Hi, I am gonna buy one of the transformers below. 0-15,0-15
MULTICOMP|MCFE015/15|TRANSFORMER, 15VA, 2 X 15V | Farnell Turkiye
Will it be enough for this DAC?
MULTICOMP|MCFE015/15|TRANSFORMER, 15VA, 2 X 15V | Farnell Turkiye
Will it be enough for this DAC?
Clave- Call me thikko, but the picture with the coloured lines on it - what is it exactly you're proposing/implying with that
?Thanks in advance,
-Andy-
Well, yes and No..
(you need 12-0-12v ac and also another feed between 9-12 volts)
So, that's two ac feeds in total.
It is possible to feed the second 9-12volt slaved from the positive rail of the recified 12-0-12 input, but as many will agree I'm sure this is a compromise as one system (digital) will have a link (and consequently a detrimental effect) on the analogue section.. Best to keep Analogue & Digital pwr lines separate.
the picture with the coloured lines on it - what is it exactly you're proposing/implying with that
Hi Andy,
On the PCB there's no correlation to components numbering present on the schematic.
I've done some 'reverse-engineering' to put on the pic the same numbering system to identify the various components.
Since I trust that according to function some components are better than others this work was essential to me for planning mods.
Colors helps identifying different power and signal traces on the PCB.
Pwr supply advice (as per AKM design spec sheet)
Quote : "...Power lines of AVDD and DVDD should be distributed separately from the point with low impedance regulator etc.."
Hope this helps !
Quote : "...Power lines of AVDD and DVDD should be distributed separately from the point with low impedance regulator etc.."
Hope this helps !
Hi,
Is there a link to this ebay seller?
Thanks
Link...
Here you go -
Full Assembled DIR9001 AD1955 (MK3A) DAC Decoder Board on eBay (end time 21-Jun-11 06:49:12 BST)
Have fun !
Here you go -
Full Assembled DIR9001 AD1955 (MK3A) DAC Decoder Board on eBay (end time 21-Jun-11 06:49:12 BST)
Have fun !
Quote : "...Power lines of AVDD and DVDD should be distributed separately from the point with low impedance regulator etc.."
Hope this helps !
Thanks, YohY.
Wow!
This DAC is terrific!
It sounds very promising...
Stock and not burn in sounds good but not so special.
It's tonal balance tends to brightness and it's not very refined.
So far I've changed the following things:
Smothing caps
Nichicon FW 3300 uF 35V for digital PSU
Nichicon FW 2200 uF 63V for Analog PSU
Bypass unchanged (100nF X7R Ceramic)
Analog post regulators
Elna Silmic II 220uF 35V - Bypass Evox-Rifa SMR 100nF 50V (Post L7x012)
BC 038 47uF 63V - bypass Evox-Rifa SMR 100nF 50V (Post LM1117)
Digital regulator
BC 038 100uF 50V - bypass Evox-Rifa SMR 100nF 50V (Post L7809)
BC 038 47uf 63V - bypass Evox-Rifa SMR 100nF 50V (Post LM117)
LPF and I/V Conversion
Wima FKP2 1000pF
Wima FKP2 3300pF
I've also mounted sockets for all other electrolytics .
What has changed?
A lot, much more refined, wider and deeper soundstage, stronger and more controlled bass, dynamics.
The most valuable change is the use of Wima FKP2s around the opamp and the opamp itself (NE5532, OP275, OPA2132, OPA211, OPA627, OPA827 in order of good sound )
It makes a lot of difference, others changes I've made are audible but more subtle.
I've yet to evaluate the socketed caps and the following are preliminary opinions subject to change.
So far I can say that 10uF Cerafines in VCOM and VREF are a nice improvement, higher value seems not useful (tried Cerafines, FMs, BC 038)
AVDD on the contrary seems to benefit from higher capacitance (tried Cerafines, BC038, Silmic II) with a fuller sound, I'm using 47uf 25V Silmic II
Also DVDD seems to benefit from higher capacitance (tried Oscon SC 10uF and 47 uf, FMs, 47uf and 220uF), I'm using SC 47uF.
