Hi Haik,
In the LPF section it will improve precision.
Use RC55Y, excellent industrial resistors and non magnetic too.
It depends on what you want to achieve... Nichicon FW (high voltage rating) are execellent for that job.
Those should be absolutely replaced, IMHO.
For three reasons:
Fine
They're Pilkor (ex-philips) and they're quite good but ceramics and SMRs can do better (see my BOM)
No, IMHO. See my BOM for suggestions.
Yes, they're vias.
In the LPF section it will improve precision.
Use RC55Y, excellent industrial resistors and non magnetic too.
It depends on what you want to achieve... Nichicon FW (high voltage rating) are execellent for that job.
Those should be absolutely replaced, IMHO.
For three reasons:
- They sound harsh
- They're low-esr which is not a good thing after a regulator.
- They're value is a bit too high, they stress the regulators, use 100uF instead.
Fine
They're Pilkor (ex-philips) and they're quite good but ceramics and SMRs can do better (see my BOM)
No, IMHO. See my BOM for suggestions.
Yes, they're vias.
at last, mine pcb arrived too
i've already assembled 3 salas v1.0 shunt regs (+5v, +-12v), got 1% Vishay resistors and other necessary components. Will post some pics later.
I've read in the thread that some legs of the chip should be joint by solder on the pcb, mine doesn't have anything like that at all...
i've already assembled 3 salas v1.0 shunt regs (+5v, +-12v), got 1% Vishay resistors and other necessary components. Will post some pics later.
I've read in the thread that some legs of the chip should be joint by solder on the pcb, mine doesn't have anything like that at all...
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I replaced the NE5532 with LME49720HA, the sound has improved in many ways.
Among the results the most musical sound I ever heard!
There are several small issues I'd like to fix:
lacks some detail and micro details, slightly brighter sound, fet bass and not as detailed now.
What OPAMP s most highly recommended to try?
I have: LT1358, LT1364, LME49720NA, OPA2137P, LT1057
Among the results the most musical sound I ever heard!
There are several small issues I'd like to fix:
lacks some detail and micro details, slightly brighter sound, fet bass and not as detailed now.
What OPAMP s most highly recommended to try?
I have: LT1358, LT1364, LME49720NA, OPA2137P, LT1057
To be honest I am not sure how the leds would/should behave normally.
If I power up the board (still a problem there maybe) without the SPDIF plugged in I get three lights, 96K, error, power, I plug in the SPDIF the 96K light goes out. I spool up the CD and the error light flickers while the disk is reading and goes out when a track starts to play. If I power up the board with the SPDIF plugged in I get two lights, error, power. I have never seen the no audio light lit up (a real wind-up... since I have no audio!).
This weekend I plan to hunt through my salvaged transformer box and find one or two I can try in place of the transformer supplied with my kit.
See if that makes any difference...
I haven't given up yet!
Bill
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Hey Bill, Do you have the ability to feed the DAC with a PC. If you have a desktop there may be a two pin (spdif-out) or three pin (spdif in - out) header on the motherboard that can be used by attaching an RCA socket directly. Some newer PCs have the spdif RCA on the rear plate.
Have you tried more than one CD player with this DAC?
Have you tried more than one CD player with this DAC?
I did try two CD players (both home brewed shigaclones admittedly), both are working in the same set up if I just switch the DAC (all other factors equal).
Anyway I just measured 61 ohms resistance across the primary winding of the transformer. This seems way too high(?) so I will go ahead and try to find a different transformer(s)....
Just for reference sake has anyone measured the resistance of the primary and secondaries in a good example of the r-core transformer sometimes supplied with this kit? I see 1.1 ohms across the 9V secondaries and 3.1 across the 15V secondaries.
Thanks folks.
Bill
Hi Bill,
I do not have the r-core from China, but the amounts you tell should be real. The 61 ohms are way wrong.
The primary winding should be "high" (a couple of kOhms), when not loaded. The secondary are usually very low (thick wire, and few windings).
Take ANY transformer, either toroidal or normal block. Measure it there.... The higher the power of the transformer, the lower the secondary winding resistance. The lower the secondary voltage, the less resistance.
I do not have the r-core from China, but the amounts you tell should be real. The 61 ohms are way wrong.
