2. amps-preamps
  3. 1040275897

What's My Problem?

OK, here's the situation . . . . hoping some of you with more knowledge and experience than I have can help me out.

On 2-channel listening, my system sounds great at low levels -- say at 9 o'clock or less on my VPC-1 passive preamp volume. Lots of openness and air, good imaging, lots of space around instruments. Of course, dynamics and bass suffer, but that's to be expected.

Between 9 and 12, the sound starts to get harsher and the soundstage begins to close up -- orchestral stuff sounds much more confused and congested. Above 12 o'clock, it's really not worth listening to.

These aren't very high levels -- 9 o'clock is my "late night with the wife sleeping down the hall" listening level, and 12 o'clock doesn't get Verdi's "Requiem" to real-life SPLs.

My first assumption is that my amplifier just doesn't have enough juice. But the RB981 puts about 200 wpc into a 4 ohm load, and I would think that would be enough to get to at least decent levels, even with my admittedly power-hungry NHT 2.3As . . . .

Alternately, I thought that maybe the 9000ES/RB981 combo wasn't ideally suited for a passive preamp. I understand that component matching is critical here, but I'm not really clear on how it works . . . . the volume gets loud enough with no problem, it's just that the quality suffers.

Then again, it could simply be "louder=more annoyance from digital harshness," and I need to replace the 9000ES with a better Redbook CDP. But it seems to me that if the CDP was to blame, the soundstage and "airy-ness" wouldn't change much as the volume increased.

Suggestions would be greatly appreciated!

Thanks!

Pat
tsrart

Showing 1 response by bluefin

bluefin
111 posts
 
There was thread about passive preamp not long ago. Some made good points there. The purpose of have an active preamp is to have a more flat input/output resistance across the spectrum as well as input amplitude. This is more important than to provide gain, most of time you probably running pre-amp with <1 gain. For passive amp, you are changing input/output impedance while turn up or down the volume. You will get good result only when your CD player (output R) and power amp (input R) can still match the vaiation of your passive pre.

If you are not happy with the result, change it to a active preamp. Otherwises, you have to switch many CD players and power amp's to fit your passive amp. IMHO, you should get rid of bottle limited parts, not swap good parts to match your passive pre, 10 times effort and make not much sense.
Your players and power amp should not be a problem with normal active pre-amp.

When people tell you shorter path is better, you have to be careful about the statement. It is over-simplified and can be totally wrong in some cases.
More to discover