rickfri
No longer lurking
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- Jul 4, 2001
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Last week when I was trying to troubleshoot a problem in my World Audio Design HD83 Headphone amplifier I got some help from divie23 and Apheared. Apheared hinted that he had not seen many reviews of how this amp sounds and maybe I should review it, so I thought I would give it a try. The first caveat is that I probably have older, less sensitive ears than 90% of the people using this board, so please take that into account when reading this review.
Since I also have a Corda Headamp-1 I thought I would try to do a side-by-side comparison. Information about the Corda Headamp-1 can be found at http://home.t-online.de/home/neier-audio. Information about the World Audio Design HD83 can be found at www.worldaudiodesign.co.uk/taps.html. For simplicity I will call the Corda Headamp-1 HA-1 and the World Audio Design HD83 HD83 throughout the rest of this review. The HA-1 is a solid-state amplifier that can be bought in either kit form or assembled, I bought mine assembled. The HD83 is a tube amp that comes in kit form and must be assembled by the buyer.
TEST CONDITIONS:
Since the HD83 has a set of loop out RCA’s I used these as inputs to the HA-1, this means that there is an extra .5 meters of interconnect between the HA-1 and the source. For headphones I used Senn 580’s with red Clou cables and Senn 600’s with blue Clou cables. I don’t know if this arrangement puts either, or both, of the amps at a disadvantage or not. I think any disadvantage is made up for by the fact that I could switch between headphones in couple of seconds, instead of minutes, so I could remember what I had heard easier. If you think that this makes for an unfair comparison please disregard the rest of this review, I used what I had.
The HA-1 was used with the cross feed disabled through the 0 headphone jack.
The HD83 can be hard wired in five different ways to match different headphones. I wired mine for 250 ohm or greater headphones to match the Senns’. I also made two modifications to the stock HD83. World Audio forgot to send me a power cord for the HD83. When I e-mailed them to make sure it was just a standard power cord they said yes and that they would send me one, since I had some power cords laying around I said I would use one of those. I decided to enlarge the hole for the power cord and installed a male IEC connector. Both the HA-1 and HD83 are equipped with Volex power cords. The other mod I made was to use some Belden 1506A cable between the RCA jacks and the volume pot instead of the smaller wire supplied by World Audio. I would have used it between the output of the pot and the input to the tubes but I couldn’t get my hands to work with the larger wire in the space provided, so I used the smaller wire supplied by World Audio.
EQUIPMENT:
Cambridge Audio D500SE
Cambridge Audio K500 Isomagic Isolation Platform
Art DI/O (Both amps either separately, or combined, will accept the high output of the Art, so I used no attenuators.)
DIY interconnects all around
TEST CDS:
Bruckner “Te Deum” (DG 410522-2) Karajan Wiener Philharmoniker
Copland “Fanfare for the Common Man” (Telarc CD-80078) Lane Atlanta Symphony Orchestra
Keith Jarrett “The Koln Concert”
Milt Jackson “Night Mist”
Patricia Barber “Modern Cool”
Dire Straits “Brothers in Arms”
Leonard Cohen “More Best Of”
Eva Cassidy “Live at Blues Alley”
Alison Krauss + Union Station “New Favorite”
TEST RESULTS (finally) :
Highs – The highs sounded cleaner and “higher” on the HD83. This was especially noticeable on the background vocals on “The Future” off the Leonard Cohen CD and the coral arrangements on “Ti Deum”.
Midrange – The mids sounded slightly better on the HA-1. The male vocals on “Te Deum” and “Brother in Arms” were more distinct and clearer. The snap of the snare drums on many of the recordings was sharper and crisper.
Bass – The HD83 has a real edge here. The bass was deeper and more defined on all of the CD’s tested. It came through the most on “Constantinople” off of the Barber CD and “Fanfare for the Common Man”. Both of these selections are heavily bass intensive, with the drums on one and the bass on the other.
Separation – The HD83 has really fine separation. You can hear each note of Milt Jackson’s’ vibes and Keith Jarrett’s’ much more distinctly than on the HA-1. Also, don’t laugh, there was a greater separation between the lead and rhythm banjos on “Take Me For the Longing” on the Alison Krauss CD.
Soundstage – (I’m using this term to mean a more open sound, less confined, I hope that is right). The HD83 opens up the sound better than the HA-1. On “What a Wonderful World” off the Eva Cassidy CD and “Te Deum” it’s almost like being in the audience at a live performance.
