Nakamichi DAC-101 (Part 3) External Power Supply For Home Audio

In this post,  I will making an external power supply for this Nakamichi DAC-101.

My goal in this modification is to have better linearity from the better power supply components. This new power supply will intended to use at home audio connect to the mains AC outlet.

From my previous post about this DAC unit, the internal 12 volt switching power supply in this unit was broken. I think this could become the common problem for every Nakamichi DAC-101 because of the poor switching power supply design. By using proper size transformer to supply to all DAC components inside this unit, it will improve the overall performance and reliability for sure.

Nakamichi DAC-101 (Part 2) The Internal Components

Continuing my previous post about initial review of the dual TDA1541 S1 DAC from Nakamichi DAC-101 is surprisingly over my expectation compares to the previous review is CD Player Sony CDP-750 using single TDA1541A.

No wonder the CDP-750 is for budget CD player while the Nakamichi DAC-101 is a hi-end car audio components will sound much better. This Nakamichi DAC-101 is install in my home audio system by using 12 volt 5 ampere low noise SMPS wall adapter as main power supply to the unit. The sound characteristic from this DAC is smooth yet detail with the strong point in the warm of the vocal presentation.

Unfortunately this unit cannot pass the first 3 hours playing in my home audio system. It burnt and break-down. So, with lots of optimism with this unit, I will continue to see what the components inside it.

Nakamichi DAC-101 (Part 1) The Hi-end Dual TDA1541A S1 DAC Review

My previous DAC review is the Sony CDP-750. It is a home CD player that targeting to budget audiophile. The components inside is all budget quality, but this CDP is using decent DAC IC from Philips, it is the TDA1541A. This DAC IC is very popular for the sound quality. But why I don't feel any good impression with this Sony CDP-750?

I have a planned to take out the DAC IC from this CD player and build one external DAC, but somehow this plan is postpone due to the problems that I had with my digital receiver unit, which none of my CS8414 works. Plus, searching this digital receiver IC today is very difficult since it is already obsolete many years ago.

So to make a shortcut, I am searching and finding a good source DAC using TDA1541A. Not single, but double TDA1541A. It is also S1 single crown specification, which have better LSB error tolerance than standard TDA1541A.

So let's take a look closely to this vintage hi-end car audio, the Nakamichi DAC-101.

Another Multibit DAC, TDA1541 Inside Sony CDP-750

The journey to experience the great multibit DAC continue.

Previously I've talked about PCM1702 and PCM1704 which they are great high performance DAC. Then again, the next DAC to be evaluate by myself is no other than the famous TDA1541 DAC. This is the only high performance vintage multibit DAC from Philips. Each IC is dual channel 16 bit stereo DAC, which is make the circuit simple in my opinion. Unlike PCM1702 or PCM1704 which they are single channel DAC per IC, this is means when using this TDA1541 in stereo only require one IC to do both channel digital conversion.

In the TDA1541 datasheet explained that this DAC configuration is using dynamic element matching (DEM) for current dividing. This configuration is a masterpiece in DAC history which is totally different to the resistor ladder (R2R) DAC. This DEM is very complex inside and high cost to built. No wonder it is already obsolete for many years ago.

Obtaining TDA1541 chip alone now days is not an easy task. It is almost impossible to get the brand new IC as well. The easy way is having it from the vintage CD player like I did right now. It is a Sony CD player CDP-750 that I will review in this post. It cost me US$100 and I think it is still a great deal.

Clarion HX-D1 PCM1704 Vs. Clarion DRX9255 PCM1702

Previously I had the Clarion DRX9255EXL which is sound amazing.

No doubt it is because the resistor ladder (R2R) multibit DAC using in this unit is dual PCM1702. This DAC shines my audio system really well.

Going further from the PCM1702 which is 20 bit sample rate, then if I want technically better, I will looking no other than PCM1704 which is 24 bit sample rate. This makes my journey to find best R2R DAC for cheap continues.

Luckily Clarion also released the car head unit with this PCM1704 named HX-D1. This unit is replacing they older model, the DRX9255. All features in this HX-D1 are all identical to the DRX9255 except it is 24 bit and HDCD ready. It also has it's own sibling to the McIntosh car audio model. This Clarion HX-D1 is share the same internal components as McIntosh MX5000.

So how the Clarion DRX9255 with PCM1702 compete with the Clarion HX-D1 with PCM1704?

Clarion DRX9255EXL (Part 3) DIY SPDIF Digital Audio Input

So here I am today doing another modification to this Clarion DRX9255EXL. The main goal is making this unit accept SPDIF digital audio input from the external source such as PC or any media player that support the digital audio output via coaxial cable. In short, this unit will become a stand alone DAC + preamplifier unit.

A brief explanation for this modification is like this. The Clarion DRX9255EXL has the ability to set the input mode from the optical input at the back of the unit. This can be done by a simple jumper or a switch from the BUS connection. But as I intended this unit to become a DAC in my home audio system, so no switch option for this unit.

Further more, with this SPDIF input available, your option for any kind source input can be widely available. This is including using USB input by making the converter to SPDIF. For the example by using PCM2706 or any others converter available in the market that will do the same. But in this post, I will not make the USB converter. I will focusing on how to make this unit to accept the SPDIF input.