Active FETs vs. Step-up phono stage designs

Lewm:

I think that part MAT02 is the same part I was refering to. As the older analog device producers get aquired by larger companies, many of these parts get lost in the shuffle, unless the customer starts screaming. Couple that with the fact that fabs for discretes are becoming more expensive to maintain...not even the Chinese want to make discretes. Large power transistors are still available, but small signal are getting tougher to find.

Suprisingly, many of the early op amps are still available, probably due to replacement requirements in military and industrial equipment. All the late 70's TL070 and 080 series are still with us, as are the the very first 741s. But special parts from Burr Brown and PMI have dissappeared.

The MAT02 certainly lives up to AW's opinion of it in the context of my preamp. I have two extra pairs, just in case. (As you know, the MAT02 is a dual section device, so one of them suffices for each balanced channel, and the section matching in terms of transconductance, etc, is way better than one could hope for in a dual section tube, plus it stays that way over time.) Everything else downstream is tubes.

The discontinued MAT02 is replaced by MAT12.

http://www.analog.com/static/imported-files/data_sheets/MAT12.pdf

Like Lew I use this at input of phono in the bottom of a hybrid cascode. It provides huge gain, low noise, and great sound.

Thanks for that URL, Dave. I did not know about MAT12. I wonder if it is equally suitable to our application, compared to the MAT02.

Lew, another hobbiest has used MAT12 interchangeably with MAT02 in this application, so I don't think there is any issue.