Hello guys!
I read this forum from years and the time is arrived when I will get involved with doing my first electric job. I want to ask your help about modding a Shure fp 42 four channel mic preamp. I own it from a while and find it to a really handful and lovely unit with great futures. The only problem is the relative loud hiss in it. You can read about this on forums (it is the same issue with the fp31) and usually the solution is to buy a Sound Devices unit for 10x more money. Unfortunatelly I don't have the money but luckily I have the passion to modify this lovely one.
Now. Here is the schematic in the manual:
https://www.google.co.uk/url?sa=t&source=web&rct=j&ei=hxmHVeutF4KrswHd7KqoDQ&url=http://www.shure.com/user-guides/us_pro_fp42_ug.pdf&ved=0CDgQFjAG&usg=AFQjCNEzfCeEtgqcTcbY3MorWn-qNIKz8A&sig2=nKTvZrn54Ms44EQ76p0qIw
I was thinking about to change the OP amps in it. The original one is the Raytheon RC4156DB. Here is the data:
https://www.google.co.uk/url?sa=t&source=web&rct=j&ei=ehqHVZC5LsKQsgH11oHQCQ&url=http://www.e2v.com/shared/content/resources/File/documents/QPSemi/Ray_4156.pdf&ved=0CB4QFjAA&usg=AFQjCNHd5a4ikRJV6PE6XLot5gs9Tg7cqA&sig2=i2vUYHrnFyL6_UAnNecq1g
As I read it before somewhere it can be replaced with the LME49740. Here is the datasheet:
https://www.google.co.uk/url?sa=t&source=web&rct=j&ei=SCCHVZa3JIKqswG7oYPIDQ&url=http://www.ti.com/lit/ds/symlink/lme49740.pdf&ved=0CCMQFjAB&usg=AFQjCNFxTg1lrkDVLC75PtGFgBsX4e-viw&sig2=Tygip2WFH9Lz-ke3ckF5sQ
I would like to ask your opinion about this idea. Should I have to modify the circuit to supply this amp or to match the signal levels? Any better solutions than mine? I am open for any modification ideas!
And please! I don't want to buy another unit. I want to improve this one and get involved in electronics.
Thank you in advance!
I read this forum from years and the time is arrived when I will get involved with doing my first electric job. I want to ask your help about modding a Shure fp 42 four channel mic preamp. I own it from a while and find it to a really handful and lovely unit with great futures. The only problem is the relative loud hiss in it. You can read about this on forums (it is the same issue with the fp31) and usually the solution is to buy a Sound Devices unit for 10x more money. Unfortunatelly I don't have the money but luckily I have the passion to modify this lovely one.
Now. Here is the schematic in the manual:
https://www.google.co.uk/url?sa=t&source=web&rct=j&ei=hxmHVeutF4KrswHd7KqoDQ&url=http://www.shure.com/user-guides/us_pro_fp42_ug.pdf&ved=0CDgQFjAG&usg=AFQjCNEzfCeEtgqcTcbY3MorWn-qNIKz8A&sig2=nKTvZrn54Ms44EQ76p0qIw
I was thinking about to change the OP amps in it. The original one is the Raytheon RC4156DB. Here is the data:
https://www.google.co.uk/url?sa=t&source=web&rct=j&ei=ehqHVZC5LsKQsgH11oHQCQ&url=http://www.e2v.com/shared/content/resources/File/documents/QPSemi/Ray_4156.pdf&ved=0CB4QFjAA&usg=AFQjCNHd5a4ikRJV6PE6XLot5gs9Tg7cqA&sig2=i2vUYHrnFyL6_UAnNecq1g
As I read it before somewhere it can be replaced with the LME49740. Here is the datasheet:
https://www.google.co.uk/url?sa=t&source=web&rct=j&ei=SCCHVZa3JIKqswG7oYPIDQ&url=http://www.ti.com/lit/ds/symlink/lme49740.pdf&ved=0CCMQFjAB&usg=AFQjCNFxTg1lrkDVLC75PtGFgBsX4e-viw&sig2=Tygip2WFH9Lz-ke3ckF5sQ
I would like to ask your opinion about this idea. Should I have to modify the circuit to supply this amp or to match the signal levels? Any better solutions than mine? I am open for any modification ideas!
And please! I don't want to buy another unit. I want to improve this one and get involved in electronics.
Thank you in advance!