tweak1 OP622 posts07-26-2018 3:09amFYI, Oppo 105 output impedance is 100 ohms. Is the Hattor still a mismatch with the AA amp?
Now we’re looking at what the Oppo can drive
I don’t know the impedance of your Hattor or is attenuation method, series, ladder or shunt.
For simplicity let’s say it’s ladder (the best one), And is say it’s a 17kohm ladder passive this impedance combined (paralleled) with the 17kohm impedance of your AA becomes half, at 8.5kohm that the Oppo will see, this to me a still good impedance for it to looking at.
You can see "if" the Oppo is 100ohms from 20hz to 20khz then the ratio into the 8.5kohm combination Hattor/AA is 1:85.
BUT!!! see that "if" the Oppo could have an output coupling cap, an if not large enough will make that 100ohm impedance rise in the bass and then your 1:85 ratio quickly diminishes which could roll off the bass to early.
Cheers George