Power amp measurement system

[LKA]

G10 post-notch preamp. IMHO it has quite good performance.

 

[LKA]

I made a compact version of the post-notch preamp. Same box (enclosure) as for notch, powered by external batteries. Gain is selectable by jumper, 1x or 100x. The PCB has two versions, one for single op-amp (OPA627,827,828, etc) and another for dual op-amp (OPA1656,etc). On the picture you can see boxed OPA827 with bypassed input/output caps (4mV output dc @40dB) and unboxed OPA2141 version (waiting for OPA1656). Second picture captures OPA827 output noise (amplification 100x) , input impedance is 50R.

 

[jan.didden]

Very nice! You make great stuff, and professionally looking!

Jan

 

[LKA]

Jan, TY.
There's one thing I regret, I should have used BNC connector, it's far more better than RCA.

 

[LKA]

Almost finished voltage divider, AAA battery holders are on the way, till arrive I made a battery pack (white color on the picture).
The front board holds the divider/attenuator, mosfet SSR, mosfet driver while the rear one is a protection logic/driver.

 

[LKA]

low thd measurement with passive notch filter, example

 

[jan.didden]

Jan, TY.
There's one thing I regret, I should have used BNC connector, it's far more better than RCA.

Yes my passive twin-tee is with BNC ;-)

Jan