Dec 30, 2018328 views

Thoughts on the THX AAA 789, Topping A30, and Emotiva BasX A100 and a little note on the Schiit Loki.

It was a good Christmas at my house. I got the THX and a Schiit Loki. I'll talk about the Loki just a bit and then get into my impressions of the THX AAA 789. The Loki: This is a super well executed little EQ. 4 bands. Ideally situated across the bandwidth for the best effect. It is essentially transparent and has a true bypass switch, or you can turn the unit off and the unit is bypassed altogether. When everything is set at 0 there is no noticeable coloration. Before the purists go off on a tear here's what I think and have always thought about EQ. EQ is absolutely awesome for compensating for a source, an amp, speakers, a room, or ears, or any combination of the above. I have some upper end hearing loss from years driving big trucks and just a little high end boost really helps. To that end the Loki is amazing. The high boost really makes the highs on the HD6xx's, 58x's, and HE400i's come out for me. Just a touch of bass is awesome on the 58x's and gives the HE400i's some of that planar punch that is a little lacking given all of their other good qualities. Anyway, if you ever fight with poor source material that's just a little too much or too little of something, I'd recommend the Loki, it's solid. Okay, the THX: Build quality: It's fine. It doesn't scream high end to me. My gain selector is slightly off of true. So when it's set to the 2nd gain position it's more at 11:45 than say 12 o'clock. But that's just the OCD in me. I'm sure if I wanted to I could probably open up the unit and adjust it so it lined up right. I only mention it because I read some mentions of this issue in the product discussions. Meh. It seems solid enough. Aesthetically speaking, in my opinion, it's a forgettable black box and that's just fine with me. Setup: I'll compare to the Topping A30 and the Emotiva BasX A100 since those are the other 2 amps I use at my desk. I used my HD6xx's since they seem to be the most common point of reference. USB input using Spotify on high quality and AIFF from iTunes library. I don't own any DSD files so everything will be from a CD quality or lesser frame of reference. Topping was on high voltage (still no idea what the low voltage setting does because it doesn't appear to affect the sound) and gain level 2. THX was on gain 2. Emotiva has no gain setting. Interconnects were Monster Cable THX shielded (back off man I got them on clearance with an employee discount from an old job selling electronics), or Amazon basics. Signal chain ran from the D30 to Loki, THX, A30, then finally the Emotiva. I volume matched and switched via the 1/4" inch during songs. Single ended: This thing sounds great. It's interesting to compare with the Topping A30 with the Burson V5i mod. That amp with those opamps is pretty amazing and to hear it go toe to toe with the THX just reinforces that conclusion. Truly. The D30/A30 stack with the Burson opamps is amazing. The Emotiva is just what it is. It sounds great by comparison. If I were to rank them by sound quality I'd say THX, Emotive, then the Topping, but truly there's not a lot separating these 3. Is the THX better? Without a doubt. They are all super quiet amps. You don't hear noise from any of them. They are all 3 very neutral in their presentation. The THX has just a little extra something. I can't put my finger on it. So I'll just leave it at that. Whatever it is it is enjoyable to listen to. Balanced: I can't compare the THX with the other 2 balanced. What I can say is that with the HE400i's, HD6xx's, and HD58x's the sound is nothing short of spectacular. That little extra something is just magnified. It's not just louder. It's more everything. More dynamic. Fuller, wider soundstage. This is just a spectacular sounding amp. I wasn't sure if going with balanced would make that much of a difference but it is noticeable. What is also noticeable is that the HD6xx's and the 58x 's both scale wonderfully. There's something about the 58x's. I know there's a lot of debate over whether they are as good as the 660s's. I don't know if I'll ever pony up the cash for those but I will say that there is something pretty special about the 58x's for a $150 headphone. Interestingly enough the only headphone that doesn't play nice with the THX are my Monoprice Monolith M560's. They sound okay through all of these amps but the only amp they sound great with is the headphone out of my Parasound Zamp. They don't sound bad, they just interplay oddly with the amps when things get busy musically and get really punchy in the mids and highs. Not sure what that's about. But I keep them around because they're built so beautifully. I wish all headphones had that kind of solid build. So where does that leave things? The THX is everything people say it is and may just represent the last amp I buy in a while. I suspect that it is capable of giving more but I have bumped up against the limitations of my $100 DAC, compounded by the limitations of my source material being CD quality or lesser. That said, the D30 and the THX AAA 789 are a pretty amazing sounding pairing. I'm ashamed of nothing. I may look into getting DSD running on my library just to check that theory but at the moment I'm too busy enjoying the music. I don't know if the THX is a "bargain" but it's certainly worth what I paid. There are people whose opinions I trust that have spent thousands on amps who say this holds its own against them. I'll take their word for it and save my cash. For anyone not wanting to invest even this amount of money into this hobby I'd say get the Topping D30/A30 stack (provided you don't have low impedance headphones or some ridiculously hard to drive headphones). Stick in the Burson V5i opamps and be done with it. It holds its own against the THX for single ended very well. Then just buy headphones. They're the more fun part of this hobby in my opinion anyway.
Pzyklon, Evshrug, and 4 others

