Digital amp comparison event.

Danny Richie · « **on:** 10 Feb 2006, 11:14 pm »

Just an update to something that was announced earlier in the North Texas Audio Jam forum. Some of you may not have noticed it there.

I am hosting an event to compare all the best digital amps, chip amps, switching amps, T-amps, D-amps etc.

Most of the major amp manufacturers have committed to sending amps and several already have.

NuForce is committed and amps are already here. I have been burning these in now for several days now.

Kevin Haskins of DIYCable is sending one of his Hypex based designs. They are in transit already and will arrive next week.

Ryan Tew of Red Dragon Audio will be sending out a pair of amps and maybe premier something new.

Tom Maker of Edge Amps has sent one of their G.5. It has been here for a couple of weeks now.

It looks like AV123 is going to send us the prototype X-amps that have just been completed.

Pat at Analog Research Technology is sending up one of their class D amps.

Stan Warren and Chuck Jones of Superphon has sent a very modified Hypex based design. I have had it here for about a week.

Brent Huskins from Media Design may either bring or send a Halcro MC20 and maybe a PS Audio GCC-500. He still has to confirm. Those are a maybe.

Dusty of Channel Islands Audio says he is covered up with getting out orders but to check back with him in February and he might can get a couple of his out to us. I need to follow up with Dusty still. Dusty???

Mark Lyon of Lyngdorf Audio has been invited and might send a SDA2175. I have not heard back from him yet as to his participation. He was just recently invited.

Then there is one more that I think I may leave as a surprise.

I have quite a group of guys coming in for this as well. A short list includes: Stan Tracht and brother, owners of Thee High End, the Usher Audio Distributor for the U.S. Then there is AC member Eric Hider coming down from Detroit. Gregg Straley from Reality Cables is coming down from Chicago. Gary Dodd of Dodd Audio and regulars from the Dallas area are coming up. Looks like Jeff Glowacki of Sonic Craft, and designer of Sonicaps, will be joining us too. There will also be a good handful of serious audiophiles. If others want to come please let me know ahead of time.

We will do a run through on the 18th of Feb. to iron out any bugs in the process and then go through it again on the 25th and 26th.

I'll post info on our web site after the event and try to compile all the comments, impressions, comparisons, and results.

Stay tuned. This one will be very interesting.

audiophile39 · « **Reply #1 on:** 10 Feb 2006, 11:22 pm »

My interest in digital amps is waning after speaking with several eminent amp designers who have chosen to pass on such technology because, as they tell me, all the hype over digital technology is just that: hype. It's basically cheap technology that is OK for home theater but inappropriate for fine-quality audio systems. As one designer told me, going from a quality analog amp to a digital amp is like going from a quality turntable to a cd player. There's no re-invention of the sonic wheel here.

jackman · « **Reply #2 on:** 10 Feb 2006, 11:32 pm »

Danny, I wish I lived closer to the lone star state! I'll have to settle for the recap from the group on these exciting amps. I look forward to hearing everyone's comments on the amps in the test.

Best of luck! Oh, and take lots of pictures!

J

Kevin Haskins · « **Reply #3 on:** 10 Feb 2006, 11:36 pm »

Quote from: audiophile39

My interest in digital amps is waning after speaking with several eminent amp designers who have chosen to pass on such technology because, as they tell me, all the hype over digital technology is just that: hype. It's basically cheap technology that is OK for home theater but inappropriate for fine-quality audio systems. As one designer told me, going from a quality analog amp to a digital amp is like going from a quality turntable to a cd player. There's no re-invention of the sonic wheel here.

It may be wishful thinking.

By the way... they are not really digital. They are analog amplifiers. There is no digital to analog conversion going on inside a Class D amplifier.

I can also name a couple "eminent" amp designers who disagree, pretty much like anything in the world of audio.

mrmusic · « **Reply #4 on:** 11 Feb 2006, 01:25 am »

Quote from: audiophile39

My interest in digital amps is waning after speaking with several eminent amp designers who have chosen to pass on such technology because, as they tell me, all the hype over digital technology is just that: hype. It's basically cheap technology that is OK for home theater but inappropriate for fine-quality audio systems. As one designer told me, going from a quality analog amp to a digital amp is like going from a quality turntable to a cd player. There's no re-invention of the sonic wheel here.

