DAC 2496 (AK4393) DAC KIT With CS8416+AK4393+5532

[pchw]

In one of my kits, I don't use opamp. In which case, I use one 0-12.6VAC transformer. I feed the 12.6VAC to the 2nd connector to power the circuit. Look back a few pages to see what I meant, I posted a couple pictures.

[50AE]

Great! Thanks for your help.

The coming week-end I'll start building the new enclosure for the DAC with 6N6P anode follower and 5C4S rectification. I don' have the choke and the power transformer yet, hopefully I'll get them these days.

I'll post pictures when done.

[Sergelisses]

Originally Posted by 50AE

I have a question. Except for the opamp, does the 15.0.15 V line powers anything else? I'm curious if I can just remove it, because I am going to do so with the opamp and put a tube output.

I can check myself, but I have the ideas now, and the DAC is enclosed. If no one replies, I'll disassemble it tomorrow and check it out. Or I will search for the PCB image.

Except for the opamp, does the 15.0.15 V line powers anything else?

Analogic +5v for AK4396
Analogic +3.3v for the CS8416

To improve the sound replace the LM1117-5v (Analogic +5v AK4396) by a SALAS SHUNT REG ........

Serge

[50AE]

Sounds very good! Thanks for the advice!

[ClaveFremen]

Originally Posted by jimchan

Thanks Clave + Erin for your efforts with this board. I have made most of the changes recommended, and really impressive performance.

You're welcome

Originally Posted by jimchan

The last change i have made was C40-43, 1500pF Wimas. Although this solved the raspiness at the treble, it also took away a lot of the realism and attach of the piano and other vocals.

1500pF? AK4393 or AK4396?

In this way you altered the LPF quite a bit, it's not a surprise that it sounds not so good...

I would search the raspiness in other places...

Exactly which parts are you using (capacitors and resistors)?

Originally Posted by NebuK

The caps after the 1117 are same as also FCs, 47uF.

They can be problematic... do a favour to yourself and order from HiFiCollective some audiograde caps, shipping from UK is pretty low.

Originally Posted by 50AE

I have a question. Except for the opamp, does the 15.0.15 V line powers anything else? I'm curious if I can just remove it, because I am going to do so with the opamp and put a tube output.

The + 15V is the source for DAC's analog 5V

Originally Posted by 50AE

Or I will search for the PCB image.

I've done a Google Documents' folder with the last BOM, schematic, LPF schematic and signal and power paths and numbering.

Give it a look:

https://docs.google.com/open?id=0B-q...UzNzhjODI5MWRm

Originally Posted by Sergelisses

To improve the sound replace the LM1117-5v (Analogic +5v AK4396) by a SALAS SHUNT REG ........

Sure it will...

In the next weeks I'll post a new shunt PS schematic, simpler than Salas one, which gave me great results with the My_Ref.

[jimchan]

Quote: Originally Posted by jimchan
The last change i have made was C40-43, 1500pF Wimas. Although this solved the raspiness at the treble, it also took away a lot of the realism and attach of the piano and other vocals.

1500pF? AK4393 or AK4396?

In this way you altered the LPF quite a bit, it's not a surprise that it sounds not so good... I would search the raspiness in other places... Exactly which parts are you using (capacitors and resistors)?

AK4396, 4562NA opamp, most other caps changed as advised, not touched C46,C47, not touched the resistors yet.
Changed C40-43 down to 100 pF now. Again nice treble, raspiness, but lose the bass.

I guess I need to use exactly 1000pF in this position, as you recommend (?) I have an MKP10 with this value I can try...(only have 1500pF FKP2 in stock ;-)

4396....4562NA....Silmic II decoupling....havn't touched any resistors yet.

[Sergelisses]

Hi ,

Actually this very simple output stage give me satisfactions !!

But you need an input capa on the preamp or amp .......

Of course the +15 -15v is a SALAS shunt reg .....

Serge

[NebuK]

Hey,

i've just taken a "couple" of macros of the board (warning, i've left them full-sized so you could zoom in and see a bit more, maybe):
dac-debug

Please don't laugh at my sometimes a little beginner~ish soldering. I've simply tried to stuff the most i could on the top of the board, maybe that was a mistake...

Anyways, i'd be really grateful if you could have a look at the board. Maybe i've done something very stupid wrong...

Also, i've noticed that receiving 96k as opposed to 44.1k audio seems to put a additional 4*C on the AK and ~7*C on the 7812.

@Fremen: I'm so grateful for all your comments and help, but still i somehow don't believe that my 1117-5v cap is the reason for this. I've put some el-cheapo cap in there which changed nothing. The el-cheapo *certainly* has enough ESR, if that should ever have been the problem. For my humble understand this rules the cap out, doesn't it? I'd rather suspect that maybe i've done something at the output of the AK wrong and it oscillates there (but nothing is audible...!) - also i've looked over the board *so* often trying to see whether everything was done correctly ;/.

Thanks again, all of you for your help. I'm really really counting on your further help with this! Thanks so much!
Regards
- Dario

[ClaveFremen]

Originally Posted by jimchan

AK4396, 4562NA opamp, most other caps changed as advised, not touched C46,C47, not touched the resistors yet.
Changed C40-43 down to 100 pF now. Again nice treble, raspiness, but lose the bass.

I guess I need to use exactly 1000pF in this position, as you recommend (?) I have an MKP10 with this value I can try...(only have 1500pF FKP2 in stock ;-)

OK, two problems:

• You're still using the AK4393 LPF with the AK4396 so high frequencies are exacerbated, often resulting in harshness
• The LM4562 is overly precise and detailed on high freqs so every minimum problem with them is thrown in your face.

The first thing to do, IMHO, is changing LPF's resistors and caps.


If, after that, highs are not as refined as you like you should also change the opamp.


OPA827 is as precise as LM4562 but it hardly get harsh.

[j baldam]

Hi any veiws on this for an output stage please.
http://www.ebay.co.uk/itm/Dual-chann...#ht_700wt_1037