http://jp-prev-audio.teac.com/product/ha-501/
One is on its way. Review soon.
Some photos of the internals.
One is on its way. Review soon.
Some photos of the internals.
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TEAC HA-501 : the last headphone amplifier
- Thread starter rjm
- Start date
Japanese company TEAC has been around since the 50's, and is still around today. The HA-501 headphone amplifier was released in 2012 as part of their '500' series of mid-size (29 cm width) stereo components aimed at a modern, computer-centric audio lifestyle. Although other products in the range are still active, the HA-501 is now sadly discontinued.
TEAC (the company also makes products under the TASCAM and ESOTERIC brands) seems to have succeeded where other Japanese audio makers like Onkyo, Kenwood, Pioneer, and JVC failed. I like to think it's because they adapted to the trends (portable audio, network audio, headphone listening, streaming, computer audio) without abandoning their core values of quality and aesthetics. It's a tightly focused product lineup, and a very attractive one in both feature set and appearance. Their new UD-701N (part of the larger 700 series) is a real tour-de-force: high-quality amp, headphone amp, preamp, DAC, and wireless network receiver all in one nicely designed package.
The HA-501, on the other hand, always felt like a bit of a throwback even on release. All analog, the entire chassis was devoted to just driving a single pair of headphones (though it does pinch hit as a simple line preamp). Considering TEAC offered headphone outs on all the other 500 series components such as the DACs and integrateds, it's understandable that most consumers would fail to see the merit of doubling their investment to get a feature they already had. Today, while the UD-501 and UD-301 DAC/headphone amps are still high quite highly sought after in the Japanese market, the HA-501 sees much less interest, typically selling used for just $200-250 USD. As such, it's a bit of a sleeper deal, if you have the source and the headphones lined up to make the most of it.
The dual-mono circuits of the HA-501 are based on a single op-amp in each channel (MUSES8920) fronting a class-A transistor output buffer. From the high-ish distortion measurements I suspect the output is running open loop. As well as being able to switch the line outs from pass-through to preamp mode, the headphone amp has the unusual feature of a damping level control, which, again from the audioscience testing, seems to simply switch 0-5 ohms into the output path rather than adjust the feedback level. Some headphones might benefit from the extra isolation, others likely won't, but it's a nice little tweak to have.* It also has balanced inputs. The nice big chunky toroidal power transformer is great to see (the chassis weighs in at a hefty 4.1 kg), though I do worry a little that the +15 V and -15 V are established with LM7815/7915 regulators instead of something nicer. I'll establish the truth when I have mine in hand. Although the HA-501 never seems to gain much popularity even within the hifi community the few reviews that I have found have been uniformly positive. Although I don't expect it to conquer my current reference, the Sapphire IV, I do expect it to play in the same league and have a similar sonic signature, though perhaps a few notches warmer and looser.
I am looking forward to its arrival, to say the least.
* I have to comment on this. Adding a damping factor control on a consumer-facing product like this is just a crazy idea, because 99% of the potential market either has no idea what it is or does, or had an incorrect understanding of what it is or does. It's that "damn the torpedoes!" attitude that attracted me. I can just imagine the meeting at TEAC between the headstrong designer (I'm imagining an old engineer guy, way past normal retirement, revered at the company) and the younger marketing team, because, yeah, the designer clearly won that battle!
TEAC (the company also makes products under the TASCAM and ESOTERIC brands) seems to have succeeded where other Japanese audio makers like Onkyo, Kenwood, Pioneer, and JVC failed. I like to think it's because they adapted to the trends (portable audio, network audio, headphone listening, streaming, computer audio) without abandoning their core values of quality and aesthetics. It's a tightly focused product lineup, and a very attractive one in both feature set and appearance. Their new UD-701N (part of the larger 700 series) is a real tour-de-force: high-quality amp, headphone amp, preamp, DAC, and wireless network receiver all in one nicely designed package.
The HA-501, on the other hand, always felt like a bit of a throwback even on release. All analog, the entire chassis was devoted to just driving a single pair of headphones (though it does pinch hit as a simple line preamp). Considering TEAC offered headphone outs on all the other 500 series components such as the DACs and integrateds, it's understandable that most consumers would fail to see the merit of doubling their investment to get a feature they already had. Today, while the UD-501 and UD-301 DAC/headphone amps are still high quite highly sought after in the Japanese market, the HA-501 sees much less interest, typically selling used for just $200-250 USD. As such, it's a bit of a sleeper deal, if you have the source and the headphones lined up to make the most of it.
