Pass XA25?

[Zen Mod]

there is a magic number , as Papa clearly wrote in XA25 manual - everything works as welding gig up to 10A , where protection kicks in , and you need to cycle power off/on to reset

so - if you need more than 10A (hardly) , go for more muscle

however , Maggies are (at least to my knowledge) having impedance nature of dumb resistor , with peak somewhere down , and that's hardly hard to drive

so , your choice is maybe hard , but certainly not to be puzzled about current demands

I remember enjoying SMG with 1.5W toob SE ....

 

[vdi_nenna]

Thanks for the replies.

I read in the XA25 manual there is current limiting at 10A so perhaps you can get more out of the F5T v2.

The F5T article says 38A into .1 Ohm. That's seems pretty incredible to me. I assumed that's all things being perfect, best case scenario.
The fuse will give out way before that, right? I mean I only have a 10A line anyway.
I suppose there needs to be a sanity check for commercial gear too. Not so much for DIY. 🙂

Hey man, if the F5T v2 can drive it, then I'll try it. 😀

 

[Zen Mod]

just look at impedance graph of Maggies and that's it

you found one on -line ?

 

[vdi_nenna]

I didn't see a graph, but it's resistive quality like you said.

 

[Hikari1]

I heard a set of Maggies (the big ones, probably 3 series) driven by a big McIntosh amp...probably 250w or so. It wasn’t that loud and it was burying the needles on the front meters of the Mac. Didn’t particularly sound that great either. I feel like it was probably a lot louder than I felt it was, kind of like the way headphones can keep you turning it up without really knowing it.

That was the day I learned magnepans were not for me.

 

[vdi_nenna]

Those are the kind of reports I'm talking about.
Not necessarily the amps fault, but a bad pairing can ruin your day.

 

[Zen Mod]

with (at least smaller) Maggies problem can't be so much in current domain , as can be in pure voltage (read - Watts) domain

to be clear - due to benign impedance modulus , all you need is decent amp , with enough watts to cover simple calculus - watts in function of speaker efficiency

 

[PKI]

I agree with ZM. Based on what Z data I've seen online they should be fine with f5t for sure and I'd assume xa25 as well. Actually as I am making a lot of different speakers I tried FW amps with speakers with all sorts of Z and sensitivities and can tell you that i found only two were loosing their performance a bit: Aleph J and J2 (clones in my case). That being said if you listen to some simple music you might never even notice that. BTW, you can always measure Z of your Maggies and see for yourself.

 

[lhquam]

I just received Stereophile Special Issue 61 which contains a review of the XA25 by Herb Reichert. I found nothing online about this review.

 

[Zen Mod]

and ....... did he found 300B in it ?

🙂

 

[lhquam]

Actually the only valve amp the XA25 was compared against was a Line Magnetic LM518.

 

[generg]

I found in a forum this comment, hope it is correct.

"John Atkinson's measurements showed that the XA-25 greatly out-performed its stated power ratings significantly, indeed. It's specified power out put is 25 watts into 8 ohms and 50 watts into 4 ohms. Atkinson's measurements were 80 watts into 8 ohms and 130 watts into 4 ohms.

Pass Labs is always quite conservative in their ratings to begin with, with the XA-25 this little amp in size is quite the powerhouse hitting way above its ratings."

 

[analog_sa]

and ....... did he found 300B in it ?

🙂

No, but he made quite an effort to like it and even brought in a mythical friend who does like it. That's before the unfortunate comparison to a cheaper Chinese integrated.

Somehow i doubt HR is the right person to review SS equipment.

 

[Zen Mod]

I got it ( article ) from my little bird 😉 ....

I know H.R. writings all the way from Sound Practices ......... he's notorious Romantic , as I am , regarding equipment sound

of course that (any) 845 based amp will be lush comparing to Laboratory Grade amp , as XA25 obviously is

Catch 22 is that Pa made small fun one , while few other (so called or real ones) Lab Grade amps are presented as something bigger than life itself

frankly ....... I know how much of challenge is to make XA25 iteration ( myself being on iteration No. 102827772 .... and counting) but it's really big question do I need amplifier as that one

disregarding fact that I really do not need more amps

 

[generg]

"Kommt ein Vogel geflogen, setzt sich nieder......"

🙂🙂

 

[Zen Mod]

....... und bedecke deinen Kopf .........

 

[generg]

Kimmt a Vogerl’ geflogen,
Setzt si nieder auf mein Fuß,
Hat a Zetterl im Goschl
Und vom Diandl an’n Gruß.

in English:

Came a bird 'flown,
Sit down on my foot,
Has a note in his Gob
And from the girl an'n greeting.

:--))

 

[kasey197]

Wow .. what a review! And to impress so thoroughly a 845 smokin audiophile🙂

I don't anyone will get upset if i attach the concluding paragraph here...

Well done to Nelson and the gang at Pass Labs

 

[vdi_nenna]

Has the line between fine tube and fine transistor amps finally been blurred? 🙂

 

[Michael Rothacher]

I'll need to reviews this amp, just to be sure.

Send review sample to:

Mike R.
XXX XXXXXX XX
XXXXX XXXXXX, XX XXXXX

😉

Very Happy News! Congrats! 🙂