Aragon D2A upgrade path?

[hihopes]

The simplest way to "tune" it is to experiment with the output DC blocking caps. Made a big difference in mine (when I was still using it).

I had the mkII upgrade in mine. It was merely a pair of complementary j-fets per channel and supporting resistors. 2sk147 and 2sj (can't remember that number any more maybe 74?)

I did a lot of playing around in the poer supply (I had the original power supply - a triangular box) Black gates and HQ bypass caps made the best improvements IRC>

 

[Scabiko]

hihopes (maybe you´re Pink FLoyd´s fan? does this question ring a "division bell"?), I played with the power supply . Changed 1500uf caps to 4700uf (sprague) and 470uf to 2200uf nichicon audio grade and high speed diodes. I am very hapy with the results. In addition, the Aragon 4004 mk2 is gorgeous. By the way, what brand of caps did you use to replace signal caps (10uf)? Thank you again.

 

[hihopes]

I tried so many output caps I can no longer remember what I ended up with, but I definitely had more than 1 cap per side there. I tried some high-voltage polyprops; I tried some Black Gate electrolytics (BTW, don't bother with their bi-polar series. I have tried them in many different positions and have always found the standard series better.) I did final bypassing with small value teflons. Perhaps I even had .22uF Russian teflons in there by the end of my experiments. You really have to try various options and see what works - but those 100v 10uF caps I had in there originally were some of the poorest polyprops I ever heard.

If I were to walk that road today, I would start out with Claritycap SA or Obbligatos, as big a value as will physically fit there (Don't think a 10uF would make it - maybe 4,7uF) bypassed with teflons. If the sound proved to be a bit too bright I would add good quality electrolytics eg Black Gate std series or your own current favourites. Then let that all run in before making any further adjustments. If you feel you want to cut treble, try small Russian PIO caps, but be careful - they are not subtle. I have tried some Mundorfs - silver and gold models - but have always found them a bit harsh in the signal path.

I also went to town with dedicated regulators for various parts of the digital board. Shoved them in wherever I could. I would suggest you look up the Teddyregs or try shunt regs if you want to go this route.

Hope this helps.

Personally, I have long since lost interest in my Aragon D2A. Many cheap modern DACS blow it away (NB:- not the overhyped and overpriced Benchmark - at least not in my system)

 

[Scabiko]

hihopes, thank you again. I´ll try. I feel a little reluctant to open it but I think I have no choice. Best regards.

 

[Jim Leach]

Great info!

I have a cheap, modern DAC and hope it will do well; however I was thinking the output transformers I purchased for that might work well to make similar improvements to the D2A...

 

[phowell1]

Hi Guys,

this thread is way old. if you can, i am interested in the ebay dac you mentioned. I searched the id number but it isnt for sale currently- is there a replacement you'd recommend?

Jim, can i ask, in the end was the ebay dac better than the aragon to your ears?

Also, i too have a d2a mk2 with ips. Was thinking to mod, so appreciate your tips!

thanks,

Perry

 

[Jim Leach]

I still haven't built up my eBay DAC so I'm stil using my D2A in stock trim.

 

[phowell1]

thanks for the reply! I feel your pain- Im new to diy and am already stalled on my first project , an armaggedon clone. It sits here half built, for almost a year. Ill hopefully tinker with it this winter.

thanks though. Is that dac kit still for sale, or is there a comparable one? I see plenty there but dont want to waste money on a dud.

 

[Scabiko]

Dear Hihopes, It's been a long time since discuccing on this post. I still have the old aragon d2a. If you have the time, I would like to ask you what happens if I remove the coupling capacitors (big whites ones , 10uf) in the signal path and use it without caps. have you ever tried this? I know it works in another dacs but not sure about this one. Please advise. Best regards.

 

[inertial]

blowed j-fet in my D2A....need schematic

Hi,
unfortunately, I have blowed my j-fets on my belowed Aagon D2a dac.

I need schematic of the output analogue stage only ( after the dacs CHIPS) plus PSU, if possible.

Anyone can help me?

P.S.: I have asked to new come back Aragion technical support, but no response at all....

Thanks for reading

Paolo
Venezia Italy

PHASELESS HIGH END , LOW COST , SPEAKERS ( personalized into the client's system/room)

 

[guilders]

Aragon D2A2

Hi guys,

I have just bought an A2D2 DAC that has been upgraded with new caps.

Here are the caps used to replace the old ones:

Panasonic Aluminium Electrolytic Capacitors - Leaded 1500uF 25V x2
Panasonic Aluminium Electrolytic Capacitors - Leaded 2200uF 25V x2
Panasonic Aluminium Electrolytic Capacitors - Leaded 1500uF 50V x2
Panasonic Aluminium Electrolytic Capacitors - Leaded 3300uF 25V x2
Panasonic Aluminium Electrolytic Capacitors - Leaded 470uF 35V x11
Nichicon Aluminium Electrolytic Capacitors - Leaded 50volts 47uF x2​

I think these are good caps.

Here are some pictures:







What do you think of the device as such?

I also wanted to know your feelings about any easy upgrade that could bring the DAC to another level.

Thanks ​

 

[Aniruth]

I just got inspiration from this thread and going to upgrade my broken D2A with new dac chip PCM 1974.

 

[forza paris]

Hi guys,

I have just bought an A2D2 DAC that has been upgraded with new caps.

