MF X-DACv3 mods

[PinkFloyd]

fergus said:

Before I came to this forum, I thought MF gear was the "dog's bollocks." Now I think differently. In fact, it's actually surprising how "good" the X-Series sounds considering the cheap components they habitually use.

Have you had a look at my pics of the X-DAC. What do you think? Ripe for some mods?

Fergus

Pictures? where? <tongue hanging out>

[rickcr42]

Before I came to this forum, I thought MF gear was the "dog's bollocks." Now I think differently. In fact, it's actually surprising how "good" the X-Series sounds considering the cheap components they habitually use.

You pretty much get what you pay for.The choices usually are crap mass produced cumsumer grade goods like you find populating the shelves at a department store-good enough for 75% of consumers.High priced over hyped designer goods that make more of a statement of how deep your pockets are or how pretty they are or middle of the road reasonably priced "tools" to get the job done but with circuitry choices good enough that the entire product can be "upgraded" to the next level like the X-Series-good enough and priced right for most consumers wanting something bettert than the average mass production "lo-fi" offerings right out of the box yet easily upgraded for the consumer wanting a bit more without breaking out the credit card and lying to the wife about how much it actually cost

[Fergus]

The pics of the X-DAC should be on the first page of this thread. If not, I've made a balls-up somewhere and I can e-mail you them.

Fergus

PS Thanks Mike for the explanation about the output caps.

[PinkFloyd]

fergus said:

PS Thanks Mike for the explanation about the output caps.

No probs Fergus, now you can see why anything <470uF isn't really optimal for all impedances of headphone.

Off to look at the DAC

[Sol]

admin said:

Off to look at the DAC

So? Waddayathink Mike?

BTW .... would the changes referred to earlier in the thread work well with a speaker set up as well as a headphone set up? Is there any difference at the DAC mod stage depending on final use?

[Fergus]

A guy from Finland, Pekka, has extensively modded the X-DAC V3, including BURSON AUDIO HDAMs, whatever they are.

Anyway, here's the link: modhifi.blogspot.com/

Fergus

[rickcr42]

www.bursonaudio.com/Burson%20Products.htm

[PinkFloyd]

sol said:

admin said:

Off to look at the DAC

So? Waddayathink Mike?

Quite honestly, I don't think a lot about Digital to analogue converters I much prefer fiddling about with headphone amps... I know there's a DAC craze at the moment but they don't make me tent in the same way an amp does ;D I'll leave things like DAC's to the experts, I haven't got a scooby.

[rickcr42]

I know there's a DAC craze at the moment but they don't make me tent in the same way an amp does I'll leave things like DAC's to the experts, I haven't got a scooby.

no expert here either but from my "tinkering" experiences it almost always comes down to how the DAC box is interfaced to the outside world that has the most effect on SQ followed closely by power supply bypasses.

On the bench it would go in order of importance :

1-Digital input interface
2-Power supply
3-Analog output interface

While in my actual listening it is more :

1-Analog output Interface
2-Power Supply
3-Digital input interface

Not saying the digital and power sections are not important just that the analog section has the most noticeable audible impact on the end sonics and why I use "iron" between the DAC Box and the outside world (as well as in the SPDIF input-the pulse transformer-and in the power lines to the actual chips-inductors).

When you have a device that lives in the RF world mated to devices who's primary res[ponse is in the AF range you do best by getting rid of all the out of band garbage both into and out of the actual digital circuit.

At least that is my experience such as it is

[PinkFloyd]

As I said... leave it to the expert ^ Rick, you're amazing mate, a true diamond geezer.

Mike.

[Fergus]

Mike, you remember ages ago, you said you'd like to mod an X-DAC V3, and that you'd do it for free just to get some hands on experience. Well, I've got all the parts here (caps, diodes, op-amps, the lot) and I've not the courage to do it myself. How's about doing it sometime in the future?

[PinkFloyd]

fergus said:

Mike, you remember ages ago, you said you'd like to mod an X-DAC V3, and that you'd do it for free just to get some hands on experience. Well, I've got all the parts here (caps, diodes, op-amps, the lot) and I've not the courage to do it myself. How's about doing it sometime in the future?

I'll have a think about it.

[buelligan]

Hey Gang,
Check out what this intrepid soul from Finland pulled off.

modhifi.blogspot.com/

Great job Pekka!

