Anybody using Wilsons or Soundlabs with Pass Labs?

Ferrari, Did you see Roma's post (Should I sell my Diva?) Could it be there is a dichotomy in perception when it comes to bass response? Shall we say, hi-fi bass, found only in audio, epitomized by truck bed mounted mega woofers, versus natural bass - like the baritone and kettle drum. I would want an amp that gets the texture and timbre of these big wave producers right rather than an amp that will substitute accuracy for cracking the plaster. My X-600 is of the former.

Fdriver has an interesting perspective. One could order/update with the SL biamp option. One could then put Alephs or X series amps on the top end and perhaps Wolcotts on the bottom, or MAs if you wish. Or even 4 channels of Pass amps, if your electrical system is up to it. I believe the new crossover configuration offered as an update by SL would lessen the bass taste issues some of the correspondents cite. I feel recordings vary in bass impact much more than the excellent electronics all the correspondent refer to. Others, credible others, have used the Sunfire 300 watt on the bass and the Wolcotts on the top. HAve fun!

The purpose of my post was not to "insult" the Pass Labs X600. I was mearly pointing out that the amplifier's bass performance (Sound Labs can hit 50 ohms or higher here!) is not acceptable. This includes playing the same recording on other speakers and taking into account the expected bass on a variety of other speaker / amp combinations. I also use test CDs that put out bass tones; the Pass just didn't like the Sound Lab impedance. That does not mean the Pass is a bad amp; in fact, when paired with the appropriate speaker, it is an outstanding amplifier.

The true test of being a real Audiophile is acknowledging that not every component in Stereophiles "Recommended List" will work correctly with other products on the list. The key is to build a system where each of the components compliment each other, instead of exposing weaknesses such as impedance issues - low or high. This is not an easy process, but very rewarding when done right.

1. Fdriver I agree with your well-stated points. The aleph series if I recall correctly has a higher output impedance than the X which *may be* a better match for the SL in the low frequencies. However with the old crossovers I found the low power ones clipped with heavy brass, etc. That being said the Wolcott or the OTLs are the best amps, IMHO, for the SLs. I was going to biamp with Alephs but got Wolcotts instead.
2. Why doesn't Stereophile,etc. test the FR, etc.,of the amps under test with the speakers that the reviewer is using? This would show true system interaction. The dummy IHF load is only somewhat germane to the system context. The tests they do now are at best academic and irrelevant...ok, they do reveal the basic quality of the amp but if the amp shows 10% distortion it should be sent back to the manufacturer before it is reviewed. Sounds like Fdriver's own tests are more relevant and systematic, even though the results cannot be used to make universal statements, but why should they?

I have a customer who had the Pass 600s driving the Sound Labs UB-1s and it worked well....The Parasound JC-1s worked enough better on the U-1s and UB-1s that the Pass 600s went away as did the OTL amps he used above 150hz.....