondary, has windings that share the magnetic field. It can have fewer windings, for a 'step-down' transformer, more windings, for a step-up transformer, or the same number of windings, called an isolation transformer. The magnetic field is shared, but the electricity itself is not - the windings are insulated so the primary and secondary wires do not connect electrically. The ratio of the number of turns of the primary and secondary windings determines the ratio of voltages on them. A transformer can also have one or more 'taps' at different points in the secondary, yielding multiple, selectable ratios.

A transformer is not an 'amplifier', because no energy is added. As other have stated, a tradeoff is made between voltage and current instead. Good transformers (which are needed for audio signals) need care in their design and manufacture, and are expensive compared to today's mass-produced electronics.

An amplifier needs an energy source for the signal to modulate/amplify. For the tiny signals typical in a head amp or even a phono preamp, batteries are a possible design choice. Otherwise, they plug into the wall, one way or another. Either are called 'active' circuits, because outside power is supplied. A transformer is passive - no outside energy needed.

I have a magnetic passive pre-amp, which uses transformers with 24 taps, for 24 volume settings. I'm admittedly a transformer fan.

 

[MRL_Audio]

@sqlsavior - great post and, for me, most informative.