Short Review - Rolls HA43 Headphone Amplifier

2003-07-26 03:02:34

I'm posting this here because many on HA use headphones, and might be looking for some amplification out of their soundcard.  I just received this product in the mail today.

The Rolls HA-43 is available from many stores online (and probably offline too) relating to "pro audio", well-discounted from some.  A simple Google search will locate it immediately.  It is a small 4-output headphone amp (one volume slider for each tap) intended for the professional or semi-pro market (studios, etc).  It comes with a small 12v, 150mA AC adapter.  The input is a 1/4" TRS female jack, so an inexpensive adapter would be necessary to use it with a soundcard (either stereo miniplug to 1/4" stereo plug, or RCA male to 1/4" stereo plug).  The outputs are all 1/4" (large plug) stereo jacks, which are gold plated. 

There's a green "Power On" LED on top, but no power on/off switch -- it seems the unit is meant to be left on indefinitely, and/or turned on and off remotely.  At <5 watts power consumption, it shouldn't make a difference.

The unit is very solidly built of heavy steel, not a typical cheap-feeling consumer item.  Weight is .45Kg (1 Lb) and dimensions are 3" x 4" x 1.25" (8 x 10 x 3.2 cm).  There are nice rubber feet on the bottom that prevent it from sliding around on a typical surface (thus getting pulled by headphone cords), although  some double-sided tape would be an even better guarantee.  There are no provisions for mounting the unit any other way than horizontally.

Initial impressions are that the unit sounds quite good.  Hooked to the Audiophile 24/96 (and with power off to the computer) there's a very slight hiss audible when volume is turned up full, but nothing that would be troublesome except to an "audiophile" looking for ultimate-fi performance.  At normal listening levels (center detente on the volume sliders) I can't hear any hiss at all on the volume sliders at the background noise level of my listening room.  I don't think the slight hissing would interfere with anyone's "normal" music listening (it's drastically less than with the Boostaroo portable amp), and is probably just fine for such practices as digital audio work and ABX'ing codecs as well.  Perhaps a better, regulated AC adapter or power supply would help.  It looks as if the box opens easily (two screws on each side with the top lifting off), so other modifications may be easy to do as well (such as replacing op-amps).

The unit gets *very* loud rapidly after center detente on the volume controls, with my Grado SR-60's... volume will be suitable for anyone who isn't trying to go deaf purposely.  Perhaps it increases a bit too rapidly -- the volume controls don't have a great deal of range, and it would be nice if they had a smoother "feel" when adjusting too.  However, it's adequate.

A report I found on Head-fi.org indicates that this device won't properly drive high-impedance headphones, but works well with the typical 32-64 ohms of most medium-price headphones.  I can't confirm or deny this report.

Overall, I'd say this is an inexpensive way to get amplification at more than reasonable sound quality out to potentially four sets of cans at once, and do it solidly with real quality construction -- no cheap, shrinkwrapped plastic boxes, this has the indestructible feel of stage musician's gear.  It probably isn't up to the specs (THD, crosstalk, S/N, frequency response) of expensive audiophile amps, but what can you say about a US $69.00 (street price) device?  Rock solid construction, and (dare I say it) made in the USA by a U.S. company -- I'm quite pleased.

For more specs and a schematic (somewhat blurred, but gives the idea), click this link -- I will leave it up indefinitely:

Rolls HA-43 Specs

(edit -- the above is also available at the manufacturer's website as a PDF file, so I won't be leaving it up indefinitely after all).

A picture of the unit connected to my PC soundcard:

Rolls HA43 - Picture

I'll also add any followup impressions to this review, if/when they come up.  Apologies that an initially short review has now become a relatively long review.

Short Review - Rolls HA43 Headphone Amplifier

Reply #1 – 2003-08-04 20:10:41

thanks for the review.  seems like a good option for quick monitoring on the cheap.