Balanced Zen v. Borbely SE Balanced

Here's another comparison request (don’t you just luv ‘em!)

I’m wondering if anyone has compared the Balanced Zen Line Stage, by Mr Nelson Pass, with the SE Balanced Line amp (EB-2000/402) by Mr Erno Borbely?

While I’m have an (increasing) admiration for the work of Nelson Pass, I am attracted to the idea of using JFETs instead of MOSFETS in a pre-amp. Indeed Mr Pass acknowledges the superiority of JFETs in certain low level applications.

Incidentally, to ascertain the performance of a “passive pre” in my system I soldered a couple of resistors in my interconnects as a voltage divider, and connected directly into my amp. Obviously I can’t alter the volume, however (as my CD player has two pairs of outputs) switching between the pre-amp and the attenuated leads demonstrated the affect of the pre-amp on the signal. Just a thought for those considering going down the passive path, but wanting to see the effects before spending a lot of money on a stepped attenuator. An alternative would be to make a series of “piggyback” RCA plugs of different values, with a female and male RCA connected via an attenuator.

Cheers,

Pete
 
Pete,

Both designs you mentioned are excellent, I have a slight preference for the Pass. I would current current source the circuit as suggested by Nelson(but try it both ways). The Borbely design, could be improved by replacing the follower, with for exmample, a single ended mosfet.

Have you considered using a shunt volume control?

Jam
 
Think Mr Pass will get the nod

While I like the idea of using JFETS, I haven't been able to easily locate the devices used in the Borbely design, so I think the Pass project will get the nod.

I'm designing the pre-amp as a modular concept so can easily replace the gain stage. I'm presently collecting data to use the same typology as the "Balanced Zen", except with JFETS.

Cheers,

Pete
 
Pete,
The use of j-fets is probably not necessary as noise should not be a problem for the signal levels involved (they would be if you were building a phonostage).
Also you would need a buffer since j-fets might not handle the current levels required and you will be forced to use a follower.

Jam