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- Written by Vade Forrester Vade Forrester
- Category: Full-Length Equipment Reviews Full-Length Equipment Reviews
- Created: 01 September 2016 01 September 2016
JE Audio is a Hong Kong-based audio company whose products we’ve reviewed fairly often and very favorably. I reviewed JE’s VS70.1 stereo amplifier in February 2012, and publisher Doug Schneider has reviewed several of their other products, most of which received Reviewers’ Choice awards. JE’s first digital product is the IS250, an integrated amplifier with a built-in DAC capable of playing up to 32-bit/384kHz PCM and up to DSD128 (5.6448MHz). That includes most commercially available PCM sources, except for files encoded with Meridian’s Master Quality Authenticated (MQA), a newish encoding system whose general acceptance is slowly progressing; and DSD256, still rather rare but becoming more available. The IS250 has both a USB input and a coaxial S/PDIF input, but it’s not just a DAC with an amp section -- it’s a full analog preamp and amp with three analog inputs: two balanced, one unbalanced. You can use it with analog sources, such as a phono preamp, a tape deck, or a tuner (remember those?). It also has two sets of analog outputs on XLR jacks: one line-level, one preamp.
Although the IS250’s preamp section uses four 6922 tubes, that’s a recent revision; the manual specifies 12AU7 and 6922 tubes. The 6922s are in current production and aren’t crazy expensive -- check your local guitar store. The solid-state power-amp section has separate sections for voltage and current gain, with a buffer amplifier between them. The entire circuit is balanced, and the class-AB power-amp section is specified to output 125Wpc into 8 ohms or 250Wpc into 4 ohms.
The price is $5000 USD, or $4100 without DAC. Nine-hundred bucks for a capable DAC is a pretty good deal; why pass it up? I can think of several reasons: 1) you hate digitally recorded music (which includes most music recorded in the last 30 years, even when released on LP); 2) you already have a DAC you like; or 3) DAC technology is advancing so fast you don’t want to tie yourself to a particular set of capabilities.
JE Audio’s products have often had unusual styling, and the IS250 is no exception. It’s tall, with a faceplate of brushed aluminum that’s wider and thicker at the bottom than at the top. For what it’s worth, I liked the sculpted design (behind the faceplate, the actual case is a typical black, rectangular box). The front-panel controls are few: a single large volume knob at the center, with a notch to indicate the setting. Below the knob are four buttons for selecting the source input: three analog and the DAC. You can use the USB or S/PDIF input, but not both simultaneously; if you have two digital sources -- say, a computer and a CD transport -- you’re out of luck.
A fifth, central button is labeled Power/Mute, which toggles between playback mode and standby (tubes off). Above each button is an LED that glows to indicate that it’s been selected. All LEDs except the center one are blue; the center one glows red (standby) or blue (playback). When I first saw photos of the IS250, I was afraid its only power switch was the one on the rear panel, next to the IEC inlet for the power cord. Had that been true, it might have made the IS250 the first component in my reviewing career rated unacceptable due to the location of the power switch -- it’s very hard to reach. But for daily use, the Power/Mute button on the front panel is all you’ll need. Below the Power/Mute button is a round window for the remote control’s sensor.
The IS250 measures 18.5”W x 8.7”H x 18.7”D and weighs 70 pounds -- that’s one big, heavy amp! You’ll have to decide whether a 70-pound integrated is within your comfort zone -- it’s way out of mine.
The left side of the rear panel is devoted to inputs and outputs, line-level and digital; the center section contains the power switch and an IEC inlet for the power cord; the right side has the left and right speaker terminals, which use nifty, unusual five-way binding posts. All of this is explained in the 20-page manual, in English and Chinese.
A silver metal remote control with shiny silver buttons controls all functions of the IS250: volume, input, power/mute. It also has a button labeled Option that doesn’t do anything. I presume it works with another JE Audio model.
The IS250’s internal DAC is a basic design with no frills -- no digital display, no clutch of confusing digital filters. It uses an XMOS USB front end and ESS Technology ES9018 Sabre DAC chips -- both are respected, proven parts. The USB driver necessary to make the IS250 work with Windows is shipped on a miniature CD-ROM. Unusually, the IS250 has an S/PDIF output jack, which can be used to drive an external digital device. The analog output section can drive another amplifier, such as one in a subwoofer.
Input impedances are industry standard for the digital inputs. The impedances of the analog inputs are 94k ohms (balanced) and 47k ohms (single-ended). Those should work with any conceivable source.
