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In the Forum: Horn-Loaded Speakers
In the Thread: S2 Hissing Sound
Post Subject: S2 Hissing SoundPosted by jessie.dazzle on: 7/18/2006
As some may know from previous posts, I have been working on horns for the Vitavox S2 as well as other drivers (I am photo-documenting the process, as it is somewhat unusual, possibly to be posted here at a later date). Last night I was able to test my first horn... it is unsealed, and unpainted, but basically done. I screwed in an S2, and listened to some music containing primarily violin and horns. Even with very inappropriate amps, the results are super-encouraging.

For now, the amplifiers I use are a pair of Lamm M1.1s (was going to look for a pair of used ML2s, but more and more considering building a pair of Meliquaides). Using the M1.1s with a pair of V.A. Parsifal/Encore (direct radiating) speakers there is a little background hiss, but nothing you would hear from the listening point. However with the S2s, this background hiss is much stronger; the level is constant and does not rise or fall with volume adjustment. It can be heard from well beyond the listening point. The hiss is equally present in all (4) S2s I have, so I don't think it is a question of the driver. With the S2s I can hear much further "into" the hiss, and observe all kinds of detail (fluctuations in the electricity?).

The hiss remains when disconnecting the ground wire for all circuits powering the system.

My question now is... Do other S2 users have the background hiss when using appropriate SET amps? Is it possible that the M1.1s generate more hiss?

I should also mention that the associated preamps are either an L1 or an L2. I recently replaced all tubes in both pre and power amps (hiss present with both L1 and L2, so the preamp is probably not the source of the hiss).

The caps I'm using are French-made SCR brand (considered to be quite good over here).

The cables going from the power amps to the drivers are (for now) my test leads made from normal zip (lamp) cord, with alligator clip-on connectors.

I'm not at all sure, but I don't remember having the hiss when using the same system (V.A. speakers) in the U.S., and it is entirely possible that it is a product of the wiring here in this 100 year-old apartment (I will be moving to a newer place soon... will install dedicatd lines).

As always, any advice would be very appreciated.

jd*

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