Here are the caps used to replace the old ones:

Panasonic Aluminium Electrolytic Capacitors - Leaded 1500uF 25V x2
Panasonic Aluminium Electrolytic Capacitors - Leaded 2200uF 25V x2
Panasonic Aluminium Electrolytic Capacitors - Leaded 1500uF 50V x2
Panasonic Aluminium Electrolytic Capacitors - Leaded 3300uF 25V x2
Panasonic Aluminium Electrolytic Capacitors - Leaded 470uF 35V x11
Nichicon Aluminium Electrolytic Capacitors - Leaded 50volts 47uF x2​

I think these are good caps.



What do you think of the device as such?

I also wanted to know your feelings about any easy upgrade that could bring the DAC to another level.

Thanks ​

This is a different dac than the one under discussion; more modern, from a technological point of view, but I think inferior, from the musical point of view.
It is never wrong to replace capacitors on devices of a certain age, and those used (they seem to be the Panasonic FM series) are of a good quality level.
Also in my opinion, if you want to have a real improvement you should guess the replacement of the standard opamps with discrete opamps; there are several around, some the result of diy projects. But the result - in general - of this replacement is all to be verified practically.
The main quality of the D2A mKII was to have a discrete analog output, which the D2A2 does not have; the latter, although of a good standard, is more conventional in the circuitry used.
The truth is that we often forget that a device responds to an overview of its parts and that they are often already optimized in their mutual matching.
And sometimes, in an attempt to improve a small thing about a device, we go to worsen its major qualities, except regret it later ... when it is too late!

 

[Jim Leach]

I just got inspiration from this thread and going to upgrade my broken D2A with new dac chip PCM 1974.

Is this a drop-in, or does an adapter board need to be made?

I see sellers on eBay offering "upgrade" kits for the Parasound and one other I think, from the same era, where the new chip is a significantly smaller form factor to the originals, and mounted on an adapter board. Not cheap, but if it does a better job, and then the discrete class A analogue stage of the D2A... Might be worth digging into.

Pleas post some pics of your work, if you don't mind!

PS I'm considering replacing the "big honkin'" caps in both my D2A and 47k. Same value I think for both so buying four might actually be a reasonable cost per...

 

[Jim Leach]

Hello everyone, I'm back!

I replaced a few caps on my d2a and now it's DOA. But, it wasn't my fault!

I replaced the two big coupling caps on the analogue board with tighter tolerance film caps and the one electrolytic on the digital board with a higher voltage replacement. I have the replacements for the rest of the orange Sprague caps, but the board is such a mess to work with I deciede to hold off on those.

Anyway, the smoke has been released- it came from C6 on the schematic (identical to C5) I think it (was) a Tantalum cap, and I am reaching out to see what a suitable replacement might be. I will replace all four at the same time, so I'm not tied to the idea of a Tantalum cap, but if that's the best choice to use in the location, I have no problem with that either.

I have attached the analogue board schematic as well as the photo of the offending cap. I have a Mouser order going for other stuff so it would be great if I could tag these on that order.

 

[forza paris]

From what I remember, the negative characteristic of tantalum capacitors is that they do not withstand voltage variations with respect to those envisaged in the project.
And when that happens they can even explode.

 

[Extreme_Boky]

Replace all tantalum caps. They tend to short with time, and then overheat and explode. That's a known issue with them. I can tell that C5 is there to decouple the positive rail, so any decent electrolytic capacitor will do, maybe 22uF...

 

[tincanear]

Hello everyone, I'm back!

I replaced a few caps on my d2a and now it's DOA. But, it wasn't my fault!

I replaced the two big coupling caps on the analogue board with tighter tolerance film caps and the one electrolytic on the digital board with a higher voltage replacement. I have the replacements for the rest of the orange Sprague caps, but the board is such a mess to work with I deciede to hold off on those.

Anyway, the smoke has been released- it came from C6 on the schematic (identical to C5) I think it (was) a Tantalum cap, and I am reaching out to see what a suitable replacement might be. I will replace all four at the same time, so I'm not tied to the idea of a Tantalum cap, but if that's the best choice to use in the location, I have no problem with that either.

I have attached the analogue board schematic as well as the photo of the offending cap. I have a Mouser order going for other stuff so it would be great if I could tag these on that order.

caps look to be psu rail bypasses, you could try some polymer caps (i.e. os-con, FP-cap) or some low-z electrolytics (panasonic fm series, nichicon kz, etc..) you might need to try several types to see what sounds best (give each type a few days of break-in with power applied before serious listening)

IIRC on another thread in the Digital Source forum, there was another device (sony CD unit or DAC ????) using PCM58 chips, with multiple trim pots to improve performance.

 

[Jim Leach]

I found the exact replacements for these, but I’m going tighter on tolerance and up on voltage. I thought electrolytics would be okay but they used tantalum when they could have used electrolytics in the first place, so I’m sticking with that. They are significantly more expensive so there must have been a compelling reason to use them.

I’ll now probably change the 12 other caps too, since I’ll have it all apart.

 

[Jim Leach]

This DAC also uses PCM58 chips but only have one trim pot (for the first bit). The Sony used all four trim pots, and I wanted to add them to this but it’s more trouble than it’s worth. Too bad because they left money on the table so to speak not going to full potential of the chip.