Pass Labs or Class`e

[barrows]

Yup, in fact all Pass Labs amps are very conservatively rated. Stereophile's website has measurements for the XA 30.5 accompanying the review.

Still, the 30.5 cannot quite do it for my speakers, the two paralleled drivers just need more... to note, I also live in a rural area, and play at high levels most of the time. I am pretty sure the XA 60.5 monos would work for me though, cannot afford them at this time though...

 

[earflappin]

Jim, you are right. When I had my 30.5 i found it to be very conservatively rated and even when it switched over it was hard to hear the transition. I love also the way Nelson has shared his immense knowledge with the DIY community through his First Watt company.

 

[earflappin]

Barrows, thanks for your vigilance in policing commentary on the forum. Greatly appreciated.

 

The substance of my point remains, however.....whatever the circuit design in the XA.5 is there is a slight coloration imparted compared to my OTL amp, which once heard would make it very difficult to live with, particularly if your system goal is to as closely reproduce the sound of live music as closely as possible.

 

Again, for those with speakers that are not OTL friendly, the Pass Labs is among the best SS amps I've heard. If you have moderate power requirements I would also recommend trying the First Watt amplifiers designed by Nelson. They use a more minimalistic, lower power design.

 

[barrows]

No worries! I am sure that you do hear different color with the Pass XA vs. the OTLs. As you noted I just wanted to be sure that readers knew there are not output transformers in the Pass amps (it is very unusual for any solid state amp to be transformer coupled on its output, McIntosh is the only amp which comes to mind).

As I said, I have loved the sound of tube OTL amps with the right speaker match. It is very important for people to understand that OTL amps will not work well with many speakers, and that they will sound significantly different with different speaker loads. In an OTL, the tubes are basically directly coupled to the speaker, and interaction between the speakers impedance and the tubes output impedance can create problems. Normally tube amps use transformers to couple the speaker load, this mitigates the problems inherent in the tubes output impedance (not a problem for solid state amps) and allows use with many types of speakers.

As you know though, with the right speakers OTL tube amps can be fabulous sounding.

 

[dmccombs]

Audio Lover seems to be shopping for speakers so it is hard to recommend a amp. In this range, the Classe and Pass Labs amp are both terrific. the deciding factor shoul dbe synergy with the chosen speaker.

 

I have 802D speakers and Classe CA-M400 monoblock amps. I have a good friend who is a Pass Labs fanatic. He has owned the 250.5, 350.5, XA30.5. We have run his amps on the 802Ds so we have lots of hours logged doing this comparison.

 

The Classe amp is terrific with the 802Ds. My top end is incredible, while the mids and low end are very good but not great. Overall the tonal balance is spot on though and a decent sized soundstage is provided.

 

The Pass 350.5 somewhat over drove the 802Ds. We never figured it out even though we did this test 3 different times, in two different rooms/setups. the bass was muddy and congested. the bass was strong, but at the expense of everything else. The 350.5 is a great amp and matches up very well with numerous other speakers, but not the 802Ds.

 

The Pass 250.5 and 30.5 didn't over drive the 802Ds. the bass was terrific, very nice midrange, and they did a good job with the high end. The 30.5 could only drive the 802Ds to a certain volume. The 60.5 would be a better match.

 

The Pass Labs amps are fantastic and be a good match for the 802Ds, but demo the model you plan to use before buying.

 

B&W uses Classe to voice the 800D series so of course it is an excellent match. IT will come down to synergy and personal preference.

 

Demo, Demo, Demo....

 

[realhifi]

Find a good dealer and they will let you take an amp home to try on YOUR speakers. Also, go listen to some Audio Research and Naim. Bigger is not always better.

 

[roscoeiii]

I'm another huge fan of Nelson Pass designs, and treasure my First Watt F1 amp (Matches great with my Weiss DAC2/Minerva DAC and Musical Fidelity preamp). I'll add myself to the list of Pass enthusiasts (though I also had a chance to visit Atma-Sphere this year and loved what I heard there too). If you don't have the option to audition a Pass amp in your own system locally, I would also highly recommend giving Mark at Reno Hi-Fi a call. He has a lot of Pass gear and offers a trial period for his sales for a reasonable restocking fee. Also often has used and demo Pass gear for which the trial period also applies. A great guy who knows Pass inside and out and can suggest the best match for your gear.

 

[johnwinkley]

Hello

I've read this thread with interest as I went through the same process - I bought some 802d's and then found that my 100W Musical Fidelity amp was inadequate - wobbly bass and generally all sounded a bit compressed and limited.

 

I read quite a few threads on groups about these popular speakers - there seems to be a consensus that they are a tough load to drive.

 

In the end I went for a Chord amp SPA1032. I'm based in the UK and they're a UK company which was part of the attraction, but this is also common configuration in many studios, including in the US. I think the attraction is the peak power capabilities and rock solid current delivery across the frequency range for harder loads ( I remember reading that its impedance can drop below 3ohms at some frequencies).

 

Anyway, my point is that Chord supply pro and hifi versions of essentially the same products (I'm reliably informed) and there are some great deals on the pro ones which differ only in that they have RCA outputs only (the hifi ones are phono and RCA). I would probably have gone Classe as a second choice but an equivalent unit would have been 2-3 times the price.

 

The chord unit is great. The combination with 802d is clinical, which I like (and I imagine is why its popular in studios) but I can imagine others preferring a warmer sound, so the points made about matching DAC and amp are clearly important. Positioning the 802d requires care too, particularly in smaller rooms and corners I'd say.

 

Cheers

 

John