Background: Old Max
I believe Year 2004 is a glorious year to be Headfiers. Thanks to new and improve versions of headphone amps released this year, including portables and several huge discounts on several solid-state amps, owning a descent headphone amp more affordable than ever. Even for those headfiers who never buy any brand new products were able to benefit from other members’ sale-to-fund-his-upgratitus-fevers. I used to own an original Max. I was mostly satisfied with it, but somehow it left me wanting something more. I guess I just wasn’t really satisfied with its highs and lows of original Max. The original Max was good, but it wasn’t that good. After learning that a Corda HA-1 sounds 70-80% of original Max, I sold my original Max and bought HA-1 to down grade so that I would have a fund for something in future.
Background: New Max
After searching for that perfect versatile solid-state amp, I finally landed on a like mint used Headroom Max with the stepped attenuator (just over a year old). This was a significant upgrade over the original Max. There are several noticeable improvements on hardware side as well. People say beauty is only skin deep; I bet they never saw new Max and old Max in person. For audio-enthusiasts, what is inside should really matters, but the appearance can’t be overlooked
. It’s good thing that both inside and outside are updated with Headroom Max around 2001. The new custom aluminum case with the 3/8” thick face/rear plates are just plain gorgeous. Its iodized finish is extremely scratch resistant so that it is virtually impossible to scratch from typical everyday use. The new Max uses two custom Avel-Lindburgh toroidal main transformers and same trusty Cardas Audio connectors and dual Neutrik locking ¼” headphone jacks with silver metal locking tabs. Frankly I didn’t dig the red locking plastic tabs of old Max
. With the custom transformers and quality parts through out the construction, the new Max provided absolute pitch black background. If your source and interconnects are up to the challenge (i.e., if they are descent), you will not hear any hum/hiss or any indication that the amp is running except for the red LED operational light. Can be considered negative if you are careless… you can easily blow your ear drums off. On the other hand, if you are a big fan of low impedance cans, such as Sony MDR-CD3000, Grado RS-1/2, Shure E3c or Etymotic ER-4P, you probably know how hiss/hum can ruin your otherwise perfect listening experience--a common problem with entry-level amps or weak sources such as some portable/personal CD/mp3 players.
If you haven’t tried or heard new Max or high-end headphone amps, let me describe what a high-end headphone amp sounds like. Here I’m assuming you have a reasonable gears, say a descent source, a good pair of headphones and adequate interconnect cables. A high-end headphone amp will help you bring out the best out of your gears assuming they are up for the task (you are as strong as your weakest link). On amps like Max, the music/sound is absolutely black (no background hiss/hum/operational noise what so ever). Your music is also extremely transparent and airy so that you don’t know there is an amp between you and your music. Most importantly, bass is articulate and tight, overall sound is extremely linear. A linearity is a term I use to describe how consistent sound balance is through out the different volume levels. This helps you to get the nearly equal amount of bass/mid/treble whether you play music in softer/quieter volume or louder volume. Some phones are more linear than the others, say in-ear-monitors like Etymotic ER-4S, some full size cans like Sony MDR-CD3000 or Grado RS-1/RS-2 are fairly linear where as Sennheiser HD-600 isn’t as linear as phones listed earlier by a little bit. Although our ears aren’t as linear as we like, having a linear amp benefit a lower-level listening experience. One other noticeable benefit of Max is its stepped attenuator option. With the stepped attenuators, sound is noticeably linear and fuller than variable volume pots using potentiometers. Often volume-levels of right and left channels do not match with those potentiometer-based volume pots; this is more noticeable in softer listening level. No such problem exist with an optional stepped attenuator equipped amplifiers such as Headroom Max. What you get is perfectly matched left and right channel that sounds full even at the whisper soft listening level. You get 24 discrete adjustments with Swiss made Elma-24 switch plus 3 gain settings, which give you total of 72 steps of volume adjustments (72=24X3). Not to mention a solid aluminum case that is strong enough to use as a wedge for your 16-wheeler when you park at the steep hill. Just kidding, I wouldn’t try this with the amp retailing $1887.00 USD.