Detail – This is the one that surprised me. I thought that tube amps were less detailed than solid-state amps. The HD83 seems to have better detail than the HA-1. The cymbals in “Fanfare for the Common Man” can be heard reverberating much longer with the HD83. On the other hand the tape hiss evident on “Everybody Knows’ on the Leonard Cohen CD is also more evident on the HD83. The HD83 is less forgiving of bad recordings.
Hum – With no recording playing I turned the volume on the HD83 up all the way and there was no hum or hiss.
Other Headphones –
Grado RS-1 – The Grados’ definitely sounded better on the HA-1. The HD83 muddied up the bass a great deal. If I had wired the HD83 for the lower impedance headphones the Grados’ probably would have sounded better. World Audio says that it is an easy job to change the settings. “Easy’, in this case is a relative term. To change the settings is about a half hour job involving the unsoldering and resoldering of 16 leads.
AKG 501 – Here’s where I’ll probably get flamed. I had always considered the 501s’ as relatively lifeless phones. After hooking them up to the HD83, I’ve changed my mind. The HD83 makes the 501s’ sound really great. They sound somewhere between the “darkness” of the Senns’ and the “in your face” of the Grados’. I don’t know why this happened, the 250 ohm setting is a couple of steps away from the setting that should work best for the 501s’(I think they are 120 ohm). I think that the thing I like the best about the HD83 is finding out how nice the 501s’ can sound.
CONCLUSIONS:
I have a Creek OBH-11SE headphone amp and consider the HA1 to be a better amp. I have never heard any tube amps except the HD83 and any comparison would be sheer conjecture. Maybe someone who has heard the HD83 and other tube amps could chime in and make that comparison.
If you’re looking for and amp to drive all types of headphones, the HA-1 is probably the better choice, and it also has cross feed a feature I really like.
If you’re looking for an amp to drive one particular type of headphone, and are willing to build it from a kit the HD83 is a very nice amp. The HA-1 and the HD83 are both in the same price range $300 to $350 depending on shipping and customs.
TWO QUESTIONS:
If any DIY type person reads this, do you know of any standoff that has detachable connector, kind of like the connectors used on fuse holders. It’s is hard trying to search for something like this on parts websites when you don’t know if they even exist or if they do, what they are called.
Does anybody know if there is some place in the US that sells ECL83 tubes? I have searched all the places I could find on the web and they either don’t carry them or are out of stock. I found some places in Great Britain that sell them, but the shipping and customs will be about the same as lifetime supply of tubes.
Since I also have a Corda Headamp-1 I thought I would try to do a side-by-side comparison. Information about the Corda Headamp-1 can be found at http://home.t-online.de/home/neier-audio. Information about the World Audio Design HD83 can be found at www.worldaudiodesign.co.uk/taps.html. For simplicity I will call the Corda Headamp-1 HA-1 and the World Audio Design HD83 HD83 throughout the rest of this review. The HA-1 is a solid-state amplifier that can be bought in either kit form or assembled, I bought mine assembled. The HD83 is a tube amp that comes in kit form and must be assembled by the buyer.
TEST CONDITIONS:
Since the HD83 has a set of loop out RCA’s I used these as inputs to the HA-1, this means that there is an extra .5 meters of interconnect between the HA-1 and the source. For headphones I used Senn 580’s with red Clou cables and Senn 600’s with blue Clou cables. I don’t know if this arrangement puts either, or both, of the amps at a disadvantage or not. I think any disadvantage is made up for by the fact that I could switch between headphones in couple of seconds, instead of minutes, so I could remember what I had heard easier. If you think that this makes for an unfair comparison please disregard the rest of this review, I used what I had.
The HA-1 was used with the cross feed disabled through the 0 headphone jack.
The HD83 can be hard wired in five different ways to match different headphones. I wired mine for 250 ohm or greater headphones to match the Senns’. I also made two modifications to the stock HD83. World Audio forgot to send me a power cord for the HD83. When I e-mailed them to make sure it was just a standard power cord they said yes and that they would send me one, since I had some power cords laying around I said I would use one of those. I decided to enlarge the hole for the power cord and installed a male IEC connector. Both the HA-1 and HD83 are equipped with Volex power cords. The other mod I made was to use some Belden 1506A cable between the RCA jacks and the volume pot instead of the smaller wire supplied by World Audio. I would have used it between the output of the pot and the input to the tubes but I couldn’t get my hands to work with the larger wire in the space provided, so I used the smaller wire supplied by World Audio.
