Quote:
Originally Posted by NelsonVandal  I've never seen it advertised as "bypassing ground". I don't even know what that means.
|
From AMB's website:
The ground channel amplifier sources or sinks the return current from the transducers, which would otherwise have been dumped into signal ground or power supply ground.
From AMB in another thread:
In an active ground amp, the load current doesn't go to ground.
From Morsel, who claims credit for the "active ground" idea:
Cmoy, I came up with the idea for using a headphone amplifier ground channel to shift responsibility for the high current reactive load of the headphones from signal ground to the supply rails, thus removing the primary source of signal ground contamination in 3 wire headphone systems.
All of these claims claim that the load currents magically go someplace other than ground, thus effectively bypassing ground.
Quote:
| Yes, but does L78xx/79xx or LM317/337 sound as good as eg AD825, LM6171 or LME49713? That's the question. |
Dunno. I haven't seen it demonstrated that either produces any actual audible differences over the other.
Quote:
| There are no perfect sounding opamps, are there? |
Guess that depends on how you're wanting to define "perfect."
There is nothing that's perfect from a purely technical point of view. But if an opamp does not produce any actual audible difference, it may well be considered "perfect" for all intents and purposes.
Quote:
| Many of them are good, but I haven't heard any without coloration. Take eg LME49720. It has an annoying dryness and "hollow" mid. With LME49710 as ground amp, it's twice the annoyance. If you use LM6171 with it's more blooming mid as ground amp, the blend gives a more neutral and enjoyable presentation. |
Well, this is all purely subjective and transcends any issue of actual audible differences so there's not much point arguing over it.
Quote:
| What tweaking is there not to do? The influence is major. Are you saying that the path to ground sounds the same no matter how it's done, as long as it's low impedance? |
No. But it's a rather simple matter to just do it right in the first place.
Quote:
| I was refering to passive vs. active ground. I regard regulators, active rail splitters and ground channel as being active and capacitors, batteries etc being passive - like CMOY or RA1. |
I know that you were referring to passive versus active ground.
And I'm saying that in either instance, all of the current emanates from and returns to the power supply caps. So you'll need just as much power supply capacity with an active ground as you would with a passive ground.
Quote:
| I never said that. This is just bitching. This is the whole point - how the return currents are handled. |
No, you didn't say that. However that's how "active ground" has been promoted and how most I've come across understand it to work. I'm just trying to set the record straight on that matter and reiterating it.
se