Background: Latest Max with Reference Module
Well, not to long ago, starting last July 15th, 2004, Headroom started to equip their amps with the new modules including the reference module for Headroom Max. You can also upgrade your older Headroom amps, except for airhead/bithead with these modules which can cost more than the price of descent pair of headphones. FYI, update cost $149 for Standard Module, $199 for Premium Module, $299 for Reference Module and $598 for two Reference Modules for BlockHead.
The last generation Max (pre-july-15th, 2004) is equipped with Vishay military-spec resisters, polyphenolene-sulfide stacked film versions of capacitors, and Texas Instruments 627 op-amps, which are rated at 55 volts per microsecond slew rates and 4.5nV/rootHz noise. Of course, all these pieces of the Max are hand picked and tested to deliver 0.1% matching between channels.
How about the latest reference module? The new Reference Module is based upon Burr Brown OPA2134 dual op-amps, which is less than ¼ of OPA627’s cost. However with 4 Intersil current buffers and 10 constant current source diodes, it is rated at an extremely high speed, 1300 volts per microsecond slew rate. That is one speedy module for sure.
I was really intrigued, but I didn’t want to bite the bullet until I know for sure that I would want to upgrade. After all, specifications are only half the story… sometimes even less valuable. What really matters is how do they really sound? The only way to be sure is to audition a new reference module equipped Headroom Max. Well I decided to ask nice people at Headroom for a demo unit so that I can spend few weeks with the new reference module equipped Max at my own home/office. Luckily Tyll, Ivy and Andrew were nice enough to arrange an in-home audition of the new reference module equipped Max with stepped attenuator.
Equipment used
Sources:
Sony SCD-XA777ES, Pioneer DV-45A, Sony CDP-X3000, 4th Gen iPod (lineout), Yamaha RP-U100 and Yamaha DP-U50.
Interconnects: MIT #2 Terminator RCAs, Monster M550, Monster Interlink 400 MKII mini to RCA, Zu Pivot mini to RCA.
Headphones: Sony MDR-CD3000s, Sennheiser HD650, Grado RS-2, Etymotic ER-4S, Sony MDR-V6
Music: Custom Made Test CDs, CDs, DVDAs, SACDs of various types of music including infamous SACD Telarc’s 1812 Overture, Op 49, and Apple lossless, AAC/MP3 encoded songs.
Sound Comparisons
The demo Max came with Loop out configuration so that I can easily connect both demo amp and mine with the same input source without splitting RCA outs with Y adaptors. I hooked up a pair of MIT Terminator 2 RCA interconnects to the demo Max and Loopout to my Max using another pair of MIT Terminator 2 interconnect.
I hooked up my Sony SCD-XA777ES and crank up the volume on both Maxes. First thing I noticed is that the new reference module is louder in volume by 5-10% over previous generation reference module. I had to crank up the volume on my Max by a notch or two to make the volume level nearly equal to that of demo unit. For the review, I compensated for the volume difference so that both Maxes are at same or nearly same volume level.
Now enough with the tease… how does the new reference module really sound? In five words, wonderfully faster and more powerful! Speed and power are wonderful things in headphone amps. Of course, without the control, speed and power are useless. However in the new reference module, the control seems to be even better than the pre-July Max. New reference module sounds more transparent and let you hear more details. Treble sounds significantly more extended and bass sounds even tighter. Two obvious benefits of increased details and speed are 1) better instrument separation and 2) better sound-imaging. More about them later. Overall, new reference module sounds even more powerful for dynamic tracks and it appears music come out effortlessly more so in new reference module than the earlier reference module.
Blackness Test:
For both low impedance cans and high impedance cans, two amps exhibited virtually same black background. As long as your source is perfectly quiet, there will be no indication of these amps are on except for the red LED lights on front right of the amps. I would rate both amps as perfect 10 out of 10 for blackness.
Dynamic/Bass:
If I were to summarize my Max’s performance, I would say it’s wonderfully dynamic. And if I were to summarize the new reference module’s performance, I would have to say superbly dynamic or sizzling. Bass sounds a bit tighter and faster by a small margin while playing extremely dynamic tracks. This is slightly more apparent using high impedance cans like Sennheiser HD650 than the low impedance cans like Sony CD3000. I noticed slightly less ringing after each cannon shots on Tchaikovsky’s 1812 Overture (Telarc SACD) using HD650, but not so obvious on CD3K. Overall I give slight edge to new reference module vs. old reference module. If I had to rate the bass, recovery and overall dynamicness of two amps, I would say 9.7 for new reference module and 9.5 for old reference module (I would reserve 10 for BlockHead equipped with the new reference modules).
