Digital Amp Comparison 2007

Danny Richie · « **on:** 14 Jan 2007, 09:33 pm »

Okay guys it has been decided that we will do this thing again.

Here is last years info: http://www.gr-research.com/amps/amps.shtm

This year I will not be the host. I will just be the co-host. It will be held at Art's house in Fort Worth this time. Art has a new house and a large dedicated (and well treated) listening room. Art has good gear too.

This one will be held just like last years event in that all head to head comparisons are made by a group of experienced audiophiles with all amps totally hidden from view.

Last years event was dominated by three favorites. One was a Stan Warren (Superphon) design, a Hypex based experiment from Gary Dodd (Dodd Audio) and the Sonic Impact T-amp.

This year we are going to limit it to production units only. If it is a product that is available (readily available) and not a one off custom something, then we want here.

This is an open invitation to all manufacturers and to any individuals that would be willing to send or bring amps. Please assist us in acquiring the amps that you would like to see here this time and pass this info on appropriately. I will e-mail out some formal invitations shortly. Let me know what you want to see here this time.

This years coverage will be seen at the new Stereo Mojo web site. http://www.stereomojo.com/

Hank · « **Reply #1 on:** 15 Jan 2007, 05:55 pm »

Date?

Danny Richie · « **Reply #2 on:** 15 Jan 2007, 06:09 pm »

We are going to shoot for the first week of March.

Want to come?

Hank · « **Reply #3 on:** 15 Jan 2007, 06:35 pm »

Yes - I could combine it with a visit to my daughter and her husband in Fort Worth. I'll watch this thread. Hey, maybe I could bring the new M-165X/custom AR ribbon tweeter two-ways that I'm about to build (got the crossover laid out and assembled one yesterday).
I bet you're cold up in WF - it's below freezing here and we're about to shut daown at 1:00pm. May be frozen in at home in the morning.

brj · « **Reply #4 on:** 20 Jan 2007, 10:10 pm »

I missed this post when I was traveling...

Ah, Danny... the first week of March? You're killing me!

Perhaps the gear will show up early at Art's place and I can run over for a sneak preview. There are several switching mode amps that have been on my audition list for some time that just haven't been able to track down. (Actually, early arrivals would be a good idea anyway, just so you guys have time to address shipping problems and otherwise check everything out completely before the comparison.)

Regardless, it should be a fun meet. I learned a lot the last time, and appreciated all of the work you did in setting it up, and especially the willingness of the manufacturers to participate. It wasn't a trivial thing for them to send their gear off to be so openly reviewed, and it spoke volumes regarding their confidence in their products. Hopefully this event will be even better!

Please keep us posted on which amps will be able to make it.

maxwalrath · « **Reply #5 on:** 20 Jan 2007, 10:17 pm »

I could send an Audiosector Patek down for the weekend.

Danny Richie · « **Reply #6 on:** 20 Jan 2007, 10:24 pm »

Now I just need to round up some participation. You guys need to start pestering the companies that you want to see here. There may be several that we haven't contacted.

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I could send an Audiosector Patek down for the weekend.

Tell me more about the company and product.

PaulHilgeman · « **Reply #7 on:** 20 Jan 2007, 10:55 pm »

I can send in a Niagara, Dual Mono Hypex UcD400 based.

-Paul

brj · « **Reply #8 on:** 20 Jan 2007, 10:59 pm »

Quote from: Danny

You guys need to start pestering the companies that you want to see here. There may be several that we haven't contacted.

Off the top of my head in no particular order:

CI Audio D-200 (Hypex based)
Nomad Audio Niagara (Hypex based)
DIY Cable's Exodus 400 (Hypex based)
Red Wine Audio Signature 70 (Tripath based)
NuForce Reference 9 SE (custom SM amp module)

Danny, you might want to post the LS6's efficiency and impedance curve in this thread and then let the amp manufacturer choose the more appropriate product from their lineup. There is sometimes a tendency to make higher powered amps more of a statement product (more expensive parts, built in power conditioning, etc.), so even though the relatively efficient LS6s may not need the extra power, the manufacturer may still want to send their higher powered units.

Art, you might also want to post the output impedance of your VAC preamp so manufacturers know what their amps are going to see.

brj · « **Reply #9 on:** 20 Jan 2007, 10:59 pm »

Quote from: PaulHilgeman

I can send in a Niagara, Dual Mono Hypex UcD400 based.

Well that was easy!

PaulHilgeman · « **Reply #10 on:** 20 Jan 2007, 11:08 pm »

LOL,

It works perfect, since the next, and upgraded batch, will be done next week, and off to a client to audition in February and then down to the comparo in march.

Perfect timing in my book.

-Paul

maxwalrath · « **Reply #11 on:** 21 Jan 2007, 01:09 am »

Quote from: Danny on 20 Jan 2007, 10:24 pm

Now I just need to round up some participation. You guys need to start pestering the companies that you want to see here. There may be several that we haven't contacted.

Quote
I could send an Audiosector Patek down for the weekend.

Tell me more about the company and product.

Well, I don't really know much...this is the company's website: http://www.audiosector.com/, and the 6moons review is here: http://www.6moons.com/audioreviews/audiosector/patek.html .

