Pass X150 Where does it sit in the overall line up ??

[Old'n'Cranky]

Errrrrrrr, i think its mine...
dad liked my amp so much that he asked me to find him one..
this j2 came up for sale that day, so, dad now owns it...
Au $2,500. genuine 240 volt version. original box and papers.
it has less than an hours use from the original owner.
so dad needs to break it in. so far he thinks it has slightly less bass and slightly harsher treble than mine.
I've told him to wait till its burnt in and then see what its like..

In other news...

My x150...
Is running.
its sitting there stabilising after the first and second round of adjustments.
Looks promising though..

bias was ~ 0.06, now 0.090, boy has the temp gone up (will check actuall temp later)
diff offset on 'bad' channel has gone from ~10v to 0.18v
on 'good' channel has gone from ~1v to 0.004v

and for both channels the absolute offset is now 0.000 - thats the lowest i can measure before going into 'manual range select' on the f179.

The channel with the higher diff offset, i cant get any lower, im at the limit of the trimpot for that one
still, 0.2 is wayyyyy better than 10 volts. its something i can live with..

Just a major difference of settings.....

absolutely DYING to see what it sounds like now.
but being patient, letting it stabilise before going over the settings again..

then let it stabilise, and recheck them yet again.....

someone said something here about 50 degrees maximum ??
Um yeah, 25 degrees above ambient, where i am, in the peak of summer would mean an amp temp of 65 Celsius.......

in that temp, i will not be in the mood for music

 

[Zen Mod]

I told ya - for Summer make Babysitter (but more potent iteration)

http://www.diyaudio.com/forums/pass-labs/186554-babysitter-papas-koan.html#post2530010

congrats for your enjoyable trip ...........

and- let us know how it sounds , and how much it buzz ...

 

[Old'n'Cranky]

ohhhhhhhh, now i see what 'baby sitter' is...
neat idea.

maybe when i have the amp installed i'll do something.
I still need to design and build its new 'home'.
I think some "babysitter" loving is required for the new 'home".

and dads J2.
its 25 watts of fury are feeding speakers dad made many years ago.
I recently redid the cabinets (mahogany. real, solid mahogany, not veneer).
added some bracing. new crossovers..
heres a pic of them being tested.
I finished them some time ago..

do you think they look, familiar

16 ohms, makes them 4333's

 

[Zen Mod]

Fugly!

 

[Old'n'Cranky]

Oh dear.
Zen has found Zen and enlightenment

Alrighty.
final adjustments made.....

bias set to 0.084v + heatsinks 25 degrees above ambient. room is 28.5, heatsinks 52.5 and 52.3

diff offset 0.15 and 0.01
tot offset 0.000 and 0.000 - both flitering between + and - values

I cannot get the settings any better, their at the edge of swinging away from 'ideal' at those settings.

letting it cool down, then I'll swap it into my system for a good test tomorrow.
wonder what the neighbors music tastes are
Actually, don't care, they can put up with me for a change

To all a massive thank you.
Not forgetting The Man Himself, Mr Pass for creating such a beautiful device.
And ZenMod for his insightful and friendly, never ending help.
Lets not forget Jacco, 3ggg, and all the others here that give so freely of their knowledge and intellect.

I bow to your wisdom
Now its time to have a kick back, and relax................................

 

[Zen Mod]

naah

we're not wise ( except The Man Himself , probably ) ....... we are just jealous

(btw - those measurements/values are more than good ; what's final PSU voltage , with said bias ?)

 

[Old'n'Cranky]

final rails with mains at 244 was 36.5

I would have loved to get one channels absolute offset lower (0.15) but the trimpot for that one is at it's limit.
I figured the total offset of 0.000 would help though.

 

[jacco vermeulen]

Now's a good time as any to tell which loudspeakers are lined up behind the X150.

(as i sit here admiring the view from my cardboard box under the bridge, i wonder if i stuffed the intellect in the shopping trolley before i passed out on two pints of white spirit)

 

[Zen Mod]

......

diff offset 0.15 and 0.01
tot offset 0.000 and 0.000 .....

clarify ;

you mean offset between outputs (diff) is 00000 ?

I know that X amps are much firmer keeping diff offset than absolute/relative one ...... ...... which one !??!

anyway - I notoriously cannot remember that nomenclature - which offset is relative , absolute , but I'm always thinking of these values directly - offset between (hots ) outputs and offset between any (hot) output vs. gnd

so - it seems that you too mixed these two terms

what's absolutely important is to have 0 between hots - where speaker is connected

few hundreds of mV between any hot vs. gnd is not critical at all

 

[Old'n'Cranky]

EKTA

fed from cd's ripped to wave, played via computers coax digital into a beresford camain dac with the passive mod via it's variable output.
so no preamp needed or used..

EDIT,

the offset that references to ground, thats the one that on one channel is 0.15v
the offset across the output terminals is 0.000 on both channels..

as you say, the important one is zero...........

 

[Zen Mod]

OK

now we need a porn

those are just words without backing

edit: and your Pa spks are better

 

[Old'n'Cranky]

More pics ?
Of what ?

Heres one of me speakers.

And surprisingly, the ektas are just that tad nicer than the jbls...
slightly smoother mid and treble, and deeper bass.

put them next to each other, and its not easy to pick the difference..

 

[Nelson Pass]

EKTAthe offset that references to ground, thats the one that on one channel is 0.15v the offset across the output terminals is 0.000 on both channels...

That's the ticket. I'm very happy that you have worked through this.

Congratulations.

 

[Old'n'Cranky]

Why thank you Nelson.

I have a feeling you've been lurking, watching the progress, waiting for us to see the obvious

Just like a proud Papa watching his kids grow into adults.

If your happy, think how I must feel.
Blowing just about every cent I had on an unknown amp.
To find it in an unloved, almost butchered state.
To finally seeing it come back into the world as it was meant to be (almost )

All I can say is.

Oh My God.
It is just soooooo smooth, and gives the sense of limitless reserves, ready to kick whatever is placed before it.

 

[Zen Mod]

is there any difference in volume of the stage and body (I'm not speaking of volume in SPL meaning , but size ) between your's and your Dad's spks ?

 

[Old'n'Cranky]

um.
not sure i fully understand you...

physical size - jbl's are ~130 liters each, ektas are ~40 liters each.

sound wise - sound stage width and depth are so close to identical its not funny.
when swapping between them, dad cant tell which one is playing.
just that one sounds a touch, harsher. (his jbl's)

whether that 'harshness' is actual harshness or 'more detail' I dont know..

To give you a better answer, i would have to have them next to each other and do a A/B comparison while taking notes on paper...

 

[Zen Mod]

good enough

( was asking for later , not for displacement )

 

[Old'n'Cranky]

there ya go. this should make it easier for those to come

Theres four more jumpers at the back of the board.
I didnt play with those, but I imagine they will be 'test headers' for the offset adjustments.

ooooooooooooooooooooh its so smooth... yummy....

 

[Zen Mod]

these 4 jumpers (each one near one correspondent cap ) are for input caps shorting , having that way DC coupled inputs - as possibility

probably is best to leave them as is

I'm still not sure about absolute-diff-relative offset terminology , but you wrote real meaning for offsets ( between hots and hots vs. gnd ) so that's OK

nice pic

 

[Duck-Twacy]

I could very wel live with a X150 and X25 duo. Second had prices should be reasonable. Wouldnt mind swapping it with my Plinius SA50/CD-LAD.