Clarion DRX9255EXL (Part 1) The R2R DAC PCM1702

You might wondering where do I start to find these original R2R DAC chip now days?

Personally I don't trust most IC seller in online market. They are either selling fakes, or original but in nonsense sky rocket price. So the simply and cheapest way to find those multibit DAC IC is inside the working unit which already using those DAC IC.

The car audio is a great to start to find those great DAC and this PCM1702 is inside the Clarion DRX9255EXL. This unit is the hi-end car audio CD player built in 1996. It has 20 bit dual PCM1702 DAC.

And why car audio? This is because the car audio manufacture can selling their product cheaper than home audio. It doesn't require large and heavy transformer for linear power supply like home audio does. This is resulting lighter and small package car audio components that can shipped cheaper around the world.

When this Clarion released 26 years ago, I believe the price is should be very expensive for a car audio equipment. But lucky me, times passes by and I can bought this unit for only US$110.

More information about this Clarion DRX9255EXL is shared the same internal components as DRX9255EX or DRX9255 or under brand Addzest for Japan Domestic Market. Of course the difference with Japan Domestic Market is in the radio frequency reception that cannot be use in different country. In my case, because I only want this unit to become an external DAC so I can ignore the region matters.

This unit also has it's own sibling. It is the Mcintosh MX406. Yes, the most popular hi end audio brand, and the MX406 is for car audio CD player using the 100% exactly layout and components as the Clarion DRX9255EXL.

The PCM1702 a vintage high performance multibit DAC from Burr-brown, Texas Instruments. If you like me, the reason choosing this type of DAC as the first journey in this multibit R2R DAC is because so tempting to the Accuphase DC-91. It using 16 pieces PCM1702 in parallel to achieve much lower noise. The picture bellow is directly taken from Accuphase official website for complete reference about the unit I mentioned. I am pretty sure that it is impossible for the sound between Clarion and Accuphase will be the same just because they using the same PCM1702, but at least I can experience almost the same sound characteristic from this PCM1702 DAC.

Before I put this Clarion on the initial test by using the built in single CD player, I shall open the case and check what components inside it.

Pretty much as expected, it not 100% original. The previous owner has "upgrade" the capacitor on the pre-amp section to the low quality non polar capacitor. Sadly for the lack of information about how to do proper components upgrade can lead to lower performance result.

I will fix this on next post for sure.

And this is the real guts inside.

The dual PCM1702 DAC along with Denon micro-processor for oversampling and channel divider between those PCM1702. The op-amp IC for LPF stage is using high performance LM4562. They are very promising components inside this Clarion DRX9255EXL.

For quick test, just join the ACC red cable to the Power yellow cable and connect to the positive of 12 volt battery. The ground connect to the negative of 12 volt battery.

I using 12 volt SLA battery or the switching power supply from old Shard LCD TV.

This unit has external DC - DC converter. This external unit is generate additional symmetric voltage about +15 volt and -15 volt to feed to the op-amp IC. Then it is regulate again to +5 volt and -5 volt as the DAC PCM1702 required.

Most of my music collection is in the SD card or in PC that was ripped from the original CD's. I found that WAV sound better against Apple lossless or 16 bit FLAC. I also have few downloaded DSD music files. Previously I am using the Chord Mojo in my home audio system.

Despite this Clarion DRX9255EXL is built in digital era, the tone setting, fader and volume is all in analog control. It still using the wiper potentiometer rather the steps digital control.

This unit is also doesn't comes with internal power amplifier. I connect the line output RCA to my home audio amplifier, which the same setup when I using the Chord Mojo as well.

I also using the same CD that I ripped to WAV files in the Chord Mojo to play the music with this Clarion DRX9255EXL.

And how is the Clarion sounds like?

This DAC PCM1702 is simply sound amazing.

The sound characteristic is very open and detail. The sound stage are all in the same level presentation. You will not hear the vocal is too forward or the instrument less pronounce, they are playing at the same level that create the sound stage so rich.

It makes me loves to turn up the volume level and I am very excited to hear all the detail from the music. Those details are far from edgy, very analog sound in my opinion. I could hear and feel how the guitarist playing the chords. Those details from changing between the chord is very real.

The bass makes the music beat at the very good timing, and I guess this is the strong points from this DAC. The music beat play very nice yet it is very musical. The vocal is also pronouce very clear and live like. I could feel the lips from the singers singing near the microphones.

Overall sound characteristic is not warm. Not even dry either. More likely analytical sound signature. With this setup, I am sure that I entering the whole new world of hi-end DAC. This is the new listening experience that I've never had before, especially from the delta sigma DAC.

Then comes in my curiosity about how the same music in DSD files vs physicals CD will be like? It is play between the Chord Mojo for the DSD file and this Clarion DRX9255EXL as the CD player.

I bought the same CD as my DSD music file stored on my SD card. It is Chantal Chamberland - Temptation music album. Once I insert that CD in the Clarion, oh my gosh! it way more better sound I get even compares to the DSD files with the Chord Mojo.

I suddenly remember that I have ever read in one audio forum that some folk disbelieve on the hi-res audio files. It is just a marketing gimmick it said. The16 bit is already sound so good. Maybe that person using the multibit R2R DAC, maybe that person are completely right after all, or maybe the others person who doesn't agree with that statement just lack of experience about how good is the multibit R2R DAC.

This picture is downloaded from Amazon.com

End words in this post, I spending US$110 for this unit is worth every penny.

I will upgrade the components inside of this unit on the next post. Mostly for the capacitors will be change to reputable quality such as Elna Silmic.

You might confronting me that this unit is not an external DAC, it is a CD player after all right?!

The answer is no.

This unit can be modify to accept the SPDIF digital audio input. This means, with your digital media player, such as PC, or anything that have the SPDIF digital audio output can be connect to this unit as the external DAC.

So stay tune for the next few post about this Clarion DRX9255EXL.

Disclaimer: Any statement and photos in this article are not allowed to copy or publish without written permission from the writer. Any injury or loss from following tips in this article is not under writer responsibility.