kelly
Herr Babelfish der Übersetzer, he wore a whipped-cream-covered tutu for this title.
- Joined
- Jan 1, 2002
- Posts
- 5,435
- Likes
- 12
As with all my reviews, the following disclaimer must be stated. What follows are my unscientific objective opinion without the aid of any measuring devices. My opinions reflect my views alone and should not be misconstrued to represent HeadFi, HeadFi's sponsors, the moderators Antness or HeadAmp.Com. Additionally, I encourage every reader to take any review with a grain of salt. One could add the following phrases to any statement made in a review like this: "to my ears", "in my system" and "in my opinion." Do take opportunities to attend local meetings and audition equipment for yourself.
Associated Equipment:
primary/final analysis:
Brick Wall PW8R15AUD surge protector
Sony XA777ES SACD/CD with ModWright "Absolute Truth" modifications
Jena Labs Digi Trio Ultra w/ Cryo Interconnect
Ven Haus DIY power cables
Jospeh Grado HP-1 headphone w/ standard cable
Sennheiser HD600 headphone w/ Cardas cable upgrade
secondary system:
PC with lossless compressed .ape files
Philips Acoustic Edge soundcard
ART DI/O DAC with Bolder modifications and Bolder PSU
Monster interconnects and digital coax cable
Standard generic IEC power cable
Etymotic ER-4S in-canal headphone w/ FixUp cable upgrade
Ultrasone HFI-650 headphone
Amplifiers available for direct AB comparison of stock Corda HA-1:
AudioValve RKV Mk II
Corda Prehead-1
HeadAmp.com's Gilmore Dynamic Headphone Amplifier
I've spent the last few weeks auditioning a headphone amplifier I've been curious about for quite sometime, Head-Fi member Antness' Kevin Gilmore designed dynamic headphone amp.
Antness began selling the amp recently after successfully completing his own and then making a run of circuit boards. Visit his web site here http://www.headamp.com/ to place an order or contact Antness directly. The short story of it is that the amplifier I have here, as reviewed, is $499 assembled. He'll sell you a complete kit to build it yourself for $369 and if you'd rather go all out and order your own parts, it's $30 for the amp circuit board and $35 for the PSU circuit board.
Looking at the photo, the first thing you'll notice is that there are two separate enclosures--in this case identical Hammond enclosures that have become popular with META42 builders. It's a longish lightweight black metal case that's quite a bit nicer than the tin mint cases of ye olde CMOYs but not really up to the extruded aluminum cases of the commercial guys.
Each of the two cases dawns a bright blue LED, too bright for this reviewer's taste. Antness has gotten the hint, though and says he'll gladly put in a resistor to take it down to something more like a power indicator and less like a flashlight. (No offense to Antness here: all blue LEDs are actually this bright, a resistor is the only way to tame it.) The headphone unit, as you can see, has a basic locking Neutrik jack. Personally, I prefer the black ones with silver tabs that HeadRoom uses on their high end amps but Antness is probably better with fashion than I am and the red breaks up the blackness a little. The volume knob on this unit is the Alps Blue--the same pot used in Meier's Corda amps and in the Sugden Headmaster, a favorite amongst Head-Fi's DIYers.
The backs of both enclosures have an DIN jack. A standard DIN cable serves as an umbilical cord between them. My CD player's power supply for the tube output stage uses the same idea but Dan Wright went with the locking jacks instead. I've suggested this to Antness - it seems that it might be a safer option. Both enclosures also have a power switch, another thing I find a bit odd. For my use, I simply left the amp portion powered on and tuned the PSU on and off when I needed too. Of course, with solid state components, you may as well leave it on all the time anyway unless you live in California.
This iteration of the amp has two sets of inputs and a long black toggle switch to switch between them, a neat bonus for an amp of this size and cost. A second black toggle switch exists just above a set of outputs that toggles between the headphone jack in the front and the output jack's preout. All of the jacks are from Dayton Audio and to from an aesthetics perspective are every bit as nice as the Cardas jacks that cost three times their price.
I was unable to secure a good power amp and speakers to test the unit as a preamp. I'm told Gilmore's amp design is excellent as a preamp and you can find some testimony to that in the DIY section here at Head-Fi (use the search feature). To be honest, I'd feel under-qualified judging a preamp myself anyway, having not rotated through nearly as many of them as I have headphone amps in the last year.
