Is there anybody out there who owns one of those magic ZAP-Filter mk II?
I think the circuit looks quite interesting, and now I'd really like to know which "ultralinear-many-GHz"-BJT's they are using. They call them "Z-Transistor".
So could one of you please have a look at your ZAP-Filter mk II and tell me what the small transistors are marked with? On the pictures, I can only see the marks on the shunt regulator's devices, then the "4F" and "2F" (BC850, BC860) from the current sources, and the "N2" marked parts (FCX491) from the output stage. The rest ist more interesting, though. Let's see if it is all marketing or if they are really using outstanding high quality parts...
Maybe this way we can figure out if the circuit is any good and maybe use it for our DAC projects... I'd also be interested in comments whether there is an improvement in sound which is worth the money you have to spend on such a unit...
Thank you!
Advertisement and schematics are here (danish):
http://www.lcaudio.dk/opgrmat.pdf
Find a high-res picture of the board here:
http://www.lcaudio.de/Tuning/Analog-Tuning/ZAP-Filter_mk_II/filter2_1Kanal.JPG
I think the circuit looks quite interesting, and now I'd really like to know which "ultralinear-many-GHz"-BJT's they are using. They call them "Z-Transistor".
So could one of you please have a look at your ZAP-Filter mk II and tell me what the small transistors are marked with? On the pictures, I can only see the marks on the shunt regulator's devices, then the "4F" and "2F" (BC850, BC860) from the current sources, and the "N2" marked parts (FCX491) from the output stage. The rest ist more interesting, though. Let's see if it is all marketing or if they are really using outstanding high quality parts...
Maybe this way we can figure out if the circuit is any good and maybe use it for our DAC projects... I'd also be interested in comments whether there is an improvement in sound which is worth the money you have to spend on such a unit...
Thank you!
Advertisement and schematics are here (danish):
http://www.lcaudio.dk/opgrmat.pdf
Find a high-res picture of the board here:
http://www.lcaudio.de/Tuning/Analog-Tuning/ZAP-Filter_mk_II/filter2_1Kanal.JPG
nFORCE said:
Thank you very much, nFORCE
Hm, according to the datasheet, those Philips parts are called BISS ("Breakthrough In Small Signal")
However, they have a transit frequency of "only" 150 MHz... Their case seems smaller than SOT23 on the pictures... And they should be marked something like "9At" or "9Ap" which is different to what we see on the pictures... Maybe you have the older version, ZAP-Filter mk I?
If they are really using smaller outline versions of the Zetex FCX491A, what about the "ultra linear GHz Z-Transistor" marketing?
Hi Sir,
MK1 here:
http://www.lcaudio.dk/zfdia.pdf
Yes, the transistor is limit at 150MHz, I think that enough, the spec = ZETEX spec, i.e. I don't know why the begineer stage need TR=1.5G and the final amp stage only need 150MHz.
Therefore the critical path should not in the 150MHz.
Regards,
nFORCE
QUOTE]Originally posted by AMT-freak
Thank you very much, nFORCE
Hm, according to the datasheet, those Philips parts are called BISS ("Breakthrough In Small Signal")
However, they have a transit frequency of "only" 150 MHz... Their case seems smaller than SOT23 on the pictures... And they should be marked something like "9At" or "9Ap" which is different to what we see on the pictures... Maybe you have the older version, ZAP-Filter mk I?
If they are really using smaller outline versions of the Zetex FCX491A, what about the "ultra linear GHz Z-Transistor" marketing? [/QUOTE]
MK1 here:
http://www.lcaudio.dk/zfdia.pdf
Yes, the transistor is limit at 150MHz, I think that enough, the spec = ZETEX spec, i.e. I don't know why the begineer stage need TR=1.5G and the final amp stage only need 150MHz.
Therefore the critical path should not in the 150MHz.
Regards,
nFORCE
QUOTE]Originally posted by AMT-freak
Thank you very much, nFORCE
Hm, according to the datasheet, those Philips parts are called BISS ("Breakthrough In Small Signal")
However, they have a transit frequency of "only" 150 MHz... Their case seems smaller than SOT23 on the pictures... And they should be marked something like "9At" or "9Ap" which is different to what we see on the pictures... Maybe you have the older version, ZAP-Filter mk I?
If they are really using smaller outline versions of the Zetex FCX491A, what about the "ultra linear GHz Z-Transistor" marketing? [/QUOTE]
AMT freak,
I haven´t had time to check what those BJT´s are marked with, however I I think we can assume that if you read something at the LC Audio site it´s true. These guys know what they are doing and are certainly not into false marketing.
As I mentioned in the other thread, I use the Zapfilter mk2 together with LClockXO2 in my SCD-XB940.
