Direct - Out DAC Build (HiFimeDIY)

[Cyber_Murphy]

Finally got around to mounting my CS4398 "Direct-Out" DAC board..

From HiFimeDIY, it comes with Good reviews excellent feedback from DIY'ers, and is especially designed for DIY in mind. It offers all pin outs that way you can DSD, coupled out or direct out, set DSD sample rates, tap spdif out, etc..

Probably the best feature is that you can replace the SRC module with jumpers and run the DAC in "NOS" mode!! At just over $100 its a real bargain ;-)

My initial listening was using the SRC with unbalanced Coupled-Out straight into my Millet MiniMax headphone amp. Feeding the spdif input with MK3 Hiface..

..Sounds really nice!! Can detect extra clarity and definitiion around the high-frequencies, and can detect another level of detail in the recordings..

Also, it doesn't seem to have that Harsh / Dry "DSP sound" that my DCX has..

My next listen will ne using the USB input with the SBT EDO app..

Eventually I will also try the Balanced Out (Not Coupled!), just need to make sure the next peice in the line can handle the DC offset

Overall I'm very impressed... Direct-Out is the way to go

Ta

CM

[Addicted to music]

NIce

[ArthurDent]

Overall I'm very impressed... Direct-Out is the way to go

Having recently ditched the four op-amp output stage in favour of transformer coupled output for my CS4398 I'd have to agree.

[Cyber_Murphy]

Having recently ditched the four op-amp output stage in favour of transformer coupled output for my CS4398 I'd have to agree.

Hi Kenn,

Interesting you should say that.. On the official Thread for this DAC board (on DIYaudio), "transformer coupled" is really popular, and gets some very, very, good reviews!!

I may consider this as an option down the track. (and also for my DCX where the AK4396 chips also get High-Praise for direct transformer outputs!!

Ta

CM

[Guest Muon]

Nice!

Cap coupled I see, I have noticed some folk like cap coupled, and some prefer transformers. Both are nice I think, if the right caps/transformers are used (personal preference mostly when you get to a certain level).

I still have the high nickel Cinemag's that I used with a CS4398 dac, It was a very dynamic and transparent sound.

Nice tidy build BTW

[pete_mac]

Nice work indeed! I've been tempted by one of those hifimediy DACs. I've got one of their smaller USB Sabre DACs on the way at the moment for my PC system.

[Cyber_Murphy]

Nice!

Cap coupled I see, I have noticed some folk like cap coupled, and some prefer transformers.

Nice tidy build BTW

Thanks :-)

Yes, the RCA (unbalanced) Out-puts are Cap-coupled via the "Mundorf M series",, but I've also wired up Balanced-Outs (via XLR) straight off the DAC pins, which are not Cap-Coupled, and carry the DC offset..

CM

[zog]

Hi CM! Wow, neat and tidy build.

How much effect does the Schaffner EMI filter have?

I just took delivery of one of these a few days ago as well, I'm currently awaiting an enclosure I ordered from ebay. I thought since I might be using this for a while I might go a step up from the jiffy boxes or metal scrap from the skip I usually use as enclosures.

Hifimediy were out of stock on their transformers, and going on some advice I've read on this and other forums I'm going to use an R-Core transformer: http://www.ebay.com.au/itm/320907768445

The enclosure I'm going for is this one: not as spacious as CM's, but enough room and not too ugly: http://www.ebay.com.au/itm/261065382898

Hopefully I'll have enough room to add an aluminium wall between the power mains wiring and the DAC portion as well.

Just planning on using the single ended "stock" output via the chunky capacitors at this stage.

I already have the Hifimediy DAA1853 DAC (this will be an upgrade from that) .. not to mention a few of their Tripath amps.

[Guest Muon]

@ CM....

So the input caps or transformers in your amp (whatever the case may be) are doing the DC blocking? the chip expects to see a certain load, does this apply with the balanced setup direct from the chip?

might be a silly question as I haven't looked into balanced very much

Edit:Unrelated, but I found the CS4398 is a pretty robust chip, where the AK4396 (AKM) chips are bloody sensitive and freak out at the mere sight of a soldering iron.

Edited October 26, 2012 by datafone

[Gordon Macfarlane]

Hi CM , lovely work. I have the previous version of the board that doesn't do dsd but has , in theory ,better crystals. It is indeed extremely good value for money. I have swapped out the Mundorf caps for Auricaps and felt that fleshed the sound out a bit more.

I had problems with my board with one CS4398 chip failing after a few mins use but the guys took the board back , repaired it and added a couple of mods to reduce distortion levels when the board is run NOS.Your board has the removable US board so this may not be an issue for you.

One word of warning , the transformer supplied by the guys is rated for 220v operation , they reckon this shouldn't be a problem but I replaced the trafo with one rated for use in Australia , just in case.

Has to be one of the biggest bargains around at the moment.

