AX100 100W Aleph-X Monoblocks

[audiodan]

Hello gl

Still...mmm yes still looking for the right speaker, heard it on some kef 104.2 and sounded the best. So now trying to track some of these old speakers down.

But yes great sounding amp, just need to lower bais as running about 60 degrees and these speakers are 4 ohm so will make one half run hotter.

Cheers

Made any more changes to yours?

[gl]

Dan,

Glad to hear things are sounding good. I haven't made any recent changes. I'm just listening.

Tad,

I'm very happy with the amps. The bass performance is excellent IMO and I have MG3.6's which are difficult to get good bass out of. The bass performance improved when the JFET front end went on but I couldn't tell you why.

Like Nelson said, Pass Labs made a generational change when moving from the XA line to the XA.5. They went to a follower type output topology among other things. I would expect serious improvement to the sound especially the bass. Still though, the XA line received very favorable reviews and is still super primo gear IMO.

I have only compared the AX100J's to my old Audio Research D115MkII and the AX100J's won hands down. I can't think of any existing DIY project out there that I would judge to be an upgrade. The Maggie's needs lots of power so I would need to build something substantial. The only thing that might do it for me is souping up the balanced version of the F4 to the 200-250 watt level. But there are other projects in the hopper first.

It's interesting to me that this thread continues to receive hits even though it's almost four years old and was started years after the main bubble of interest in the Aleph-X had subsided. The thread is mostly a rehash of stuff from other threads. It has no stars, and has not been selected by anyone as one their favorite threads. Yet the number of views is currently over 90K and growing. There aren't many threads here that get up to that number of views. So something is going on. I think it's a combination of a classic DIY design at a power level that is more than enough for most people's needs. And I think people are continuing to build the Aleph-X. I'm just happy to see that others are benefiting by what's here or being inspired by it.

OK, I'll shut up now before people start to think I'm a GR sock puppet.

Graeme

[tryonziess]

Graeme,
I believe this threads popularity lies in its content. The OT crowd stayed away and let you dazzle us with your fine project. Mostly meat and potatoes no frill.
Thanks to you and of course Rollins and Nelson.
Tad

P.S maybe when you get time you could elaborate on the newer x.5 follower output scheme. Would be nice to do up to date cloning -- with permission of course.

[scatterbrain001]

Originally Posted by michaelbehrendt

Here a scematic idea, i don´t know this will work, have to changed the Fet´s to FQP3P20 and FQP4N20 and the bt to 2SC4793 and 2SA1837, who can answer.

Michael

Hi michaelbehrendt,

I have been looking at your schematic up3ppse.pdf and like what I see, has this amp been built yet, and is it working. I need to know this before I begin to build my X100

[gl]

Hi Tad,

I appreciate your comment regarding the OT posts. I would agree. I am not sure if I would use the word dazzle to describe anything about me.

That said though, it appears that my sniveling has resulted the thread gaining five stars at least for the moment!

The XA100.5 output section (each side) appears to be a scaled up version of the F4 without the input JFET's. The 5W of SE bias is provided by adding the appropriate resistive load from the output node to one of the power rails. The XA100.5 received a great deal of speculative attention on the Aleph-X builders thread between Jan 08 and Aug 08 driven primarily by one member. Here is one of the last schematics he posted:

http://www.diyaudio.com/forums/pass-labs/28336-aleph-x-builders-thread-post1584055.html

It's a relatively credible effort and includes lots of hints and tips from Nelson. On the down side there are number of confusing things shown and many missing values. And there is at least one thing that IMO will produce oscillation. Nevertheless, I believe that one of the experienced heavy-duty builders on this site could make this work and work well. Myself I'm not willing to lay out the time and money and take the risk.

The design referenced by scatterbrain001 has similar issues. For instance there is no way to adjust the output bias.

I generally don't attach any value to schematics unless they represent something that someone has built, and debugged, and liked the sound of.

Graeme

[Nelson Pass]

Originally Posted by gl

That said though, it appears that my sniveling has resulted the thread gaining five stars at least for the moment!

That was me.

[gl]

Thank you.

[tryonziess]

Graeme,
Not sniveling just hard work. From what I have been reading Nelson has no patients for sniveling. He hints and cajoles but does not give it all up. Hell he might even decide to bread crumb us to x.5 and that one elusive resistor value you have wanted.

By the way are you real pleased with your maggies the pair only cost 599.00.

Tad

[gl]

I'm very pleased with the Maggies. I have the MG3.6's and they cost more than 599.00.

As noted in the thread, I have since found the right resistor value for me by experimentation and listening.

Graeme

[tryonziess]

Graeme,
I was talking about Magnapan's introduction model. That level is something I can justify. At my age I have become very frugal with money.
This forum allows a lot of us to obtain extremely high quality audio without the excessive out lay of cash. I could never see myself buying audio equipment today like I did 30 years ago.
Anyway I will quit OTing this thread.
Tad