CanJam at RMAF 2012: The Sennheiser HDVA 600 Balanced Headphone Amplifier

Sennheiser HDVA 600 ($1599) and HDVD 800 ($1999)
It's been over a decade since I helped develop the world's first balanced headphone amplifier, the HeadRoom BlockHead (Stereophile review here). At the time, it was as much a PR stunt as a serious effort to get even better sound from headphones. Turns out, balanced headphone amplification is a pretty good thing, and many small enthusiast companies have followed suit. To the best of my knowledge, however, none of the larger companies have produced a balanced headphone amp...that is until now. I can't tell you how cool it is for me to see balanced connectors on the front of Sennheiser's new amps.

One of the important things to know about balanced headphone amps is that the right way to build one is to have four separate and matched amplifier channels in the amp. Two each for the left and right channels, one amplifying the normal signal, and one amplifying the inverted signal. Beware of headphone amps in which the signal is single-ended somewhere in the circuit.

It appears that Sennheiser gets this, and their press release includes this information:

Signal processing in the hi-fi devices is fully symmetrical. That means that not only the signal input into the amplifier is symmetrical but also the signal output and therefore the connection to the headphones. “The fully symmetrical principle effectively compensates for interference and distortion. The sound therefore becomes much clearer as total harmonic distortion is minimized," explained Axel Grell, Sennheiser’s high-end product manager at Sennheiser. However, the headphones can also be connected using a normal 6.3 mm jack plug. The amplifiers are also equipped with an asymmetrical input socket; when using this input, the incoming signals are symmetrized before further processing takes place.

More information on the amps can be found in Sennheiser's press release; their German website pages (in English) for the HDVA 600 and HDVD 800; and in this Sennheiser YouTube video.

johnjen's picture

Ok so did you have to pay extra to get Capt. Kirk in the picture? winksmiley

It will be interesting to hear your review of this new amp.



Dinny FitzPatrick's picture

Believe it or not HiFiMAN had a big poster of Shatner with their gear at the HiFiMAN booth.

Limp's picture

"…the right way to build one is to have four separate and matched amplifier channels in the amp."

Another right way to build a balanced amplifier is of course to have a four channel input and a normal two channel differential output. After all the real benefit of balanced operation is in the interconnections.

Phos's picture

I see the momentums over to the side, did you get a chance to try them out?  

Tyll Hertsens's picture

They were okay...but didn't wow me. I'll have to spend some time with them to form an opinion.

Dinny FitzPatrick's picture

I did not like the HD700 at all.

Tyll Hertsens's picture

Me neither.

John Grandberg's picture

I'm one of the few who enjoyed it for the most part. I know a lot of people who really disliked it, and made fun of me for my opinion. Oh well. 

I do get the feeling the HD700 sound would get old after a while. But for short term listening stints I enjoyed it, with the right front end and amp. Kind of like some Grado models I guess.

Tyll Hertsens's picture

I won't hold it against you, John. :)

Dinny FitzPatrick's picture

I wouldn't mind trying the HD700 out of the Luxman P-1u.  That's a combo I could see (maybe) working.