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Old 13th September 2009, 12:02 AM   #481
JohnW is offline JohnW  Hong Kong
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Hi Guys,

I have to be very brief I’m afraid as I’m crazy busy with products going to production and an Inbox of over 600 Emails…

The 24Bit filter was designed after I left PT – I had no input on the design. A couple of years back I bought a Dacapo / DC from EBay – which had a 24 Bit filter fitted – first time I listen to it.

While it had “firmer more pronounced Bass” over the HDCD filter, it had a narrower sound stage and “brighter” more digital upper end.

Later I got to measure the filter and found very bad “Digital distortion products” – typical of rounding errors – it turns out that whoever designed the filter module had not enabled the digital filters “internal dithering function” to handle its truncation errors.

Maybe PT realised there error and correct on later filters (this may help explain the difference between the two 24bit filters).

My experience of Low ESR capacitors while having a very detailed sound can also sound very clinical and “Bass light”

I’ve had good results in the past with a “standard” Phillips capacitor range – but I don’t recall the series now.

Again, sorry for the brief reply,

JohnW
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Old 13th September 2009, 12:30 AM   #482
IanAS is offline IanAS  England
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Thanks for that John.

Here's a photo of THIS 24 bit filter, hope there's not a problem with it being shown? It is 10 years old now.

It does look rather modified!

I'll see if I can make enough sence of the data sheet to determine if any of those modification looking changes enable the “internal dithering function”.
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Last edited by IanAS; 13th September 2009 at 12:34 AM.
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Old 13th September 2009, 12:46 AM   #483
IanAS is offline IanAS  England
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Quote:
Originally Posted by Pass lover View Post
The caps from my CD player have also been removed . Luckily there is no sign of leaking caps at all
Yes there is. Many of them have started leaking and eating into the gold pads. Those faint rings from the base of the capacitors are the liquid residue.

You need to clean that off.
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Old 13th September 2009, 12:54 AM   #484
IanAS is offline IanAS  England
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Quote:
Originally Posted by Pass lover View Post
please tell me more about polar or non-polar type of cap for replacement, aswell as parallel the caps: -negative (-) polar with (-) polar and positive with positive? Am I right?

What kind of the leaking caps are? Polar or Non-polar? Can I use either of them to replace the leaking caps?
Non-polarised capacitors have no polarity and do not have the -ve stripe down one side. They can be connected either way around.

The leaking ones are polarised capacitors. Polarised capacitors can explode if connected the wrong way around.
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Old 13th September 2009, 10:20 AM   #485
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Default which caps please help

Hi Ianas

Thank for your advice. I did search google for more inf about how to replace a cap. Now I know abit about caps.

But I would like to hear from other members who did replace the caps successfully ( no master what the cap is)

Which one:
Rubycon ZLH or ZL
Cerafine
Oscons
Black Gates
Aerovox
Panasonic FC
Nichicon KZ

I also found that there is Panasonic cap
http://uk.farnell.com/panasonic/eeuf...25v/dp/1219472
http://uk.farnell.com/panasonic/eeuf...25v/dp/1219472
with ripple current at 3750mA and imp 0.012 ohm. According to the data, it is a bit better than Rubycon ZLH and ZL????? Is it true?

Ianas : which caps did you use actually to replace for Dacapo?
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Old 13th September 2009, 05:59 PM   #486
IanAS is offline IanAS  England
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Quote:
Originally Posted by Pass lover View Post
Which one:
Rubycon ZLH or ZL
Cerafine
Oscons
Oscon Conductive Polymer
Black Gates
Aerovox
Nichicon KZ
Nichicon Conductive Polymer
Panasonic FC
Panasonic ECA series Audio grade(Panasonics blub on these ECA: High Quality Audio Grade. High Fidelity. Low Distortion. High Resolution. Low Range Loudness.
For improved sound quality they feature a special electrolyte and vibration controlled outer Sleeve.)



Ianas : which caps did you use actually to replace for Dacapo?
I used Rubycon ZL as they were
cheap,
available,
recommended by several people inc in this thread,
sold by some on-line HiFi shops for an inflated price as 'excellent caps, similar sounding to Black Gates'. (Similar to Black Gates! Yeah right! Similar colour and made by Rubycon!)

I think it probably doesn't matter all that much in this circumstance which 'ordinary' caps are used. We're not asking them to deliver current. The main thing to get better sound quality seems to be to parallel some 'special' ones across them.

Unless your disposable wealth level permits exclusive use of 'special' ones, eg, Black Gates. Conductive Polymer caps appear to be in this category, but I'm currently unsure of their effect at bass and they only come smallish values.

10 years ago, with a friend we used to make and sell PSUs for CD players. We used 1000uF Nichicon KZ series before the discrete regulator(s) and Black Gate standard series in and after. I didn't use then in this DaCapo due to them being so very much larger for the capacitance. And also to save money, it was not known whether the white noise problem could be cured so there was no point in investing a larger sum only for it to be wasted.

They seem to be quite good, nice to listen to, by very laid back compared to Black Gates. The KZ's can cause a boomy bass when paralleled across a 10,000uF. Black gates = slam propelled by amazing dynamic range and speed at all frequencies, both on their own or paralleled across something larger.

The other thing to bear in mind is that the bridge diodes in the DaCapo are not all that beefy, and the transformers aren't either. Might be wrong with this one as I've not tired it, but all previous experience suggests that a very good separate PSU can't fail to improve this DAC.

The one I used on my 7350 DAC, with only drew 100mA, had 20,000 of the Nichicon KZ, discrete reg.'s, 1200uF black gate, 1000uf OsCon. For and output of ±15V DC. I'd have used ONLY Black Gates though if I could have justified the cost as my pals supply, equal in all ways except Black Gates instead on KZ's was Sooo much more 'powerful' and slam bam wallop!
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Old 14th September 2009, 02:48 AM   #487
JohnW is offline JohnW  Hong Kong
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Hi,

Yes sadly the 24 Bit Module is a REAL mess - design and build quality.

Pin 44 (last Pin on the QFP) should be Grounded - its appears floating (High) in your module - you can just solder bridge to the row of Grounded pins next to it.

John
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Old 14th September 2009, 01:24 PM   #488
IanAS is offline IanAS  England
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Yes, it is floating. I've just checked.

Thanks for that

I'm only guessing but it rather seems that who ever populated that board mistakenly soldered the last floating pin of the 7350 instead of the last floating pin of the 5847!

I'll put that right. And have a listen before and after.

Another way that this assembly might be lacking is that the three 317's are fed direct from the +16V rail that feeds the +5V TO220, whereas all the other (digital) 317's are fed from the 8.2V regulator, thereby double regulating.

I've found in the past that double regulating with decoupling in between in a CD player can make a (surprisingly!) large improvement to the sound.

I guess one of the chips in one of the filter variants must have needed a higher voltage?
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Old 14th September 2009, 09:06 PM   #489
russel is offline russel  Europe
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Quote:
Originally Posted by Pass lover View Post
Hi,



I am not sure about the trade-mark name of amps or DACs John W will be with. However, I did find the first Pink Triangle amp 2009 reviewed at:

http://hometheaterreview.com/pink-tr...-amp-reviewed/

mine
I mentioned this to an ex PT person and they said only 14 of these were ever made before the company folded.

Russ
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Old 17th September 2009, 03:32 PM   #490
muz640 is offline muz640  Australia - Aboriginal
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Quote:
Originally Posted by JohnW View Post
Hi Guys,

I have to be very brief I’m afraid as I’m crazy busy with products going to production...
Did someone say production? is this the A******* Dac?
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