Sim Audio Moon 230 HAD Headphone Amplifier Review

It has been a pleasurable two weeks with what I believe are two good headphone amps and two extra ones thrown into the mix. I’m coming from a Vincent KHV-111 MKII headphone amp and while it is a headphone amp with a hybrid stage/tube, it’s just that a headphone amp. The sounds coming out of it when using the tube input, while detailed a typically stated with tubes, no bass.

    I decided that it was time for an upgrade so I ordered both a Sim Audio Moon 230 HAD and a Oppo HA-1. The Moon comes with a standard three pin power cord and a Standard sized remote that will operate all of Moon’s components, a manual and that’s it. You will have to download the USB drivers from the internet as they don’t come in the box. I also listened to the Questyle CM800 (twice) and the Sim Audio Moon 430HAD (twice) (a mistake, but more on that later). I ordered the Sim Audio 230 (Music Direct) first and had it for a week before the Oppo arrived (Audio Advisor). I let the Sim Audio Burn in for 10 hours (by letting music play) and took a listen and I then let it burn in for 3 days straight nonstop with various music.

The volume knob has a good solid feel and turns smoothly. The remote control, controls the power on/off the input and volume control, that’s it but it will control another one of Sim Audio’s Amps or Cd Players, the remotes are all standard size and fare. (Universal)

Music used for this review, Dave Matthews Band Crash, Before These Crowded Streets, Dave Holland Quintet Extended Play Live at Birdland, Bella Fleck and the Fleck tones UFO, Incognito Adventures in Black Sunshine, Chuck Loeb- In a Heartbeat, Chon- Grow and Jarule Pain is Love, Garrett Brennan- When I’m Called Home (DSD) and David Elias-Vision of Her (DSD and a 10-hour session of Pink Noise (You-Tube). Headphone used Sennheiser HD558, Audio Technica ATH 50’s, Pioneer SA-A1000, Grado SR 325 and Beyer Dynamic DT-880 Pros 250 ohm versions and my sources were the Yamaha CD-S2100 SACD and my computer with a Pangea Pure Silver 2 meter USB.

My impressions were the Moon which is a small Headphone amp, never gets hot regardless of how long you run it, (there is a small vent about three inches long on the right side of the unit with two inch slit holes. The Sim Audio Moon has a standard quarter inch and a TPS input and it supports DSD with fixed and Variable inputs, USB, Optical, and coaxial inputs. I listened and the first impression that I got was this is it allows you to hear a lot of detail that you miss, even on a full blown system. There were times that I had to take the headphone off because I thought that someone was calling me or knocking on the door or floor. This headphone amp is a detail freak; it brings you whatever is on the mix.

My wife has two Bluetooth speakers, one a Harmon Kardon and the other one from Sam’s Club, both loud and she plays them in the morning and several times I had to take the headphones off during this review period because I thought she was up playing music, but it was all in the headphones. Each of my headphones have a different character, the Audio Technica’s are an all-around headphone for people that like more bass, but hate the Beats by Dre brand.
  The Sennheiser HD558 and the SR 170 wireless have a little more balance to them. The Pioneer’s are coming into their own with a neutral sound and the bass is starting to improve. The Grado SR 325 are a bright headphone that puts the mids and highs first. The Beyer Dynamics are neutral as well. The Sim Audio plays to the strength of each one of the headphones showing the different characters quite well. When I want that extra detail, I put on the Grados and when I want more bass, I play the Audio Technica, you can tell right away.

    Week 2 the Oppo HA-1 came and I saw this big box with a smaller box inside, which is as big as the whole Moon regular box-the outer box is obviously bigger to protect the unit. The Oppo is a much bigger unit, black in color and weights over 20 pounds, all aluminum with the bottom opened cutout and a small area on the top cutout. This is a Class A design and it runs warm. I ran it for three days as well, same procedure as the Sim Audio.
The Oppo is feature packed, an LCD Screen, Balanced inputs and preouts and the same digital inputs as the Sim Audio. The Oppo has Bluetooth with a small antenna, a small remote, XLR input, an Apple USB front input jack and a quarter inch adapter in the box. The manual for the Oppo has raised ink on it and when you open the manual you have a rice paper like sheet and then the manual and the same thing for the ending page. It comes in a black cloth cover for the unit and a standard three pin cable (like the Sim Audio) The presentation is first class. My impressions are this thing is feature rich, they threw the kitchen sink in. It has three menus/screens standard, Spectrum Analyzer and V/U meters.