A complete part list for this amp exist on the web page mentioned earlier so I won't bore you with a detailed explanation of what's under the hood. What I will say is this, though, Kevin Gilmore himself and others in the know have reaffirmed that an all discrete amp design can easily be made or broken by the quality of the parts used and the quality of the PSU. In both of these areas, the HeadAmp.com model is no slouch despite achieving a modest price point. I'd caution anyone who has maybe heard a Gilmore amp but not heard it with a proper PSU to hold out for another audition.
This was a challenging review for me. When someone like me is given opportunity to test out a new amp, I won't lie about it--it's me versus the amp. I know without a doubt that there isn't a perfect component on this planet and I feel it is my duty and obligation to find these faults, bring them to the surface and expose them. To put it frankly, this amp kicked my ass. I struggled to find a fault with it.
I'd been sandwiching it between the modded ART DI/O DAC and Ultrasones mostly at work and using the HD600 and Grado HP-1 at home and I had trouble identifying anything at all wrong that I could attribute to the amp. Oh sure, there were problems. I'd previously taken issue with some of the HD600's finer points and while the ART DI/O was an awesome band for the buck, it was undeniably a tad peaky in the treble and lush to a fault in its soft bottom and mid-bass.
But it wasn't bad... in fact, with that very combination it was very, very good. I'd previously made comments like, "Why doesn't anyone make a headphone amp that has the same sensibilities of some of the better power amps?" What I meant by that was that it seemed most amps would get one quality right or another. Either the bass was good and the treble was not quite as airy and articulate enough or the opposite would occur and the amp would sound lightweight. I'd even at one point bought a Sugden Headmaster and found myself taking issue with that otherwise awesome amp for being just a little bit glassy on top and a little bit under weighted in the bass.
From the moment I first heard this amp, all those preconceptions went away. The qualities I wanted in an amp were NOT mutually exclusive and I held in my hand, in two tiny Hammond enclosures, the proof of that. At that time, it frankly didn't quite sound like any other amp I'd heard before. It was fast and smooth like the Sugden but had bass and blackness reminiscent of the Max. It made me wish I'd had either or both of them available for AB comparison.
In any case, the obvious thing was that this $500 amp had completely outclassed my DAC. Driving that point home was the arrival of the new Corda Preamp. It was honestly difficult to tell the two amps apart when connected to the ART DI/O. This surprised me. The Gilmore was an all discrete design and the Prehead was opamp based. In truth, the amps were not completely identical but it wouldn't be until I could connect them to my heavily modified Sony XA777ES that the differences would present themselves.
In other words, despite being from completely different designs, the two amps had achieved VERY similar results. I consider this the greatest of compliments to both Jan Meier and Kevin Gilmore and I have to admit... I take a little but of pride in knowing that both of these guys who are obviously a lot smarter than I am have similar ideas as mine about what exactly good sounding amp is.
I'll save the details of that comparison for the Prehead review that should be up in a few days. I also took time to compare the Gilmore to my standing favorite amp, the AudioValve RKV II--an OTL tube amp. In this, my old favorite really had the upper hand in creating this huge lush soundstage that is completely seductive. The RKV had a more lush lower midrange and a rolled off top. The RKV is simply the best amp in the world to relax to, never offensive... but not what you'd call the most accurate thing in the world, at least not when sitting next to Antness' little amp.
I've always been shy of using words like "analytical" and "musical" but I know that's what a lot of you guys are looking for. I'll put it this way, if analytical means having the smallest iota of detail separated and every instrument given a tight sharp focus, then this is a very analytical amp, one of the most analytical amps of any headphone amp I've heard. Now, on the other hand, if we were define musical as being the ability to make me tap my foot and make me feel like part of the music instead of just sitting back and dissecting every note, then Gilmore can only be described as musical. So you tell me, which one do you think it is? Maybe the terms aren't so mutually exclusive after all.
I can't tell you how hard it is to find an amp that can get the drums, cymbals AND the piano right. The lower registers of a piano simply sound "wrong" to me on most equipment. I guess it's a matter of not having the bass extension needed to believably pull off the secondary harmonics or some other gibberish I wouldn't understand, but the fact remains that a piano is simply very hard to be convincing. And then you have cymbals -- they have to be sharp and sweet at the same time, fast on the attack but smooth on the decay. Drums you want to be tight with a hard bottom, enough impact and raw bass strength but with a real fleshy sounding skin. The Gilmore pulls it all off... provided you have a good source and a headphone you like, of course.
