Nelson Pass (x)ono clone.

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.
Look at rstaudio web (in links menu) for schematics, you can also purchase very nice factory made pcbs from him. Below you can see some pictures of my brothers design (click on the picture to enlarge it):

The overside of the moving magnet pcb.
The underside of the moving magnet pcb.
The assembled moving magnet pcb. Notice! There is an error in the mm2pcb bill of material: Change R20 and R43 from 6K8 to 15K ohm.		Pcb file updated 2007.12.15
The overside of the moving coil pcb.
The underside of the moving coil pcb.
The assembled moving coil pcb.		Pcb file updated 2007.09.22
The assembled powersupply pcb. I have improved the psu a little in the new version with extra capacitors to reduce hum with additional 15 dB.		Pcb file updated 2007.12.15
Front of the finished moving magnet cabinet.
Back of the finished moving magnet cabinet.
The inside of the finished moving magnet cabinet.
Front of the finished moving coil cabinet.
Back of the finished moving coil cabinet.
The inside of the finished moving coil cabinet.
CAD files for the moving magnet cabinet.		CAD file updated 2007.12.15.
CAD files for the moving coil cabinet.		CAD file updated 2007.12.15.
I use this Mascot 24V/1A AC transformer from RS.

This page was last updated 2009-09-13.