Is D for Dry? Class D...


Class D sounds dry and lifeless... thats all, carry on
128x128b_limo
Ricevs,
Thanks for your insights.  Francesco at Rouge Audio says that their amps benefit from 500 hours of break in.  PS Audio says 300.  Have you taken a broken in stock Rouge Studio N-10DM and compared it to broken in stock PS Audio M1200 ?  After your mods, what are the tonal differences between your modded amps to the stock versions, after break in?
zephyr24069,
Reading the Legacy Audio site, it appears that the IV1 monos, IV2 dual monos, and IV4 ultra all use probably the 1200 AS1 module for each channel.  They are all in the Master Series.  The regular IV4 and IV7 are in the lower Performance Series, and probably use the 1200 AS2 which is a compromise in stereo and multichannel, since available power with all channels driven is reduced due to shared power supplies.  So I suppose that the performance of the IV1, IV2 and IV4 ultra are nearly identical in each channel.  Am I correct?  Did you compare IV2 to IV4 ultra?  It seems you have two Valor speakers, so I wonder why you got the IV4 ultra instead of IV2.

You might want to get the stock Rouge Studio N-10DM for $1550 delivered, which seems to be comparable to the Legacy IV2.  See for yourself as you A/B with your IV4 ultra.  I think I will get the Rouge, and then later consider ricevs' mods.
I have a pair of PS Audio Trio A-100's that I've upgraded by removing the 15 year old B&O ICE Modules and replacing them with current 2021 revisions of the same 200ASC modules. So, kind of a frankenstein amp because this mix of parts never existed "in the wild". In any event, they sound amazing. I use them to bi-amp my speakers for summer listening, because my Pass Labs X5 is just too hot to use in my small listening room in the summer, in Arizona. 
I have never seen or modded a Rouge or PS Audio amp. However, they will both benefit the same from the mods. I spent 6 months modding the IceEdge module so this is why I know my mods will work. Tonal differences? Way more to sound than tonal differences. Maybe you mean sonic benefits? Please call me if you want more info. Now back to your regular program.

No, you can clearly see the stereo IceEdge modules in ALL of Legacy’s amps. They do not use the AS1. Buying AS2s in bulk makes more sense, since they make a lot of multichannel amps.
"Sorry Zephyr, my comments were not meant as an insult or disrespect, and if you took it that way, I apologize.

I’m biased towards Wilson Audio speakers, and my feelings are the same as yours in regards to other manufactures. However, bias does play a big part in anyone’s purchasing decision."


@golfnutz  I did not take it in either of those ways at all so no worries and thank you for your post.  I only took the implication that my positive comments on the amp after 12 months of hearing it and knowing exactly what it can do in the context of how I've implemented it including cables, speakers, etc...were drawn primarily from brand affinity.  Believe me, brand affinity does not overrule what my ears are looking for to the extent that I would misinterpret or misreport the results just because the folks at Legacy take fantastic care of their customers in all the many years since my first purchase back in the early 2000s...
"No, you can clearly see the stereo IceEdge modules in ALL of Legacy’s amps. They do not use the AS1. Buying AS2s in bulk makes more sense, since they make a lot of multichannel amps."

Definitely agree with @ricevs here based upon all I've been told or seen with the cover off the amp;  the modules in mine are definitely 1200AS2's used 1 per channel no a 4-channel amp.