One of the more elusive instruments is the xylophone. I found myself listening to the Gilmore one afternoon when I realized for the first time, "Hey, that's an xylophone!" You have to understand, I'd heard this CD a thousand times and always thought it was a keyboard. I can't tell you exactly what it is that makes one distinguishable from the other, but whatever it is, the Gilmore has it and few other amps do.
So here I am and I've described a world class amp in a $500 package. I can't tell you how much I feel like I've put my credibility on the line here. But here's what you have to keep in mind: this amp is not from some big commercial company with a staff of employees, customer service and PR--it's just one guy who borrowed with permission an excellent little design by a God-like engineer with a hobby. It doesn't come in a fancy enclosure and it doesn't use the absolute most expensive parts on the market. So what I'm saying is, yes it drives like a Ferarri, but you have to admit, it looks a bit more like a Golf on the outside.
And if I have one complaint about the amp, that's it. I wish someone were offering a higher class version of the Gilmore. I admit it, looks matter to me, and the Gilmore doesn't look the way it sounds. Still, I'm sure a lot of you think the twin enclosures are cute and everyone loves a blue LED.
I do have one other complaint. I've gotten rather accustomed to the option of having crossfeed and from what I gather, implementing a good crossfeed filter that would not be detrimental to the sound of the amp is quite a challenge. I look forward to seeing someone overcome this but I know in truth it goes a little against the designer's wishes. Gilmore is a purist at heart and this design was never meant to have crossfeed. He'd argue that anything that potential degrades sound shouldn't be included and I'd probably agree with him. I'd take the better sounding amp over the one with the most features, and that's exactly where this amplifier finds itself.
I know there are those of you who would ask me to compare this amp to some of the designs by other DIYers out there, and I can only say this: It really isn't fair to compare amps designed to be affordable, for battery use and portability in mind with one that was designed from the ground up to be a no compromise amplifier. It's simply not a valid comparison and the other DIY designers owe no apology for that.
To put it in summary, if you're looking for the absolute best sounding amp for $500 and you can afford to sacrifice the fancy enclosure and features to get it, look no further than here. On the other hand, make sure you really do have a good source behind it. You'll hear everything your source has to offer with this one, for better or worse.
Associated Equipment:
primary/final analysis:
Brick Wall PW8R15AUD surge protector
Sony XA777ES SACD/CD with ModWright "Absolute Truth" modifications
Jena Labs Digi Trio Ultra w/ Cryo Interconnect
Ven Haus DIY power cables
Jospeh Grado HP-1 headphone w/ standard cable
Sennheiser HD600 headphone w/ Cardas cable upgrade
secondary system:
PC with lossless compressed .ape files
Philips Acoustic Edge soundcard
ART DI/O DAC with Bolder modifications and Bolder PSU
Monster interconnects and digital coax cable
Standard generic IEC power cable
Etymotic ER-4S in-canal headphone w/ FixUp cable upgrade
Ultrasone HFI-650 headphone
Amplifiers available for direct AB comparison of stock Corda HA-1:
AudioValve RKV Mk II
Corda Prehead-1
HeadAmp.com's Gilmore Dynamic Headphone Amplifier
I've spent the last few weeks auditioning a headphone amplifier I've been curious about for quite sometime, Head-Fi member Antness' Kevin Gilmore designed dynamic headphone amp.
Antness began selling the amp recently after successfully completing his own and then making a run of circuit boards. Visit his web site here http://www.headamp.com/ to place an order or contact Antness directly. The short story of it is that the amplifier I have here, as reviewed, is $499 assembled. He'll sell you a complete kit to build it yourself for $369 and if you'd rather go all out and order your own parts, it's $30 for the amp circuit board and $35 for the PSU circuit board.
Looking at the photo, the first thing you'll notice is that there are two separate enclosures--in this case identical Hammond enclosures that have become popular with META42 builders. It's a longish lightweight black metal case that's quite a bit nicer than the tin mint cases of ye olde CMOYs but not really up to the extruded aluminum cases of the commercial guys.
