Sunfire TGA-7401 user review

Ok, watched Avatar and listened to a couple good multi-channel SACD's on my new Sunfire TGA-7401. There are very few reviews on this amp, professionally or in this forum, so I thought I would post my impressions. As well, I got a lot of mixed feedback when talking to audiophiles regarding Sunfire amps, particularly in combination with my speakers - Paradigm Signatures. Love/hate relationship for many with Sunfire amps it seems. So I was hesitant to make the leap since it was a non-returnable special order from my dealer. But I am SO glad I did since I am 100% satisfied.

First, this amp is dead SILENT. I had to return an outlaw 200x7 amp I had in the past because it had hum issues. My Onkyo 875 receiver is dead silent and that is what I want from any amp I put in my system. Music simply comes out of silence at all volumes, awesome. I don't think I can stress how much that means to immersion when listening in a VERY quiet environment. It runs fairly cool, but got pretty warm to the touch after several hours of Avatar at reference volume. It is, however, in a small space with no side clearance, about an inch clearance across the top, and closed in the back aside from a slit in the bottom for the cables. I don't believe there is another class AB amp on the planet that could survive there. Even so, I plan on adding some vent holes to the back to give it at least some ventilation.

All I will say is there is nothing like amplifier headroom My speakers are finally at their full potential. I can drive my speakers into audible distress with this amp, but of course I immediately back off. I have a little learning curve before I figure out what my speakers can handle without distress. It is, however, a different stress than what I heard from my receiver. With the receiver, the speakers got harsh from distortion long before my speakers were at their limits. With this amp the sound is absolutely smooth, right up until my speakers cry uncle. Avatar at reference volume was just awesome! My Onkyo 875 simply could not deliver those kinds of dynamics. I attribute this to the headroom of the amp. I have very revealing speakers and Pink Floyd: The Dark Side of the Moon sacd 5.1 mix blew me away. The soundstage is awesome and the clarity is incredible. By far the best I've ever heard it. I liked that sacd before, but until now I was not blown away by it. Lets just say I'll be listening to that one more often now.

I'm of the camp that believes that amongst quality built amps, they will all basically sound the same when not driven to clipping. So avoidance of clipping is the holy grail I seek. For my speakers, I think a found the holy grail. I rate this amp as exceptional.

400x7 class AB channels in a compact enclosure. Reasonably priced. Quiet. Excellent dynamic headroom....I'm a very happy camper.

You are correct. The output stage is, however, class AB and so will produce AB type output. It is the swithed mode power supply that classifies it as a class H, which has the effect of increasing THD compared to a traditional AB design.

It is IMHO that this increase in THD, in this amp, is inaudible. At least to my ears.

Not yet. I'm Going to wait a bit to try current source until I've spent some time with the amp. I'm still "exploring" the voltage outputs

Interesting Barry. Having thought about it, I don't think I'm interested in intentionally changing the amplified signal. I bought my speakers because they are exceptionally flat (at least down to 70Hz or so) and I want as accurate a representation of the source as possible. The current source outputs just seems a bit antithetical to that goal. I will likely eventually hook it up just to hear how it sounds, but I won't keep it that way. I'm not a fan of "adjusting to taste", I just want as close as I can get to faithful reproduction although I know that is not entirely possible. I'm curious, what speakers do you have? Are they a horn speaker?

I agree and I've already opened up the entire back of the cabinet the amp is in. The amp is described as having "virtually no heat production". It's close, but not entirely without heat production. But considered it is pushing up to 400W into 7 channels it is, quite simply, a remarkable design.


I initially thought sunfire amps were digital and when I first realized it was AB and learned of the Downtracker power supply I immediately thought it was gimmicky. Once I educated myself on the design I realized it was ingenious and a legitimate major advancement in amplifier tech. IMO at least. I marvel at the fact that 400Wx7 channels are stuffed into a remarkably small -unvented- enclosure. I didn't appreciate how small this amp was until I actually handled it, I mean it's only a bit more than half as tall as my 875 - a receiver I know you're pretty familiar with.

I looked very hard at class D amps prior to my purchase and although most all user reports they are outstanding amps, I still am not crazy about the current design limitations, at least as far as I understand them, particularly the measured roll-off of upper frequencies. As far as I can tell this limitation is apparently not audible to most people, so it is more superstition on my part than something I would likely hear. But all amps have their particular design issues. I suspect I would have been very satisfied with one of the ICE module amps I was looking at. I think at $600.00 for 200Wx5 the Class D amps would be in short supply due to demand

Speakers are one of those things that you just have to listen to make a choice. When I was in the market for a speaker I first looked at good reviews that actually measure the speakers response to make sure it measures very flat, and then I went to listen. I've never heard the Polk's, but one person's "bright" is another person's "perfection". By far, speakers are the largest variable to the sound of your system and, IMO, need to be listened to if you want to make a good decision.

And I would be remiss if I didn't point out that your polks likely sound "bright" due to room acoustics, an area that most folks ignore completely. Room acoustics probably account for at least 50% of the sound you're hearing from your speakers. Do you have a room correction system on your receiver? This can help tremendously to tame the room acoustics in lieu of physical traps and absorbers. If it is a room issue causing the Polk's to sound "bright", there is a good chance most speakers will sound bright when placed into your room.