[Zyca]

Before the main article, I'd like to say we are very proud to present our new headphone amp/pre-amp combo HA-006+, it is based on Dr. Gilmore's DynaLo design while keeping the price affordable to everyone.  We have confirmed with Dr. Gilmore that this unit comes with his approval and blessing.    aa aa aa




Click photo for full size image.

Sheer Audio HA-006+ (DynaLo) is a pure class A, high performance headphone amp/pre-amp that provides excellent performance, great sound, powerful presentation, crystal clear details and all done while making the music very enjoyable.




Dr. Kevin Gilmore's renowned Dynamic Headphone Amp (AKA: DynaLo) has long been regarded as one of the very best headphone amps around, and many custom builders and amp makers had made many high end products based on this design.  However, most of them costs in excess of $500USD, and some even managed to blow past $1000USD.  Does it have to cost that much to own and enjoy one of the most detailed, involving and enjoyable headphone amp around?


Well, with our Sheer Audio HA-006+ it is no longer the case, because we have worked very hard to provide the essence of DynaLo without the huge price tag.  All important details and the essence of DynaLo is done properly and by the book, and Dr. Gilmore himself have listened to the original version and like the result a lot.[/color]  The HA-006+ improves on the original version by finer tuning of the sound, with smoother sound, better soundstage and great decay.




How's Sheer Audio HA-006+ Sounds Like?:

• Neutral Sound Signature: HA-006+ is designed to taint sound as little as possible, it sounds very transparent and introduce minimal coloration to allows the music to speak for itself.
  
• Effortless Drive: Powerful parallened Bi-Polar transistor output stage makes music sound effortless and natural with even the most demanding headphones.  No longer will you have to endure wobbling bass, piercing treble, muddy mids or other effects of improperly driven headphones.
  
• Open Sound Stage: Open and free sounding sound stage, music will not sound congested or overly exaggerated sound stage.
  
• Precise Instrument Imaging: Revel the finer details of sound, and clearly present each instrument and where they come from.
  
• Highly Detailed Sound: All the details will be presented to you in a natural fashion, and you will be hearing a lot more of the details in your music that you have been missing.
  
• Lively Bass: Excellent bass extension with vast amount of detail, and of course, the proper KA-BOOM that Dr. Gilmore demands. It won't be that muddy boom that you hear with other headphone amp.
  
• Listenability: With the ability to extract all the details, we still keep HA-006+ very enjoyable with non-fatiguing sound.  After all, it would not be fun to listen to something that will fatigue you out quickly.
  

What other qualities does Sheer Audio HA-006+ have?:

• Easy Installation: Works just like any other headphone amp or pre-amp, just plug the power, signal and your headphone on and you will be ready to rock!  It also work extremely well as pre-amp for your active speaker or power amp.
  
• Built-in Power: HA-006+ is equipped with a very robust and powerful internal power supply, no longer will you have to put up with a wall wart power supply.
  
• Highly Refined Design: While Dr. Gilmore's design is already excellent, we have developed many revisions using different parts to make HA-006+ sound great and affordable at the same time.
  
• Quality Connectors: High quality locking headphone socket and quality gold plated copper RCA connector ensure excellent connection in and out.
  
• Quality Components: Using precision parts throughout the entire headphone amp, fully shielded signal wires, carefully hand matched transistors, and a purely direct-coupled setup.  All done in the quest for better sound.
  
• Custom High Powered Transformer: We used a transformer with specs far exceeds the requirement of the circuit, providing plenty of clean power to HA-006+.
  
• Compact & Stylish: Sturdy metal chassis that looks perfectly at home whether it is on your desk or on the stereo rack.

The back of HA-006+, 1 set of analog input and 1 set of pre-out (shown with silicon rubber cover on), input voltage select switch (115V and 230V).

Click photo for full size image.



Sheer Audio HA-006+ Basic Specs:

• Hand Matched Transistors: Matched to very close tolerance for better stability and performance
  
• Pure Class A Operation: Pure Class A operation, with over 100mA per channel capability, easily drives most dynamic headphones.
  
• Fully DC Coupled Circuit: No signal distorting capacitor or DC servo in the signal path, allowing better and more neutral frequency extension.
  
