Pass 150.5 vs. Pass 250.5 ?

@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 ....

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.

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.