Each of the two cases dawns a bright blue LED, too bright for this reviewer's taste. Antness has gotten the hint, though and says he'll gladly put in a resistor to take it down to something more like a power indicator and less like a flashlight. (No offense to Antness here: all blue LEDs are actually this bright, a resistor is the only way to tame it.) The headphone unit, as you can see, has a basic locking Neutrik jack. Personally, I prefer the black ones with silver tabs that HeadRoom uses on their high end amps but Antness is probably better with fashion than I am and the red breaks up the blackness a little. The volume knob on this unit is the Alps Blue--the same pot used in Meier's Corda amps and in the Sugden Headmaster, a favorite amongst Head-Fi's DIYers.
The backs of both enclosures have an DIN jack. A standard DIN cable serves as an umbilical cord between them. My CD player's power supply for the tube output stage uses the same idea but Dan Wright went with the locking jacks instead. I've suggested this to Antness - it seems that it might be a safer option. Both enclosures also have a power switch, another thing I find a bit odd. For my use, I simply left the amp portion powered on and tuned the PSU on and off when I needed too. Of course, with solid state components, you may as well leave it on all the time anyway unless you live in California.
This iteration of the amp has two sets of inputs and a long black toggle switch to switch between them, a neat bonus for an amp of this size and cost. A second black toggle switch exists just above a set of outputs that toggles between the headphone jack in the front and the output jack's preout. All of the jacks are from Dayton Audio and to from an aesthetics perspective are every bit as nice as the Cardas jacks that cost three times their price.
I was unable to secure a good power amp and speakers to test the unit as a preamp. I'm told Gilmore's amp design is excellent as a preamp and you can find some testimony to that in the DIY section here at Head-Fi (use the search feature). To be honest, I'd feel under-qualified judging a preamp myself anyway, having not rotated through nearly as many of them as I have headphone amps in the last year.
A complete part list for this amp exist on the web page mentioned earlier so I won't bore you with a detailed explanation of what's under the hood. What I will say is this, though, Kevin Gilmore himself and others in the know have reaffirmed that an all discrete amp design can easily be made or broken by the quality of the parts used and the quality of the PSU. In both of these areas, the HeadAmp.com model is no slouch despite achieving a modest price point. I'd caution anyone who has maybe heard a Gilmore amp but not heard it with a proper PSU to hold out for another audition.
This was a challenging review for me. When someone like me is given opportunity to test out a new amp, I won't lie about it--it's me versus the amp. I know without a doubt that there isn't a perfect component on this planet and I feel it is my duty and obligation to find these faults, bring them to the surface and expose them. To put it frankly, this amp kicked my ass. I struggled to find a fault with it.
I'd been sandwiching it between the modded ART DI/O DAC and Ultrasones mostly at work and using the HD600 and Grado HP-1 at home and I had trouble identifying anything at all wrong that I could attribute to the amp. Oh sure, there were problems. I'd previously taken issue with some of the HD600's finer points and while the ART DI/O was an awesome band for the buck, it was undeniably a tad peaky in the treble and lush to a fault in its soft bottom and mid-bass.
But it wasn't bad... in fact, with that very combination it was very, very good. I'd previously made comments like, "Why doesn't anyone make a headphone amp that has the same sensibilities of some of the better power amps?" What I meant by that was that it seemed most amps would get one quality right or another. Either the bass was good and the treble was not quite as airy and articulate enough or the opposite would occur and the amp would sound lightweight. I'd even at one point bought a Sugden Headmaster and found myself taking issue with that otherwise awesome amp for being just a little bit glassy on top and a little bit under weighted in the bass.
From the moment I first heard this amp, all those preconceptions went away. The qualities I wanted in an amp were NOT mutually exclusive and I held in my hand, in two tiny Hammond enclosures, the proof of that. At that time, it frankly didn't quite sound like any other amp I'd heard before. It was fast and smooth like the Sugden but had bass and blackness reminiscent of the Max. It made me wish I'd had either or both of them available for AB comparison.
In any case, the obvious thing was that this $500 amp had completely outclassed my DAC. Driving that point home was the arrival of the new Corda Preamp. It was honestly difficult to tell the two amps apart when connected to the ART DI/O. This surprised me. The Gilmore was an all discrete design and the Prehead was opamp based. In truth, the amps were not completely identical but it wouldn't be until I could connect them to my heavily modified Sony XA777ES that the differences would present themselves.
