[RLCrisp]

Hi All,

Finished my first amp (PIMETA) a few weeks ago and have been enjoying it a lot. I switched over to the line out of an ipod for my current source and the original gain (I think I came up with something like 10.5 - the multiloop complicates it a bit) is a bit too much for when I use my A900ltd (40 Ohm). My preferred listening level is barely after the wiper actually starts making contact and I would like a bit more range in adjustment. It is better when I use my ER4S but I still don't go much past 1/4 of the pot range.

Since I was going to order connectors and cables to make some interconnects I was thinking about making an "output resistance" interconnect for low impedance phones on high gain amps that is nothing more than a series resistor in each channel. Any suggestions for good parts/boutique resistors to fit this role? (I was thinking somewhere around 25-50 Ohms).


Thanks,
Ryan

 

[RLCrisp]

Also, I am trying to avoid simply changing the gain. For the most part the gain is great, but when using it with ipod line out and low impedance phones it is a bit much. I would like to make this cable for use with high gain/low Z phones.

It doesn't seem as if it should impact performance much at all so I think this is the easiest/best way of solving the problem. Open to suggestions though.

 

[synaesthetic]

It won't necessarily impact performance but it will change the sound character of the headphones, quite possibly enough to make you dislike them.

When I plug my AD700s into my portable amp and flip the P-to-S switch, it's like all the dynamics are sucked out of the headphone. They just sound weak and ineffectual. But the P-to-S switch does great things for my ER-4P... any lingering sibilance vanishes, the bass tightens up.

Anyway, if you're determined to do this, just get a big phone plug and solder the resistors to each of the signal terminals, then connect the cable itself to that. Hot glue it all up to provide strain relief and prevent shorts, screw on the cap and go.

A 120 ohm resistor seems to be the standard for adding output impedance. Most amps with selectable output resistance, 120 ohms is what's used.

 

[FallenAngel]

Yep, strongly recommend just changing the gain. 10x is pretty high unless you have a VERY weak source and VERY hard to drive headphones.

 

[dumbears]

Sorry for hijacking this thread.

I wonder if sb can comment on the sound signature of the resistors in different brands or even some web links.

Moreover, there's another question always pops out of my head: what should I use: low-ohm or high-ohm resistor for output? By "low-ohm", I take that as "use the lowest ohm as long as the noise is diminished", while by "high-ohm", it's "to have a better soundstage, etc...".

Thanks!