Help ...... excesssssssive sssssssssssssssssssss


I would be eternally greatfull of any asssssissstance
given to remedy a condition that my ssssystem is ssspewing
out.

I guess it's called Sibillance.
well it ssssssucks.

I have tried inserting different preamps/amps/tubes as
well as 3 different cartridges (shelter 501 II, Grado Ref.
music makerIII )
no help.

different cables have been tried too.
I used the VPI jig for setting up the cartridge & used magnifing goggles to get it right on the money.
VTF set at 1.75gm
always playing with VTA & no help.

I am wondering if the tonearm or wiring could be cause?

here is my setup:
VPI TNT Base
Teres wood platter
JMW12.5 Arm
Music Maker III cartridge
VPI phono cables

Mapleshade copper ribbon I/C's
Decware Preamp
Decware Phonostage
First Watt F1
Mapleshade Speaker cables
Hornshoppe Horns

The music my system makes is wonderful EXCEPT for the
sibillance exageration, if I can get rid of this problem
I will be an extremely happy camper.
socoaste

Showing 1 response by shadorne

I suspect the problem is your extremely unusual choice of amp and speakers.

First Watt F1 is a current power amplifier...it will attempt to drive your speakers with a current that is independent of impedance load.

Your speakers only have one driver...it is unlikely that the impedance curve is anywhere near flat ....even it might be an easy or efficient load to drive.

I don't know the impedance characteristics of your speakers but most speakers are such that they tend to be of higher impedance at higher frequencies and usually high around the resonance point of the driver (which for 4 inch is probably some where in the lower mid range or bass).

The end result of this combination is that you will accentuate the speaker response according to the impedance curve...i.e. emphasize the resonance frequency and accentuate the treble (if your speaker behaves as most speakers do) => you will get significant bass and treble response boost and this is why you hear so much sibilance

Current amplifiers are rarely used in audio applications for this very reason....they need to be carefully matched to a speaker with a flat impedance curve.