In other words, despite being from completely different designs, the two amps had achieved VERY similar results. I consider this the greatest of compliments to both Jan Meier and Kevin Gilmore and I have to admit... I take a little but of pride in knowing that both of these guys who are obviously a lot smarter than I am have similar ideas as mine about what exactly good sounding amp is.
I'll save the details of that comparison for the Prehead review that should be up in a few days. I also took time to compare the Gilmore to my standing favorite amp, the AudioValve RKV II--an OTL tube amp. In this, my old favorite really had the upper hand in creating this huge lush soundstage that is completely seductive. The RKV had a more lush lower midrange and a rolled off top. The RKV is simply the best amp in the world to relax to, never offensive... but not what you'd call the most accurate thing in the world, at least not when sitting next to Antness' little amp.
I've always been shy of using words like "analytical" and "musical" but I know that's what a lot of you guys are looking for. I'll put it this way, if analytical means having the smallest iota of detail separated and every instrument given a tight sharp focus, then this is a very analytical amp, one of the most analytical amps of any headphone amp I've heard. Now, on the other hand, if we were define musical as being the ability to make me tap my foot and make me feel like part of the music instead of just sitting back and dissecting every note, then Gilmore can only be described as musical. So you tell me, which one do you think it is? Maybe the terms aren't so mutually exclusive after all.
I can't tell you how hard it is to find an amp that can get the drums, cymbals AND the piano right. The lower registers of a piano simply sound "wrong" to me on most equipment. I guess it's a matter of not having the bass extension needed to believably pull off the secondary harmonics or some other gibberish I wouldn't understand, but the fact remains that a piano is simply very hard to be convincing. And then you have cymbals -- they have to be sharp and sweet at the same time, fast on the attack but smooth on the decay. Drums you want to be tight with a hard bottom, enough impact and raw bass strength but with a real fleshy sounding skin. The Gilmore pulls it all off... provided you have a good source and a headphone you like, of course.
One of the more elusive instruments is the xylophone. I found myself listening to the Gilmore one afternoon when I realized for the first time, "Hey, that's an xylophone!" You have to understand, I'd heard this CD a thousand times and always thought it was a keyboard. I can't tell you exactly what it is that makes one distinguishable from the other, but whatever it is, the Gilmore has it and few other amps do.
So here I am and I've described a world class amp in a $500 package. I can't tell you how much I feel like I've put my credibility on the line here. But here's what you have to keep in mind: this amp is not from some big commercial company with a staff of employees, customer service and PR--it's just one guy who borrowed with permission an excellent little design by a God-like engineer with a hobby. It doesn't come in a fancy enclosure and it doesn't use the absolute most expensive parts on the market. So what I'm saying is, yes it drives like a Ferarri, but you have to admit, it looks a bit more like a Golf on the outside.
And if I have one complaint about the amp, that's it. I wish someone were offering a higher class version of the Gilmore. I admit it, looks matter to me, and the Gilmore doesn't look the way it sounds. Still, I'm sure a lot of you think the twin enclosures are cute and everyone loves a blue LED.
I do have one other complaint. I've gotten rather accustomed to the option of having crossfeed and from what I gather, implementing a good crossfeed filter that would not be detrimental to the sound of the amp is quite a challenge. I look forward to seeing someone overcome this but I know in truth it goes a little against the designer's wishes. Gilmore is a purist at heart and this design was never meant to have crossfeed. He'd argue that anything that potential degrades sound shouldn't be included and I'd probably agree with him. I'd take the better sounding amp over the one with the most features, and that's exactly where this amplifier finds itself.
I know there are those of you who would ask me to compare this amp to some of the designs by other DIYers out there, and I can only say this: It really isn't fair to compare amps designed to be affordable, for battery use and portability in mind with one that was designed from the ground up to be a no compromise amplifier. It's simply not a valid comparison and the other DIY designers owe no apology for that.
To put it in summary, if you're looking for the absolute best sounding amp for $500 and you can afford to sacrifice the fancy enclosure and features to get it, look no further than here. On the other hand, make sure you really do have a good source behind it. You'll hear everything your source has to offer with this one, for better or worse.
