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Onkyo DX-130 CDP mod
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Author:  roggom [ 15 Jan 2009, 21:29 ]
Post subject:  Onkyo DX-130 CDP mod

I have been reading the cdp mod posts and sounded like something fun, and with an older cdp not much loss of it does not go well.
I started with an Onkyo DX-130, I really liked the brand back in the day. I had an integra amp and the loading tray on this one is soft and it plays darn well for only a 16bit DAC.

Since the draw on the the power supply is only minimal, in the teens, I went with the old RS back to back using a 1.2A 6-0-6 as the second and the onkyo as the primary. Since the Onkyo was pumping out 17VAC I ended up with 180vac and 147 after pi filtering.
The heaters are run from a seperate 450mA 6-0-6 with a virtual center and hum circuit ( I use ac heat).

Image

I used some project boards designed by dsavitsk, and schematics by the Lampazator. But I had to adjust them, one because I am on a led cathode kick right now and because I ran into simalar issues as Alan. The initial sound had WAY too much gain and sounded like a $2 boombox cranked all the way up. Some load line testing and tube changes, I ended up with a 6cG7 (20 Mu).
Image

This unit uses a YM3020 16 bit external opamp DAC and 2 PC4570's in a unity gain/ bandpass congfig. I "stole" the signal right off the chip at pins 1 and 16. I do not have a schematic, a little bird dogging and jumper testing and I followed the circuit flow from the rca's back to the dac.

Image
Image
Image

Well it came together nice and sounds great! More soundstaging and since the old circuit is intact I am able to do side by side comparisons.

Author:  RiGuy [ 15 Jan 2009, 22:17 ]
Post subject:  Re: Onkyo DX-130 CDP mod

I am so jealous that you have no problem knocking that together. I would be lost in my CDP. That looks like a lot of fun. So, good soundstage but not ground breaking new sound? Was it worth the time and parts? Well, most fun tinkering is worth it I guess.
Ri

Author:  Gio [ 15 Jan 2009, 22:30 ]
Post subject:  Re: Onkyo DX-130 CD-Player (CDP) tube modifications

Great work Rogers. That is just superb. I like keeping the opamp side as well. Are the boards from a group buy? If not, can you post a link?

Ri, it helps that the CDP has a lot of room. All of mine are pretty cramped.

Cheers

Author:  roggom [ 16 Jan 2009, 00:13 ]
Post subject:  Re: Onkyo DX-130 CDP mod

RiGuy wrote:
I am so jealous that you have no problem knocking that together. I would be lost in my CDP. That looks like a lot of fun. So, good soundstage but not ground breaking new sound? Was it worth the time and parts? Well, most fun tinkering is worth it I guess.

I spend almost too much time with my hobby. 20+ years as a Sailor in the US Navy, this is my way to release some constructive energy LOL. I have built so many little circuits that is was easy to spot the opamps and the various power handling circuits.

I have to say this sounds spectacular. I guess a good analogy would be the loudness button on a receiver, don't take it literally as certain frequencies are enhanced at a log ratio etc, but at the closed eye sound difference. it did not happen instantly thogh, initially it sounded horrible, I had to do some good math and some simulations to get it right. Luckily I have various tubes around to roll in as this was supposed to be a 6n1p circuit with a 47k plate resistor,

Gio, dsavitsk site is here http://www.ecp.cc/diy-audio.html the board post was here http://headwize.com/ubb/showpage.php?fnum=5&tid=2523, but not sure if he has any more left. They are some real neat boards makes proto work a breeze.

Rogers

Author:  CrazzyAbtTubes [ 16 Jan 2009, 18:01 ]
Post subject:  Re: Onkyo DX-130 CDP mod

roggom wrote:
I have been reading the cdp mod posts and sounded like something fun, and with an older cdp not much loss of it does not go well.
I started with an Onkyo DX-130, I really liked the brand back in the day. I had an integra amp and the loading tray on this one is soft and it plays darn well for only a 16bit DAC.

Since the draw on the the power supply is only minimal, in the teens, I went with the old RS back to back using a 1.2A 6-0-6 as the second and the onkyo as the primary. Since the Onkyo was pumping out 17VAC I ended up with 180vac and 147 after pi filtering.
The heaters are run from a seperate 450mA 6-0-6 with a virtual center and hum circuit ( I use ac heat).

I used some project boards designed by dsavitsk, and schematics by the Lampazator. But I had to adjust them, one because I am on a led cathode kick right now and because I ran into simalar issues as Alan. The initial sound had WAY too much gain and sounded like a $2 boombox cranked all the way up. Some load line testing and tube changes, I ended up with a 6cG7 (20 Mu).

This unit uses a YM3020 16 bit external opamp DAC and 2 PC4570's in a unity gain/ bandpass congfig. I "stole" the signal right off the chip at pins 1 and 16. I do not have a schematic, a little bird dogging and jumper testing and I followed the circuit flow from the rca's back to the dac.

Well it came together nice and sounds great! More soundstaging and since the old circuit is intact I am able to do side by side comparisons.

Awsome, great work, :up: I can see that this is becoming quite a popular mod, although I decided to leave out the tube stage for space reasons and plus I have made beefier power supplies in my JVC and because I found the case to small to work with I had to make a new one, a bit of a working progress though.

I really wish I could download my pics because I have tonns of them. A good improvement you can make for the rest of the cd player are cap upgrades, get silver micas for the 1-1500pf values and I found this to be a good comprimise, but I had all values on hand all ready so that is easy for me to say. You can also get non polar electrolytics and add a regulated power supply for the D/A and motor drive circuits, I will explain this when ever I get my pictures posted, damn camera cable! :down:

Author:  roggom [ 16 Jan 2009, 20:18 ]
Post subject:  Re: Onkyo DX-130 CDP mod

CrazzyAbtTubes wrote:
I will explain this when ever I get my pictures posted, damn camera cable! :down:

I am sure you put some work into your mod, I am waiting for another Maggie to arrive and I get itchy to build something after a few days. I have way too many headamps. So now I have a Tube RIAA, Tube modded CDP and Tube amplifier. Next a Tube DAC, something like this

Image

http://www.wavelengthaudio.com/usbdac.html but I will sacrifice size to allow for through hole components. Not very fond of smd. This is just a vision but not based on the exact design, $10k there is no way.

Rogers

Author:  CrazzyAbtTubes [ 16 Jan 2009, 22:44 ]
Post subject:  Re: Onkyo DX-130 CDP mod

looks real cool :up:

Author:  Gio [ 17 Jan 2009, 14:59 ]
Post subject:  Re: Onkyo DX-130 CDP mod

Rogers,
My CDP has a digital out, so rather than mod, I am in the market for a DAC. It seems like a better solution since I can also improve the DAC this way.

I will be very interested in knowing what you do. Which DAC were you planning on using?

Cheers

Author:  CrazzyAbtTubes [ 20 Jan 2009, 11:30 ]
Post subject:  Re: Onkyo DX-130 CDP mod

Actually my plan is to build one of these at some point as well, for the same reason, I could get better performance from it than from modding the cd player.

I did happen to find a Datel DAC-HK12BGC-2 chip laying around, too bad it is only mono so I would need two in order to make a stereo D/A converter, this chip is huge!

Author:  roggom [ 20 Jan 2009, 23:23 ]
Post subject:  Re: Onkyo DX-130 CDP mod

I have been looking and looking, there are some nice designs out there but for the most part it is a dac then a basic common cathode tube circuit afterward. I will keep checking.
Rogers

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