Recommendations for Phono Stage (RIAA?)

[LucasAdamson]

Originally Posted by peranders

You have my monster RIAA amp, only for people with no heart condition

Now that's dedication!

I'm still looking...

...the John Linsley Hood phono stage kit is £110 and £75 for the power supply, making £185, which is just too much for a kit right now. My turntable, a Technics SL-1210 Mk2, was much less than that.

Any more suggestions?

[binspaul]

Hi,

Try Bugle phono stage: Hagerman Technology LLC: Bugle Opamp Moving Magnet Budget Phonostage DIY Kit

Best regards,
Bins.

[Conrad Hoffman]

FWIW, I've been very happy with circuits similar to what National published in their app notes for the LME series of op-amps when they introduced them.

[LucasAdamson]

I have been researching different solutions and concluded that opamps produce much cheaper, reasonable quality products, but that the very best hi-fi designs are fully discrete.

How true is that?

[Conrad Hoffman]

Condensing a huge topic to a few sentences, there are a couple philosophies. High gain with significant negative feedback. Low gain with less negative feedback. Commercial opamps will have huge open loop gain and operate with a lot of negative feedback. Much audio mythology says this is bad. The hallmark of most discrete design, other than power amps, is simplicity and low gain, coupled with lower amounts of feedback. Much audio mythology say this is good. You have to decide what your definition of good and bad are. I believe you'll find Pass designs fall into the simple, elegant and low feedback group, and people certainly have high regard for them. Personally, I tend towards high gain, high negative feedback and low distortion. Hopefully without odd harmonics and the errors of the past. There have been plenty of bad opamp designs, but today we have parts that need make no apologies. IMHO, there are multiple paths to get where you want to go.

[peranders]

Conrad, you are partly right. If you have an one opamp solution the feedback will not be very high, sometimes even to little to achieve an accurate RIAA curve.

[binspaul]

Hi,

Try RETRO from twisted pear audio. The link is: Retro - A fully symetrical phono stage with RIAA filter

Best regards,
Bins.

[LucasAdamson]

I have settled on the "Atlantis." It is a single ended, Class A, zero feedback RIAA Phono pre-amp, by Mads K Hoaas. Here's the schematic for the MM version, which I am making:



I have PCBs on the way

I like that it is discrete, as I'm inclined to be suspicious of op-amps, even though I have them in my DAC and I am largely ignorant as to why they are less desirable for hi-fi than discrete solutions.

[binspaul]

A simple and accurate Phono Preamp design is available at: http://pdfserv.maxim-ic.com/en/an/AN1931.pdf