Thanks to the generosity of Leckerton Audio, Nankai, and dw6928 I have received three new portable headphone amps to listen and post my impressions. The corresponding amps are: UHA-3, MiniBox-E, and a Max version of the Go-Vibe V7.
All three fit comfortable in the category of portable being on the smaller end, although not miniature. The UHA-3 has a built in USB DAC, which I will not be testing at this time because I do not have my iBasso D1 to compare too. I will start by describing the physical attributes of each of these units, w/ features I like and those, which I believe, can be improved upon.
When I first received the MiniBox-E I was surprised at its small size and overall quality presentation. I was a bit worried that the volume control would be easy to accidentally move and cause the volume to reach WAY LOUD levels! Well I am glad to report that in the configuration that I would use it that would not be the case. See the picture below (click on the thumbnail to view the full size picture)
The MiniBox-E also makes it very easy for the diy’er to try new op-amps. This because of the sockets already installed by the manufacturer. At this time I do not have many op-amps available so I will pursue swapping LM4562 for the NE5532 in the future. The thumbnail below demonstrates how easy the swapping of op-amps will be.
The MiniBox-E has three additional switches (to the power switch) that further expand the use of the unit. The P to S switch adds a 75-ohm resistor to both the left and right channel, same value as the P to S adapter sold by Etymotic. IMO this is a nice feature for those w/ sensitive IEM’s or those who listen at very low volumes. The other two switches are a bass boost and a soundstage expander (SFOR). More discussion on the switches in the sound comparison section.
Lastly I will mention that a silver Mini to Mini and a wall wart to charge the internal battery are included in the purchase price of $149. In the packaging/ergonomics my only gripe is that an instruction booklet should be included to describe the various features/functions.
When I first opened the Leckerton Audio UHA-3 the first thought that came to mind was: tidy. There is a flow to the way the amp is put together, almost like it should be. This amp features an USB DAC and Leckerton includes an USB Cable, which also charges the internal battery.
With regards to the Lithium Ion battery I am happy to report that it would be an easy swap for any user. Once you have removed the two front and two rear screws (no need to remove the volume pot knob) you can slide the board out and the internal Lithium-Ion battery is held together in a spring type holder. See the thumbnail below to better understand what I am trying to describe.
Sadly the use of SMT components prevents the average user from op-amp rolling. However when you consider the amount of components needed to have an USB DAC w/ a Headphone Amp in such a small package it is mind blowing!
The UHA-3 has a gain switch Low is a 0dB and High is 18dB. This is the same as gains of 1 and 6 respectively. An idiosyncrasy of the UHA-3 is that the on/off switch is on the back.
The UHA-3 comes with an instruction sheet. Two minor gripes in the packaging/ergonomics would be that rubber feet should be included and that it should be made in black as well as silver. Not much as far as gripes considering that you can get a pack with 12 rubber feet at Radio Shack for about $2.00 Note: The input and headphone out plugs are far apart for most users, if you use the largest mini plug on BOTH the input and the headphone they will not fit. If used only on the input (example: an ALO iPod Dock) then you will be ok.
It is good to get my hands on the Go-Vibe V7 thanks to dw6928. Having owned a V5 and two V6 it feels like an old friend is back. I love that Norm chose to use the large thumbnuts to secure the battery plate. I have been know to be a klutz and lost small screws or nuts. They may look peculiar but IMO it is the right move.
The enclosure is the tried and true Hammonds just like in the UHA-3. It is black J and it does have the fancier rings at the end caps. The unit I have on loan is the max version w/ a DC input (no charging) to help prolong the battery life. It has a gain of 4.
I do have one gripe w/ the packaging/ergonomics and it is with the fact that the battery is not firmly held in place. Although damage may never occur having the battery move around does not inspire confidence. If it were my unit I would find a way to prevent or at least minimize the banging around of the battery.
For today’s comparison I will be using my 4th Generation iModded iPod Photo 60Gb. The files are apple lossless, and the interconnect is a Revelation Audio 99.999% Silver Cryo. For headphones I will use an Ultrasone PROline 2500 re-terminated to a 1/8” plug and a Senn HD580 w/ an HD650 cable and an HD600 grills. Since the HD650 cable terminates in a 1/4” plug I am using a Grado ¼” to 1/8” adapter.
For music I will be using:
1.Keiko Matsui, Night Hawk’s Dream from the Full Moon and the Shrine CD
2.Fourplay, Free Range from the Yes, Please CD
3.Jane Monheit, Over The Rainbow from the Come Dream with Me CD
I started the listening test and everything was going well, or so I thought. Well, I realized that I had been burning in the UHA-3 via the USB input. Since now I am feeding the signal via the mini input I realized that all the components going from the mini input to the amp section have had 0 hours of burn in. So I will burn in the amp using the mini input for the next week or so. I hope I can keep dw6928’s Go-Vibe V7 for an extra week.
Sorry guys for my error will come back on this next week.