I was really suprised how well the little T-amp did at your last shootout...I preferred a Clari-T to it, a dual-mono, tricked out Clari-T to the regular version, but I thought the Patek was head and shoulders better. I've had all of them in my system.

Danny Richie · « **Reply #12 on:** 21 Jan 2007, 02:43 am »

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Danny, you might want to post the LS6's efficiency and impedance curve in this thread

The impedance load is not much of a problem.

Sensitivity is conservatively rated at 90db with a 1 watt/1 meter measurement. That is a bit deceptive though as they will easily hit some high SPL's with very little power.

An amp with good drive will be a plus though as there are plenty of woofers to control.

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CI Audio D-200 (Hypex based)

I sent a PM to Dusty and have heard nothing back yet. You might ask him in his forum.

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Nomad Audio Niagara (Hypex based)

Paul, if it is a commercial product and is available for sale then you are welcome.

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DIY Cable's Exodus 400 (Hypex based)

I have exchanged some e-mails with Kevin, but have yet to convince him to participate this year. You might ask him in his forum too.

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Red Wine Audio Signature 70 (Tripath based)

I invited him, but Vinnie is not sure whether he can have product ready in time. It is still about 7 weeks out. Beat him up a little in his forum over it

and maybe can swing it.

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NuForce Reference 9 SE (custom SM amp module)

I don't know if those guys will be willing to have their stuff A/B'ed next to everything else out there. We might get a pair of theirs one way or another though.

Ryan Tew of Red Dragon Audio is going to try to get a pair here this year.

It looks like we'll have a new Halcro as well.

Michael from MGL Audio Laboratories, Inc. www.mglaudiolabs.com has also offered to send one of their new products.

Mark Lyon of Audio Systems in Austin, Texas 78756. www.audiosystems.com Has offered to send one of the Lyngdorf amps again. This one was very good last year.

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Well, I don't really know much...this is the company's website: http://www.audiosector.com/, and the 6moons review is here: http://www.6moons.com/audioreviews/audiosector/patek.html .

I wonder if they offer completed products or just kits. I might have to contact them. I'd love to hear it.

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I was really suprised how well the little T-amp did at your last shootout...

The funny thing about that little amp is how transparent it really is. It sounds more like the front end components than having any real sound of its own.

HumanMedia · « **Reply #13 on:** 21 Jan 2007, 04:35 am »

And remember to warm those UCD products up for about 40 mins before comparing.

LoudandClear · « **Reply #14 on:** 21 Jan 2007, 07:18 am »

I know it's an integrated, but how about the Onkyo 9555?

http://www.us.onkyo.com/model.cfm?m=A-9555&class=Amplifier&p=i

Lots of people chattering about this one . . .

Anyone around here heard it yet?

maxwalrath · « **Reply #15 on:** 21 Jan 2007, 04:27 pm »

Quote from: Danny on 21 Jan 2007, 02:43 am

Quote
Well, I don't really know much...this is the company's website: http://www.audiosector.com/, and the 6moons review is here: http://www.6moons.com/audioreviews/audiosector/patek.html .

I wonder if they offer completed products or just kits. I might have to contact them. I'd love to hear it.

Quote
I was really suprised how well the little T-amp did at your last shootout...

The funny thing about that little amp is how transparent it really is. It sounds more like the front end components than having any real sound of its own.

The Patek is offered as a completed product...it meets the qualifications of the shootout.

brj · « **Reply #16 on:** 21 Jan 2007, 05:17 pm »

Quote from: LoudandClear

I know it's an integrated, but how about the Onkyo 9555?

http://www.us.onkyo.com/model.cfm?m=A-9555&class=Amplifier&p=i

Obviously the final selection will be up to Danny and Art, but I can think of two relevant questions:

1) Do you know of a source that would let Danny borrow one?

2) Does it have power-amp inputs? All of the other amps will be fed from the same pre-amp, and unless the unit has power-amp inputs, you won't know whether any differences you hear are due to the pre-amp portion of the unit or the power amp portion.

brj · « **Reply #17 on:** 21 Jan 2007, 05:22 pm »

I don't think I've really heard a Gainclone style chip amp before... I think I might have heard a DIY one once, but didn't have a chance to critically listen. That could be an interesting addition.

Just for my own education, in what "class" of amp do the gainclones fall? I haven't heard them called class D or T, like the other analog switching mode amps listed.

GHM · « **Reply #18 on:** 21 Jan 2007, 06:00 pm »

Quote from: brj on 21 Jan 2007, 05:22 pm

I don't think I've really heard a Gainclone style chip amp before... I think I might have heard a DIY one once, but didn't have a chance to critically listen. That could be an interesting addition.

Just for my own education, in what "class" of amp do the gainclones fall? I haven't heard them called class D or T, like the other analog switching mode amps listed.

AFAIK the Gainclone is an analog amplifier or DC amplifier. It doesn't fall in any class of Digital...
I've never seen it referred to a class. Maybe some one else can shed some light here? Here's one article on Op amps .
]http://www.sakurasystems.com/articles/Op-amps%20Junji.html]

jhm731 · « **Reply #19 on:** 21 Jan 2007, 06:05 pm »

Your Digital Amp Comparison 2007 should include a TacT amp with Aberdeen/MauiMod upgrades.