The Oppo has a source switch that you can turn to go through the various options and if you leave it at an option it will automatically select it or you can push the source selector knob in to select it. The Bluetooth feature works well you install the software and the software has more features and is more pleasant to use than the small remote. The Bluetooth allows you to control the volume and stop the track and select any of the inputs. All of the knobs have a good feel and finish to them. The Oppo sounded very good after the third day and the Oppo can be turned all the way up and it is clean without distortion. At first the Oppo made almost all of my headphones sound the same, but it came around and you could hear differences, but the OPPO never warmed up to the Beyer Dynamic DT 880 250 ohms, they sounded flat and not a good match.

The Sim Audio allowed me to hear every instrument through all of the headsets that they could produce. The Oppo, although it came around, it was never as clear with voices or allowed that air around the instrument effect, there was something missing. The Sim Audio with the Beyer Dynamics sounded good and I could listen at a comfortable level about 12 o’clock on the dial, with the Oppo I had the volume sometimes past three o’clock and although clean, it was veiled. The most I ever had the Sim Audio at was with the exception of the Beyer’s was nine to ten o’clock on the dial. The Sim Audio just seemed like it had more juice. The Oppo does have a high/low gain switch, which I tried on low and the headphones loss their life, all but the Audio Technica, which had to be turned almost all the way up, but this is understandable with the different impedances. The Oppo gets quite warm but the aluminum body acts as a heatsink and it only get so warm and levels off, but a problem for me would be in the summer time as it gets quite hot upstairs.

  Upon ordering the Oppo, I also ordered the Pangea silver USB cable and it made a huge difference over my Belkin USB. The Sim Audio took more of an advantage of it than the Oppo and the sound improvements were worth the cost, I wasn’t going to buy the Audioquest Diamond or Carbon in 2 meters because I couldn’t justify the cost. Between the two units the Sim Audio is the better unit for strictly sound quality, the Oppo wins on features and I think most would be happy with either, I didn’t get a chance to use the balanced input for the headphone, because all of my headphones were single ended.

The Oppo is a great first start for them and believe me I did try and justify keeping them both and they both can be used for preamps, but my regular preamp is better than both of them. Now for the two throw ends headphone amplifiers. I was at my local dealers and I got a chance to try the Sim Audio 430 with DAC and the Questyle CM800, with a set of Audioquest Nighthawks, which I will be ordering soon. The Sim 430 is the 230 on steroids.
  It has one stereo balanced and two mono balanced as well as the same DAC used in the 230 HAD, which you pay $800.00 extra for $3500 w/o DAC and $4300 with DAC.

The Sim 430 can drive any headphone to max level and the sound quality is sublime, you hear every instrument, every voice in RCA and through balanced mode, everything tightens up and becomes even better, better bass detail, more air around the instruments, put simply the Sim Audio 430 is a Beast with a Capital “B” and yes it can be used as a preamp alone. The Questyle is very good, but to use the balanced feature you must buy two of them and stack them and at $2500 for one it becomes a difficult decision for most of us for a headphone amp. The construction of the Questyle is first rate with aluminum construction and solid electronics. The sound quality is above both of the Sim Audio 230 and Oppo with you hearing almost as much detail as the Sim Audio 430, but w/o the power. So how would I rate them, if money isn’t an object, but the Sim Audio 430, it’s that good.

The Questyle would come in second, followed by the Sim Audio 230 HAD and the Oppo HA-1 pulling up the rear. The rear isn’t bad in this class because the Oppo is an excellent first attempt by Oppo that will only get better. I even tried to justify keeping both and putting one with my main system and one with my headphone only or home theater system, but in the end if I’m going to spend this much for both, I might as well wait and get what I really want which is a Sim Audio 430, but I can’t have a unit that cost what my preamp cost unless, I’m going to replace my preamp, an Audio Research LS-17se. Oppo has a two-year warranty and Sim Audio has a 10-year warranty. I also looked at the Bryston BHA-1, SPL Phonitor 2 and the Burson soloist, but I quickly dismissed the Burson because I don’t like the stepped volume control and I read of some problems with it including distortion if not used regularly and one user taking it apart on You Tube and spraying WD-40 in it.

I have to say I had to agree with these guy’s( below) assessment of both units the Oppo and Sim Audio, but I figured you wanted to hear it from a real guy that made a real choice with nothing to gain, both are great units, but if sound quality is paramount then the Simaudio $1500 (I paid $300 less Demo at Music Direct) if features that you are going to use is paramount and good sound quality then Oppo. I will tell you this it’s just luck that I ordered the Sim Audio first because I tried out their 310 LP phono preamp and knew of their quality and the discount. This is being honest if I had gotten the Oppo first with discount (Demo Unit), I never would have ordered the Sim Audio and I would have been happy with the OPPO. I will be sending the Oppo back, could I afford them both, yes, but why. and!Simaudio-MOON-230HAD-Headphone-Amplifier/c112t/568e99cb0cf21dc8b18fff... .