Personal review of BHA-1
I have the bha-1 headphone amp and the bda-1 dac patched to an iMac by aes/ebu via an April Music Stello u3, giving a full compliment of supported sample rates by xmos. By a-b comparison, the onboard usb is less impressive and not as versatile, so im pleased to have the Stello which permits me to separate my computer, hard-drives, and dac over considerable distance without appreciable signal loss. To be honest though the onboard usb of the dac is really not bad at all, though it is less exciting than the stello or the coax inputs..
Ive spent the last several weeks growing incredibly fond of my investment into high fidelity audio. Together the bha sounds incredible, provided that the digital source is playing a good recording. It simply blows my mind how sweet and tonally wonderful it sounds. Sounds are full bodied without being overly warm. Frequency response seems totally neutral, with nothing sticking out. Bass is rich and moves with authority. Mids are balanced perfectly with highs and lows, and present all of the smoothness found in a well mastered recording. Highs are crips and yet smooth and without simblance or grain. All styles of music sound great, but a poor recording will come out sounding Just that way. This is because detail retreval from this combo is exceptional and world class. It sounds world class and i could want for very little or nothing in terms of sound quality. This amp and dac sound incredibly beautiful and make me most happy. The sound is just so.. Perfect.
But this isnt the whole story, and as important as sound quality is, theres more to the design.
This headphone amp needs to be left on to sound its best. When cold, it sounds bland and takes a few hours to days to reach its capabilities. Dont ask me why, but its conisistent with what others have noticed and is consistent with class A amp character. So my advise, leave it on 24/7 and pay the few extra cents a day to the power company, otherwise youre not getting the full potential of the amp.
There is some Source bleed from the input selector, as expected. This is Hard to avoid, but its no deal breaker. Theres very little, demonstrating the quality of the toggle switch, but it is noticible if you have another input playing and your listening to a track with some delicate quiet moments. Especially in the evening, when the world becomes quiet, if you have a second source playing, it will need to be stopped. As a note, the only audio equipment ive seen that hasnt demonstrated this quality has been with very high quality allen and heath mixing boards. But even still, sources on the same channel bleed. All other integrated amps or pre amps ive owned have demonstrated this... And its an effect due to the toggle switch or any other switching mechanism. Im sure someone could dream up a switching method that managed to seperate and isolate sources better, but the design time, testing and cost hardly seem worth it.
The balance pot is of exceptional quality and without a bypass. There is a solid and smooth center notch that for all intents and purposes marks it perfectly channel matched. A bypass would have been a nice thought, but without one its hard to say if sound quality would be noticibly improved. Switch or pot, neither is perfect and having a balance knob may serve its purpose for those with uneven hearing.
Now... how could this wonderful amp be improved?
The volume pot curve, level of attenuation and gain selections .... Well.. They Can pose an annoyance. one will likely overlook these little weaknesses due to the wonderful sound quality spewed from the bha-1/bda-1 combo. But, nevertheless, Volume control is finicky at times and often not as even and intuitive as one would hope. I cant help but feel a little extra attention from the design team wouldve gone along way. I'd speculate that today, folks in bryston design have a solution dreamed up but couldnt impliment it for one reason or another, or were simply asked to ready the design once it was found to be good enough for most people. Im sure marketing would disagree, but design is a process, and improvement come incrementally. Maybe someone at bryston has tweaked it, but for those of us in the consumer world, were stuck with a tempermental volume knob that has a way of spoiling the fun if youre anywhere near either end of the knob. Perhaps im wrong and developing a more linear feel (yes, db attenuation is logarithmic) was an unsurmountable challenge, but as a novice diy audio hobbyist, i kind of doubt it. In fact, the only thing that keeps me from coming up with my own solution or replacement is how much i value and appreciate the 20 year warrenty. None the less, a passive balanced inline stepped attenuator may be on the diy to-do list this summer... But we'll have to do some research before getting to that as one wouldnt want to destabilize the amp by messing about with impendance before being reasonably certain such a solution would be safe, effective, convenient and affordable enough to implement. At the very least, this demonastrates my desire to make up for this inconvenience, and as much as i would like bryston to offer a solution, im not holding my breath. They have pride, and should be proud, because this amplifier is creme-de-la-creme. So dont let the little details desway your interest. Just be aware that when you discover it for yourself, your likely to feel the way many of us do. A wee tad bit of "i wish it was a little better"
Theres always the fading of the honeymoon period and this may explain why some audiophiles drift from component to component.
Yes, the attenuator problem arises from the need to accomidate a full variety of headphones. So This powerful and wonderful amp has a volume pot that seems hyper-polar; what i mean is, the first few and last few degrees of rotation are -extremely- steep, while the rest seems to need a good twist to make any difference at all. At night, With my sennheiser hd650's and AKG 702's, I find the lower portions dont go low enough before the channel balance is lost - and one ear, then the other - drops suddenly to a still audible trickle. This begs for a lower gain setting which would serve well for both loud recordings and sensitive headphones. Perhaps a lower gain setting might provide a more amiable preamp out gain and fuller sweep too. Beter yet, couldnt the preout have been fitted with its own custom fit attenuator? At the end of the volume knob, channel balance is lost again and there is a sudden and very profound increase in volume. At first i wondered if my unit was fitted with a faulty volume pot, but with reading ive learned that this is somewhat To be expected. It seems to me a more conventional attenuator curve coupled with a variety of selectable gain levels would have fit the bill better, and allowed us to get the best of full volume sweep from a variety of cans. i find im always somewhere near the very top or very bottom and it makes for a little compromise as i try to dodge these issues to get to a comfortable volume level.. I often wish it was fitted with a nicely chosen stepped attenuator. I think both an additional lower and a higher gain setting would have helped tremendously, as well as a better choice in volume pots. Im under the impression that headphones like the he6 could use a pinch more oomph especially when playing quieter recordings.
All in all im extremely satisfied with my balanced set up. As to claims that it might not truly be balanced in to out, im of the current belief that it is, and what ever it is, it produces a magnificent sound both single ended and balanced. Ive taken to the 4pin out as the dual 3 pin seems like a silly ritual and a clumsy idea perpetuated by circumstmances of its initial beginings. Balanced opperation appears to offer the slightest smidge more control and a little clearer, ever-so-slightly more forward sound... Which could be explained more by how its driven than by its balanced ground.
Im thrilled bryston has taken interest in us headphone enthusiasts and decided to develop this wonderful amp. Going forward i hope they reissue a second reincarnation with a few tweaks to the potentiometer/attenuator, a few more gain settings, and perhaps a couple new features such as a variable crossfeed as found on the phonitor and a line out for dubbing and patching purposes. I recall seeing photos of bha-1 prototype with a second mini headphone onput and wish that was incuded in the production version, or better, a second 1/4" se headphone output so as to avoid using ugly, noisy splitters. Idve prefered if the mini jack input was another rca. mini jacks are rarely status quo in high end audio, and in the event that an ipod is being used, mini to rca cables are widely available. Lastly lockable rear xlrs wouldve been preferable though minor.
Im very pleased with my bha and i encourage enthusiasts to consider it as your go to headphone amp upgrade. Where it matters most this amp shines. Really, th eonly thing worth addressing would be the volume, and gain situation, but in absense of a better volume pot i may keep my eye open for a solution - preferably a modification brainstormed by and offered by bryston.
