[dr.larkos]

Quote:

Originally Posted by josep /img/forum/go_quote.gif IMO anything over 30, say 50$, is overkill here as inside the V-DAC there are switching PSU's as stated before. A bike (12V and 5 to 10 h) battery+slow charger does cost around this too and will be the cleanest psu. The important thing is to have a decent and regulated PSU, something the original walwart it is not (and, SQ aside, the unit heats in protest to it).

Don Jose, I tend to agree with you in this case-given the presence of those internal switching power supplies. I am not a modder (I believe you are) but most certainly the ideal would be to bypass or eliminate those internal switching power supplies. I guess this must have been the reason why Musical Fidelity stopped the plan to produce an upgraded external power supply for the V-series. What they had in mind (one including chokes) sounded like what has been the standard PS for their top of the line DACs and CD players (A3 & Trivistar, for example--I still own an A3.24) before the less expensive X series, but those internal switching PS's in the V-DAC must have gotten in the way to make the whole exercise worthwhile at their intended price point--just as you say.

In any event, aside the issue of convenience and the relative complexity of the battery set up which in itself costs more than US$30 anywhere in the world, US$30 do not buy the same in Europe than in the US. Second, how we define a "decent and regulated" power supply? What percentage level of regulation, what level of voltage ripple (rms or peak-to-peak), what level of RFI generation constitute a decent power supply acceptable to you, to me, or to someone else? I am sure that, in principle, nobody will deny that the cleaner the power coming into the V-DAC, the better (internal switching elements or not). But, where do you begin and where do you stop and still remain within the realm of inexpensive "decency," relative to the price of he V-DAC, to attain true reference level performance? Without doubt same paradox as with the quality of the transport needed.

A battery set up is not by definition a solution (aside of the inconvenience issue)...type and quality varies significantly there with varied sonic results--Adds's experience with a relatively inexpensive battery solution comes to mind-- and those battery set-ups that are recognized as "decent" enough by a broad audience cost several hundred dollars in the US (even more in Europe or Australia, I imagine).

Salud, buena musica y buen sonido y, por supuesto, muchas pesetas para gastarlas en ellos.......dr.larkos

 

[dr.larkos]

Quote:

Originally Posted by Calvin&Hobbes /img/forum/go_quote.gif Dr.larkos wrote "I thought of doing same but procrastinated and now laser part is no longer available, so, just in case, I save my premium $K+ EAD T-7000 dedicated transport for critical listening sessions". Did you check this german supplier? That's where I got my spare part from. Costed me 150 bucks (no longer available now); but then it guarantees a double lifetime (for my player, that is). JusTone Lasereinheiten nahezu aller Hersteller. Auch "hard to find parts" Lasereinheit, Laserpickup, Laserunit, Pickup, Laser, Laserkopf, Laufwerk, Mechanism

Calvin&Hobbes, you rock...they have it (US$168), simply phenomenal, many thanks

dr. Larkos

 

[josep]

"Hola Doctor"

Ah, "pesetas", they are away long ago and we have to deal with Euros now... lots less zeros on the prices, good WAF factor you know

IMO 50% of the retail price of the V-DAC is were "sanity" is, and beyond that we are going too far and maybe should look for a different unit, new or used. Those (around) $100 give place for some nice caps, an opamp and a "decent" (=any external PSU rated for 2A or above, that is 5x the current demands of the unit) PSU.

Maybe you do not want to change caps or nothing inside? Fine by me, but do not spend then more than $50 on the PSU alone. It is just my opinion anyway...

As for batteries, well, 10 seconds gave me on ePay this unit 300313289323 and this charger 290316553043 (item numbers pasted), for $20 inside US you have it (and the only hassle is letting in charging on the night or when not in use, you can have the V-DAC plugged to the battery anytime).

And yes I think the transport is important too. Fortunately for those among us using computers (myself not 100% yet however) when done right this can be very very fine.