[Cyber_Murphy]

Hi Guys, Thanks for the feedback

@Zog: It's hard to say what affect the AC line filter has, and it could start debate.. But I always use one for "line level" projects (not power amps),, and I always use a high quality one like Schaffner, not the "Jaycar" types.. Your R-core transformer looks nice! I'm sure that will be fine,, even better thant the one from hifimediy I'd say.. I was tempted to see my old mate at "Harbuch electronics" and get a custom made transformer like I usually do for my projects,, but it takes too long!! The case I used was on special from Altronics, it's a "shallow" 2U rack case, I cut the rack handles off with a hack-saw :-) The "stock" output is coupled via some nice 'Mundorf M series' caps. The beauty of this board is that you can also wire up true 'direct-out', either balanced or unbalanced,, and even experiment with your own caps and transformers!!

@datafone: Regarding the AK4396's,, I manually installed 3 of these using an ordinary soldering in my DCX2494 And I'm about to perform the same procedure for another member on here too. You can read here, post # 42

Yes, if using direct out (Non Coupled) you'll need to ensure the next piece in the chain has DC blocking! I used XLR's that way I could carry V+ and V- (and GND) from each channel (L + R) externally for easy access,, but I can still wire up a single-ended connection,, it doesnt have to be a balanced approach, I just use pin 1 + pin 2 (GND and V+) and leave V- floating.. The coupled outputs are the same,, they use V+ and GND and simply leave V- floating..

Actually, you need to be careful using direct out straight off the pins! It is suggested that you use a series resistor on both V+ and V- pins to protect the CS4398 from damage (current limit)..

Ta

CM

[Cyber_Murphy]

Hi CM , lovely work. I have the previous version of the board that doesn't do dsd but has , in theory ,better crystals. It is indeed extremely good value for money. I have swapped out the Mundorf caps for Auricaps and felt that fleshed the sound out a bit more.

I had problems with my board with one CS4398 chip failing after a few mins use but the guys took the board back , repaired it and added a couple of mods to reduce distortion levels when the board is run NOS.Your board has the removable US board so this may not be an issue for you.

One word of warning , the transformer supplied by the guys is rated for 220v operation , they reckon this shouldn't be a problem but I replaced the trafo with one rated for use in Australia , just in case.

Has to be one of the biggest bargains around at the moment.

Hi Ozcal,,

Thanks for the tip about the transformer!! The mains fuse is specified at 100mA,, but I blew 3 in a row just switching it on!! I have now used 250mA, which seems ok,, maybe what you're saying has something to do with this?? I may look at replacing the transformer for one rated at 230 (240V) volts as well..

Tell me more about the "Auricaps" caps..?? Where/how much etc.. Did you actually remove the Mundorfs, or just use the spare 'direct out' through-holes..??

CM

[hochopeper]

Selecting fuses for low current circuits with a transformer is often hard to get a good value. Try a slower acting type rather than larger value sometimes too, the turn on current can be quite high. Switch on current is from the low impedance primary coil, because small toroids are run with core saturated. Rod Elliot's website has a good article on fuse selection, which I would recommend.

I'll be posting a few photos later this weekend with my own new DIY dac, though a bit different to this one

@ CM....

So the input caps or transformers in your amp (whatever the case may be) are doing the DC blocking? the chip expects to see a certain load, does this apply with the balanced setup direct from the chip?

might be a silly question as I haven't looked into balanced very much

With balanced you only need to connect _+ and - signal and as long as the offset on both is the same it is of little consequence. If you accidentally short one of those signal wires to ground and you have a DC coupled amp then you can have some chaotic results

Edited October 26, 2012 by zman

[Gordon Macfarlane]

Hi Ozcal,,

Thanks for the tip about the transformer!! The mains fuse is specified at 100mA,, but I blew 3 in a row just switching it on!! I have now used 250mA, which seems ok,, maybe what you're saying has something to do with this?? I may look at replacing the transformer for one rated at 230 (240V) volts as well..

Tell me more about the "Auricaps" caps..?? Where/how much etc.. Did you actually remove the Mundorfs, or just use the spare 'direct out' through-holes..??

CM

.

Hi CM , the Auricaps replaced the Mundorfs. I used the same value 2.2uf and these are available from Soundlabs here in OZ : http://www.soundlabsgroup.com.au/p/AU-2U2-400-10/2.2uF+400V+10%25+Auricap

I have some Jantzen superior Z caps on the way : http://speakerbug.com.au/shop/index.php?main_page=product_info&cPath=14_7&products_id=102.

Both of these caps seem to be described as natural and musical sounding.

[Guest Muon]

Leon has mentioned he will be stocking the new XO Auricaps very soon I think, they are said to be a step up from the current standards.

[ArthurDent]

Hi Kenn,

Interesting you should say that.. On the official Thread for this DAC board (on DIYaudio), "transformer coupled" is really popular, and gets some very, very, good reviews!!

I may consider this as an option down the track. (and also for my DCX where the AK4396 chips also get High-Praise for direct transformer outputs!!

Ta

CM

The only real downside of using transformers is the cost as good ones aren't cheap. Neither though are really high end caps (Duelund etc) I guess, but if I had the choice between transformers and caps at the same cost I think I'd still prefer the transformer route. Very nice build BTW.

