M
MarkW
New member
MISTERQCUE,
The Jensen one I am interested in is:
http://www.jensen-transformers.com/as/as083.pdf
There are lots of other circuits there, including phantom powering, making a condenser tube mic using one of their transformers, etc.
John Hardy (no web page, but does have E-mail) makes the 990 op-amp, the finished amp, and sells some of the other components. In his info pack, he sends the original AES paper that Deane Jensen wrote about it (990=discrete component op-amp module). Other people make 990 compatible discrete op-amps (Millenia Media and Fred Forsell).
The INA103-based one is in the applications booklet for this chip at the Burr-Brown site (www.burr-brown.com). This is the easiest circuit--the instrumentation amp and a servo. No expensive transformer. The Grace preamps use the 103 as the front-end.
Both of these can have a lot of gain (60 dB), so these are not beginner projects (oscillation, hum, etc.), but what the hell?
The Jensen one I am interested in is:
http://www.jensen-transformers.com/as/as083.pdf
There are lots of other circuits there, including phantom powering, making a condenser tube mic using one of their transformers, etc.
John Hardy (no web page, but does have E-mail) makes the 990 op-amp, the finished amp, and sells some of the other components. In his info pack, he sends the original AES paper that Deane Jensen wrote about it (990=discrete component op-amp module). Other people make 990 compatible discrete op-amps (Millenia Media and Fred Forsell).
The INA103-based one is in the applications booklet for this chip at the Burr-Brown site (www.burr-brown.com). This is the easiest circuit--the instrumentation amp and a servo. No expensive transformer. The Grace preamps use the 103 as the front-end.
Both of these can have a lot of gain (60 dB), so these are not beginner projects (oscillation, hum, etc.), but what the hell?