Ricevs: Still keen to know (via IM or a website) what mods you offer as I was sincere in my prior post about investigating them and assuming they won't cross with anything already done in the amp design by Legacy or void warranty considering them seriously.
If you want to know anything about my mods then please call me.  Any mod done to an IceEdge module will void all warranties with the manufacturer (Legacy, in your case)  and with IcePower.  This is one reason most would not be interested in mods to expensive gear, like the Legacy.  The modded Rouge Design would cost you very little.....the IceEdge modules (modded or stock) are super reliable.  All 12 of my modded amps from 2019 are still going strong.  
"If you want to know anything about my mods then please call me. Any mod done to an IceEdge module will void all warranties with the manufacturer (Legacy, in your case) and with IcePower. This is one reason most would not be interested in mods to expensive gear, like the Legacy. The modded Rouge Design would cost you very little.....the IceEdge modules (modded or stock) are super reliable. All 12 of my modded amps from 2019 are still going strong. "
@ricevs Thanks for the post.  I have no idea how to contact you.....at least let me know how to look you up and find your phone#
That's a nice bunch of tweaks you got there. A few are new even to me. And bonus points for noticing demagnetizing CDs only lasts about 7 minutes. Well done!
What is true in audio is what we can hear.  You can argue about science but it is just thoughts in your head.  What is real, is what we hear.  Both de-staticing and demagnetizing a CD will improve the sound.  This can easily be heard.  The effects of the procedure, however, are brief.....do to the spinning of the plastic CD......building up more static.  Your ears are on your head........the ego is in the mind.  Use your ears.....they work.
You can argue about science but it is just thoughts in your head. What is real, is what we hear.
Expectation bias is also very real. Perhaps have doing the destatic thing, measure what it does? You'd need a CD with test signals on it.
Both de-staticing and demagnetizing a CD will improve the sound.
Like I said it’s a furphy and to those promoting it.
Maybe to de-static, but we weren’t discussing that.
But you’ve got nothing but "snake oil" voodoo for the de-magnetizing.
@atmasphere  When are your Class D amps coming out? I just sold an amp and looking for a new one.


And that’s where demagnetizing the aluminum CD disc furphy started back in 1996, and should stay. Along with all the other "snake oil" like directional mains fuses, Shun Mook mpingo disc etc etc etc 
When are your Class D amps coming out? I just sold an amp and looking for a new one.
We're doing limited shipping of Beta production right now. As with many things associated with the pandemic, we've run into supply side shortages that have caused us to design and fabricate some parts that should be 'off the shelf'.
Class D sucks. 
I’ve said it many times. Dry and lifeless, sure. I’ve been weary of anyone stating that it can be really good. Short of being utilized for subwoofer amplification I had ruled it out pretty much completely. I mean, what could better class A/AB/Tubes? My ears don’t lie. I’ve been around. Case closed, not interested…Or so I had convinced myself. 
Then comes along GaN (Gallium Nitride) class D. Never heard of it. “Oh God, class D, here we go again”, I thought initially. I didn’t care to be honest. 

Enter AGD. Unknown company. They seemed to have some really good reviews/feedback coming from those whose ears I’ve come to trust by and large. So okay I was curious…Apprehensive? Hell yes, and doubtful it could better really good SET amps.  
But regardless I was willing to take a risk and demo a pair of monoblocks (AGD Audions), yes doubtful and ready and willing to discount them. 
And then I LISTENED…
At first I sat there a bit confused at what I was actually listening to…I continued to simply LISTEN. 
This was altogether DIFFERENT. “This can’t be class D”, I thought…WTF 

My paradigm for what I had thought audio 
to exist within was being shifted with every track…this is (was) pretty amazing! 

This changed everything for me with regards to my pursuit for sonic excellence. I could no longer deny that class D done right can exist right up there with best of the best. 
Sounds like hyperbole, I’m well aware. It’s simply what I’ve discovered and felt this thread deserved some truth. 
Enjoy! 

Seems to me you've made out like this AGD Class-D amp has only just now made you a D class convert in a big big way. 🙄

Just looked at your posting history, you've been very active in the positive on these AGD Class-D amp now since March. (makes one wonder why you did not state this 🤷‍♂️) 
https://forum.audiogon.com/search/index?page=2&query=AGD&sort=date&username=davkobza

Then, you have been recruited recently as a fuser, maybe that's what you really heard?😉
https://forum.audiogon.com/posts/2179941

Cheers George


davkobza
I know exactly where your coming from, i thought the same about Class D for over a decade listening to the so called latest and greatest.

Like you the AGD's changed what i had thought of Class D in the most positive way. My music has never sounded better.

PS, ignore the person from the funny paper.

And now the ring leader, who thinks these AGD's can drive Wilson Alexia’s 0.9ohm bass loading so they can give their very best.🤦‍♂️
george
You do these drive by posts and really have nothing to add from first hand experience you form opinion from others opinions. Your stuck in the 80's and have not moved past. You really need to spend time listening to music instead of forums.

I also do not own Wilson Alexia's so who cares. 

Your posts are quite comical and show little value, just more BS to get past.
I also do not own Wilson Alexia’s so who cares.
It was you that inferred it could drive the them to their best. You are the one that’s comical and preaching BS not me. If your going to shill something get your facts right
It’s nice all the Class D detractors have a thread to dump in. As you can see there are so many of them (detractors).  Maybe a dozen or so.  

Meanwhile sales of Class D based gear continue to skyrocket. Go figure.

Alternate realities don’t seem to rule in reality.
progress is inevitable, some times for the better sometimes for the worse

in audio, there are always great engineers and impassioned music lovers striving for positive progress using new techniques and technologies

on the other hand, many people don’t have the time, energy, money or attention span to keep up and be truly aware of the progress being made by those who are making it

those people don't like to admit the above, and prefer to express negativity on discussion boards such as this


It’s nice all the Class D detractors have a thread to dump in.


There are different types of Class-D detractors, some only "dump" on those ** claims made by shillers of certain brand Class-D’s, who have no idea what they claim, especially in regards to what types of loads they are capable of driving.
If they didn’t make these false ** claims, there would be no confrontation from those detractors.

I for one have heard certain Class-D amps sound great, "with the correct speaker", and have acknowledged it here on Audiogon.

Cheers George
I do not see claims being made, but people expressing what they experience hands on there is a difference.

The "correct speaker" applies to any amp regardless of class and not just class D.
George goes on about this EPDR thing. But he's not clear on what the impact will be on a class D amplifier other than saying that they won't drive it.

Almost any class D amp made today has an output impedance that is often a good order of magnitude lower than traditional class AB designs. This is because the On resistance of the output devices is (especially if GaNFETs are used) literally only a few milliohms (our amp has an output impedance of 10 milliohms as an example). When you have an output impedance that low, if a speaker has an effective EPDR that causes it to be effectively slight less than 1 ohm the class D amp will still behave as a voltage source while driving it. This is for the simple fact that at 1 ohm the class D amp may well have a damping factor of over 100.


That's not the same thing as the amp falling flat on its face! However there is a chance that the class D amp will go into current limiting mode to protect the output devices. GaNFETs are tricky to heatsink and as a result the heatsinks you have to use are unlikely to move heat away from the output devices fast enough to prevent failure when driving such a load. So the prudent designer will have some sort of protection circuit even though the output devices can easily handle the current.

As I've pointed out a good number of times in the past, the limits of class D amps to drive a low impedance are the same as they are for a conventional class AB amp: current rating in the output devices, current available from the power supply and heatsinks enough to move heat away from the output devices.


Ironically its the GaNFETs that George has been so enamored of in the last couple of years where this heat problem is most likely to occur; conventional MOSFETs are often packaged in a TO220, TO240 or other package that can be easily heatsinked.


Now we should be clear about one other issue regarding EPDR. In most speakers the region where this might be a problem is often just a very narrow range of frequencies, IOW not the entire impedance curve of the speaker! If this is the case with a speaker that has such a low EPDR rating, it won't be much of an issue for a class D amp because there just isn't enough energy needed  over this narrow range to heat up the output devices. The Wilson Sasha and Sophias are good examples of speakers of this, and in practice mean almost nothing to any class D amp. At most clipping onset might occur slightly quicker, but frequency response is unaffected.

George accuses me of shilling nearly every time I explain anything about class D, so I reiterate that what I've said in this post has to do with most class D amps that are available today.  
Go and read any thread and you'll have georgie calling anyone a shiller who doesn't agree with him. It's his fallback accusation.

Before long, he'll be calling you sunshine, which in Australia, is a big insult due to it's effeminate connotations.

Next, he'll use **** notations in his spelling to use curse words to get around the mods.

Aside from that.....

All the best,
Nonoise

Before long, he’ll be calling you sunshine
Trust fusers to back each other sunshine.(because your soooo bright) 
(not you Ralph, the other fuser here with the AGD)

Ironically its the GaNFETs that George has been so enamored of in the last couple of years
Yes I have, and still do, but never that GaN could drive .9ohm bass loads like the Alexia’s to their best. Refute that Ralph
As I said the AGD has no chance of driving the Wilson Alexia to sound their best in the bass because of their .9ohm impedance load. And refute that also Ralph.

Go and read any thread and you’ll have georgie calling anyone a shiller
Especially owners that claim these amps can drive those types of loads. Which gives out the wrong info on what they can drive, they do it because they are shilling.
From the Wilson website page for the Alexia 2:


Measurements Sensitivity 89 dB @ 1 watt @ 1 meter @ 1 kHz Nominal Impedance 4 ohms / minimum 2.54 ohms @ 85 Hz Minimum Amplifier Power 20 watts per channel Frequency Response 19 Hz – 32 kHz +/- 3 dB Room Average Response [RAR]


We can see that Wilson does not think this speaker hard to drive with a 20 watt minimum. Because the AGD has such a low output impedance I think it should be able to drive this speaker quite well, depending on the power of the amplifier and the size of the room. If you have a larger room all you would need is more power.


So I guess I’m refuting the idea that a class D can’t handle this speaker (any more or less than any other class AB amp of the same power might). I really don’t see what the problem is.

I spoke to Jerron that works at Wilson (for the last 20 years) and he is in complete agreement. He says the older Alexia was a bit harder to drive but the class D amps handled it no worries at all.
So I'm going with a 'furphy' on this one.



I’m refuting the idea that a class D can’t handle this speaker

Ralph, don’t skew things around "to seem" to suit your next product.
I did not say "won’t handle", I said will not get "the best" out of the Alexia’s bass because of it loading.
We have the Alexia’s here in front of us and know what they like to get the best out of them in the bass, and it’s not Class-D yet. (Maybe in the future when they can come close to doubling from 8ohm to 4ohm to 2ohm wattages like big better linear amps can)

Keep going like this and it will look like your shilling again, because of your yet to be released GaN Class-D
Shows you do not know what your talking about, look at the AGD spec's. And the only Wilson speakers i own are the 5.1's and XLF's  and not the Alexia.

So from your posts you have the AGD's powering the Alexia? Otherwise your blowing hot air and you only have opinion.
Post removed 
Butt out, please, I was talking to Ralph🙏 (you didn't start the thread  b_limo did.)
First sign of a shiller. Here some more for you to agonize over.

Interviewer: I ask Alberto Guerra , why put solid state components inside an old 6550 vacuum tube envelope, bet it’s not vacuum’ed back out and sealed again either.
"Company founder Alberto Guerra admitted that he did it largely for the sake of visual aesthetics. “Otherwise a class-D amp just looks like a box”

PS: OK he’s shown all his cards, with that statement.

AGD is just GaN based Class-D slid into a "bogus" empty 6550 tube envelope, which uses (horror) the base pins for all it’s contacts, everything has to go through them, input output power supply rails everything🤢 
Just the whole gutted tube thing, stuffed with solid state, and still using all the tube pins as power/current transmitting contacts, guess in time it ensures return service work when those pins start to corrode and arc over????




Was going to check out the AGD gear, 14 day return privileges for $7k in unknown gear with zero dealers.

NOPE!
And the above post means what? That he was thinking literally outside the box?

What's the issue with tube pins? I own 70+ year old Western Electric Amps and 300B tubes and have never had issues with tube pins, sure sockets can get loose but that's a one minute fix and tube pins are easy to clean.

What AGD has done is brilliant on more than one level.
What’s the issue with tube pins? I own 70+ year old Western Electric Amps and 300B
See that what I mean, absolutely no idea.
Your not pumping any where near 400w and the current you would with a 300b just 🤣

What AGD has done is brilliant on more than one level.
I said it before you have no idea, and whatever your getting for this shilling, he needs to take it all back because your hopeless at it..

OK Sunshine.

What’s the issue with tube pins? I own 70+ year old Western Electric Amps and 300B tubes and have never had issues with tube pins, sure sockets can get loose but that’s a one minute fix and tube pins are easy to clean.

What AGD has done is brilliant on more than one level.

No not brilliant, more inept, but guarantees return service work in the future (maybe not so stupid.$$)
There’s a HUGE!! difference in output wattage and current going through the tube pins, compared to a 10w SE 300B even a push/pull one . (do your homework) 
Especially if the AGD is "trying" to drive Wilson speakers with low bass impedances.
You may as well have those nasty spring clip speaker terminals on the back of the AGD, because that’s just as good as the tube pins and the speakers are hooked through those to the GaN output stage in the 6550 tube envelop.
Jeff Rowland is reading...and taking notes
He doesn't have to take notes, as NO WAY you’d see JR doing high wattage/current signal transfer through those sorts of contacts, EVER!.

Cheers George