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My thoughts on my first Class D amp

I recently started 2 threads on this site, Narrowing down choices in a Power Amp  and also High Power Amp, Does it Matter at Lower Volumes.

I am grateful for all the input, and thought I would share the results of those posts.

Summary is: I have a Baetis Audio Server, going into a T+A Dac8, into a Mark Levinson ( ML ) 326S into a ML532H power amp. The amp loses a channel on occasion, with strange popping noises sometimes, other times just a single ( not very loud pop ). Time to get this amp fixed or buy another amp.

Well, I am getting the amp fixed, but I bought a Class D RCVTech set of monoblocks. 

So, having said all this, WOW. Very happy.

My wife and I sat down last night, and played a variety of music, from the Baetis server. No new music, no streaming, existing tunes we have listened to for years. Nothing but an amp swap.

The RCVTech MPA-1200 monoblocks 

1)  definitely better stereo separation, 

2) definitely way better bass, these monoblocks double down to 700 wpc at 4 ohms, something the ML532H did not do. A world of difference on bass

3) overall better sound, even at low volume.  Not bright or fatiguing at any time. 

4) more detail, listening to existing tracks we have owned for years, more small background detail, 

I wasn't fully sure of what I was buying, but, now, I realize that while I will repair the ML532H, its future use is in question. I am keeping these Monoblock RCVTech MPA-1200 amps in place. 

The buying process was easy, the right questions were asked, delivery was fast, for a customized build.

I have the Class A input with 380 wpc at 8 ohms, 700 wpc at 4 ohms, 700 wpc at 2 ohms, THD + N = 0.0009%.

Since this is Class D, not sure how much more money I would have to spend to better this with a conventional build Class A amp?  I was considering Pass Labs, who were suggesting XA100.8 or larger.  Some day I may actually get to hear these Pass Lab amps, but, there is no urgency, now.

 

robeffy
hilde45's avatar
hilde45
5,994 posts
 

@jaymark This comment of yours caught my attention:

I really like my high end class D amps, for sure.  They sound great.  I am a bit more enthralled with my A/AB amp that I will though continue to rotate with them.

After trying a several Class D amps – AGD Audion, NAD M23, and a DIY Hypex based unit, I am in agreement with your comment about Class D lacking "meat on the bones" and "presence." I also agree that not all amps can do everything, so this is not a negative for Class D, though of course it would cool if they could gain those attributes.

My question to you is how you would rate the Class A/AB amps against Class D for the attributes that Class D brings – quickness, clarity, speed, and whatever else you think Class D does well.

The reason I ask is that, if I get the gist of your final remark, I also suspect that the "demise" of A/AB is really a head-fake by the Class D marketers. 

I'm currently on the lookout to try a Class A/AB amp that might do both presence (à la Class A) and quickness (à la Class D). I'm thinking, maybe a Hegel H20 or something else.

Any comments on all this?

 

corelli
1,167 posts
 

@hilde45 

My Marantz Ruby, which uses Hypex outputs, does not sound the least bit thin or lacking "meat on the bones".  For me it has never been class as much as implementation of a given design.

robeffy's avatar
robeffy OP
79 posts
 

@jaymark   I was seriously considering the PSAudio M1200, the JC1 and the NAD M23, once I started to read reviews on Class D.  This was a real eye opener episode for me. Also looking Coda Continuum No 8 V1 or V2, Rotel Michi. 

@mapman I still want to hear Pass Labs amps.  No one I know has them, and I live 4-5 hours drive north of the nearest dealer.  Not sure they would agree to send me an amp for "home demo" purposes, actually fairly sure they would not. Oh well. I looked into Coda Continuum No 8

@hilde45 Great question of Jaymark.  Curious to hear his answer.

robeffy's avatar
robeffy OP
79 posts
 

@corelli I ended up buying a pair of RCVTech monoblocks, Hypex NCX500 modules, with 1200 watt power supplies, and Muses02 Class A input section.  All I have to compare with is the Mark Levinson 532H amp, Class A/B, and the RCVTech MPA1200 amps are definitely better.  I would not say thinner sounding at all.  I would love to take these to someone's house with a super high end Class A amp and compare... not going to happen, I don't know anyone around me with that setup.. So, I ended up following your advice!

hilde45's avatar
hilde45
5,994 posts
 

@corelli The DIY Hypex I tried had a similar module to the Ruby, the NCx500. It is fast and harsh and lacks presence, meat.

But...implementation makes a big difference, so maybe that's why the Marantz might sound better. Or your pairing with speakers. Or the room. Could be a lot of things.

But in my room, with all the variables stable, the GaN amps (NAD and AGD) sounded better but still lacked presence.

 

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