The remote control had a nice heft, its textured surface provided a secure grip, and its rounded corners will be appreciated if you drop it on your coffee table -- or foot. (Don’t ask how I know.) There’s little chance the included batteries will fall out; six small Phillips-head screws hold the access door in place.
Setup and use
The IS250’s size and weight made it a challenge to get it up onto my equipment rack. It needs a large, open, well-ventilated shelf, but it also needs to sit where its controls will be easy to see and touch. Many racks may not have shelves large enough to support the IS250 at a convenient level. Enlisting the help of several friends whose backs are stronger than mine, I placed the IS250 on the top shelf of my rack -- the only shelf deep enough and with enough vertical clearance to ensure adequate ventilation. That put the amp at eye level -- not the ideal position for a one-person lift. The only other possible location would have been the bottom shelf, which met none of the IS250’s requirements. Of course, I could have depended entirely on the remote control. There’s a good reason for separates.
I connected my SOtM sMS-1000SQ streaming network player to the IS250’s USB input via an Audience Au24 SE USB cable. Audience Au24 SX speaker cables connected the power-amp section to my speakers. I also connected my Sony XDR-F1HD tuner, modified by Radio X, to the unbalanced input jacks using Crystal Cable Piccolo interconnects. If you hate banana plugs because they lose spring tension and fit too loosely into speaker terminals, the IS250’s terminals let me tighten down on the bananas -- a very useful feature. However, they also made it hard to insert the bananas, until I figured out how to open up the connectors. No stock power cord was provided, so I used a Clarity Cables Vortex cord, which has worked well with everything I’ve used it with. To evaluate the IS250’s bass performance, I disconnected my subwoofer.
My streaming network player uses a Linux-based operating system, so I didn’t need to install the IS250’s Windows USB driver. I just ran the USB cable from the SOtM player to the IS250, launched the iPeng 9 app on my iPad (this controls the SOtM), picked the first album that caught my eye, and turned up the volume -- carefully. Music flowed from the speakers! It doesn’t get much simpler than that. Since the IS250 has no display, it tells you nothing about the signal it’s receiving; instead, it depends on your playback app or player to give you that information, and since the iPeng 9 app doesn’t do that, I was in the dark.
The IS250’s multiple analog inputs told me there was more to this amp than its DAC, and I wanted to check out how they sounded. I needed to use a better source than my tuner, so I connected my turntable, using my Audio Research SP20 preamp only as a phono preamp. New and very nice Audience Au24 SX balanced interconnects connected the SP20 to the IS250.
The IS250 exhausts warm air through vents in its top panel, so it needs ample headroom. Still, after I’d used the amp for an hour or so, it was only slightly warm to the touch. The IS250 was, thankfully, extremely quiet, like most of today’s amplifiers. There were huge reserves of power available; driving my sensitive horn speakers, I never turned the volume control higher than the 10:00 position. Even with my sensitive speakers, the remote’s volume adjustment gave me sufficiently fine control over the volume. Some remotes have two volume positions, too loud and too soft; the IS250’s remote had a useful range of settings.
The tubes were shipped already installed. The manual forbade removal of the top plate, which would also seem to prevent replacing the tubes. Seeking clarification of this policy, I learned that the warning is intended to keep users out of an area of potentially lethal voltages inside the amp; JE Audio recognizes that users will, at some point, need to replace tubes. Just turn off the amp several hours before you open it up.
You shouldn’t leave the IS250 on continuously -- tubes do wear out. The tubes’ expected lifespan is 2000-3000 hours, with gradual degradation after that period. That’s a reasonable lifespan for 6922 tubes: 750 four-hour listening sessions. There’s no timer to tell you when that period has passed, so you’ll have to go by ear. The warranties -- three years parts and labor; 90 days, tubes -- seem reasonable for a $5000 integrated.
Turning on the IS250 was a bit tricky, and is not well described in the manual; here’s what I found: After everything is connected and the IS250’s power cord is plugged into the IEC socket on the rear panel, first turn on the power switch adjacent to that socket. This places the IS250 in standby mode; the LED over the Power/Mute button on the front panel should glow red. Turn the volume control all the way down. Now, push and hold down the Power/Mute button for about a second. That will take the amp out of standby, warm up the tubes, and get it ready to play. The IS250 takes about 40 seconds to warm up, during which time all five of the lights above the buttons flash blue in sequence across the faceplate, as if searching for an active source (they aren’t). When the amp is warmed up and ready to play, the lights stop flashing and the light above the Power/Mute button turns blue. Push the button of the input you want to play; the LED above that button glows blue, and the amp is ready to play the source you’ve selected. Turn on the source, turn up the volume, and enjoy the music. Push the Power/Mute button and immediately release it to put the amp in Mute without turning off the tubes. Push it again to take it out of Mute, and it plays immediately. You can do all of this using the remote control.
