Pass 150.5 vs. Pass 250.5 ?

depends on what kind of music you listen to and the levels you like listening at.
Can you e-mail Focal and ask them which of these 2 will be the most appropriate?

In my experience, the bigger amps will provide better control of the bass and will run with less effort and strain on high volumes.

Focal JMlabs speakers are very easy to drive, I'm driving a pair of Micro-Utopia's with about 20 tube watts. I think that the 250.5 may be overkill, the 150.5 would not only be sufficient but might sound better as well.

Jond, your speakers are monitors.
1027BE are floor standers. I don't see any relation between these 2 pairs of speakers. Your last statement is a bit confusing. Can you please expand on how the 150.5 may sound better than 250.5 on 1027BE?

Jond is right. At least partially. These Electra's can be driven even with 300B SE amp. I tried it at home with Audion 300B and I had quite good result with it. Very nice and open mid-range with quite good bass extension and excellent timing. The problem is that I am looking for much better and more authoritative bass control - one that I had with Bryston 4B-SST (which on the other hand was a bit closed in the mid-range). Therefore, I am formulating my question now a bit different: would I get these virtues with Pass Labs X-150.5 ?

Dejanm, excuse my ignorance, but I don't get it.
You say that the speakers are efficient enough to be driven by a 300B SET amp, yet you mention you liked the bass control of a SS amp that puts out hefty 300w/ch into 8ohms. You want a 150w/ch amp to have the same bass control?

I tried both 150.5 and 250.5 with diva utopia. Both drive it to adequate level. 250.5 has quite a bit more detail. The treble is slightly hotter with the 250.5 and the base was a little disintegrated with the midrange ( probably due to speaker side firing woofer). X150.5 is less detailed and less dynamic (comparatively) but overall a more coherent and musical presentation. Room is about 25 x 16 ft. X350.5 is better than both which is what I use now.

Audphile1 I was making a general comment on the efficiency of JMlabs designs, and since floor standing speakers are typically more efficient than monitors it stands to reason that if my monitors are efficient than a floorstanding model from the same manufacturer may be even more efficient. My comment on the 150.5 versus the 250.5 simply takes into account the commonly held, and with good reason, belief that a lower powered amp from a given manufacturer will sound better, usually sweeter and more pure, than a higher powered one. Given that, plus the fact that I've read many users who state that the 150.5 is a better sounding amp, even to the point that a tech at Pass said it to someone as well.

@Audiophile1

I said that I would like to have more bass control than SE valve 300B provided - something that heavy SS amps like Bryston are providing. Whether Pass X-150.5 will provide the same class of bass control is something that I really do not know - that is actually the reason for my question on this forum. In addition to that, Pass is not quite the same as Bryston, meaning that maybe its 150 W can produce the same low level magic as 300 W of Bryston. Although, maybe it will not be the case ? Does anybody have any concrete experience with this Pass amp ?

I was listening the older model X-150 connected to Thiel Cs2.4. Very unpleasent speakers to drive - they need a lot of current. It was a direct comparison with Mark Levinson 331 (source was also Mark Levinson 390S directly connected to one of these two amps with XLR HMS cables). Speaker cables were also HMS. And ... Pass X-150 outperformed Mark Levinson 331 in every respect. But Mark Levinson 331 is "only" 100 W/ 8 ohm.

So I was thinking if it did it with ML and very difficult speakers, maybe it will do the same magic with my Focals compared to Bryston .... Or another analogy shoud be taken: it did it to Mark Levinson because it has more power ...

That is the question now ....

Glai,

Thanks a lot for this comment. That was the kind of information that I was looking for.

Which pre-amp have you been using during these tests ?

When I was comparing 150.5 and 250.5, I was using the Hovland HP 100 preamp and placette passive ( I use a Bat now), I also had a pass X1 which I used with 150.5 but not the 250.5. I love the pass amps but I prefer other brands for preamps ( Pass preamp is not as fluid as I like). Many people like pass preamps though.

Before X250.5 was available, the 150.5 was billed as a 150 with a nicer faceplate with no mechanical difference. since the 250.5 and 350.5 have been introduced, x150.5 is integrated into the 0.5 line which implied the new 0.5 technology. THis is a little confusing to me but I really only cared about the sound. I am sure pass lab could help clarfy this. (Great service and support).

If I were to do it again and I had Altos (front firing) or 1027Be, I would get the x250.5 assuming the bass alignment problem is due to side firing woofers/room intereaction. I know u'd be happy with both but the issue is to pick the better one or at least the one with more potential.