The improvements with these upgrades where nothing short of shocking.
So the answer on your question;
"Maybe this way we can figure out if the circuit is any good and maybe use it for our DAC projects... I'd also be interested in comments whether there is an improvement in sound which is worth the money you have to spend on such a unit"
You bet!
LC Audios stuff are right up there with the best IMO. And since they use no signal caps and no feedback, the resolution is better than anything I have heard. (talking ´bout amps now).
The Aleph5, Gammut D200 and ARCVT100 was not good enough to replace my Zapsolutes. Therefore I´m very curious on the new XA amps from mr Pass. Maybe this is what I need to better my amps. Or I simply have to go with the latest Zapsoutes mk4.1.
/Peter
I haven´t had time to check what those BJT´s are marked with, however I I think we can assume that if you read something at the LC Audio site it´s true. These guys know what they are doing and are certainly not into false marketing.
As I mentioned in the other thread, I use the Zapfilter mk2 together with LClockXO2 in my SCD-XB940.
The improvements with these upgrades where nothing short of shocking.
So the answer on your question;
"Maybe this way we can figure out if the circuit is any good and maybe use it for our DAC projects... I'd also be interested in comments whether there is an improvement in sound which is worth the money you have to spend on such a unit"
You bet!
LC Audios stuff are right up there with the best IMO. And since they use no signal caps and no feedback, the resolution is better than anything I have heard. (talking ´bout amps now).
The Aleph5, Gammut D200 and ARCVT100 was not good enough to replace my Zapsolutes. Therefore I´m very curious on the new XA amps from mr Pass. Maybe this is what I need to better my amps. Or I simply have to go with the latest Zapsoutes mk4.1.
/Peter
Pan said:
The ZAP Filter mk II is around 275$, pretty much for such a circuit... Ok ok, they have to pay the engineer and probably won't be selling 100.000's of those boards, but still...
LCAudio products have been discussed at length here already, not all of us seem to like their sound.
What the LCAudio clock is concerned, it's is also quite expensive, yet only a more or less standard circuit with a BFR92A and some high speed logic. The famous KWAK-clock can be built for... say 10 to 20$ ... and seems to be better. At least this is what people say, I haven't yet had an opportunity to compare them.
This of course doesn't mean I contradict you, I just say I haven't heard it yet and want to be sure... Understand the circuit... Check if there is something behind their marketing... Maybe I'll buy a ZAP-Filter, maybe I'll tweak it, or maybe I'll try building a similar circuit myself... Don't know yet. Just don't want to risk much, since I don't have the money to try many different output stages.
So if you have time one day to have a quick look at your board and tell me about the markings on the SMD transistors, I'd be very happy... Of course I understand if you don't want to open a carefully tweaked CD-Player again, but maybe someone else can help..?
Thank you all.
AMT,
If anyone can build something better than the Zapfilter2 for lesss money I say congrats, I would also do that in such case.
The other readily made boards (of similar quality) on the market cost more as far as I know. So for someone who wants to put down about $400 for Zapfilter + LClock and mod a CDP that can compete (and beat) all or most players out there, IMO it´s a ******* bargain
About the clock. If someone can build a similar or better clock for $20, then go for it. I don´t think everyone can though. So if you want a solution that can be fit in the machine in a lunchbreak that lift your player enormously, then LClcok is a very worthwile investment, and in audiophileterms ($) peanuts. I have read about several people make coments on LClock being as good as or better, then the competition. I have not tried any other clock than LCclock, but I can assure you my jaw dropped the night I installed it.
No problem with open the machine as I did the mods myself, but there is the time issue, and I believe that all I can see is what you can see on the high-rez picture on the LC site.
I bought a SCD-XB940 unheard, knowing I would upgrade it, so the sound of the machine itself was of little interest. Of course I listened to it after I bought it, but it sounded like crap, so I didn´t use it for months until I did the modifications. After the mods it produces (in my set up) the best sound I´ve ever heard. Nothing I have heard comes close to the natural high resolution of the Zapfilter feeding my Zapsolute class A amps, really. I have good speakers also.
The easy way is to send Lars Claussen (LC...) a mail and ask anything you want to know.
Oh.. and if you find a way to mod and better the Zapfilter, please tell me, as if this amazing piece of board can be made better, I´m in
/Peter
If anyone can build something better than the Zapfilter2 for lesss money I say congrats, I would also do that in such case.
