Smack and IEMs?

[Jim R.]

Hi Dan,

I don't see any specific mention of testing the smack with IEMs, so wondering if you or any of the other guys and gals at the shop have tried this?  I'm mostly concerned about noise on the typically higher sensitivity IEMs, and if it's not an issue, that's great.

Of course I'll give it a try for myself in a couple of days too.

Thanks,

Jim

[tdogzthmn]

I use my ER4S fairly often with my Crack and get good results.  They are on the higher impedance side for an IEM at 100 ohms and I would hope they sound even better on the Smack!

[Doc B.]

Hmm, you know what? I didn't think to try my TF10Vs. I'll take them with me to the show and try them out there - might even buy a Westone ES cable for them while I'm there. I find them kind of rolled off on top once you get a good seal, but they are comfortable on those long walks where I fool myself into thinking I'm burning off this world class beer gut I've developed in my old age.

[Paul Joppa]

...  I'm mostly concerned about noise on the typically higher sensitivity IEMs, ...

For high sensitivity phones, you would crank down the impedance, which means a bigger step-down ratio of the output transformer. Lowest is 16 ohms, which is 9dB quieter than the highest 128 ohm impedance setting. If you have even more sensitive phones, you could substitute the OT-2 used in Stereomour and the new SEX 2.1; it has 6dB less output voltage and therefor 6dB less noise.

[Jim R.]

Paul,

My IEMs are 37 ohms, but I can't find a seensitivity rating yet.  Thanks for the idea on the transformers, but I probably wouldn't want to build the amp to suit just one pair of headphones, but with the switching board set on 16 ohms, and the extra series resistance (if I'm remembering that correctly) I'm guessing it will be ok, but I can just see what happens when I'm at the show.

Going to try them on the s.e.x. too.

-- Jim

[Todd R]

Hey Doc,
Little off topic, but what value is the volume pot in the Smack?
I got a nice Alps pot sitting here doing nothing that I might like to use.
Todd R

[Doc B.]

100K ohms.