Regards
Josep

 

[nuvira]

Hi,
Cambridge DacMagic USB input is Max to 16/44k.
How about V-DAC max input of USB ?
I'm not talking about Upsampling.
tnks.

 

[josep]

As stated previously it does use the CM2706 chip for USB: you can see the database around but, as all the TI-BB usb dacs, its max is 16 bit and 48kHz.

If you are looking for higher resolutions it must be said the options 'today' are just a handful of DACs, the ubiquous Benchmark being probably the best example... and not much else. Look for Audiotrak if you want something cheap with 24/96 without drivers, or the popular M-Audio Transit with drivers.

 

[dr.larkos]

Quote:

Originally Posted by josep /img/forum/go_quote.gif As stated previously it does use the CM2706 chip for USB: you can see the database around but, as all the TI-BB usb dacs, its max is 16 bit and 48kHz. If you are looking for higher resolutions it must be said the options 'today' are just a handful of DACs, the ubiquous Benchmark being probably the best example... and not much else. Look for Audiotrak if you want something cheap with 24/96 without drivers, or the popular M-Audio Transit with drivers.

Gentlemen, this is what I use as the USB interface for my computer audio: E-MU 0404 USB2. I believe there are several heavy threads in Audio Circle, DIY, and in this and other forums. It is actually a high-end full function computer interface with A/D/A features (using top of the line AK A/D & D/A converters), and having duplex I/O USB capabilities at a price point targeted to consumer semi-pro recordists (about $200 in the US). The rest of consumer USB DAC's out there (low, mid, or high end), besides sampling limitations, are for the most...what else?...DAC's (no A/D conversion) and, consequently, have only an USB input (usually the much slower USB 1) and no USB output-- meaning they can only play back audio files out of the computer but cannot record into the computer from external analog or digital sources. This beauty (click on "specifications" tab to se the level of performance) can handle up to 24 bit/192KHz samples in AES/EUB format (up to 24 bit/96KHz in SPDIF format--the format's intrinsic limitation) in both directions (I/O) on a PC. Apple users, unfortunately, due to driver limitations, are restricted, I believe, to up to 48KHz sampling. It does not automatically upsample or downsample, you set whatever sampling you desire. It also benefits from upgrading the stock wall-wart to a quality regulated linear power supply.

E-MU Systems - 0404 USB 2.0 - USB 2.0 Audio/MIDI Interface

Cheers......................dr.larkos

 

[nathan_h]

I was going to pick up an aftermarket switching power supply and ran across this one.

Generalsaving :: AC Adapter for LCD flat panel monitor 12V 6A

Is the 2.5mm plug the right size?

--

Or

80W 12V 6.6A AC/DC Switching Power Adapter (110/240V) - eBay (item 400028298199 end time May-30-09 18:48:08 PDT)


---

Or maybe this because it has multiple tips?

FRYS.com*|*KENSINGTON (K38050RR)

 

[dr.larkos]

Quote:

Originally Posted by josep /img/forum/go_quote.gif "Hola Doctor" Ah, "pesetas", they are away long ago and we have to deal with Euros now... lots less zeros on the prices, good WAF factor you know IMO 50% of the retail price of the V-DAC is were "sanity" is, and beyond that we are going too far and maybe should look for a different unit, new or used. Those (around) $100 give place for some nice caps, an opamp and a "decent" (=any external PSU rated for 2A or above, that is 5x the current demands of the unit) PSU. Maybe you do not want to change caps or nothing inside? Fine by me, but do not spend then more than $50 on the PSU alone. It is just my opinion anyway... As for batteries, well, 10 seconds gave me on ePay this unit 300313289323 and this charger 290316553043 (item numbers pasted), for $20 inside US you have it (and the only hassle is letting in charging on the night or when not in use, you can have the V-DAC plugged to the battery anytime). And yes I think the transport is important too. Fortunately for those among us using computers (myself not 100% yet however) when done right this can be very very fine. Regards Josep