Soundstage, Depth, Imaging and Transparency:
This is the areas that the new reference module is obviously improved on already excellent old reference module. As I mentioned earlier, the new reference module has more snaps. Bass seems to be tighter and faster than the old reference module. Trebles sound livelier, more energetic and snazzier than before. Overall soundstage width and depth appears to be almost equal but in some instants, new reference module sound just a tad bit narrower. May be being too fast has something to do with it? Instrument separations on new reference modules are breathtakingly good. It is definitely easier to pin point the location of instruments on the new reference module than the old one. Of course, old reference module isn’t too shabby, but new reference modules add more realism and 3-dimensional effects to overall presentation. Overall, I give 10 to the new reference module and 9.5 for old reference module for soundstage, depth, sound-imaging, transparency and air!
Smoothness and Liquidness:
What? A liquidity in solid-state amps? Well, I find the smoothness and liquidness are two other important attributes of amps. Obviously solid-state amps can’t touch glowing glass bottles (tubes) in liquidity or ultra smoothness edgeless delivery. However these are also important characteristics of solid-state amps as well. Two amps are both very smooth, but in slightly different kind of ways. To me, the new reference module is frozen-custard smooth, where as the old reference module is Starbuck’s cappuccino with a shot of Bailey smooth. Let me elaborate! The old and new reference modules have similar tonality, but the old reference module sounds a just tad bit warmer than the new reference module (which can be heard as a slightly colder sounding). For typical music selections, this may not be very obvious, but when I listen to violin or cello, the old reference module sounds a tad bit warmer. Both amps are excellent with virtually grainless presentation and can even be described as organic, but I prefer the old reference module for its smoother sound and more liquid-sounding when playing tracks with electric guitars. Even for female vocal oriented tracks or violin solo, I prefer the old reference module over the new one by a fair margin. There is something more emotional about the old reference module than the new one. May be the old reference module left a permanent sound imprints on my brain to make me think how certain songs should sound. Regardless, I give 9.0 for overall smoothness rating for the new reference module and 9.5 for the old reference module (this is in solid-state amp scale). Of course if I were to rate RKV MKII or Singlepower MPX with 6cg7 here, they would be rated at 100 or so.
Conclusion
Well it has been very interesting couple of weeks. Without a question, the new reference module improved several areas of already excellent or near-perfect sound of the previous reference module. This is a significant improvement over what I still consider one of my reference standards in solid-state performance. The new reference module continues Headroom’s hallmarks in excellence in transparency, sound-imaging and superbly dynamic presentation. They both are brutally honest amps--they reveal all the flaws and limitations of your equipment and recording. You don’t want to use these amps with badly encoded MP3s, trust me on this
.
The new reference module improves treble so that it is significantly more extended, yet delivered edgelessly. Tight bass reach and impact is equal if not better than the old reference module. This new reference module equipped Max with stepped attenuator is quite simply one of the best headphone amps I've heard yet. On the other hand, the old reference module sounds smoother between two. In addition, the old reference module sounds slightly more neutral between two, but this is too subjective and highly arguable IMHO.
Is this worth upgrade for existing Max or MOH owners? Well it depends on each individual and their preferences. Just a fair warning: for the review, I was exaggerating the differences between two fine amps so that I can illustrate the differences/improvements. For casual listeners, this may be a minor improvement or may not even detectable. Then again, I highly doubt that a casual listener would spend this kind of money on a dedicated headphone amp. I also listen to both amps using less refined sources (call it economical if you will) including iPod, PCDPs, and an affordable universal SACD/DVD/CD player (Sony DVP-NC685V). Although differences can be heard, they aren’t just as obvious as more qualified sources. I guess if you do not have a high-end source (definition of high-end equipment is subjective to your own), may be upgrading to a better source should be your first priority. Of course, most people spending upward of $1500 for an amp ($1887 for full-retail), they probably own very descent sources already. Please take my opinion as few grains of salt at most as with other recommendations/comments in this forum.
