New phono pre? Check electrical cart loading. The VTA is a mechanical adjustment.
could a different power cord cure sibilance?
recently upgraded my phono pre to an AR PH3SE modded by Great Northern. In a different league from its predecessor, a stock EAR 834P, but now there is too much sibilance on some vocals (e.g., on Thriller or MFSL Amercian Beauty). Definitely caused by the phono pre. I understand that the tubes used could contribute to excess sibilance, have tried various types, and will try others. Could the power cord affect this too? It's about the only other variable. Currently using Signal Cable Sivler Resolution pc. Recommendations welcome.
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- 14 posts total
What Daverz said X3! Even more so if you are using a moving coil cartridge. It appears that your EAR had an input impedance for moving coil cartridges of 515 ohms. See the last paragraph under the sub-heading "The Inside" in this review: http://www.audiophilia.com/hardware/Analogue/reviews/ear834p.htm Your ARC phono stage has a default input impedance of 47K (47,000 ohms), assuming it wasn't changed during the modification process. http://www.audioresearch.com/ph3.html. It includes provisions to change that value, I believe by inserting resistors of the desired value internally. Moving coil cartridges (assuming that is what you are using) usually require a low-value resistive load (tens or hundreds of ohms) to dampen what would otherwise be a high frequency resonant peak. That peak is often at inaudible ultrasonic frequencies, but associated with it would be a frequency response rise in the upper treble, that would, among other things, over-emphasize sibilants. This paper is somewhat technical, but is worth skimming through: http://www.hagtech.com/loading.html So the bottom line, assuming you are using a moving coil cartridge, is to change the resistive loading to around 515 ohms or to some other value within the cartridge maker's recommended range. If it is a moving magnet cartridge, then load capacitance becomes important, as explained in the Hagtech reference, which would also have effects on the upper treble, although to a lesser degree under typical circumstances. Regards, -- Al |
1. Maybe the new component has subtly changed the tonal balance ? Sometimes a leaner bass may also manifest itself as a more forward overall sound, bringing into sharper focus other tonal characteristics. Experiment with a little larger Toe-out on the speakers This will also create a wider sound stage. Also try moving the speakers back a little towards the wall / corner. Careful speaker positioning can do wonders, and IMHO is one of the most neglected solutions... |
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- 14 posts total