Great review. Just bought the Fiio K3. I’ll try to review that
I've been living with this amp for a week. I have noticed that the THX, with very well mastered source material does bring out more detail than the Topping but you have have to scrutinize quite a bit. The Emotiva just blows both of them out of the water for headroom and immediacy, as long as you don't mind the potential of hearing some background hiss with sensitive IEM's although from the forum on this amp in Head-Fi passive attenuators apparently fix this issue pretty handily. I'm quite happy with my little setup and feel pretty comfortable that regardless of the cans I have a solution that can power them effectively and sound good doing it. Now, on to buying more cans!
Experiment 3: HD6xx's balanced out of THX into right cup, Topping A30 and Emotiva single ended into left cup, volume matched. I found this site with various samples at different bit rates and types (DSD, PCM, MQA, etc). So I tried all that my D30 could handle. I'm still experimenting because I don't want to dismiss DSD out of hand. In my personal experience, in the past I had a DVD audio copy of The Flaming Lips Yoshimi album and it sounded incredible on the player I had back then. Sadly that player died and I haven't been able to listen to it, or the SACD's I got back then in years. But I clearly remember that and Springsteen's Devils and Dust dual disc sounding amazing on my home setup (Denon 3805 pushing a pair of circa 1986-7 Klipsch Fortes). So I know that higher bit rates can make a difference. Again, the Topping A30 with the Burson mod and Emotiva both hold up admirably. I've read that the THX isn't a "true" balanced amp. I'll take people's word for it. I don't notice a huge difference between any of these 3 amps. Slightly more bass response from the THX and Emotiva than the Topping. Slightly wider soundstage on the THX. I posited previously that I wondered if I may be bumping against limitations of my source material (a distinct possibility because Spotify is 320kbps Ogg Vorbis and my iTunes library is mostly AIFF files ripped from my CD collection). So I tried these files in their various formats provided my Topping D30 could decode them. Is there a difference between the 16bit 44k original files and the 24bit or DSD recordings? Yes. But, perhaps it's just my old ears making their limitations be known, but to me we're talking about very marginal gains. Or perhaps these are differences that are more pronounced via better speakers/headphones? I'm new to the headphone game and all of this equipment is sitting at my desk. I use my big system with just an old Yamaha CDX-1030 into the Denon and Fortes and it sounds spectacular. I've never felt a need to upgrade anything so I never did. But I did want something to listen to at my desk and down the rabbit hole I went. I purchased the HD6xx's because people refer to them as reference headphones. The HE400i's are similarly voiced, the HD58x's were just an impulse buy. In any case is it possible that none of these are capable of producing a listening experience similar to that of my Fortes or, for that matter, the Elac UniFi UB5's I have hooked up to a Sprout in my living room? Maybe I just don't get this hobby but it's mind blowing to me that I could spend this much money on this much gear and although I do get a lot of enjoyment out of my now collection of headphones, I don't get nearly the same listening experience. It just feels like I'm chasing my tail and I don't think it's reasonable to have to spend $1,500 dollars on a pair of headphones to get the sound quality of a $400 pair of Elacs. Maybe I started out with the wrong expectations. I'm just shocked that it's this difficult to get good fun and musical sound out of headphones.
Experiment 2: I ran single ended to the left driver of my HE100i's and balanced to the left driver. I volume matched and swapped between the Topping and Emotiva for the left driver and I have to say, there's not a lot in it. All 3 of these are great. Seriously. The HE400i's have an impedance of 35ohms so supposedly they shouldn't play nice with the Topping given its 10 ohm output impedance but it sure didn't seem to make much of a difference. In a blind test I honestly think you'd have a hard time differentiating between them. I totally don't regret getting the THX and between the 3 amps I think I'm pretty set to meet the demands of whatever cans I purchase in the future. It is validating to know that all that initial research that led me to the Topping stack as my first headphone DAC/amp setup was money well spent. I can't recommend the Topping setup enough.
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Really? That's interesting. I'll have to read more on this. It is interesting to me because my other pair of planars the Monoprice Monolith M560's can get loud on any of my amps but only sound really good on one of them, but when they sound good they are pretty spectacular. The HE400i's however sound good on pretty much anything I've tried them on and are quickly becoming my go to cans.
Yeah, they’re not affected by output impedance, BUT the quality and power of the amp make a big difference. While a T50RP can reach enough volume on an iPhone 6S (at almost max setting, ha!), the soundstage is greatly compressed, bass is less impactful, and generally it will have a weaker sound compared to a desktop amp. And the T50RP is super hard to drive, lower volume output at any given setting than any other headphone I’ve tried yet, but it’s 52 Ω impedance is also really low. Meanwhile, my Sennheiser HD 58X Jubilee (150 Ω) get plenty loud on almost anything I plug it into (including a tiny DAP I have that’s about the size of the square iPod Nano, a bit thicker), but it really sounds special from my higher end sources and amps.
Okay, I did a bit of an unfair comparison. I went balanced out from the THX and compared to the Emotiva. The Emotiva has the output resistors bypassed and by their admission this is potentially more noisy. Cranked up to 8/10th I can hear the amps noise floor. So then I started playing music (after turning it back down) and I will say I could definitely hear a little noise in my HD6xx's. This was at an above comfortable listening volume. Balanced at the same volume on the THX and there was zero noise at all. Surprisingly the Topping A30 on gain 3 cranked to the max was also silent. Just goes to show you don't have to spend an arm and a leg to get a really nice sounding little setup. Next stop for me is finding a worthy DAC to replace the D30 that might actually show what the THX is capable of.