Two more cents: It is easy to lump all switchers in one category and discount the merits of a whole technology. And there are problems, most notably switching noise. But the advantages are enormous and attractive. The efficiency alone is worth a bit of work, and the high damping ratio gives most switchers a tighter and cleaner sound with great woofer control. Please remember that all switchers are not created equal. Most have analog input stages that have a huge bearing on the overall sound of the amp. That's why we need this comparison event...to determine whether or not actual sonic attributes and, or, "flavors" do indeed exist. The prototype we sent is one of the amplifiers being considered for production, and the only switcher. We sent it because it is good enough to take on any other circuit under consideration. We hope to learn alot from this process and hope others do, too. Yogi said it best,"it ain't over 'til it's over".
Chuck Jones
Superphon

JoshK · « **Reply #5 on:** 11 Feb 2006, 01:39 am »

I am just going to request that you do at minimum a single blind test, being a semi-scientific mind. If you group gets rather large, you might want to do a trade off, since only 3-4 people can honestly sit near the sweet spot.

I imagine if it is semi-blind that the comparison becomes harder as power of suggestion is strong, esp peer suggestion...so anonymous polling is also strongly encouraged.

Danny Richie · « **Reply #6 on:** 11 Feb 2006, 01:53 am »

This was discussed in the thread in the North Texas Audio Jam forum.

All comparisons will be blind. All amps will be hidden from view behind a foam wall panel that will be laid across the floor. It is 2' tall and 6' long. No one will know what amp or amps are playing.

All amps in stand-by (next in line) will be plugged in and warming up. Stan Warren even sent some cool little input shorting plugs to use during warm up.

peakrchau · « **Reply #7 on:** 11 Feb 2006, 02:21 am »

Quote from: audiophile39

...several eminent amp designers who have chosen to pass on such technology because, as they tell me, all the hype over digital technology is just that: hype. It's basically cheap technology that is OK for home theater but inappropriate for fine-quality audio systems. As one designer told me, going from a quality analog amp to a digital amp is like going from a quality turntable to a cd player. ....

Sony had been plugging away at CLASS D digitally switch output amplifiers since the mid 80s. The encoding scheme to convey amplitude information back then was somewhat different and probably more un-refined than today's chips. I heard the Panasonic digital receivers amps and found them to be seemingly never phased by whatever it was asked to play...sounding very precise controlled and focussed. Compared to my Bipolar amp (sounding a little less refined and confused when things got busy) it just did not have the same sort of "swing".

P.S. Why isn't NuForce on the short list ?

PeAK

AphileEarlyAdopter · « **Reply #8 on:** 11 Feb 2006, 02:44 am »

Quote from: peakrchau

Sony had been plugging away at CLASS D digitally switch output amplifiers since the mid 80s. The encoding scheme to convey amplitude information back then was somewhat different and probably more un-refined than today's chips. I heard the Panasonic digital receivers amps and found them to be seemingly never phased by whatever it was asked to play...sounding very precise controlled and focussed. Compared to my Bipolar amp (sounding a little less refined and confused when things got busy) it just did not have the same sort of "swing".

P.S. Why isn't NuForce on the short list ?

PeAK

Would it be preposterous to suggest that the Panny be included in this shootout ?
I am driving a pair of Silverline Sonatinas with the Panny XR55 in biamped mode with a Blue Circle MR1200 power conditioner, Nordost shiva Power cord and Zu Wax speaker cables.
The other day I cranked up Loreena Mckennit and was immersed in such a warm and rich sound.

bpape · « **Reply #9 on:** 11 Feb 2006, 03:41 am »

Try the Panny on a speaker that requires serious current and dips down to sub 3 ohms in places and you'll see why it's not on the list. It literally falls apart. As long as you feed it an 'easy' load, it does a nice job.

I'll be very interested to hear the outcome of this trial. The advantages of some of these technologies seem to be huge if the potential drawbacks can be minimized. I'll admit up front that I still have a bias against these types of circuits mostly from previous experience. Trying the Panny on a couple of sets of somewhat difficult to drive but well executed speakers (Snell, Dynaudio, Revel) and hearing it just choke and even shut down a couple of times didn't do anything to ease my fears or change my mind.

I'm sure that it's like anything else. Pretty much any technology, given enough research and experimentation can be perfected. Now it's just a matter of how far it can be taken. Will it ever compete with a Bolder? A Berning? Futterman? Probably not.

As I said, I'll be anxious to hear all of your impressions after this event.

TNT · « **Reply #10 on:** 11 Feb 2006, 04:22 am »

Quote from: bpape

I'll be very interested to hear the outcome of this trial. The advantages of some of these technologies seem to be huge if the potential drawbacks can be minimized. I'll admit up front that I still have a bias against these types of circuits mostly from previous experience. Trying t ...