The primary winding should be "high" (a couple of kOhms), when not loaded. The secondary are usually very low (thick wire, and few windings).
Take ANY transformer, either toroidal or normal block. Measure it there.... The higher the power of the transformer, the lower the secondary winding resistance. The lower the secondary voltage, the less resistance.
I replaced the NE5532 with LME49720HA, the sound has improved in many ways.
Among the results the most musical sound I ever heard!
There are several small issues I'd like to fix:
lacks some detail and micro details, slightly brighter sound, fet bass and not as detailed now.
What OPAMP s most highly recommended to try?
I have: LT1358, LT1364, LME49720NA, OPA2137P, LT1057
I tried LME49720 biased in class a, AD8066 and LT1364. LME49720, although it had great timbre when biased in class a, was outperformed by the other two opamps. Ad8066 and lt1364 where both really good in terms of resolution and seperation. Ad8066 has a huge soundstage, but LT1364 is musically more engaging and is currently my favorite. I intend also to try LT1028 and OPA627
I ordered the kit including the transformer.
These are the values that I just measured;
Prim: 0--115V= 38,8 Ohm 0--230V=124,9 Ohm
Sec: 0--9V= 5,4 Ohm 0--15V= 8,4 Ohm
Haven't tested the transformer though.
Regards
Thanks for checking. Seems your secondaries have much higher resistance than mine.... I'm trying to do some study about transformers... seems pretty endless!
Bill
Bill have you tried using only the 12-0-12 inputs with the solder bridge?
It seems like there is a problem with your 9v windings, or try feeding it with a wall wart. The 9volt winding needs to be powered on first, else the AK will miss its reset point.
Its a Triumph Thunderbird Sport by the way.
It seems like there is a problem with your 9v windings, or try feeding it with a wall wart. The 9volt winding needs to be powered on first, else the AK will miss its reset point.
Its a Triumph Thunderbird Sport by the way.
Hi, anyone got any suggestions please.Hi, I have my unmodded DAC running into my Exposure preamp's tuner input which is marked 10K.
Is this a good match or could I mod the amp to match it better.
cheers
I tried to run a simulation of 5V power supply.I've yet to try it:
It gave me great results with the FE and it's much simpler (and cheaper) than a Salas shunt that, BTW, it's probably overkill for an opamp.
The resulting voltage was 5.4V, is that right zener?
Which Zener diodes NEED for the output voltage of: 3.3V, 5V, 12V, -12V ?
Yes, it is.
According to the datasheet the maximum allowed suppply voltage is 6.0V, so it should be fine.
BTW 1N5229B can be used instead so to have ca 5V.
You can see it reading the datasheet.
Choose a diode witha voltage raging that is 0.7V less than your desired voltage.
Hi Dario,
Built my second PCB this WE, this time from unpopulated board using your BOM - certainly better performance again compared to the simple mods I made to my first 'populated board'
In one of your first posts you wrote a capacitor comparison paper which was quite interesting. Do you have a new version of this you can share with us?
Thx,
JimChan
Built my second PCB this WE, this time from unpopulated board using your BOM - certainly better performance again compared to the simple mods I made to my first 'populated board'
In one of your first posts you wrote a capacitor comparison paper which was quite interesting. Do you have a new version of this you can share with us?
Thx,
JimChan
Finally tried it
I've just tried a simplified version of my shunt (it replaces only MC7x12, not LM1117-5).
It's for sure an improvement in clarity, detail, particularly bass but it's not a night and day difference.
As I was expecting OPA827 high PSRR limits the upgrade effectiveness.
Probably we can have a better improvement focusing on LM1117-5 (Va)
You're welcome.
Probably yes but I can't say for sure.
Hi Jim,
no, that one is the more recent.
I'll try in next weeks Nichicon FP Caps which are very well regarded.
I've just tried a simplified version of my shunt (it replaces only MC7x12, not LM1117-5).
It's for sure an improvement in clarity, detail, particularly bass but it's not a night and day difference.
As I was expecting OPA827 high PSRR limits the upgrade effectiveness.
Probably we can have a better improvement focusing on LM1117-5 (Va)
You're welcome.
Probably yes but I can't say for sure.
Hi Jim,
no, that one is the more recent.
I'll try in next weeks Nichicon FP Caps which are very well regarded.
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