Now, should I pull the trigger and upgrade my reference module? Well my problem is that I promised my wife that I would buy her a house first before I buy another headphone related gear. Yikes, it looks like this upgrade will cost well over 1000 times the cost of Reference Module upgrade. On the bright side of note, I can host a local meet at my own home in very near future. Anyone selling a good newer two story home (brick and wood construction, no siding), 10 foot ceiling, walk-in closet, hardwood floor, 2 car garage with a minimum of 3,000 sq ft of living space? Oh yeah, a huge finished basement with lots of power outlets is must so that I can host future Headfi meetings.
I believe Year 2004 is a glorious year to be Headfiers. Thanks to new and improve versions of headphone amps released this year, including portables and several huge discounts on several solid-state amps, owning a descent headphone amp more affordable than ever. Even for those headfiers who never buy any brand new products were able to benefit from other members’ sale-to-fund-his-upgratitus-fevers. I used to own an original Max. I was mostly satisfied with it, but somehow it left me wanting something more. I guess I just wasn’t really satisfied with its highs and lows of original Max. The original Max was good, but it wasn’t that good. After learning that a Corda HA-1 sounds 70-80% of original Max, I sold my original Max and bought HA-1 to down grade so that I would have a fund for something in future.
Background: New Max
After searching for that perfect versatile solid-state amp, I finally landed on a like mint used Headroom Max with the stepped attenuator (just over a year old). This was a significant upgrade over the original Max. There are several noticeable improvements on hardware side as well. People say beauty is only skin deep; I bet they never saw new Max and old Max in person. For audio-enthusiasts, what is inside should really matters, but the appearance can’t be overlooked
If you haven’t tried or heard new Max or high-end headphone amps, let me describe what a high-end headphone amp sounds like. Here I’m assuming you have a reasonable gears, say a descent source, a good pair of headphones and adequate interconnect cables. A high-end headphone amp will help you bring out the best out of your gears assuming they are up for the task (you are as strong as your weakest link). On amps like Max, the music/sound is absolutely black (no background hiss/hum/operational noise what so ever). Your music is also extremely transparent and airy so that you don’t know there is an amp between you and your music. Most importantly, bass is articulate and tight, overall sound is extremely linear. A linearity is a term I use to describe how consistent sound balance is through out the different volume levels. This helps you to get the nearly equal amount of bass/mid/treble whether you play music in softer/quieter volume or louder volume. Some phones are more linear than the others, say in-ear-monitors like Etymotic ER-4S, some full size cans like Sony MDR-CD3000 or Grado RS-1/RS-2 are fairly linear where as Sennheiser HD-600 isn’t as linear as phones listed earlier by a little bit. Although our ears aren’t as linear as we like, having a linear amp benefit a lower-level listening experience. One other noticeable benefit of Max is its stepped attenuator option. With the stepped attenuators, sound is noticeably linear and fuller than variable volume pots using potentiometers. Often volume-levels of right and left channels do not match with those potentiometer-based volume pots; this is more noticeable in softer listening level. No such problem exist with an optional stepped attenuator equipped amplifiers such as Headroom Max. What you get is perfectly matched left and right channel that sounds full even at the whisper soft listening level. You get 24 discrete adjustments with Swiss made Elma-24 switch plus 3 gain settings, which give you total of 72 steps of volume adjustments (72=24X3). Not to mention a solid aluminum case that is strong enough to use as a wedge for your 16-wheeler when you park at the steep hill. Just kidding, I wouldn’t try this with the amp retailing $1887.00 USD.
Background: Latest Max with Reference Module
Well, not to long ago, starting last July 15th, 2004, Headroom started to equip their amps with the new modules including the reference module for Headroom Max. You can also upgrade your older Headroom amps, except for airhead/bithead with these modules which can cost more than the price of descent pair of headphones. FYI, update cost $149 for Standard Module, $199 for Premium Module, $299 for Reference Module and $598 for two Reference Modules for BlockHead.
The last generation Max (pre-july-15th, 2004) is equipped with Vishay military-spec resisters, polyphenolene-sulfide stacked film versions of capacitors, and Texas Instruments 627 op-amps, which are rated at 55 volts per microsecond slew rates and 4.5nV/rootHz noise. Of course, all these pieces of the Max are hand picked and tested to deliver 0.1% matching between channels.