[Sol]

buelligan said:

Hey Gang,
Check out what this intrepid soul from Finland pulled off.

modhifi.blogspot.com/

Great job Pekka!

Like Fergus I keep meaning to mod my X-DAC V3 (Didn't you get yours done by Zanash in the end Fergus?) - I suspect that it would probably yield massive improvements to SQ, 3D imaging etc ... I regularly looka that website. One element I can't work out is how to arrange the diodes in the bridge, nor where to ground the IC shielding

[Fergus]

I've seen Peka's mods to the X-DAC. What's everyones opinion on these BURSON HDAMs? Are they worth buying, or, pound-for-pound, are you just better going for a good quality op-amp? I've bought a couple of OPA2604s and, from Mike, two AD826s.

No, Sol, I didn't get my X-DAC modded by Zanash. Poor guy, he's probably modded so many over the years, he's fed up looking at them.

I just don't like touching anything digital. There's a lot of difficult and precise soldering needed, especially around the smaller capacitors. The more I look at it, the more I think my abilities aren't up to it. I just hope Mike takes pity on me.

[rickcr42]

I've seen Peka's mods to the X-DAC. What's everyones opinion on these BURSON HDAMs? Are they worth buying, or, pound-for-pound, are you just better going for a good quality op-amp? I've bought a couple of OPA2604s and, from Mike, two AD826s.

The Bursons are just a discrete op amp aimed at the audiophile and that being the only one is popular as an alternative.If you look to the PRO arena you can find several versions that work very well and may be worth a look also.Being "pofessional" parts they alll follow a standard footprint making "DOA Rolling" (discrete op amp rolling ) a real possibility

www.johnhardyco.com/990OpAmpDetails.html

www.forsselltech.com/products.htm

recording.org/users/kev/discrete_op-amps.htm

i can if needed provide links to around 30 more DOA's

[rickcr42]

BTW-If I ever get my shit together (daylight from the daily grind of survival mode leaving not a lot of free time for anything not self indulgent as a means to unwind ) I might be open to doing the odd DAC mod since I have more than a small amount of experience getting good bang for the buck results even though I feel it is within anyone's grasp that can operate a soldering iron to roll their own and especially so if they get away from the "glitz" mods and concentrate on mods with a proven track record and that mostly have good science to back up the methods.

These "improvements" go directly to correcting the areas where manufacturers cut corners to keep cost down and have little to do with the "Engine",the actual DAC,but with interfacing the engine to the outside world so is more

1-Isolate the SPDIF intput that feeds the digital receiver with a pulse transformer
2-Isolate the mains lines that feeds the power supply
3-Isolate the AC to DC section (proper snubber before the rectifier)
4-Isolate the power feeds to each chip so they various circuit blocks don't "talk" to each other
5-Isolate the digital ground noise and any out of band harmonics by using a 1:1 line isolation transformer on the output.

That will get you 90% of any potential improvement no matter what the actual circuit with the final 10% going to cleaning up the digital receiver chip interface,adding a TRUE 75 Ohm input and finally choosing the best passive parts for the position/role played in the circuit with some of this going more to taste and instinct than good science since anny two resistors having the same contruction method will measure the same but can sound totally different in circuit

[Sol]

Rick now that is interesting stuff .. and Mike and I have been hatching a plan involving my X-DAC V3 and his soldering iron .. so feel free to chip in. We've discussed amp rolling ... the merits of some nice looking but not necessarly sound enhacing mods (I consider myself scolded Mike ) .. the obvious diode changes. But other than that were looking for inspiration.

Do you see any benefits with Discrete opamps .. as opposed to the standard IC type?

1-Isolate the SPDIF intput that feeds the digital receiver with a pulse transformer
2-Isolate the mains lines that feeds the power supply
3-Isolate the AC to DC section (proper snubber before the rectifier)
4-Isolate the power feeds to each chip so they various circuit blocks don't "talk" to each other
5-Isolate the digital ground noise and any out of band harmonics by using a 1:1 line isolation transformer on the output.

BUT, how would one go about that ... is there anything I can do (photos etc.) to get you thinking about the MF X-DAC V3 and what might be easy bolt on / simple changes that we can get into Mikes hands. Don't want to overwhelm the man ... or indeed impose on *your* ideas .... but it would be good to see if we good get any of these ideas down into the circuit with minimal fuss.