Must See: DIY tube headphone amp

[headphonecrazy 0]

Extract from Head-fi's post by Kelly:

 

A more careful look will notice the sides of this amplifier are heatfins--I'm not sure how valuable heatfins actually are on an amplifier like this, but the enclosure does get rather warm and anything to displace some of that warmth is probably worthwhile. More than that, I just think they look cool. The enclosure seems to be the standard metal alloy case with somewhat expensive thick faceplates and laser etching on the front panel--all nicely done, with faceplates matching the quality and thickness of those on the Max. My only real complaint with the enclosure is that bottom plate that screws onto the amplifier doesn't have a rounded edge and is rough to the touch. That's not something you'd probably notice if you had it set up for normal listening. I can assure you the amp is heavy enough that you're probably going to want to park it in one spot.

 

I don't actually know the details of all the ingredients in this one so my descriptions here are purely from actual use. I never even had a chance to pop the hood. The jacks, both RCA and headphone, are sturdy and seem to be of good quality, though likely not the same expensive ones you find on HeadRoom amps. The jacks on this amplifier are not the locking Neutriks, though that is what I saw pictured on their early prototype. The pot has a thick, sturdy feel to it and seems to be of good quality but I'm not sure which pot it actually is.

 

The back panel is home to a pre-out and two source inputs. Again, this is a bit like the standard issue Max. The source switch to this amplifier, however, is thankfully located on the front panel. A power switch is also located on the front panel and a glowing LED can be seen in the middle. Remember, I'm a sucker for this stuff but the really cool thing is that during warm up the LED is red but after a few seconds the LED switches to blue. I've seen this before in expensive speaker amplifiers but this is the only headphone amp I've seen do this. Maybe it's just me but I thought it was cool.

 

If you'd like to see more pics of the amp, visit the company's website at http://www.sonicadventure.biz/. Most of what I've said here may be obvious from the photos. What is perhaps not so obvious is the cost of the amplifier. Would you believe me if I told you that you were looking at an amplifier that costs only $370US plus shipping new?

 

At this price, surely the amplifier becomes a powerful alternative to the ASL MG Head. Other options at this price? Not many, as far as I'm concerned. The Corda HA-1 is a nice solid state. Other than that, my options would quickly turn to DIY amps. So for commercial "entry level" home based dynamic headphone amps we now have a solid state, a tube and a hybrid. The world is now complete.

 

Besides getting a hefty case for such a paltry sum, the other thing you may not be used to getting at that price is the frequency spectrum. Oh sure, the Corda gives you all but the deepest bass response and the MG Head gives you a very nice cross section of the midrange. But the entire frequency spectrum? Comparisons to the Max come to mind once again. The SonicAdventure gives you the whole thing--from the sharpest highs to the deepest lows and without any noticable tonal shifts. It's very nice to find a balanced sound in such a modest amp.

 

I can't help but wonder if this is partially owed to its hybrid design--tube input with MOSFET output. The other headphone amplifier with a design of this type is the Melos SHA-1, another real overachiever that has, unfortunately, been long discontinued. Perhaps not so surprising then, is that I found this amp's personality to be more similar to my memories of the Melos than to any other amp I've heard.

 

The combination of very smooth textures, a low noise floor and the ability to drive a variety of headphones have made the Melos a popularly resurrected headphone amp with people who can manage to get hold of one. This combination of headlining traits is the same one found in the SonicAdventure Reality.

 

Of course, the Melos had a bit more going on and while I didn't have the Melos here for AB comparison, I'd have to give the nod to my memory of the Melos in overall preference. Where the Melos was completely clean and articulate, the Reality has a bit of a smear between string instruments. It's really as if the amplifier has a soft focus filter, an effect that's both little bit frustating when you're looking for details but extremely relaxing when you're not.

 

In stock form, this may cause those who have a priority shift toward the analytical to think about another amplifier. However, at least for those of us with a pair of Sennheiser HD600 or Grado HP-1 at, this is great amp to kick back and relax with.

 

For comparisons sake, I had the Sugden Headmaster, AudioValve RKV II and Corda Blue all on hand. Not really a fair fight since the SonicAdventure costs so much less than any of the other amps. Each of the more expensive amps beat the Reality in absolute low level detail and articulation. However, when it came to bass authority, the Sonic completely stomped both the Corda and the Sugden.

 

It was in comparison to the RKV, though, where I had trouble finding as much favor with the amp. As some of you already know, the RKV has become my favorite headphone amp and as such, it's honestly been hard to even want to listen to any other amps when I had it in the room. But again, the RKV is twice the price. The Sonic actually beats the RKV in high frequency extension, the achilles heal of the RKV. It matches the RKV in output across the rest of the spectrum, including the bass.