Beneficial il also the decoupling of the opamp with electrolitics (used 10uF Cerafines), the use of Oscons on DVDD of CS8416 and also the use of a high capacitance elco on AVDD of CS8416.
Now I'm wating some burn-in of caps and chips and more modern solid elcos from Asia (SEPC 100uf and 470uF, NCC PSA 220uF, Fujitsu 100uF, Nichicon LF 100uF). It will took a month or so...
I suspect that the bright tonal balnnce of this DAC is due to resistors in the analog signal path... I'm awaiting also some PRPs
Also the poor L7x12 regulators could be responsible...
Ah, a final note, as is now (after the mods) it's not so far from the modified analog stage of my Sony SCD-555ES (bigger difference it's the tonal balance), which however is always the transport...
This DAC is terrific!
It sounds very promising...
Stock and not burn in sounds good but not so special.
It's tonal balance tends to brightness and it's not very refined.
So far I've changed the following things:
Smothing caps
Nichicon FW 3300 uF 35V for digital PSU
Nichicon FW 2200 uF 63V for Analog PSU
Bypass unchanged (100nF X7R Ceramic)
Analog post regulators
Elna Silmic II 220uF 35V - Bypass Evox-Rifa SMR 100nF 50V (Post L7x012)
BC 038 47uF 63V - bypass Evox-Rifa SMR 100nF 50V (Post LM1117)
Digital regulator
BC 038 100uF 50V - bypass Evox-Rifa SMR 100nF 50V (Post L7809)
BC 038 47uf 63V - bypass Evox-Rifa SMR 100nF 50V (Post LM117)
LPF and I/V Conversion
Wima FKP2 1000pF
Wima FKP2 3300pF
I've also mounted sockets for all other electrolytics .
What has changed?
A lot, much more refined, wider and deeper soundstage, stronger and more controlled bass, dynamics.
The most valuable change is the use of Wima FKP2s around the opamp and the opamp itself (NE5532, OP275, OPA2132, OPA211, OPA627, OPA827 in order of good sound
)It makes a lot of difference, others changes I've made are audible but more subtle.
I've yet to evaluate the socketed caps and the following are preliminary opinions subject to change.
So far I can say that 10uF Cerafines in VCOM and VREF are a nice improvement, higher value seems not useful (tried Cerafines, FMs, BC 038)
AVDD on the contrary seems to benefit from higher capacitance (tried Cerafines, BC038, Silmic II) with a fuller sound, I'm using 47uf 25V Silmic II
Also DVDD seems to benefit from higher capacitance (tried Oscon SC 10uF and 47 uf, FMs, 47uf and 220uF), I'm using SC 47uF.
Beneficial il also the decoupling of the opamp with electrolitics (used 10uF Cerafines), the use of Oscons on DVDD of CS8416 and also the use of a high capacitance elco on AVDD of CS8416.
Now I'm wating some burn-in of caps and chips and more modern solid elcos from Asia (SEPC 100uf and 470uF, NCC PSA 220uF, Fujitsu 100uF, Nichicon LF 100uF). It will took a month or so...
I suspect that the bright tonal balnnce of this DAC is due to resistors in the analog signal path... I'm awaiting also some PRPs
Also the poor L7x12 regulators could be responsible...
Ah, a final note, as is now (after the mods) it's not so far from the modified analog stage of my Sony SCD-555ES (bigger difference it's the tonal balance), which however is always the transport...
Attachments
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Wow, nice job Clave...
I see you have not done all the mods you suggested in last BOM (like C1 is unchanged and some more... ) ... or have you tried them but found no improvement (or simply didnt have the caps ) ?
I am a bit confused with the list of changes you made at the top of the post... could you please edit it and put the position where the change had been made (like C24 ,C25... changed to Nichicon 3300 etc... )
Hope that you dont mind my inexperience ...