The IS250 sounded quite listenable right out of the box, but grew more open and relaxed with break-in. JE recommends 100-200 hours of break-in -- I played the IS250 for 200 hours before doing any critical listening.
Aside from the challenge of placing the amp on my rack, setup was strictly plug’n’play.
For a digital input, the IS250’s DAC section sounded remarkably like analog. There was no hint of digital artifacts -- no glare, no etch, no unnatural brightness. I began my listening with Allegri’s Miserere, in a recording by the Tallis Scholars that’s revealing of such artifacts (24-bit/96kHz FLAC, Gimell). In this a cappella choral performance, recorded in a church, one group of singers is at the front of the soundstage, with a smaller group of soloists some distance behind them. The IS250 exhibited none of the nastiness of some digital components; it sounded very smooth. At first, I thought the high frequencies were rolled off, but soon realized that they were merely free of glare. I could hear that the smaller group of singers was behind the main group, and there was no smear that this separation sometimes adds to the sound. However, the sense of depth was not quite as pronounced through the IS250 as I’ve heard through other components. The solo tenor in the main group can sound a bit edgy, but the IS250 didn’t depict him that way -- he sounded very natural.
A new acquisition is Mari Kodama’s recording of all of Beethoven’s Piano Sonatas (DSD64/DSF, Pentatone/Primephonic). I’ve long enjoyed Kodama’s performances on CD and SACD (all now ripped to my hard drive), but the opportunity to acquire them in their original DSD format was irresistible. The piano sound in Sonata No.32 was very powerful yet detailed. I’ve long thought that DSD recordings of pianos are capable of realistically depicting a piano’s hammers hitting the strings, and this recording is a good example. The lower registers of Kodama’s Steinway D sounded powerful and realistic, and the IS250 reproduced that characteristic across the entire audioband, from lowest notes to highest -- the result sounded like a whole piano. Kodama’s phrasing and dynamic variations were crystal-clear; I could tell how well she understood the structure of the piece. The IS250 captured the soft passages in the second movement as delicately as one could imagine, yet they were always audible. What a recording!
Another recent acquisition from Pentatone/Primephonic.com was the Houston Symphony’s fine performances of Dvořák’s Symphonies Nos. 7 and 8 (DSD64/DSF, Pentatone/Primephonic). The orchestra’s newish conductor, Andrés Orozco-Estrada, led generally excellent performances; though I felt the last movement of Symphony No.8 dragged a bit, it perked up at the close. Listening to this recording, a friend observed that the IS250 had a very ballsy sound, a description I can’t improve on: lots of energy, dynamics, and midbass punch. I also observed that the IS250 portrayed each section of the orchestra with unusual clarity, telling us exactly how the orchestra played every part of the symphony -- most recordings blur things together a bit. Although the soundstage sounded realistic, spread nicely between the speakers, I wondered if the recording used multimiking. The tonal shadings of each group of instruments were realistically portrayed. Strings are sometimes a challenge for digital recording, but through the IS250, the Houston strings sounded sweet and natural -- the antithesis of early digital.
On the old audiophile favorite “Folia Rodrigo Martinez,” from La Folia 1490-1701 (16/44.1 AIFF, Alia Vox), Jordi Savall and his band oozed energy and detail, their finely defined macrodynamic shadings making obvious how much fun they were having. Through the IS250, bass was well defined and punchy, extending surprisingly deep for my speakers. The wood block stood out more than usual, while other percussion instruments were easy to follow, though not emphasized by elevated high frequencies. Savall’s viola da gamba sounded sweet, and the IS250 clearly depicted his vigorous bowing.
No review is complete without a recording of a girl with a guitar. I switched to the LP of The Best of Eva Cassidy (Blix Street 10206) so I could enjoy Cassidy’s cover of Cyndi Lauper’s “Time After Time.” The sound was oh, so smooth, with the warm richness we expect from LPs: no peakiness or etch, vanishingly little surface noise, punchy but not boomy bass, plentiful detail, and just right harmonics. The expressiveness of Cassidy’s voice was very clearly depicted. She didn’t just sing the words -- she interpreted them to tell a coherent, meaningful story. Nice record -- very nice. Listened to via its analog inputs, the IS250 was a very capable integrated amplifier. If you don’t need a DAC, it’s a very good analog-only component, with a potent-yet-smooth sound that was never harsh or brittle.
