This is the filter changes I did to the Gigaworks DAC to remove the second opamp and to straighten out the filter section of the DAC.
You can see the original values and the values that I changed to in parenthesis. Just tap the signal from the lifted resistors (and maybe add output caps of 4.7uF) The before/after RMAA tests of the modifications can be found here.
I’ve been modifying my Gigaworks Ebay DAC and think that the results is really showing. The second opamp is completely removed, the filter is changed to Cirrus Logics filter example from their prototype board and the first opamp is replaced with GD-Audio’s Earth HDMA. It sounds absolutely marvelous. Here’s the before and after graphs
This is the second part on how to improve the quality of an old CD player. You can find the first part here. In this section I’m going to show you how to install a better, more stable clock circuit into your 505. This particular clocks comes from Kingwa, that has a series of clocks for improving DVD players, CD players and DACs. The price is reasonable. I’ve installed them in three different units and had zero problems, so the quality seems good.
Ok, so why install a new clock? Isn’t there one in there already? Yes, your right. But by using better parts like crystals with lower ppm and also design a very clean power supply to feed the clock, you can make your player sound much better. And the reason is lower jitter.
But what is jitter? There is plenty of really good places to go read up on it. Here’s some.
http://www.audiocraftersguild.com/AandE/cd-jitter.pdf (PDF warning)
http://www.stereophile.com/reference/590jitter/
Ok, lets look at the schematic. Here you can see the clock and two capacitors, C404 and C403 and the clock is X401. The clock is feeding into the DAC (PD2029A) (you can find the complete schematic in part one)
We need to remove the crystal X401, and the two capacitors, C403 and C404. The old load capacitors are no longer needed. The next step is to connect the Kingwa clock to the DAC. As seen on the schematic, the clock is 16.9344Mhz, so we need to use the correct outlet from the Kingwa clock. There is three different divisions of the clock. You need to solder two connections. One for the ground, labeled GND, and the one just next to it, labeled 1/4F0.
Now we need to feed the signal generated from the new clock to the DAC. Connect one of them to the hole in C403 furthest away from the DAC. I put the GND line here. The other one should go where the old clock used to go. Use the one closest to the large capacitor for the DAC (see picture).
The Kingwa clock is going to need power. Any voltage between 10-30 V DC will do. I will have an upcoming article about the power supply I built for it. You will find the connectors for the power on the over side of the Kingwa clock.
Next step, testing. Put in a cd. If you have the cover removed when doing this REMEMBER DANGER HIGH VOLTAGE! No touchy touchy while doing this. Not on the part we soldered but on the power supply. Anyway, If you didn’t know this you really should not be doing this in the first place.
When you press power it should read the TOC from the CD. Press play. If the display shows the seconds ticking, you can turn the player off, unplugg and put the cover back on.
elgrandee
Why whould I need this?
All albums and songs are mixed differently. So in iTunes some albums sounds very loud whilst other is rather low. This has increased in something called the Loudness War. Producers of albums soon realized that if you mix an album really hot, it will sound louder then the other songs on crappy stereo equipment. So essentially you have a lot of music in your iPod/iPhone with albums recorded at totally different volume. That’s why you have to constantly change the volume knob to correct for this. Here Apple comes to the rescue with it’s Automatic Volume Settings. Unfortunately the algorithm Apple chose to use to determine the volume of the song is made to be quick, but not particularly accurate. This mean that the songs does come out all over the place volume vise.But there is an good solution to this problem, and it?s name is ReplayGain.
This is program that analyzes the music psycho acoustically and then makes an assessment on witch level the song/album should be. Unfortunately Apple haven’t embraced this techique even though it’s totally open. Shame on you Apple.
ReplayGain application
But there’s a sollution. An application called iVolume that goes though all your songs in iTunes and makes sure they have the same level. This mean that you can be certain in that you won?t have ear blead when a song of Sting ends and Mötorhead comes on.
The software is super easy to use, just start it and iTunes, make sure you have ?Sound Check? enabled in preferences in iTunes. After that you just push a button.
One downside only, the price is $29.95 witch I think is a bit high. But for me It was a must, it transforms the pleasure of listening to music.
Part two of this series is now up. Read on how to install a better clock.
So I bought this Pioneer PD S-505 for $40 to test how good audio quality I’m able to squeeze out by modifying it. But It will not be just the standard subjective judgement of improvement but also measurements. Back in 2000 you had to pay about $400 for it. It uses the stable platter which means you have to put the CD in upside down. So let’s get going.
The steps I planned is the following:
Ok, lets look at some stuff we need to do. First we have to remove the mute transistors. Less stuff in the audio path equals better sound. The transistors is just there to make the measurements look better for reviews. So they have to go.
Click for larger image
So transistors Q403, Q404, Q453 and Q454 is removed. Desolder och just clip the pins (carefully) with a wire cutter.
Next step, time to desolder the opamp which is a rather old opamp (NE5532). Desolder the opamp IC405 and solder in a socket for easy testing with different opamps. I settled on LM4562 at first.
Remove the heaphone opamp if you don’t going to use it. It’s better to buy an external headphone amplifier like V-CAN Tube Headphone Amplifier or better.
That’s about it for today. Next installment, upgrade the clock to improve jitter numbers…
On to part two on how to add a better clock to your PIONEER PD S-505
There’s a lot of articles on the net about modding and enhancing the sound quality of your audio equipment by replacing components etc. But you never see measurements to backup their claims. Well, I’ve been busy the last two days taking a ten year old middle range CD player and trying to make it to sound really good. But I also have done measurements before and after doing the mod (within reason) and so far it actually confirms that modding really works (if done right). Now, let’s face it, the best measured equipment isn’t necessarily the one that sounds the best, but still, it’s interesting to see what kind of effects different modifications have.My best sounding DAC does not measure as well as some other ones I have. And I have started to get quite the collection.
Will be back with a writeup and test diagrams when I’m finished…
Over a year ago this guy contacted me to get permission to use this picture for an album cover. I sent him a high res copy and told him that he could use the picture but that he had to send me a copy of the album when it was finished. My guess was I would never hear from him again. But to my surprise I got an email from him yesterday asking for my address and if I wanted the album signed by the artist! Things like this makes me believe in the human being again. I just assumed he would forget to send the album, which is what I probably would do.
I don’t think they used used ReplayGain.