Josep, many thanks for your words of wisdom. On the PSU, I already own one of those $200 linear regulated units that I use for my phono preamp. Regarding mods, I revisited your posts in this thread dealing with that subject. I understand now much better what you are referring to. Two of the mods i) replacing the ancient NE5322 and ii) eliminating or upgrading the output capacitors is something very similar to what I had done by someone, with great results, to my Musical Fidelity A3.24 (which I still own, as I indicated in a previous post). The modder I used actually followed to the letter the recipe in the link below. He got rid of the output capacitors and eliminated the DC offset problem using the trim-pot solution described in the link. Perhaps you could also get rid of those output capacitors altogether in your V-DAC by implementing this trim pot solution, provided you can locate the required resistors to be replaced by the pots. As you said in an earlier post, must likely the V-DAC circuitry is just a rehash of previous MF’s DAC circuit designs—although I do notice my A3.24 had two NE5322’s and the V-DAC has only one (if I understood you correctly)….are the NE5322’s in my A3.24 used for same purpose than the single one in the V-DAC ? In the A3.24, they are used at the I/V conversion stage….the single one in the V-DAC, seems to me, is in the analog filter stage (the analog section of the A3.24, for what I understood, is all discrete, no opamps).

diyAudio Forums - musical-fidelity-a3.24 mods - Page 1

Cheers……………………….dr.larkos

PS: Lastima las pesetas....en el clasico brindis, "euro" no rima con " salud, pesetas, y mujeres con buenas t*tas"...erosion cultural, definitivamente!! dr.l

 

[nathan_h]

Quote:

Originally Posted by nathan_h /img/forum/go_quote.gif I was going to pick up an aftermarket switching power supply and ran across this one. Generalsaving :: AC Adapter for LCD flat panel monitor 12V 6A Is the 2.5mm plug the right size? -- Or 80W 12V 6.6A AC/DC Switching Power Adapter (110/240V) - eBay (item 400028298199 end time May-30-09 18:48:08 PDT) --- Or maybe this because it has multiple tips? FRYS.com*|*KENSINGTON (K38050RR)

Woops, I just re-read the AC adapter that came with the V-DAC and see that is says 500mah, not 5000mah! Bit of a difference.

So something like this switching supply would probably cover it, right?

12V/2A AC-DC Power Adapter

 

[josep]

Yes this one will do.
Btw interesting website this one... the "PicoUPS" with this same PSU and a battery will be the "killer PSU" to me

 

[nathan_h]

That's not something they actually offer or make, right, but something you can conceive of based on other things they are sellingn

 

[nathan_h]

By the way, I found more details on it.

'"2.5/5mm barrel connector, center positive."

Looking back through this thread, I thought I saw someone specify the barrel size and polarity, but I cannot find it now. Anyone know if this is the same?

 

[dr.larkos]

Quote:

Originally Posted by nathan_h /img/forum/go_quote.gif By the way, I found more details on it. '"2.5/5mm barrel connector, center positive." Looking back through this thread, I thought I saw someone specify the barrel size and polarity, but I cannot find it now. Anyone know if this is the same?

Nathan, definitely it is not. The inside diameter, I believe, is either 1.35mm or 1.3mm (both seem to work)....unfortunately, I have not heard or read any statement regarding outside diameter. Must likely it is 3.5mm but it could be 4.1mm. I called the MF importer in the US and they say will call me back with confirmation of exact diameters (we'll see if they deliver). In any event, easiest solution is to cut off plugs at plug end of stock and new PS cables--leaving about 1 inch tail--and exchange them keeping polarity correct: center positive, I believe, which should be clearly indicated in the casing of the PS's (a partially open circle with a dot in a center with a line pointing to the center dot and a + sign...or a minus sign if center negative). If by any chance one is center negative and the other is center positive, then, simply solder the stock plug reversing the color coded twin wires in the cable (one of the twin wires always has a white line over all of its length). I would recommend exchanging the plugs and not the cables as the new cable is likely to be a bit more substantial that the cable of the stock PS and, therefore, sturdier and more apt to handle the higher amperage of the new PS (if any higher amp demand may ever occur).

