[jrtrent]

I'm moving to an apartment, where headphone listening will necessarily increase.  I replaced an ailing Linn LK1 preamp a couple of years ago with an OmegaStar PAT 5 bought used from AVA.  The headphone jack operates by running the power amplifier's output to the pre-amp, and then out to the speakers, but this arrangement sounded dreadful when I tried it for both headphones and speakers.  Possibly the LK2 power amp has characteristics incompatible with that hook-up scheme. 

Just wanted opinions of options:

1.  replace the still perfectly good LK2 with an AVA 250EX or 260EX to drive the Linn Saras and hopefully work well with the Omegastar PAT 5 pre-amp for headphone use (perhaps even drive the speakers better than the LK2?)

2.  replace the OmegaStar PAT 5 with an Omegastar EC pre-amp whose headphone jack is not dependent on the power amp (AVA News also mentions that the EC chassis features an improved power transformer, so perhaps it outperforms the OmegaStar circuitry in the PAT 5 chassis?)

3.  buy an outboard headphone amp

On an unrelated topic, has the Longhorn cartridge been discontinued?

[avahifi]

The old Pat-5 chassis headphone circuit simply drives the headphones from the power amp, thru a high current selector switch built into the preamp chassis that switches between two sets of speakers and headphones.  It should not have any effect on the sound quality of either the speakers or the headphones unless the amplifier is not a common ground device (got any specifications about the amplifier??), or (a remote possibility) --- the Pat-5 headphone switch wiring is miswired or defective.

What headphones are you using? In what way is the sound "dreadful"?  Give me a call at 651-330-9871 and we will try and help you get to the bottom of this problem. Lets try and get what you already have working properly first.

The OmegaStar circuit set will sound the same no matter what chassis it is in, so changing to a new OmegaStar EC is not the right approach short term.

Note that if your amplifier actually is incompatable with a common ground headphone circuit, we could always simply build an OmegaStar dedicated headphone amplifier board into the OmegaStar Pat-5 (cost you about $200 installed), and then you could do away with the speaker wire connections to the preamp for headphone use.

Frank Van Alstine

[jrtrent]

Egads! What a quick response!  I didn't figure you'd even be looking in on a Saturday.  I'll give you a call and likely make arrangements for having the OmegaStar dedicated headphone amplifier board installed into my PAT 5.  That way, if my 20 year-old amplifier fails, I can still use the headphones.  Another reason I like that option is that I won't need to change my cabinetry, which was designed around the petite dimensions of the LK1/LK2 combination--a 17" chassis simply wouldn't fit.

It's been so long since I tried it, I don't remember specifically what made it "dreadful."  With so much stuff in boxes for the move, I'm currently unable to put my hands on the owner's manual, but Linn emphasized that their stereo amplifier design was, in effect, two separate amplifiers, each with its own power supply and fed by separate windings on the transformer.  Maybe it isn't a common-ground design.

Oh, as to headphones, I use Grado SR125's and a pair of old Koss Pro-4 AA.  For apartment living, the Koss with its sealed design has advantages in blocking out the delightful sound of playing, screaming children, not to mention the construction project across the street.