Need for Bode plot in DSO? Need for 4 channels in analog audio?

[capslock]

The new low cost 12 bit DSOs from Siglent have been released, and their hardware specs beat the newisch 12 bit Rigols by far (and Rigol have a reputation for bugginess). I'm not sure how the 12 and 14 bit scopes by Owon that have been around for far more time than even the Rigols fare in comparison.

Anyway, the Siglents have the option of doing a Bode plot if you shell out extra for an outboard waveform generator:

https://www.eevblog.com/forum/testgear/sds800x-hd-review-demonstration-thread/msg5293741/#msg5293741 (beginning of review thread)
https://www.eevblog.com/forum/testgear/sds800x-hd-review-demonstration-thread/msg5293771/#msg5293771 (scroll down half way in this post)

How useful is this in audio? In a power amp, you'd first have to break the loop and somehow reduce the gain, e.g. by feeding the input from a much attenuated signal.

Also, is there any point in getting 4 input channels? I understand they can be useful in digital circuits (even if a digital analyzer is more suited), but I can't remember having wished for more channels in linear audio.

 

[gpapag]

I'd love to have a scope doing a 500 points bode plot with at least 60dB dynamic range as shown in your two links above.
4 channels come in handy when checking I2S lines, otherwise not of much use in audio.
But if one can pay for the package, why not?
George

 

[Mark Tillotson]

I found a use for 4 channels with audio - when using bootstrapped supplies is useful to monitor both supplies and the error and output waveforms: