Class D amps that are superior to all or most?


Recently, I have heard about some Class D amps that may be close to the best there is regardless of class. Certainly, this technology has been in development for decades. The main issue has always been the switching power supply. In this regard, I have taken notice of AGD. They have created a whole new power supply that “switches” at a frequency 100 times the normal silicon based MOSFET. The designer uses a gallium nitride based PS. Interesting, it is enclosed in the KT88 glass envelope that sits on top of his amps. I am aware of two more pricey amps that seem to be also at the top- the Solution and the Merrill. There must be others that compete for the title. After my thread, “Is there a SS amp that can satisfy a SET guy?”, I am still on the quest.
Don’t want to spend $50K!
mglik
This is what I think.  Legacy buys stereo modules.  They use them in all the amps.  So, an i-v8 would have 4 stereo modules (8 channels).  The regular i-v4 has two stereo modules (4 channels).  The I-v4 ultra has 4 stereo modules (8 possible channels) but they use just one channel of each module so they are basically mono amps.  This gives more power for each channel and zero cross talk.  Each channel is already bridged, so you cannot bridge an already bridged amp.  So, no the i-v4 ultra cannot be bridged in any way.  It already has 1200 watts into 4 ohms on each of its 4 channels.  How much power do you need?  I believe the i-v2 dual mono stereo amp has 2 stereo amps and then just uses one channel of each amp to make it mono.
I have had mostly good A/AB amps over the years and one tube amp. Some amps were hell with some speakers, so amp/speaker synergy is still critically important no matter what you think you prefer. (I prefer a 'system sound' which starts with the best speaker I can afford with the sound I prefer, and then adds electronics in support of it.)

I now use a W4S STI-1000 integrated in my main system. It's my first Class D amp.  I use the DEAD SILENT pre-amp switching into a dsp room correction unit, then back the the STI-1000's power amp section.

This feeds a pair of highly resolving (perhaps slightly warm) near full-range two-way loudspeakers. The sound works for me with stunning detail and treble resolution second to none with never a bit of fatigue at all. The bass is solid and tight within limits of the speaker's ability.

I agree with other W4S owners in their characterizations, and have no doubt that the ST-1000 amp can feed the load of the Martin Logan CLS. I owned SL3s as mains for sixteen years (and still own them but now displaced as mains).

If I was made of money I might experiment with other amps but as of now I fortunately do not feel the need. The W4S Class D works extremely well in my system. I have none of the Class D prejudices others rant about.



To @ricevs   I am a long-time Legacy customer of many of their speakers and also happen to be an owner of the i.V4 Ultra amp since May of 2020 (very happily and very impressed I might ad).

The "ULTRA" build is using 4 stereo 1200AS2 boards with each single board as I understand it being dedicated and applied to power 1 channel.

What I can tell you for sure is that I have been extremely happy and impressed with this 4-channel amp (and have a friend with an i.V3 Ultra and another with an i.V2 that are equally impressed). I, like the 2 guys that I know, have been in this hobby for about 3 decades each and were early on firm tube amp lovers followed by "big expensive solid state lovers and bigots" for Class A and/or AB designs costing 10s of thousands of dollars and weighing 100-200 and more pounds. Note I still love great tube, Class A and AB solid state for the record and appreciate the merits of any reference-level amplifier.

I will not throw out manufacturer names for things I've owned and even more that I've heard  but I will say there are some big names on the list that I've owned and more that I've heard deeply that I remember and respect very much that today would have a hard time competing with what I'm hearing out of this Legacy i.V4 Ultra so I am inclined to agree with everything qualitative that is said in the review based upon my direct listening experiences only owning this amp.

I don't however want to get into a '&*^%^#$' contest with anyone who takes umbrage at the claims in the review.

It's a fantastic, musical, dynamic, detailed, powerful amplifier design that weighs a fraction of what I'm used to dragging up and down stairs, etc. and costs what I think is an incredibly reasonable price.  I'd suggest to anyone that it is well worth a listen to a well broken-in demo on a good system and do some careful listening; you might be very surprised and pleased at what you hear!


"This is what I think. Legacy buys stereo modules. They use them in all the amps. So, an i-v8 would have 4 stereo modules (8 channels). The regular i-v4 has two stereo modules (4 channels). The I-v4 ultra has 4 stereo modules (8 possible channels) but they use just one channel of each module so they are basically mono amps. This gives more power for each channel and zero cross talk. Each channel is already bridged, so you cannot bridge an already bridged amp. So, no the i-v4 ultra cannot be bridged in any way. It already has 1200 watts into 4 ohms on each of its 4 channels. How much power do you need? I believe the i-v2 dual mono stereo amp has 2 stereo amps and then just uses one channel of each amp to make it mono."

To @ricevs  great post....that is what I understood last year when I spoke with Dudleston at Legacy before deciding to buy the i.V4 Ultra....
I am sure the Legacy amps are very good. Stock IceEdge modules in a box. However, most people would want the dual mono iV2 amp that retails for $4785 (most don’t need or want a four channel amp like the $8700 iV4 Ultra). You can buy a stereo dual mono amp using mono IceEdge modules from Rouge Audio Design in Italy and have it delivered to your door for $1600.......a savings of $3185!!!!! I can also do mods on any IceEdge amplifier for very little money that improves their sound. Of course, many do no like buying via mail order and also from small companies and also don’t care for modding. I fully understand. The IceEdge modules are seriously reliable.