• Dual Independent Power: Two independent regulator circuits, dedicated high current +/-15V analog power for the amp circuit.
  
• Pre-amp Output: High quality variable output via RCA, can be easily used to drive active speaker or power amp.  Performs perfectly as a high quality pre-amp.
  
• International Voltage Compatibility: Simple flick of a switch will allow you to switch between 115V (usable for countries of 100 to 125V) and 230V (usable for countries of 200 to 250V).
  
• Included Accessory: Computer grade power cable, will include the proper type for customer's region.
  
• Dimensions: 145mm * 270mm * 80mm (Width * Depth * Height, excluding knobs and connectors).
  

Neat and tight interior, circuit and component layout are all highly optimized.  You can also see the quality locking headphone socket.

Click photo for full size image.




Price: $280USD plus shipping.

For ordering, please check out our web site at:
http://www.acoustic-fun.com/catalog/index.php






All right reserved, no part of this text and photos/images may be used without permission.

[santacore]

Nice looking amp at a great price point, this should do well.

Any chance we could start a demo tour of this unit? That would do a lot to get the word out.

[srb]

Yes, nice looking unit and affordable.
 
I don't see the smoked acrylic top cover you mention, however.  I see a one-piece "U" shaped steel(?) cover.
 

Compact & Stylish: Sturdy metal chassis with smoked acrylic top cover, it looks perfectly at home whether it is on your desk or on the stereo rack.

Steve

[Zyca]

Yes, nice looking unit and affordable.
 
I don't see the smoked acrylic top cover you mention, however.  I see a one-piece "U" shaped steel(?) cover.
 

Compact & Stylish: Sturdy metal chassis with smoked acrylic top cover, it looks perfectly at home whether it is on your desk or on the stereo rack.

Steve

My mistake, it is corrected now.\


Thanks

David

[cryoparts]

Very nice.  You definitely need to take out a sponsored ad at Head-Fi to tell those guys about this.

How about a four channel version  for balanced?

Lee

[Zyca]

Very nice.  You definitely need to take out a sponsored ad at Head-Fi to tell those guys about this.

How about a four channel version  for balanced?

Lee

Thanks, that had been considered, balanced version can be fitted into the current chassis with the connector upgraded to the same one used by AKG-K1000.  But that will depend on how good this current one sells.


Thanks

David

[Zyca]

Well, great news everyone!  We have just updated our HA-006+ with noise level so low that is impossible to detect even with the very sensitive Grado and ER4P earphones!

We used to have a few customers complain about their headphone is able to hear a soft humming sound in the background.  After some very extensive testing, we found that it seems to be mainly focused on low impedance headphones/earphones.  There are several ways to solve this problem, including simply damp out the noise (and the music at the same time) with a cheap resistor.  We discard that idea almost as fast as it came up, as it would reduce the ability of the headphone amp in controlling the headphone properly.

At the end, in combination with other tunings, we also upgraded the headphone amp's transformer to the same quality ultra low noise transformer that KECES headphone amps are using.  The size is smaller than the original EI transformer, but it is actually able to provide better output spec and emits much less noise than before.

For customers who ordered the original unit, we will be sending out email invitation for a free "home coming" service upgrade to have your HA-006+ up to the new standard.  This is due to the massive improvement that this upgrade provides, and of course the original circuit board will be retained, as the same circuit board is still used (nothing wrong with it) in new version of HA-006+


For identifying the new version of the HA-006+, just check the rear end to see if there's a laser sticker saying "HA-006+ Plus Edition", if it is, it is the new version!


Now, as we all come to expect, there should be some photos showing the difference between the new and the old, and here we go.


The new smaller, yet more powerful and much quieter (electromagnetically speaking) Toroidal transformer.



More details on the wiring, took me a bit of time to figure out a neat way to tuck in all the wires.




Another view of the wiring.


I'll try to get some equipments together and see if I can show the difference on a scope.   But that will take me a couple of days, I'm currently working with out my eye glasses, and it was kinda painful to do detail work without it (it is out for repair, hopefully will be back in a couple of days).


Thanks

David