New way to make a balanced gainclone?

[MtBiker]

Has anyone ever looked at the Maxim MAX435 for well, any audio application at all? Would this be a good candidate for a balanced-in/balanced-out buffer to a pair of IGC's?

[PRR]

> good candidate for a balanced-in/balanced-out buffer to a pair of IGC's?

Might get more comment if you posted a link to the MAX435 datasheet PDF so us lazy geeks don't have to hunt for it. (Yeah, copy/paste to Google, click twice.... we be lazier than that.)

Hmmmm.... that's way too good for audio. But at $3 bulk, apparently $5.13/each in-stock off Maxim's online store, "too good" is not a cash problem. It will still need RF-neat layout and decoupling.

Max supply voltage is +/-6V. You have to make/fake that somehow. However most small chips used before power amps will need their own supply, this is no worse.

The gain calculation is strange for chip users. Transconductance? You can take the suggested circuits and get a known gain, but they are all for the very low load impedances associated with 100MHz chores. We 20KHz people don't need double-terminated 50Ω lines, and they eat power we don't need to eat. Should be possible to scale-up, though you can't go too far if you want a low output impedance.

The peak output voltage may be just a few volts. I'm befuddled by the strange operation, Maxim's awful-blurry PDF, and east coast humidity.

CMRR sure is good and to incredible frequency.

There is no(?) spec on output current balance. I don't know if we care, assuming it is within a few percent.

There is no(?) spec on distortion, IMD, intercept, or anything to suggest linearity. Guessing what they are doing, linearity is very good but not perfect. For-sure needs an ear-test.

One annoyance is the 1uA input current. And it has a strong temperature drift. Even the 0.5uA input current of a NE5532 can force lower input resistors than we like. I suspect even with 10K input resistors we will want capacitors between this chips outputs and a power-amp input.