Nelson Pass XONO
Description:
Not so long ago a friend of mine gave me an old Lenco L75 record player he had found on the local recycling station. As it turns out the Lenco is in fine shape and I have only supplied it with a new headshell and an Ortofon OM10 super pickup. I then decided to build a good RIAA amplifier and because I am a great fan of Nelson Pass the choice was easy: build a (x)ono amplifier. I persuaded my brother to design the pcb's and they turned out to be really nice.
So how does the (x)ono sound?
Well so far I have had the opportunity to listen to the moving magnet amplifier part and I have compared it to the RIAA in a 15 years old Audiolab 8000A, and a 20 years old NAD 3020. I must say I prefer the (x)ono, I like it's warm, pleasant and open wide sound picture.
I have now finished the moving coil amplifier part and had a chance to compare it to an Ortofon moving coil step up transformer with a Ortofon moving coil pick up, and I prefer step up transformer + moving magnet amplifier combination over the moving coil amplifier + moving magnet amplifier. The last combination has a more closed sound picture.
During the tests, I was a bit worried about the amount of hum, but as soon as the amplifiers was mounted in their cabinets the problems was solved. All I can hear now is a small amount of whiz even with the moving coil amplifier running.
Update: I have just replaced my Ortofon OM10 pickup with a Denon DL 103 moving coil pickup, and I must say that this is the pickup I should have used from the start. The DL 103 has a much warmer sound, is more dynamic, has much better bass, and a very good stereo image. The combination of the ono amplifier and the DL 103 is very well balanced and they compliment each other.
Open rstaudio.de web for schematics, you can also purchase very nice factory made pcbs from him.
Picture gallery:
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The assembled power supply pcb. I have improved the power supply a little in the new version with extra capacitors to reduce hum with additional 15 dB.