How about the latest reference module? The new Reference Module is based upon Burr Brown OPA2134 dual op-amps, which is less than ¼ of OPA627’s cost. However with 4 Intersil current buffers and 10 constant current source diodes, it is rated at an extremely high speed, 1300 volts per microsecond slew rate. That is one speedy module for sure.
I was really intrigued, but I didn’t want to bite the bullet until I know for sure that I would want to upgrade. After all, specifications are only half the story… sometimes even less valuable. What really matters is how do they really sound? The only way to be sure is to audition a new reference module equipped Headroom Max. Well I decided to ask nice people at Headroom for a demo unit so that I can spend few weeks with the new reference module equipped Max at my own home/office. Luckily Tyll, Ivy and Andrew were nice enough to arrange an in-home audition of the new reference module equipped Max with stepped attenuator.
Equipment used
Sources:
Sony SCD-XA777ES, Pioneer DV-45A, Sony CDP-X3000, 4th Gen iPod (lineout), Yamaha RP-U100 and Yamaha DP-U50.
Interconnects: MIT #2 Terminator RCAs, Monster M550, Monster Interlink 400 MKII mini to RCA, Zu Pivot mini to RCA.
Headphones: Sony MDR-CD3000s, Sennheiser HD650, Grado RS-2, Etymotic ER-4S, Sony MDR-V6
Music: Custom Made Test CDs, CDs, DVDAs, SACDs of various types of music including infamous SACD Telarc’s 1812 Overture, Op 49, and Apple lossless, AAC/MP3 encoded songs.
Sound Comparisons
The demo Max came with Loop out configuration so that I can easily connect both demo amp and mine with the same input source without splitting RCA outs with Y adaptors. I hooked up a pair of MIT Terminator 2 RCA interconnects to the demo Max and Loopout to my Max using another pair of MIT Terminator 2 interconnect.
I hooked up my Sony SCD-XA777ES and crank up the volume on both Maxes. First thing I noticed is that the new reference module is louder in volume by 5-10% over previous generation reference module. I had to crank up the volume on my Max by a notch or two to make the volume level nearly equal to that of demo unit. For the review, I compensated for the volume difference so that both Maxes are at same or nearly same volume level.
Now enough with the tease… how does the new reference module really sound? In five words, wonderfully faster and more powerful! Speed and power are wonderful things in headphone amps. Of course, without the control, speed and power are useless. However in the new reference module, the control seems to be even better than the pre-July Max. New reference module sounds more transparent and let you hear more details. Treble sounds significantly more extended and bass sounds even tighter. Two obvious benefits of increased details and speed are 1) better instrument separation and 2) better sound-imaging. More about them later. Overall, new reference module sounds even more powerful for dynamic tracks and it appears music come out effortlessly more so in new reference module than the earlier reference module.
Blackness Test:
For both low impedance cans and high impedance cans, two amps exhibited virtually same black background. As long as your source is perfectly quiet, there will be no indication of these amps are on except for the red LED lights on front right of the amps. I would rate both amps as perfect 10 out of 10 for blackness.
Dynamic/Bass:
If I were to summarize my Max’s performance, I would say it’s wonderfully dynamic. And if I were to summarize the new reference module’s performance, I would have to say superbly dynamic or sizzling. Bass sounds a bit tighter and faster by a small margin while playing extremely dynamic tracks. This is slightly more apparent using high impedance cans like Sennheiser HD650 than the low impedance cans like Sony CD3000. I noticed slightly less ringing after each cannon shots on Tchaikovsky’s 1812 Overture (Telarc SACD) using HD650, but not so obvious on CD3K. Overall I give slight edge to new reference module vs. old reference module. If I had to rate the bass, recovery and overall dynamicness of two amps, I would say 9.7 for new reference module and 9.5 for old reference module (I would reserve 10 for BlockHead equipped with the new reference modules).