The dual-mono circuits of the HA-501 are based on a single op-amp in each channel (MUSES8920) fronting a class-A transistor output buffer. From the high-ish distortion measurements I suspect the output is running open loop. As well as being able to switch the line outs from pass-through to preamp mode, the headphone amp has the unusual feature of a damping level control, which, again from the audioscience testing, seems to simply switch 0-5 ohms into the output path rather than adjust the feedback level. Some headphones might benefit from the extra isolation, others likely won't, but it's a nice little tweak to have.* It also has balanced inputs. The nice big chunky toroidal power transformer is great to see (the chassis weighs in at a hefty 4.1 kg), though I do worry a little that the +15 V and -15 V are established with LM7815/7915 regulators instead of something nicer. I'll establish the truth when I have mine in hand. Although the HA-501 never seems to gain much popularity even within the hifi community the few reviews that I have found have been uniformly positive. Although I don't expect it to conquer my current reference, the Sapphire IV, I do expect it to play in the same league and have a similar sonic signature, though perhaps a few notches warmer and looser.
I am looking forward to its arrival, to say the least.
* I have to comment on this. Adding a damping factor control on a consumer-facing product like this is just a crazy idea, because 99% of the potential market either has no idea what it is or does, or had an incorrect understanding of what it is or does. It's that "damn the torpedoes!" attitude that attracted me. I can just imagine the meeting at TEAC between the headstrong designer (I'm imagining an old engineer guy, way past normal retirement, revered at the company) and the younger marketing team, because, yeah, the designer clearly won that battle!
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Let's begin then.
The quality of the external hardware is impeccable. Tight tolerances, no shortcuts, just absolutely solid. So handsome, with a wonderfully tactile 70's aesthetic going on with the dials and switches. Not a blue LED to be seen, just warm reds and orange. It's a nostalgia trip just to turn the unit on: the power toggle switch with its machined aluminum cap and internal dust protector could have been ripped from an Atari 2600. Anyway - ahem - I digress...
The amp is a heavy, dense brick with a density that would put some power amplifiers to shame. It also runs pretty warm. To meet the specified 1.4 W into 32 ohms (!) class-A the output bias current needs to be at least 300 mA amounting to 8-9 W continuous heat dissipation per channel, very much in line with the 22 W rated power of the unit. The "standby" power is given as 0 W but that seems to be the power draw when powered off from the front panel. In other words, this thing burns through ~20 W whenever it's turned on, regardless of whether you are listening to it. Something to keep in mind.
I gave it a quick listen. As I'm sure you were anticipating, it balances slightly warm with a laid-back top end. It may not be the ideal match for the HD-600s, which have a similar sonic signature. It immediately energizes the HD-600 drivers, however. Effortlessly powerful. There is no nastiness, no glare that I associate with cheap voltage regulation or poorly implemented op amps. The noise floor seems low. There's a kind of "nothingness" when turning the volume up that indicates high quality, low noise circuit design, yet it never seems clinically clean to the point of sterility. To summarize in one word, it sounds analog. In two words, Gloriously analog.
Now if you excuse me I'm going to have fun for a bit. Further reports will have to wait until the Chord 2Qute arrives and I can give some impressions of how it pairs with a reference DAC.
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Round 1. Casual listening.
Direct comparison between the HA-501 and Sapphire IV with Sennheiser HD-600 headphones and connected to the analog output from a Google Chromecast Audio streaming from Soundcloud.
The Chromecast line out is a bit rough and the highs sound a tad synthetic, but it has a lively, rhythmic presentation that makes for engaging low-fi listening. It's perfectly fine for homebrew, heavily electronic tracks that populate most of Soundcloud.
It is immediately clear that the sound of the TEAC is softer, warmer, and more rounded than the Sapphire, which feels faster and is distinctly more aggressive in tone. The Sapphire throws out a bigger soundstage and puts more kick into the dynamic transients.
Victory goes to the Sapphire here. The HA-501 is enjoyable, but I enjoyed the Sapphire more. It came down to more tonal warmth vs. more dynamic clarity, and I preferred the extra clarity.
Direct comparison between the HA-501 and Sapphire IV with Sennheiser HD-600 headphones and connected to the analog output from a Google Chromecast Audio streaming from Soundcloud.
The Chromecast line out is a bit rough and the highs sound a tad synthetic, but it has a lively, rhythmic presentation that makes for engaging low-fi listening. It's perfectly fine for homebrew, heavily electronic tracks that populate most of Soundcloud.
