yklee118
100+ Head-Fier
- Joined
- May 19, 2007
- Posts
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If when listening at my computer station, I have an M-Audio Sonica USB output directly to the amplifier and to the Sennheiser HD650 with the Cardas cable, Senn HD280, or the AKG K701 with the Moon Audio Silver Dragon. After the mutliple mixed reviews I have been reading regarding the LDM+, I have to say that the audio quality is soley dependent on the source, however influenced by the cables used to transmit the signal from source to amp, and then to the headphone. I use the first version of the Moon Audio Blue-Dragon (back when it was a silver wire) and the results were better than with the shellbrook. The LDM+ is a great little amplifier, however there isn't enough wattage drive to bring the headphones to rather generous output, the current is there, however not enough of a power drive to make the audio sound serious. Bass does exist, however again it depends on how dynamic is the passage between first and second concerto..
After I got word from David that a new model of the Little Dot portable amplfier was available, I decided to check it out and purchase the unit. I will give both an initial and after burn-in test review to keep the forums talking for weeks (i hope that is). Until then, feel free to pester and send me e-mails saying that I know nothing about audio. or Something I guess. Again thanks for welcoming me to the Forums and I hope to give you some more juicy details of the upcoming Little Dot MK1 amplifier. See You All SOON
UPDATE AUGUST 03, 2007
I have the amplifier and I have to say it is one very prestigious amplifier. A three level gain switch to accommodate a wide range of low to high impedance headphones. In fact this would be one of the few portable amplifiers that have the ability to effectively drive a set of 600-ohms cans. Currently the amplifier is undergoing a 48-hour initial burn-in period with most of Apple Lossless audio through my M-Audio Sonica USB set. I will provide another update in regards of the sound quality. So far, the Little Dot MK-I is paired with the Sennheiser HD650 with the Cardas Cable upgrade with the Moon Audio Blue Dragon mini-interconnect as the source cable from audio source to amplifier. Right now the audio definition and sound stage presentation is better defined than that of the Shellbrook Mini-Head. I also received additional information from Texas Instruments about the amplifier chip that is used in the amplifier that is a Class-A biased chip while Little Tube hasn't commented about the audio class it fall under. Anyway I will see if the pics can be uploaded on to the site to give the forum a taste of what the Little Tube people can actually come up with. I will also give another review of the infamous Little Dot Micro+ that I still currently own (Paired occasionally with the Sennheiser HD650, however mostly with the HD280).
Another update will be posted soon as I reach both a 48-hour and 60-hour burn in mark. Please be patient and i will reward the group with a clean review of this amplifier. For pictures of the Little Dot MK-1 amplifier, the best place to view them is from little-dot's website at www.little-tube.com
AUGUST 14TH 2007
After passing the 80-hour mark, I have to say that this is one very comparable amplifier to my Audio Alchemy. The highs are very detailed, yet warm for long-term listening. Mid-range tones and harmonics are very balanced and the low-frequencies are very well defined. This is a completely different result than its predecessor, the Little Dot Micro+. I am an audiophile, however I will never void the warranty of the unit, so I did not open the unit.
Here are the specifications of the Little Dot MK1
Technical Specifications:
National Semiconductor LM4562 High-Fidelity Op-Amp for superior audio fidelity and ultra-low noise and distortion
Socketed 8-pin Op-Amp design for easy user replacement and "op-amp" rolling
Texas Instrument TPA6120 Headphone Amplifier Circuit
4x 500mA/H 3.7v Rechargeable Lithium-Ion battery
Approximately 20 hours battery life per charge
Frequency response: 10 hz~200 Khz (-1dB)
THD+N: 0.001% (32 ohms, 100mW)
Recommended Load Impedance: 8 ohm~600 ohm
Power Output:
30 mW @ 600 ohm
60 mW @ 300 ohm
150 mW @ 120 ohm
500 mW @ 32 ohm
User Adjustable Variable Gain: 2, 4, and 8x
Included 18V AC Charger for recharging and/or power supply for home use
Dimensions (Metric): 95 mm length by 70 mm width by 24 mm height
Dimensions (American): 3.74 inches length by 2.75 inches width by 0.95 inches height
Weight: 192g or 0.42 lbs (including battery, not including AC Charger)
1 Year Warranty
My own company ACCG-Xponent GmBH works in both the computer and high-end audio industry, so I have technicians who purchased another one of these units to determine the amp's class-biasing, and they have determined based on the information provided by National Semiconductor and Texas Instruments that their circuits are considered as Class-A amplfication circuits. However my technicians have discovered that even though the amp operates in class-A, during highly dynamic passages such as the HDCD released of Independence Day and James Horner's 24-bit recording of TITANIC, that is when the amplfier switches to A/B mode.
