opa 509 diagram same as lm3875?

[moonshow]

hi

i've been searching diagrams for opa 509 but havnt found any. can i use the schematics of the inverted lm3875 and just replace it with opa 509?

what voltage trafo should i use here.


thanks

[carlmart]

Originally posted by moonshow

i've been searching diagrams for opa 509 but havnt found any. can i use the schematics of the inverted lm3875 and just replace it with opa 509?

what voltage trafo should i use here.

You mean the OPA549.

You can use the same 3875 schematics, but not the resistors values.

On a recent thread there were some comments on these OPA chips needing less gain, as their bandwidth is smaller than the LMs.

100K and 10K might do the job, but be prepared to listen to the system and change the larger resistor for a smaller (or higher) one and listen to what does change.


Carlos

[theChris]

the opa549 schematics are a little different as they have an optional current limiting resistor and diodes for protection purposes.

[pinkmouse]

Originally posted by carlmart

100K and 10K might do the job, but be prepared to listen to the system and change the larger resistor for a smaller (or higher) one and listen to what does change.

I currently use 220k and 20k, mostly because I have lots of 220ks

[carlmart]

Originally posted by pinkmouse


I currently use 220k and 20k, mostly because I have lots of 220ks

It should be fine

[miguel2]

The 220k resistor can be SMD .

Miguel