 

The bass quality, however, is quite different with the SonicAdventure. Both amps are taught and responsive but the Sonic is the dryer of the two making the amp seem more typical of a solid state than the smooth continuous sound you may generalize tube amps as having. Still, for some people having a smooth, "tube-like" midrange with a quick, authoritative "solidstate-like" bass, this hybrid may be just what you're looking for. I had to admit, as much as I loved the little ASL MG Head, it's rolled off bass is what prevented me from truly enjoying it.

 

The other amps also present also had a bit of a larger headstage. It's difficult to talk about headstage because we each intepret it so differently but there seems to be enough common-ground that it's worth mentioning. The SonicAdventure is tight and focussed, again reminding me more of the Melos and HeadRoom Max than the wide open MG Head and RKV.

 

When I first inquired about the amplifier, Katsudon warned me that it seemed to do better with some headphones than others. I tried to ignore what he said in hopes that my own expectations wouldn't be biased by his opinions, but I wondered which headphones would work best when I got it. To my surprise, all three of the headphones I had on hand--Grado HP-1, Sennheiser HD600/Cardas and Etymotic ER-4S/FixUp--performed equally well. Since all three are at very different impedances, I'm left to suspect the amp would pair easily with most headphones. I suspect the difference between Katsudon's impression and mine is simply a matter of us auditioning the amp at different stages.

 

The bottom line is for such a low price, this is a killer budget amp. I know my impressions are based only on the stock amplifier, too. I look forward to reading what other people think of it after they've had a chance to do some tuberolling and poke around inside. I'm betting with not too much work, the amp would find itself easily gaining ground on its more expensive competition. As it is, the amp is a solid alternative to the MG Head which in my book is a pretty nice place to be.

 

 

I'm getting my contact in China to make that call first thing tomorrow morning.

Edited October 7, 2003 by headphonecrazy

[N@Z 0]

Headphonecrazy, you are absolutely nuts!

 

Shame the tubes are hidden away like that, part of the appeal is seeing them glow.

 

Keep 'em coming though!

[evil-zen 0]

N@Z, there is a reason why he names himself headphonecrazy.

anyway good luck for the search.

[N@Z 0]

Yes, very aptly named.

 

This amp is DIY? Kelly must really like alot of bass if he feels the MG Head has rolled off bass unless the one he had didn't have the OTL mode.

[headphonecrazy 0]

I think it comes as DIY or for about 20 bucks more fully assembled.

[fishball79 0]

$20 more for assembly only!? Jeezus no point buying kit lah... if one wants to mod then just undo the thing and desolder parts loh...

 

jtfoo,

 

Ahhh you're right. Custom toroidals are $$$ too...

[huangyong 0]

nice.... headphonecrazy.....

the amp is a hybrid amp....dunno sounds nice or not???

look at that price!!, if the sound quality is on par or better than XCANs, i might consider it.....

[fishball79 0]

Considering this is a mosfet hybrid not opamp and that the X-cans is as cheapskate as it gets, yes Im sure this one will be better in alot of ways.

[fishball79 0]

By the way did anyone notice THESE tube head amps???

 

http://www.2000ok.com/news/013.html

 

http://www.2000ok.com/news/015.html

 

 

 

 

[huangyong 0]

DIY amp from PRC seems good at its price......

Voxel sms me that his latest setup is HD 600 pair with a DIY amp from PRC which made up of 10 TUBES!!!!!! amazing......may be can ask him to post his amp pics here......

Edited October 8, 2003 by huangyong

[Mackie 0]

Looks and sounds good man. Set me thinking on a bedside setup now. Gees.........this forum is E?il.....and money is the root of it all.

[N@Z 0]

I never realised the market in China (?) is really into tube amplification. Is it mainly for export or domestic consumption?

[Mackie 0]

Flows both ways. Even HK is feeding their long-chalked expertise in this area to mainland China. I also heard the better LPs are exported to China for sale than retained in HK because of better profits and larger demand.

[N@Z 0]

LOL! That didn't last long Mackie! At one point I thought of getting an EMP for my bedside rig but thought against it since the Cayin is cheaper so the MG Head will probably get bumped to the bedroom, double up as a night light (i.e. if I don't sell it off!) while my portable amps for the TV & travel.

[Mackie 0]

In any case, I will request a high but reasonable standard of performance from any new gear that dares to empty my coffer......which is essentially quite empty.