Cheers......................dr.larkos

 

[Calvin&Hobbes]

Quote:

Originally Posted by dr.larkos /img/forum/go_quote.gif Calvin&Hobbes, you rock...they have it (US$168), simply phenomenal, many thanks dr. Larkos

Good for you! I am sure your player is more than worth it

Q: could you or Josep for all those non-technical folks like me simply sum up the two essential mods in a dummy-proof manner?
What and where to replace: pictures with arrows perhaps?! / required part numbers / approximate prices of the exchange parts / how many caps? /which opamp?).
I know there has been a shortlist before, but simply lost track due to too many details. I will then perhaps purchase the parts and have it done by a skilled person. Your remark on your other MF DAC with similar mods makes me reconsider this.

 

[dr.larkos]

Quote:

Originally Posted by Calvin&Hobbes /img/forum/go_quote.gif Good for you! I am sure your player is more than worth it Q: could you or Josep for all those non-technical folks like me simply sum up the two essential mods in a dummy-proof manner? What and where to replace: pictures with arrows perhaps?! / required part numbers / approximate prices of the exchange parts / how many caps? /which opamp?). I know there has been a shortlist before, but simply lost track due to too many details. I will then perhaps purchase the parts and have it done by a skilled person. Your remark on your other MF DAC with similar mods makes me reconsider this.

Yes, Calvin&Hobbes, definitely worth it. It is a 40-pound dedicated transport, made by Enlightened Audio Designs (EAD). I bought it in 1993 (paid around $2500) and it was considered State of the Art at that time—in fact, EAD’s proprietary reclocking circuit in the unit achieved a jitter specification rated at less than 10 (yes, ten) picoseconds RMS typical, which was remarkable then and it is a benchmark even today. I believe, it has achieved classic status….granted, of no much medium term future--other than a substitute for weights in your home gym--unless you get a spare laser. A Google search shows many owners clamoring for repair advice, as--although most may not realize it--by now, the performance of their lasers starts to decline as the lasers approach the end of their lives, before total failure strikes. Once you replace the laser and add some lubrication to the obvious mechanical components, all is back to its former glory. Many thanks again.

Back to the V-DAC mods. Here I defer to Josep or Spore. I am like you, I rather hire an expert...although I manage to understand electronics, never learned how to solder properly electronic components into a PCB. Anyway, josep and spore seem to prefer a different opamp to put in place of the ancient NE5322 (why MF is still using the NE5322 beats me…maybe they have thousands and thousands of them in stock)—josep used the OPA2604 which has an excellent reputation for sweet an yet detailed sound, while spore used the LME49860 which I am not so familiar with. Josep’s mods are described in post #388 with pictures in post #411 (but no arrows to guide you to exact locations). Spore has a list of his mods (post#497, short list, and post#501, longer list), but they are not necessarily ranked or prioritized. Perhaps either one, josep or spore could provide a list in descendent priority with, hopefully, Farnell part number.

As for me, I would start at the analog output section—dealing with the obvious compromises, namely, changing output capacitors (or ideally eliminating them, if DC offset issue could be somehow fully contained with trim pots or something of the sort) and upgrading NE5322 opamp. Then, I would go upstream gradually and very carefully....the V-DAC is a unit already considered great sounding by many, so, a race to change all the elements in the original great recipe (under the assumption that all change is good) does not make any practical sense, never mind how well regarded or relatively inexpensive the new components may be…in your case you have to factor in the labor cost of your hired moder (euros, or “friendship abuse,” or whatever other form of payment you agree).

Cheers………………………….Carlos