It is immediately clear that the sound of the TEAC is softer, warmer, and more rounded than the Sapphire, which feels faster and is distinctly more aggressive in tone. The Sapphire throws out a bigger soundstage and puts more kick into the dynamic transients.
Victory goes to the Sapphire here. The HA-501 is enjoyable, but I enjoyed the Sapphire more. It came down to more tonal warmth vs. more dynamic clarity, and I preferred the extra clarity.
Round 2. Getting serious.
TEAC HA-501 with Chord 2Qute (+Brzhifi 12V/4A power supply), USB connection to Windows 10 PC (32 bit / 192 kHz), Sennheiser HD-600 headphones.
I'll give a full report on the 2Qute later, suffice to say here it is excellent. Now, everything comes together and the AH-501 delivers its true potential. It, too, is excellent. In an absolute sense, without reference to any other amp, it delivers musical satisfaction without an obvious point of criticism or complaint. Yes, the bass might be slightly slower than the Sapphire 4, the highs less prominent, but these traits can be enjoyed as the character of the amp, and as elements to mix and match with the other components in the chain to a desirable end result. The overall voicing is "robust" without being insistent, a pleasant richness without being squishy. The soundstage is especially good - solid, with more depth than I'm used to. (Thanks to the Chord DAC I'm sure, but the amp doesn't fumble the subtle imaging cues.)
I also need to highlight the aesthetics and tactile feel of the TEAC design. It is a delight to use with all the controls just so, and is extremely "living room comfortable" in a way that my DIY efforts don't quite attain.
TEAC HA-501 with Chord 2Qute (+Brzhifi 12V/4A power supply), USB connection to Windows 10 PC (32 bit / 192 kHz), Sennheiser HD-600 headphones.
I'll give a full report on the 2Qute later, suffice to say here it is excellent. Now, everything comes together and the AH-501 delivers its true potential. It, too, is excellent. In an absolute sense, without reference to any other amp, it delivers musical satisfaction without an obvious point of criticism or complaint. Yes, the bass might be slightly slower than the Sapphire 4, the highs less prominent, but these traits can be enjoyed as the character of the amp, and as elements to mix and match with the other components in the chain to a desirable end result. The overall voicing is "robust" without being insistent, a pleasant richness without being squishy. The soundstage is especially good - solid, with more depth than I'm used to. (Thanks to the Chord DAC I'm sure, but the amp doesn't fumble the subtle imaging cues.)
I also need to highlight the aesthetics and tactile feel of the TEAC design. It is a delight to use with all the controls just so, and is extremely "living room comfortable" in a way that my DIY efforts don't quite attain.
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Eeek! I realized I never got around to filing a follow up on this. There's not too much to add, though. It's definitely a keeper, and I've made my peace with what it is and how it sounds. The synergy with the 2Qute is significant, they really do complement each other. I'm not 100% convinced that the 2Qute is the last word in my quest for a really good DAC, but if its main flaw is a sightly forward, insistent presentation, the more rounded, laid back character of the HA-501 is the perfect filter to keep everything balanced correctly.
The HD600 headphones are also a key part of the equation. The slight midbass "plumpness" of the HA-501 is kept in check by the natural leanness of the open-back Sennheiser headphones. Switching in my closed-back Sony MDR-1As its hopelessly boomy. The Sonys, in contrast, are great plugged directly into a smartphone or laptop. Synergy, I as said.
I confess I cannot hear any difference whatsoever between the different damping settings. Probably to be expected with the 300 ohm resistance of the HD600s, adding a couple more ohms isn't going to do much at all. Against 32 or 16 ohms, it may well be a different story.
Final word: The Teac HA-501 is old school. Like 1970's old school. Classic muscle car approach to performance, big and beefy, unashamedly inefficient. A solid recommend.
The HD600 headphones are also a key part of the equation. The slight midbass "plumpness" of the HA-501 is kept in check by the natural leanness of the open-back Sennheiser headphones. Switching in my closed-back Sony MDR-1As its hopelessly boomy. The Sonys, in contrast, are great plugged directly into a smartphone or laptop. Synergy, I as said.
I confess I cannot hear any difference whatsoever between the different damping settings. Probably to be expected with the 300 ohm resistance of the HD600s, adding a couple more ohms isn't going to do much at all. Against 32 or 16 ohms, it may well be a different story.
Final word: The Teac HA-501 is old school. Like 1970's old school. Classic muscle car approach to performance, big and beefy, unashamedly inefficient. A solid recommend.