[johnnylexus]

Just got my HA-5000 from jmcmasterj. I have not plugged it in yet.

There are two sets of inputs on the back ... one is marked "AC Coupled" and the other is "DC Direct."

What is the difference?

Can I use both sets ... say one for CD Player and one for PC soundcard?

 

[Fitz]

The AC input passes it through a pair of capacitors to block any DC offset from the source, the DC input just goes straight into to the amp.

 

[johnnylexus]

what does that mean?

 

[Fitz]

Quote:

Originally Posted by johnnylexus what does that mean?

It means use the AC input unless you know your source doesn't have any significant DC offset.

 

[grokit]

Bumping this thread to find out what kind of sources may have DC offset. Is the AC coupled vs. DC direct RCA inputs more of a Japanese thing? I can't find any examples for when to use one kind of input over the other. Would I just try DC direct input first, and if I get noise or clicking switch to the AC coupled input?

 

[Mad Max]

Just stick to AC input to be safe.

 

[grokit]

I found out some more info; it turns out that the only time you should have to use the AC coupled input is when you have something like an i/diyMod that needs the external vcap/iMod dock, and want to use it with a regular LOD without the external caps. The AC coupled input has the caps inline to protect the circuitry, but it can be slightly rolled off in dynamics compared to the DC direct input, so it's better to use the DC direct input in most cases. No wonder AT opted not to market this amp outside of Japan as it's a bit confusing, and could be something of a liability.

 

[Mad Max]

So those caps should be swapped out for better ones? I see.

 

[grokit]

Quote:

So those caps should be swapped out for better ones? I see.

I don't know if I would go that far. They are probably good, but maybe not in the same league as the vcap dock. And you can't switch between inputs anyways. I am probably just going to put RCA plugs on the AC coupled input but it's nice to know that it is there. I may try it with my iMod out of curiosity, just to compare the sound with my RWA female iMod dock. There has to be other sources that would need those kind of AC coupled inputs, I just don't know of any myself -- it may be something that is more common in Japan.