Good job! , just tell me....when you say harsh tonal balance , is it your system or just the dac compared to something else ?
Thanks
I see you have not done all the mods you suggested in last BOM (like C1 is unchanged and some more... ) ... or have you tried them but found no improvement (or simply didnt have the caps )
?I am a bit confused with the list of changes you made at the top of the post... could you please edit it and put the position where the change had been made (like C24 ,C25... changed to Nichicon 3300 etc... )
Hope that you dont mind my inexperience ...
Good job! , just tell me....when you say harsh tonal balance , is it your system or just the dac compared to something else ?
Thanks
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Yes, I would also like to hear impressions of the dac with the opamps bypassed.
Thanks
It just started...
I see you have not done all the mods you suggested in last BOM (like C1 is unchanged and some more... ) ... or have you tried them but found no improvement (or simply didnt have the caps )
I'm waiting some caps from Asia and Canada and some mods will be done when others are 'stable'.
At the moment I'm using what I have available at home.
Remember these are temporary, it' a work in progress...
Smothing caps
C23 Nichicon FW 3300 uF 35V for digital PSU
C24, C25 Nichicon FW 2200 uF 63V for Analog PSU
Bypass unchanged (100nF X7R Ceramic)
Analog post regulators
C38, C39 Elna Silmic II 220uF 35V (Post L7x012)
C34, C31 BC 038 47uF 63V
C21, C11 bypass Evox-Rifa SMR 100nF 50V (Post LM1117)
Digital regulator
C27, C8 BC 038 100uF 50V - bypass Evox-Rifa SMR 100nF 50V (Post L7809)
C29, C9 BC 038 47uf 63V - bypass Evox-Rifa SMR 100nF 50V (Post LM117)
LPF and I/V Conversion
C41-C43 Wima FKP2 1000pF
C46, C47 Wima FKP2 3300pF
Still very experimental
C33, C35 Elna Cerafine 10uF 50V
C30 Sanyo Oscon SC 47uF 16V
C32 Elna Silmic II 47uF 25V
C3 Panasonic FM 220uF 16V
C28 Sanyo Oscon SC 47uF 16V
No, I'm comparing it to my SACD player and other sources.
BTW I didn't write that is harsh, but bright.
What I mean is that the tonal balance have, IMHO, too much high frequency content...too much but good and refined.
It's the decoupling of 47HC04, it shouldn't have any influence on sound... I've changed it with a same value BC 038 but just for aestetics...
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Thanks so much...
BOM file says that default values of C24 and C25 are 2200 uF 25V ...and you changed just voltage to 63V , not capacitance...why is that ?
My DAC board has Nichicon 2200 uF also but it is 35V... should I replace these with higher voltage rating ?
Somewhere you mentioned 100 uF and later 47 uF on some caps ...what do you find is better (c30 31 34 39 ..) ?
Also I see bypasses missing around 4396 chip... on purpose?
Cheers
BOM file says that default values of C24 and C25 are 2200 uF 25V ...and you changed just voltage to 63V , not capacitance...why is that ?
My DAC board has Nichicon 2200 uF also but it is 35V... should I replace these with higher voltage rating ?
Somewhere you mentioned 100 uF and later 47 uF on some caps ...what do you find is better (c30 31 34 39 ..) ?
Also I see bypasses missing around 4396 chip... on purpose?
Cheers
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You're welcome
The original Nichicons are not so bad.
Higher voltage rating means lower esr and dissipation factor
I suggest you to start with Wimas and opamp. IMHO they are the most rewarding mod
If sound character varies by variety of opamps, thus, there is something wrong here. Since that opamps are active class AB devices, avoiding these devices between source and amplifiershould be the first attempt in modding process.
With this approach, you are just minimizing efforts of possibilities during tweaking. If, what you trying to get is already there (we are talking about pure sound), you have to be curious for efforts onto get it again.