The other readily made boards (of similar quality) on the market cost more as far as I know. So for someone who wants to put down about $400 for Zapfilter + LClock and mod a CDP that can compete (and beat) all or most players out there, IMO it´s a ******* bargain
About the clock. If someone can build a similar or better clock for $20, then go for it. I don´t think everyone can though. So if you want a solution that can be fit in the machine in a lunchbreak that lift your player enormously, then LClcok is a very worthwile investment, and in audiophileterms ($) peanuts. I have read about several people make coments on LClock being as good as or better, then the competition. I have not tried any other clock than LCclock, but I can assure you my jaw dropped the night I installed it.
No problem with open the machine as I did the mods myself, but there is the time issue, and I believe that all I can see is what you can see on the high-rez picture on the LC site.
I bought a SCD-XB940 unheard, knowing I would upgrade it, so the sound of the machine itself was of little interest. Of course I listened to it after I bought it, but it sounded like crap, so I didn´t use it for months until I did the modifications. After the mods it produces (in my set up) the best sound I´ve ever heard. Nothing I have heard comes close to the natural high resolution of the Zapfilter feeding my Zapsolute class A amps, really. I have good speakers also.
The easy way is to send Lars Claussen (LC...) a mail and ask anything you want to know.
Oh.. and if you find a way to mod and better the Zapfilter, please tell me, as if this amazing piece of board can be made better, I´m in
/Peter
AMT freak I have most of the circuit figured out and I am making some simulations right now.
Do you have a high resolution picture of the board from under?
I am trying to figure out the exact values of the Zener diode that biases the input pair and how the connection really is in the input for non balanced current input. what happens to ground when 4 is shorted?
There is an npn transistor that gives a voltage to the bases of the input pair when the current inputs are into them as common base.
Any ideas are welcome. A version of this circuit with normal parts would be cool. O don´t really like SMD parts.
Do you have a high resolution picture of the board from under?
I am trying to figure out the exact values of the Zener diode that biases the input pair and how the connection really is in the input for non balanced current input. what happens to ground when 4 is shorted?
There is an npn transistor that gives a voltage to the bases of the input pair when the current inputs are into them as common base.
Any ideas are welcome. A version of this circuit with normal parts would be cool. O don´t really like SMD parts.
Zap-filter Parts
Hi ,
AMT-Freak, thanks for the kind words about the KWAK-CLOCK.
I haver never had a closer look at the zapfilter but in the Lcaudio XO-2 the following SMD transistors are used:
the very small 1Dp and 3Kp
and the larger AA P07.
As most manufacturers have their favorite parts this may be helpfull.
Hi ,
AMT-Freak, thanks for the kind words about the KWAK-CLOCK.
I haver never had a closer look at the zapfilter but in the Lcaudio XO-2 the following SMD transistors are used:
the very small 1Dp and 3Kp
and the larger AA P07.
As most manufacturers have their favorite parts this may be helpfull.
Pan said:Can you give me more info please?
I use the output directly from the VC24 chip, balanced mode to the Zapfilter.
----------------------------------------------------------------------
If you measure the noise level in the 940's PS and audio path, you will find a lot of crud everywhere. No amount of decoupling helped and eventually I found that undoing the ground at the digital output and running a star scheme was the answer. This reduced the noise level appreciably. I also had to shield the signal lines with copper tape.
I think this is a basic design problem as Sony quickly discontinued the 940 which has more inductors than you can imagine in a player.
Can you pl post or email me on your Zap connections as I may try the Zap 1 in the unit?
Fred
I´ll try to find my old schematic. If my memory serves me I think the Zap2 is connected to pin 26, 27 and 28,29. It´s possible it´s 27, 28 and 29, 30.
Also, when connected "intuitevely" this way, one channel is reversed. The signal at this place is the first point the DSD/RBOOK is in analog domain.
Later..
/Peter
Also, when connected "intuitevely" this way, one channel is reversed. The signal at this place is the first point the DSD/RBOOK is in analog domain.
Later..
/Peter
The N2 transistors are FCX491A, chosen for their high linearity, and hfe. The 5 GHz bandwidth, that some users in this discussion room claim we use in our marketing material is NOT for this part, but for the BFR92A used in LClock.
The term Z-Transistor is not even found in connection with any of the products discussed here, we use Z transistors in our The End Millennium Power Amplifier kit.... hmm
How did you mix that one up so much AMT-FREAK
The term Z-Transistor is not even found in connection with any of the products discussed here, we use Z transistors in our The End Millennium Power Amplifier kit.... hmm
How did you mix that one up so much AMT-FREAK
AMT-freak said:
In the simplified schematics of "ZAP-Filter mk II" (to be found in your CD upgrading catalogue), there is a "Z" next to the output transistors.
The diagram can be found at www.lcaudio.dk/zfdia.pdf and
there is no Z next to the transistor. There is a note, though,
that it is a Zetex device. Maybe you have a different version of
the diagram where Zetex is abbreviated to Z?
BTW what is a Z-transistor?
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