It would have been useful to compare the JE Audio IS250 with another integrated amp of similar output power, but I didn’t have one. Instead, I compared it to my own system, which uses a PS Audio DirectStream DAC ($5995), an Audio Research SP20 preamp ($9000), and a Berning ZH-230 power amp that puts out 30Wpc ($8360). That’s a total of $23,355, not counting the interconnects from DAC to preamp and from preamp to amp, which might add another $2000. The much more expensive SP20 has lots of fancy features, like a timer that tells you how many hours you’ve put on its tubes, a balance control, phase-inversion and mono switches, and a digital volume-level display -- all useful, none absolutely essential.
Miserere was just as smooth and a smidgen more detailed than through the IS250. Highs were slightly more extended, and the solo tenor sounded very expressive. There was more of a sense of depth, with no smearing of the rear solo group. Kodama’s performance of Beethoven’s Piano Sonata No.32 was powerful when it needed to be, extremely delicate when that was called for. Transients of hammers striking strings were quite well delineated, while the sustained parts of notes -- when the note dies off after being struck -- were very lifelike. As Kodama phrased the sonata, macrodynamics of individual notes were easy to follow. Through my reference system, the overall tonal impression was of a sound that was just a bit brighter and more open. That made the overall envelope of a note sound more realistic.
Dvořák’s Symphony No.8 exhibited a bit more detail through my reference components, giving the sounds of the orchestral instruments even more realism. There was a smidgen more dynamic punch, making Orozco-Estrada’s reading sound more energetic, which I appreciated. In “Folia Rodrigo Martinez,” there was just a bit more sheen on the viola da gamba’s strings. It was easier to distinguish between the baroque guitar and the harp as they echoed a fragment of the melody across the soundstage; the IS250 had made them sound a little more similar to each other. This is a hard test -- many components make even less of a distinction between these instruments. There was plenty of detail; even the opening cascabels sounded more distinct. Bass was similar to the IS250’s: very good.
Switching back to the turntable and Cassidy’s cover of “Time After Time,” I heard a more palpable soundstage with more precise localization of instruments with my components, and more detail that translated into a more expressive reading of the song -- which, of course, was Cassidy’s stock in trade.
It shouldn’t come as a surprise that the IS250 didn’t quite match the sound of my much more expensive reference system; what’s surprising is how close it came: perhaps 90% of the way for a bit over 20% of the cost. That’s what I call a real value.
If you have suitable space on your equipment rack for the JE Audio IS250 and the strength to hoist it up there, this integrated amplifier-DAC is well worth considering. Its warm, detailed, relaxing sound exceeded my expectations, and it was completely unfussy to use. JE’s first digital effort must be graded a complete success, and, unsurprisingly, its analog section continues their tradition of great sound. If you have a turntable, you’ll need an external phono preamp -- but you may have one already. The IS250, like the other JE Audio models we’ve auditioned, sounded really splendid. It would be a great addition to many systems.
. . . Vade Forrester
- Speakers -- Affirm Audio Lumination, JL Audio Fathom f110 subwoofer
- Amplifier -- Berning ZH-230
- Preamplifier -- Audio Research SP20
- Sources -- Linn LP12 turntable on custom isolation base, Graham Engineering 2.2 tonearm, van den Hul Platinum Frog cartridge, Sony XDR-F1HD tuner (modified by Radio X); SOtM sMS-100SQ streaming music player with sPS-1000 power supply; QNAP T-251 NAS for music file storage; PS Audio DirectStream DAC
- Interconnects -- Audience Au24 SX (balanced and unbalanced) and Au24 SE (USB), CablePro Freedom (unbalanced), Crystal Cable Piccolo (unbalanced)
- Speaker cables -- Audience Au24 SX
- Power cords -- Audience powerChord e, Blue Marble Audio Blue Lightning, Clarity Cables Vortex, Purist Audio Design Venustas
- Power conditioner and distribution -- Audience aR6-T
JE Audio IS250 Integrated Amplifier-DAC
Price: $5000 USD; $4100 USD without DAC.
Warranty: Three years parts and labor; 90 days, tubes.
Unit L, 5/F, Block 1
International Industrial Center
2-8 Kwei Tei Street
Phone: (852) 3543-0973