[proid]

As i have read, the Mini3 outperform a regular cmoy because it has ground channel so i have a Grado Ra1 clone which is a cmoy and sounds very good using two 9V battery and real ground. So can i improve the sound of RA1 by adding an active ground channel? 

 

[joeyjojo]

It's an elegant option in AMB amps as one circuit board = one channel, so you can easily make 3 identical boards and use one to sink the return current, which is a bit nicer electrically as each driver "sees" the same device on each side. It probably won't be an option for your RA1 for space reasons and/or it's probably all on one board, but if it comes as 2 identical circuit boards you could certainly build a 3rd.

 

[wakibaki]

Quote:

As i have read, the Mini3 outperform a regular cmoy because it has ground channel so i have a Grado Ra1 clone which is a cmoy and sounds very good using two 9V battery and real ground. So can i improve the sound of RA1 by adding an active ground channel? 

 
Absolutely not. It will make the crosstalk worse.
 
w

 

[KimLaroux]

Yeah... This is a matter of debate. It's all just opinions. There are "objective evidences" proving both ideologies. Which means, there are no evidences.
 
You can do whatever you want, really. We just can't tell in advance what the results will be. Maybe if you convince yourself of the improvements, then you'll hear improvements. 
 
But hey if you're bored and want to do something, then I'm all for it. 

 

[proid]

But  the Mini3 is simple a cmoy with a ground channel and better opamp that outperform the regular cmoy and both the M3 and B22 use a ground channel too so what is the benefit of a ground channel?

 

[wakibaki]

Some people thought up the idea of a ground channel.
 
They built amplifiers with it. They did measurements they thought showed it was better. They sold the idea to a lot of people, even though some other experts thought their theory was flawed. 
 
Later somebody else came along with professional test equipment and did some measurements that were very hard to argue with, that showed that it was worse.
 
The people who thought up the idea could not admit that they were wrong.
 
In truth I think the difference is so small you can't hear it, but many people, particularly people who bought or built one, still believe the amplifiers with a ground channel are better. Because you can't hear the difference, only measure it, the belief persists among people who don't understand the engineering.  
 
That's what I think, but not everybody agrees.
 
w

 

[jcx]

Quote:

Yeah... This is a matter of debate. It's all just opinions. There are "objective evidences" proving both ideologies. Which means, there are no evidences.

wrong - there are objective measurements of "3-channel" flaws that are predicted by engineering theory
 
confusing/conflicting  "naive subjectivist"/fanboy opinion is not at all the same as saying there is controversy in the engineering theory or measurements
 
even AMB had to concede that TRS common gnd contact R was much larger cause of cross talk than a good implementation of active or passive gnd - when I convinced him to measure on the headphone side of the connector
 
 
as pointed out above the technical flaws in many "3-channel" implementations are likely below controlled, blinded AB/X subjective hearing thresholds - by comparing their magnitudes to other hearing threshold studies results
 
 
this should be true for B22 amps - and the output Z and distortion, psrr, and noise related claims, objections to "3-channel" - the basic amp is so good on these qualities that it unlikely any difference can be heard between gnd type
 
other build issues are much more likely to cause audible differences such as power transformer choice, chassis gnding details, internal wire routing details