EQUIPMENT:
Cambridge Audio D500SE
Cambridge Audio K500 Isomagic Isolation Platform
Art DI/O (Both amps either separately, or combined, will accept the high output of the Art, so I used no attenuators.)
DIY interconnects all around
TEST CDS:
Bruckner “Te Deum” (DG 410522-2) Karajan Wiener Philharmoniker
Copland “Fanfare for the Common Man” (Telarc CD-80078) Lane Atlanta Symphony Orchestra
Keith Jarrett “The Koln Concert”
Milt Jackson “Night Mist”
Patricia Barber “Modern Cool”
Dire Straits “Brothers in Arms”
Leonard Cohen “More Best Of”
Eva Cassidy “Live at Blues Alley”
Alison Krauss + Union Station “New Favorite”
TEST RESULTS (finally) :
Highs – The highs sounded cleaner and “higher” on the HD83. This was especially noticeable on the background vocals on “The Future” off the Leonard Cohen CD and the coral arrangements on “Ti Deum”.
Midrange – The mids sounded slightly better on the HA-1. The male vocals on “Te Deum” and “Brother in Arms” were more distinct and clearer. The snap of the snare drums on many of the recordings was sharper and crisper.
Bass – The HD83 has a real edge here. The bass was deeper and more defined on all of the CD’s tested. It came through the most on “Constantinople” off of the Barber CD and “Fanfare for the Common Man”. Both of these selections are heavily bass intensive, with the drums on one and the bass on the other.
Separation – The HD83 has really fine separation. You can hear each note of Milt Jackson’s’ vibes and Keith Jarrett’s’ much more distinctly than on the HA-1. Also, don’t laugh, there was a greater separation between the lead and rhythm banjos on “Take Me For the Longing” on the Alison Krauss CD.
Soundstage – (I’m using this term to mean a more open sound, less confined, I hope that is right). The HD83 opens up the sound better than the HA-1. On “What a Wonderful World” off the Eva Cassidy CD and “Te Deum” it’s almost like being in the audience at a live performance.
Detail – This is the one that surprised me. I thought that tube amps were less detailed than solid-state amps. The HD83 seems to have better detail than the HA-1. The cymbals in “Fanfare for the Common Man” can be heard reverberating much longer with the HD83. On the other hand the tape hiss evident on “Everybody Knows’ on the Leonard Cohen CD is also more evident on the HD83. The HD83 is less forgiving of bad recordings.
Hum – With no recording playing I turned the volume on the HD83 up all the way and there was no hum or hiss.
Other Headphones –
Grado RS-1 – The Grados’ definitely sounded better on the HA-1. The HD83 muddied up the bass a great deal. If I had wired the HD83 for the lower impedance headphones the Grados’ probably would have sounded better. World Audio says that it is an easy job to change the settings. “Easy’, in this case is a relative term. To change the settings is about a half hour job involving the unsoldering and resoldering of 16 leads.
AKG 501 – Here’s where I’ll probably get flamed. I had always considered the 501s’ as relatively lifeless phones. After hooking them up to the HD83, I’ve changed my mind. The HD83 makes the 501s’ sound really great. They sound somewhere between the “darkness” of the Senns’ and the “in your face” of the Grados’. I don’t know why this happened, the 250 ohm setting is a couple of steps away from the setting that should work best for the 501s’(I think they are 120 ohm). I think that the thing I like the best about the HD83 is finding out how nice the 501s’ can sound.
CONCLUSIONS:
I have a Creek OBH-11SE headphone amp and consider the HA1 to be a better amp. I have never heard any tube amps except the HD83 and any comparison would be sheer conjecture. Maybe someone who has heard the HD83 and other tube amps could chime in and make that comparison.
If you’re looking for and amp to drive all types of headphones, the HA-1 is probably the better choice, and it also has cross feed a feature I really like.
If you’re looking for an amp to drive one particular type of headphone, and are willing to build it from a kit the HD83 is a very nice amp. The HA-1 and the HD83 are both in the same price range $300 to $350 depending on shipping and customs.
TWO QUESTIONS:
If any DIY type person reads this, do you know of any standoff that has detachable connector, kind of like the connectors used on fuse holders. It’s is hard trying to search for something like this on parts websites when you don’t know if they even exist or if they do, what they are called.
Does anybody know if there is some place in the US that sells ECL83 tubes? I have searched all the places I could find on the web and they either don’t carry them or are out of stock. I found some places in Great Britain that sell them, but the shipping and customs will be about the same as lifetime supply of tubes.
