Alternative to MC step-up phono transformer

[Mellotronix]

I have already covered my phono preamp fails in other threads, so I won't bore you with the details, but I did order a new Sutherland, which should get here on Friday, In the meantime, I plugged my VPI Prime Scout directly into the MM pre on my Yamaha AS801 integrated amp with surprisingly good results, considering that the Grado Statement cartridge only outputs about 1.0mV. But having the volume up so high on the Yammy could be dangerous should someone switch sources without adjusting the volume.

I decided to try an using an old Focusrite USB computer audio interface as a step-up preamp. Basically, I'm running the turntable audio directly through the Scarlett 2i4. The USB's only purpose is to power the unit.

Turntable output--->Front of Scarlett (inputs 1 and 2 using RCA-¼" adaptors)
Scarlett Balanced Outputs 1 and 2--->Yamaha AS 801 MM phono input (again using RCA -¼" adaptors)

Gain staging: The potential for a distorted, noisy mess exists here so it pays to work with the gain staging to get the best signal with the least amount of distortion and lowest possible noise. I have the Scarlett Inputs set to Instrument and the gain is exactly halfway. Pads are off. The Direct Monitor knob is set fully to "Input." The Monitor pot is up ¾.

After much knob twisting and button pushing, I found the above to give me a nice, punchy signal with no audible distortion and very low noise at regular listening levels. I've almost given away this old Scarlett several times, but I keep finding uses for it.

 

[AvFan]

I have a 2i4 as well but only use it for digitizing my records and I never thought to use it essentially as a head amp. Interesting.

Good call on the Sutherland. I really enjoy my PH3D however it has no power supply issues, just 16 D cells! Enjoy!

 

[Mellotronix]

I have a 2i4 as well but only use it for digitizing my records and I never thought to use it essentially as a head amp. Interesting.

Good call on the Sutherland. I really enjoy my PH3D however it has no power supply issues, just 16 D cells! Enjoy!

You have no idea how close I came to purchasing that unit. How often do the batteries need replacing?

 

[AvFan]

You have no idea how close I came to purchasing that unit. How often do the batteries need replacing?

Sutherland recommends changing the batteries annually and I could see how it would be a mess if one or more leaked. I've only had mine for a few months and it is still going strong on the new ones I installed. I had to laugh; it takes 16 batteries and Costco sells them in packs of 14.

FYI, I use one of two SUTs I own with the Sutherland' and its gain is at or near its lowest setting for my MC carts. Fine combo.

 

[Mellotronix]

Sutherland recommends changing the batteries annually and I could see how it would be a mess if one or more leaked. I've only had mine for a few months and it is still going strong on the new ones I installed. I had to laugh; it takes 16 batteries and Costco sells them in packs of 14.

FYI, I use one of two SUTs I own with the Sutherland' and its gain is at or near its lowest setting for my MC carts. Fine combo.

Thanks for the info. The Scarlett is obviously not going to replace a good SUT. It's just not designed for that purpose, but sometimes you have to make do with what's available. I thought about using my Schiit Valhalla 2 headphone amp as a SUT but never quite got that far.

 

[AvFan]

I've made some pretty good 96/24 recordings with the 2i4 (and VinylStudio software) so while not expensive I think it does what was intended. That you found another use for it is pretty cool. I have a Schiit Lyr 2 headphone amp and never thought to try it as a head amp either.

 

[sqlsavior]

The Eternal Cleverness of the Audio Mind...

 

[rothwellaudio]

I haven't seen your other threads about "phono preamp fails" but the Grado cartridge is a bit unusual. They call it a "fixed coil design" and in terms of its electrical characteristics it's more like a high output moving coil than a low output moving coil. Its coil impedance is 72 ohms with 30mH of inductance, which is a lot higher than a typical LOMC. Many modern Ortofons for example have a coil resistance of about 5 ohms with inductance so low they don't specify it. Audio Technicas have about 25uH inductance, so over a thousand times less than the Grado. Anyway, that means the Grado isn't particularly well-suited to use with a step-up transformer. Transformers like to work with a source impedance as close to zero as possible, and the Grado is a lot farther from zero than most LOMC cartridges.

The best way to handle this cartridge (in my opinion) is to use and active mc phonostage with a gain of about 55dB and a load impedance of at least 1k, preferably higher. Grado recommend a load of 47k, though you would probably get away with less than that. The Sutherland phonostage looks to be ideal because it does exactly what this cartridge needs.