I doubt a Berning wouild ever measure low in THD, due to high THD of tube, and complexity of chopping the plate current and reconstruct it.

If it didn't measure good, would it sound uncolored?

trekker · « **Reply #11 on:** 11 Feb 2006, 02:28 pm »

Quote from: peakrchau

P.S. Why isn't NuForce on the short list ?

PeAK

It is.

Quote from: Danny

NuForce is committed and amps are already here. I have been burning these in now for several days now.

...

bpape · « **Reply #12 on:** 11 Feb 2006, 03:42 pm »

I don't want to drag this off topic so I'll keep the response to TNT short. IMO measured THD is probably one of the least important things. Measurements in general IMO are overrated in many cases. Listen to a Futterman. It will measure like crap but sounds absolutely gorgeous.

What it sounds like, how it drives the speakers, how it images, etc. IMO are all orders of magnitude more important than distortion measurements - unless you want to watch an oscilliscope while you're listening

.

art · « **Reply #13 on:** 11 Feb 2006, 04:34 pm »

Gary Dodd stopped by my house last night, and picked up one of our small ICEpower-based amps.

Danny:

The gain on that amp is lower than most. 24, maybe as low as 22 dB (I forget...been a while since I measured that one.) The gain is set lower than most amps as it was intended for use in a use in a balanced system, where you pick up 6dB at the preamp out. It will run single-ended without futzing with any jumpers; just plug in whichever one you are using.

Since this will be a comparison event, you might want to set levels using a SPL meter. Do not use a sine wave source to do this with any of the ICEpower-based units. Pink noise will be ok, and I would advise using that in any case.

Have fun, guys...............

rustydoglim · « **Reply #14 on:** 11 Feb 2006, 10:54 pm »

We decided to pull out because we don't have to time to work with Danny to configure and evaluate his system to our satisfaction. That was the agreement that we have with Danny before we sent the amp over. We need to have final approval of the setup and sound before we will agree to go ahead. Unfortunately we need to prepare for the high end audio show in Germany at the last minute which coincide with this audition.

I have to acknowledge that we are now acting like a cautious big company

JeffB · « **Reply #15 on:** 11 Feb 2006, 11:25 pm »

Wow that is a huge list of amplifiers to compare. Seems like a big job. Still, I think it would be interesting to mix in 1 high quality solid state non-digital design and 1 high quality tube design. It would be interesting to see if the difference went un-noticed of if they stick out.

goskers · « **Reply #16 on:** 11 Feb 2006, 11:27 pm »

Hmmm, that is very interesting.

Does that mean that you will not sell a nuforce amp to anyone until you know for sure that the system synergy will be ideal?

zybar · « **Reply #17 on:** 11 Feb 2006, 11:36 pm »

Quote from: nuforce-jason

We decided to pull out because we don't have to time to work with Danny to configure and evaluate his system to our satisfaction. That was the agreement that we have with Danny before we sent the amp over. We need to have final approval of the setup and sound before we will agree to go ahead. Unfortunately we need to prepare for the high end audio show in Germany at the last minute which coincide with this audition.

I have to acknowledge that we are now acting like a cautious big company

Why do you need final approval of his setup?

What is unique about Danny's setup that would not work with your amp?

While I agree that system synergy places a role in the overall quality of the sound, a good product is a good product, unless it used incorrectly.

I think this is especially true with amps.

Very disappointing turn of events, but not suprising...

George

kfr01 · « **Reply #18 on:** 12 Feb 2006, 12:21 am »

Quote from: nuforce-jason

We decided to pull out because we don't have to time to work with Danny to configure and evaluate his system to our satisfaction. That was the agreement that we have with Danny before we sent the amp over. We need to have final approval of the setup and sound before we will agree to go ahead. Unfortunately we need to prepare for the high end audio show in Germany at the last minute which coincide with this audition.

I have to acknowledge that we are now acting like a cautious big company

hmm. Disappointing indeed. It makes me think that nuforce amps must either be:

1) not very versatile; or
2) not as good as the other "digital" amps on the market.

Neither is probably the case; Nuforce the company is probably just scared of a negative review.... but jeesh, have some confidence in your own products.

It makes me think, gosh, why would I ever take a chance on a nuforce product if the company itself seems to have low confidence in its own products.

jimmyp58 · « **Reply #19 on:** 12 Feb 2006, 12:52 am »

Good decision Jason.