X2.5 pre-amp

Hi all, I'm a newly register member to this board. I hope I am welcome here even if I am not electrically trained.

Has anyone heard this new Pass Labs X2.5 pre-amp? How does it sound compared to the X2 it replaces?

I have a BAT VK-20 pre-amp driving the BAT-VK200 power amp and I'm thinking of upgrading to a Pass lab pre-amp. Will the new X2.5 be a significant enough improvement or do I need to go to double decked X1? Space is a concern.

I am currently experiencing a loss of low level details, and I find that the BAT VK-20 needs a long run-in time, after turn-on from standby to sound it's best.

My friend showed me the schemetics of the X2.5 and it shows much simpler circuitry layout than the X2.

Will there be a new X1.5 to replace the X1 soon?

Appreciate any comments.
 
Hi, i am also new here....

I've seen the inside of both the x1 and x2.5 preamps.
They use almost the same audio circuitry.
The difference is in the simplified and integrated powersupply.

The sound should also come fairly close to the x1 and not the older x2 which uses a completely different amplifier and controll topolgie.

The sound of the newer pass model x2.5 was in the situations that i listened somewhat clearer but also sharper (depending on other audiogear?). The older pass x2 uses a different circuit with a very simple discrete opamp and sound warmer and richer.

:)
 
What is the typical warm-up time required?

I noticed with my BAT pre-amp and power-amp that I need to turn it on for more than 8 hours before the sound stabilize. Any observation about the X2.5? Will longer warm-up period before each listening session smoothen and enrich its sound? Would a few more weeks of running-in the unit brings it better warmth compared to the X2? :D
 
X2.5 warm up time

Hi,
in my experience it takes a lot of time for the x2.5 to reach optimal performance.

I've listened to the preamp in combination with the X250.
(Here the x250 takes more than a month of full power up time to reach optimal performance)

The x2.5 takes a few weeks of standby or listening time (class A circuit) but the sound character did not change dramaticly.
The change is in the refinement and controll. The sound becomes more natural, less mechanic.

The warmth will never come close to the old X2 with different cicuitry.

:)
 

murphys33

Member
2002-02-06 12:02 am
Frank,
What prompted you to upgrade from X2 to X2.5?
When I upgraded, I wanted more speed and control... found the X2 a little slow / or maybe too warm for my taste. Like you, I am using the X250. But I must confess that my set isnot broken in yet as I have been kept busy at work since my purchase. I am eager to let the set run in.. what were your experiences?

regards,
murphys
 
Hi murphys,

First i havo to tell that it is not my personal system but that of a close friend. We come together to listen quite often so I know what his system can do (also compared to mine).

Personally I am working on a d.i.y. preamp based on a pass design. The quality i heard there led to my advise to test the X2/X2.5. The decision was also made on the sound of the previous system which was already on the warmer side and the nice remote controll function.

The big advantage in sound of the X2.5 is the open en extreme dynamic resolution of the system. But the first weeks it sounded mainly uncontrolled and agressive. Only after weeks of playing time the system began to sing, the sound became natural (not forced) and fluid, quite a dramatic change!

In my experience the system has to be powered up all the time, the preamp can't be turned off but the poweramp should'nt be set to stand by. It takes a little more on the mains bill but its worth every penny (the pass system is not that cheap after all).

Best regards.
:)
 
Why no passive pass-through?

Thanks everyone who responded to my questions

During the last 3 weeks, I have been experimenting with various turn-on configurations and have come to conclusion that pre-amps (my BAT VK-20) do indeed needs a lot of time to reach optimal performance. The sound becomes more natural, less mechanic. There is better refinement, sweetness and openess in the frequency extremes. The fall back of the soundstage into the space behind the speakers is certainly very welcome indeed in my restricted listening space. Now I leave the SACD player and preamp turned-on 24/7.

I have one question now regarding passive pre-amps. I don't find any thread discussing this issue on this board.

Why doesn't Mr Pass design passive pass-through on his PASSLABS pre-amps? Afterall he did that on the ADCOM 750 pre-amp. Would be nice to have the options on the X2.5.
 

BrianGT

diyAudio Moderator Emeritus
2002-01-21 2:42 pm
near Atlanta, GA
www.chipamp.com
Nelson Pass said:
I believe Wayne is finishing a passive volume control
with a remote control for his next PassDIY contribution,
so I suggest you watch for it.

Anything ever come of this? I haven't heard anything about it since. I have been watching for it...

On another subject, it is a shame that the patent hasn't gone through yet for wayne's x volume control. I want to see the workings of it. The patent office is too slow! How long has it been?

--
Brian
 
Thanks everyone who responded to my questions

During the last 3 weeks, I have been experimenting with various turn-on configurations and have come to conclusion that pre-amps (my BAT VK-20) do indeed needs a lot of time to reach optimal performance. The sound becomes more natural, less mechanic. There is better refinement, sweetness and openess in the frequency extremes. The fall back of the soundstage into the space behind the speakers is certainly very welcome indeed in my restricted listening space. Now I leave the SACD player and preamp turned-on 24/7.

I have one question now regarding passive pre-amps. I don't find any thread discussing this issue on this board.

Why doesn't Mr Pass design passive pass-through on his PASSLABS pre-amps? Afterall he did that on the ADCOM 750 pre-amp. Would be nice to have the options on the X2.5.

The last version of the Pass Aleph L is half passive and half active