Acurus DIA-150 Integrated amplifier

I have a rare Acurus DIA-150 that I have owned for about 5 years now. This is the remote controlled 150wpc Direct Input Amplifier that Acurus built in the late 90's. It is essentially a high gain Acurus A150 amplifier with a passive remote controlled preamplifier integrated in front of the amplifier. I performed a few mods to this unit, namely I installed what I call the Aragon MkII mod which is the installation of small value electrolytic and polypropylene film bypass caps directly onto the amplifier boards, right after the rail fuses. This mod showed up in the Aragon amps in the 4004 MkII and all later Aragon amps (never in the Acurus amps). It was the backbone of the MkII sound improvements IMO. In addition a number of the front end resistors were replaced with Dale low noise mil-spec types. These are the same resistors that you’ll find in the more expensive Aragon amps. I also changed out the stock el-cheapo binding posts for Vampire BP's. They look stock but are far more capable than the original binding posts, they accept full insertion depth banana plugs and larger gauge wires. No problems existed on this amp prior to the upgrades so there were no repairs performed on this amplifier.

After the upgrade work to the amplifier I set the bias up slightly higher than stock. This change in combination with the MkII mods to the DC rails helps to tame a lot of the brightness that many experience with the Acurus amps. I connected this amplifier up to a dummy load and distortion analyzer and it puts out a solid 162 watts per channel into 8 ohms with both channels being driven and the THD+N at that power level was .05% which is better than spec.

This DIA-150 was missing the original remote when I got it. The original remotes for the DIA-150 are a similar style to the RL-11 & 28k preamps but the DIA-150 has more buttons and is a different IR coding. I have never seen one up for sale on Ebay. I tried RL-11 and 28K remotes and neither of those worked for it. I ended up buying a Home Theater Master SL-9000 universal remote. These are the same remotes that Mondial included with the Aragon Soundstage and the Acurus ACT-3. It controls every function on the DIA-150 except the balance. For me this is never an issue as balance is a set it and forget it thing in my system. I'm most worried about Power, Volume & Mute control which all work fine with this remote. BTW the balance pot is not broken, the DIA-150 has an LED that flickers on the front panel when its receiving an IR code and it never flickers for the balance. So it’s not an issue where its receiving a IR code and nothing happens. The remote's just not sending the DIA-150 balance IR signal.

Cosmetically this amp is in decent shape but it has a couple of issues. The upper left and right corners of the faceplate were bumped pretty hard before I got it. I cleaned them up and blacked them out, so it’s hard to see in the pictures. The face plate itself is very clean. In fact with the corners cleaned up and blacked out the amp looks near mint sitting on top of my rack in my medium lit audio room. The faceplate is what is most visible anyway. The upper cover has a slight upper bend to it near the front on the right and left hand side right over the heat sink. I thought about trying to smooth it out, but I’m worried I would mess up the finish of the top cover which is in beautiful condition except for a mark near the right heatsink that was once again blacked out. Notice the pictures are using a bright flash, so this is worst case. I can tell you that if not for the bright flash you wouldn't be able to see most of the imperfections I'm mentioning in the lighting of a typical audio room. Overall I rate it a 6/10 due to the quality of the face plate and I'm a very picky person when it comes to cosmetics...

In case you're wondering about my background I go by the name MONDIALFAN at Audiokarma. I and a few of my customers have shared a number of my Acurus and Aragon projects there. I have been upgrading and repairing Mondial components for several years now.