Edited October 26, 2012 by KenTripp

[Guest Muon]

I went with the Cinemag CMOQ-2H as they are great bang for buck, at about $60 each http://cinemag.biz/output/output.php

Apparently "Bud" on diyaudio makes nice ones around a similar cost, and some liked some of the Jensen models and some of the Sowter's, but getting into Sowter territory is definitely getting up in cost!

A lot of folk liked the UTC A-20 vintage transformers, and the prices shot up during the life of that thread over on the above forum where the Gigawork dac was being discussed.

What did you go with, Ken? Jensen's? apparently one of the Jensen models was heavily favored and was near the cost of the Cinemag's, not bad at all.

Edited October 26, 2012 by datafone

[Cyber_Murphy]

With balanced you only need to connect _+ and - signal and as long as the offset on both is the same it is of little consequence.

Hi Zman, thanks for the tip re fuse selection. (Yes, the 100mA were "fast" type. Might try 100mA Slow-Blow as you suggest).

So, tell me more about direct balanced connection.. Are you implying this for connecting to an unblanced (RCA) pre-amp, to use V+ for Tip/center conductor and V- for Sleeve/GND and no DC blocking needed?? Or, for balanced inputs (XLR) on pre-amps, to use V+ for pin 2 and V- for pin 3 and leave pin 1 open?? Thanks for claryfying ;-)

@Ozcall: So either of those 2 caps you linked would make a noticable improvement on SQ?? 40 odd dollars doesn't seem too much to spend for a lift in SQ..

Thanks

CM

[hochopeper]

So, tell me more about direct balanced connection.. Are you implying this for connecting to an unblanced (RCA) pre-amp, to use V+ for Tip/center conductor and V- for Sleeve/GND and no DC blocking needed?? Or, for balanced inputs (XLR) on pre-amps, to use V+ for pin 2 and V- for pin 3 and leave pin 1 open?? Thanks for claryfying ;-)

Sorry I didn't word it particularly well earlier.

With a DC coupled balanced circuit you will have both + and - terminals at a DC voltage of DAC Vcc/2. This is ok as when you feed this DC into a balanced input of an amplifier stage the two subtract and you are left with no DC offset. ie a balanced amplifier will not amplifier the common DC voltage of the two signal wires.

One of my test DAC's was a WM8741 DC coupled to a headphone amplifier (3xLME49990 + 1xLME49600 per channel). The opamps performed BAL-SE conversion so it was SE output, there was 2.5V between AGND and + and AGND and - but between output AGND and + there was 0VDC.

[ArthurDent]

What did you go with, Ken? Jensen's? apparently one of the Jensen models was heavily favored and was near the cost of the Cinemag's, not bad at all.

Jensen, no but I do like their motto "No Hum, No Buzz, No Bull!".

I used the usual Lundahl LL1690 that seems very popular with this DAC.

http://www.lundahl.se/pdf/1690.pdf

[Cyber_Murphy]

Try a slower acting type rather than larger value

Yep, I re-installed 100mA (as specified) but this time "slow blow".. No probs after many on/off restarts

Thanks

CM

[hochopeper]

Good to hear CM!

[zog]

@Zog: It's hard to say what affect the AC line filter has, and it could start debate.. But I always use one for "line level" projects (not power amps),, and I always use a high quality one like Schaffner, not the "Jaycar" types.. Your R-core transformer looks nice! I'm sure that will be fine,, even better thant the one from hifimediy I'd say..

I've decided to incorporate that idea, after seeing yours and zmans build, since I'm trying to put a bit of effort into this build - I've ordered a Schurter IEC socket/switch that has a built in emi filter, its made in Switzerland and with a suitably Teutonic brand name. I've got a few other quality EMI filters around (stripped from medical equipment) but they are too big for my enclosure.

My build continues to go slowly as I await random bits to arrive from ebay

[Cyber_Murphy]

It's worth the wait Zog :-)

I had my DAC board for about 4 weeks before I got around to building it..

**Last night I had a good listening session (with my Headphone rig) using "NOS" mode for the first time!! Wow,, I loved it!! It's the first time (I think??) I have heard a NOS DAC.. There is a definate lift in SQ when playing my CD rips (16/44) thats for sure.. More vocal presentation, Eg; more tonal nuances, more emotional / moody,, more flowing,, a touch more detail as well.. Playing 24/96 the difference wasnt as dramatic as with 16/44,, but it was still there,, more relaxed, not so tense.. A Really nice experience :-)

Not knowing much about NOS,, I imagine this is the impact it's supposed to have..??

**FYI when removing the SRC module: I seemed to have damaged one pin on the connector of the SRC module while removing it .. It's a tight fit. It got stuck when trying to pull it off the board, and the tiny copper sleeve on the connector ended up being left behind on the pin of the mating connector on the DAC board.. It doesnt affect NOS mode however.. But it will need attention if I plan to re-install the SRC module for "Up Sample" mode!!

Ta

CM

[zog]

..well a relaxing cup day holiday spend assembling mine to the level it is playing music.

I still need to do the front panel and input selector mount, I'll have to mount that up a bit on a platform.

Only a few songs in, but sounding good, and more importantly, it worked first go.