Soundstage, Depth, Imaging and Transparency:
This is the areas that the new reference module is obviously improved on already excellent old reference module. As I mentioned earlier, the new reference module has more snaps. Bass seems to be tighter and faster than the old reference module. Trebles sound livelier, more energetic and snazzier than before. Overall soundstage width and depth appears to be almost equal but in some instants, new reference module sound just a tad bit narrower. May be being too fast has something to do with it? Instrument separations on new reference modules are breathtakingly good. It is definitely easier to pin point the location of instruments on the new reference module than the old one. Of course, old reference module isn’t too shabby, but new reference modules add more realism and 3-dimensional effects to overall presentation. Overall, I give 10 to the new reference module and 9.5 for old reference module for soundstage, depth, sound-imaging, transparency and air!
Smoothness and Liquidness:
What? A liquidity in solid-state amps? Well, I find the smoothness and liquidness are two other important attributes of amps. Obviously solid-state amps can’t touch glowing glass bottles (tubes) in liquidity or ultra smoothness edgeless delivery. However these are also important characteristics of solid-state amps as well. Two amps are both very smooth, but in slightly different kind of ways. To me, the new reference module is frozen-custard smooth, where as the old reference module is Starbuck’s cappuccino with a shot of Bailey smooth. Let me elaborate! The old and new reference modules have similar tonality, but the old reference module sounds a just tad bit warmer than the new reference module (which can be heard as a slightly colder sounding). For typical music selections, this may not be very obvious, but when I listen to violin or cello, the old reference module sounds a tad bit warmer. Both amps are excellent with virtually grainless presentation and can even be described as organic, but I prefer the old reference module for its smoother sound and more liquid-sounding when playing tracks with electric guitars. Even for female vocal oriented tracks or violin solo, I prefer the old reference module over the new one by a fair margin. There is something more emotional about the old reference module than the new one. May be the old reference module left a permanent sound imprints on my brain to make me think how certain songs should sound. Regardless, I give 9.0 for overall smoothness rating for the new reference module and 9.5 for the old reference module (this is in solid-state amp scale). Of course if I were to rate RKV MKII or Singlepower MPX with 6cg7 here, they would be rated at 100 or so.
Conclusion
Well it has been very interesting couple of weeks. Without a question, the new reference module improved several areas of already excellent or near-perfect sound of the previous reference module. This is a significant improvement over what I still consider one of my reference standards in solid-state performance. The new reference module continues Headroom’s hallmarks in excellence in transparency, sound-imaging and superbly dynamic presentation. They both are brutally honest amps--they reveal all the flaws and limitations of your equipment and recording. You don’t want to use these amps with badly encoded MP3s, trust me on this
The new reference module improves treble so that it is significantly more extended, yet delivered edgelessly. Tight bass reach and impact is equal if not better than the old reference module. This new reference module equipped Max with stepped attenuator is quite simply one of the best headphone amps I've heard yet. On the other hand, the old reference module sounds smoother between two. In addition, the old reference module sounds slightly more neutral between two, but this is too subjective and highly arguable IMHO.
Is this worth upgrade for existing Max or MOH owners? Well it depends on each individual and their preferences. Just a fair warning: for the review, I was exaggerating the differences between two fine amps so that I can illustrate the differences/improvements. For casual listeners, this may be a minor improvement or may not even detectable. Then again, I highly doubt that a casual listener would spend this kind of money on a dedicated headphone amp. I also listen to both amps using less refined sources (call it economical if you will) including iPod, PCDPs, and an affordable universal SACD/DVD/CD player (Sony DVP-NC685V). Although differences can be heard, they aren’t just as obvious as more qualified sources. I guess if you do not have a high-end source (definition of high-end equipment is subjective to your own), may be upgrading to a better source should be your first priority. Of course, most people spending upward of $1500 for an amp ($1887 for full-retail), they probably own very descent sources already. Please take my opinion as few grains of salt at most as with other recommendations/comments in this forum.
Now, should I pull the trigger and upgrade my reference module? Well my problem is that I promised my wife that I would buy her a house first before I buy another headphone related gear. Yikes, it looks like this upgrade will cost well over 1000 times the cost of Reference Module upgrade. On the bright side of note, I can host a local meet at my own home in very near future. Anyone selling a good newer two story home (brick and wood construction, no siding), 10 foot ceiling, walk-in closet, hardwood floor, 2 car garage with a minimum of 3,000 sq ft of living space? Oh yeah, a huge finished basement with lots of power outlets is must so that I can host future Headfi meetings.