The rear gain switch serves a specific purpose with IEM and low impedance phones such as earbuds and other cans below 150-ohms. For me however, I set the gain to 8X since most of the earphones including the HD280 and OMX90 Sennheiser. Since the nature of the LM4562, noise is not even a factor and the floor noise is virtually non-existent.
I personally have been a Sennheiser headphone user for over ten-years, and I have switched back and forth with other headphones to hear how they would compare with Sennheiser. The primary reason why I continue to use Sennheiser's products is the overall comfort of the audio reproduction and wear. Sony headphones offer great and detailed sound, however if driven higher than their recommended RMS and not their peak output, then the sound becomes rather bright. Audio Technica has a similar issue, however when it comes to their closed headphone series such as the one I own, which is the ATH-W5000, that is where the name shines in both details and balanced harmonics with virtually no fatigue over long-periods of time. Aside from the Alessandro and Reference series, I find most of Grado's lineup to be rather overly bright and uncomfortable with my head shape.
Anyway back to the sound quality aspect of the review. The Little Dot MK1 has many of the current drive qualities from the Little Dot Micro+ however with one advantage, which is the ability to drive 600-ohm impedance headphones. Portability is a plus with an amplifier such as this with a rather accessible price point like with the LDM+. Many forums members must admit that not all headphones, IEMs, and earphones will match with the LDM+, LDMK1, and other amplifiers since each amp design and manufacturer use a specific style to increase the signal gain and output stage therefore creating a subtitle audio signature that is bespoken by the characteristic of the amplifier chip. Take for example the MAXIM IC MAX9724, which is used in the LDM+. Using a rather unique method for driving headphones without the use of expensive caps and resistors, it is able to drive headphones up to 300-ohms within an SPL range of 88 to 100-decibels. I can assure you that none of these chips are used in the LDMK1 since my technicians did void the warranty with their units by examining the unit in full detail to provide me with the necessary information to give to the masses today.
The LDMK1 presents many details with the same intensity as having a Jeff Roland 8 paired with a Hovland HD100 and VPI turntable with an SME7550 arm playing Butterfly Lovers. During dynamic passages, the amp delivers the current and power drive to provide excellent harmonics that will make the listener feel as though they are sitting about six rows before the main stage of the orchestra. Warm, detailed, and very much like a tube amplifier without the usual headaches of an amplfier of that class. I let the forum be the judge of that however. LDMK1 was mostly paired with the Senn HD650, however the ATH-W5000 had 20-hours with the amp, and so did the OMX90 (which by the way sound absolutely warm with many nuiance details normally not heard with some other amps due to output gain). I will continue with the rest of the review in due time. For now I have to get back to work. Please e-mail if you would like some answers to some questions. YKL
FINAL COMMENTS AFTER 300-HOURS OF BURN-IN 10-24-2007
As today, the Little Dot MK-I has been used with the Sennheiser HD650 while the Shellbrook has been reserved to the ATH-W5000. This amplifier has a very musical feel with this headphone pairing with hardly any transistor like characteristics. The source is from my Hovland H100 pre-amp out and through the newly restored Proceed CD-1 transport. Using the Telarc's released 1812 Overture, etc. conducted by Erich Kunzel, I have notice all of the details with no veil present as so mentioned by many Sennheiser users. The soundstage is well presented with a level great detail and three-dimensional feel. To provide some perspective, this amp coupled to the souce material and the Sennheiser cans, it is like sitting center and third from front-row leveled. The warmth of the sound has been tamed by using silver cables provided by Moon Audio "Silver Dragon" and the Silver Dragon headphone cable. Cardas cables do tend to fatten up the bass and low-mid-range frequencies so I use these cables for critical and home listening.
To finish with this review, the LD-MK1 is great amplifier for the price range. However price has nothing to do with the sound. The XIN Supermacro-Reference, which i am borrowing is an excellent amp, however there are some qualities that the XIN has that I do not quite appreciate especially when mated to the Audio Technica ATH-W5000. These qualities are not present with the Little Dot MK-I. And as mentioned some warmth of the audio can also be felt with the amp that I own, and again can be tamed by changing the source material or the cables. As for using the i-Pod, I use the 3rd-generation model as reference since Stereophile and the Chinese Audiophile magazine rated this generation of i-pod as Class-B audio device. The audio quality is superb and the XIN would be about three-notches higher. The only caveat with the XIN that absolutely do not appreciate even after the thousands of hours that was previously put on the unit is the slower bass response accompanied by slightly loose in the lower frequency range. Other than that the XIN is an excellent amplifier upgrade over the LD-MK1.
As stated, I am audiophile, a crazy one at that, however my ears are young and with 12-years of experience. I love music and play the cello. the Little-Dot-MK1 is an excellent amplifier for those who love music and would also love the tube-like warmth that is associated with this amp. I hope that this review is helpful for both the beginners and the audiophiles. THANKS all for the warm welcome and have a blissful musical day.
