DIY RIAA for MC cartridges

[Lautreamont]

Hello everyone,

I think the weakest link in my analogue setup at the moment is my phono stage. I'm currently using an entry-level Pro-Ject Tube Box with a Denon DL-103R. The cartridge is mounted on a restored SME 3012 tonearm fitted to a wonderful custom-built belt-drive turntable with an external power supply and a large acrylic platter.

For a long time, I've wanted to try both a vintage Ortofon SPU and an original Decca FFSS, preferably paired with a suitable step-up transformer. The problem is that I have to admit my understanding of the whole phono stage/SUT landscape is quite limited, so I'm hoping to learn from those with more experience.

I've had great luck finding an underground tube amplifier builder who built me an exceptional 45/46 single-ended DHT amplifier using top-tier components at what I consider a very fair price. A friend of mine has had similar success finding vintage equipment, often finding it to outperform many contemporary products while being affordable.

That experience has made me think if I could find a vintage phono stage however as I understand it, the classic integrated amplifiers usually had the phono sections built in, so I'm curious whether there are standalone vintage RIAA stages that represent similarly good value. My initial thought was to pair one with a Partridge- or Jørgen Schou-based step-up transformer, especially if I eventually move to an SPU or Decca cartridge.

I've read quite a bit about Abbas Audio, Audio Antiquary, and EM/IA. They all seem to have excellent reputations, but they're also considerably more expensive than what I paid for my amplifier, which makes me reflect whether there are overlooked vintage alternatives that offer exceptional performance for the money. Or perhaps I should go the "DIY"-way. Does anyone know of designers who are talented in this regard?
So I'd love to hear your thoughts:

• If you were building around an SPU or Decca FFSS, which phono stages and SUTs would you be looking at?
• Are there particular vintage RIAA stages that deserve more attention?
• Or would you recommend staying with a modern design instead?
• Do you know any designers who masters RIAA production?

I appreciate any guidance or recommendations, thanks all!

 

[joe83]

The diy kit for the Ear 834 sounds as good as any I’ve heard and can be put togeather for very little, you might like using vintage parts. I have an original and another with vintage parts and both sound amazing

 

[Redboy]

The SPU and FFSS are very different animals. The SPU (a moving coil cartridge) will require an SUT; the FFSS (moving magnet) does not. The FFSS cartridges will also need a different tonearm or adaptor too, but that's not what you're asking here...

There aren't many standalone vintage phonostages out there. I think you'd do better to look for a well-regarded newer production model, either secondhand or kit-built as @joe83 suggested. You could buy a good MM level stage and add an SUT when you use the Ortofon cartridge.

 

[asilker]

Since in your title it says DIY, I assume you're not terrified of the idea of slangin' a little Solder. If that's truly the case, why not build yourself a tube phonostage.

Here's what I did:
I had a Scott in the shop with a problem in the phonostage.
In an effort to troubleshoot the phonostage I ended up drawing a schematic of it start to finish.
I had recently finished building a tube line stage and thought to myself, "what if I put the HH Scott phonostage, in front of the sweet little line stage I built and put it all in one pretty box?"
So I ordered what I needed and got to work.

To get it to work with low output moving coil cartridges i put a Cinemag step up transformer in front of the phonostage.
Secondary wired across the 47k phono input.

You can do the same thing to any of the old RIAA stages in any old amp that you like, and you'll end up with a well designed and highly functional tube riaa stage.
The brilliant thing about antique phonostage designs is that they almost always use active RIAA equalization via a feedback path around the stage which has a side effect of reducing noise.

Passive RIAA is what everyone talks about today, but much like open baffle speakers, single ended triode power amps, and feedback free listening, High Fidelity playback is much more achievable if you stick to established best practices...
View attachment 123722View attachment 123723View attachment 123724View attachment 123725

Great looking unit!