Hello all,
Anyone here tried the following unusual idea:
http://www.lampizator.eu/digilampizator ... zator.html
Anyone here tried the following unusual idea:
http://www.lampizator.eu/digilampizator ... zator.html
Square waves are rarely square in the real world these days, as long as monotoicity is maintained, its surprising how bad a 'square wave' can look, yet the data gets through unaltered.
More interested in the sound than whether the dac locks. Anyway, simple enough to try so I'll give it a go.
Anything you use as buffer will improve the SPDIF output of the crappy SAA7220... That is not something special.
The use of a TUBE/VALVE or a JFET as a buffer for SPDIF is unusual/speacil.
Most SPDIF circuits would use something along the lines of direct output or via a 74HCxxx buffer.
Question remains-how does it sound? Will try to answer that soon...
Most SPDIF circuits would use something along the lines of direct output or via a 74HCxxx buffer.
Question remains-how does it sound? Will try to answer that soon...
Using a tube or FET will work. It will give you great gains in novelty.
Using the circuit you linked to will get rid of many anomalies by bandwidth limiting. Whether that bandwidth limiting is severe enough to impair the sound is not evident from the rather crude and uninformative photo on that page. Additionally, because the source impedance will not be 75R, you'll have the benefit of ringing at the far end of the coax cable. As before, whether it's severe enough to audibly impair the sound is something you'll have to determine experimentally.
With enough effort and expense, you can probably get a tube circuit to almost equal the performance of a five cent logic chip and a resistor.
Using the circuit you linked to will get rid of many anomalies by bandwidth limiting. Whether that bandwidth limiting is severe enough to impair the sound is not evident from the rather crude and uninformative photo on that page. Additionally, because the source impedance will not be 75R, you'll have the benefit of ringing at the far end of the coax cable. As before, whether it's severe enough to audibly impair the sound is something you'll have to determine experimentally.
With enough effort and expense, you can probably get a tube circuit to almost equal the performance of a five cent logic chip and a resistor.
like the 74hc74, lol?
By the way, the site I linked to appears to show that use of the tube "squares up" the spdif. Have a look.
By the way, the site I linked to appears to show that use of the tube "squares up" the spdif. Have a look.
Last edited:
Yeah, you got it. Stick a resistor on the output to get you 75R source and you're done. But it gives you nothing exotic to talk about on teh internets.
Any idea why he deliberately misterminates the sending end? It couldn't be because he doesn't actually understand what he is doing? Maybe, as he claims that it is "fully aligned" to the cable impedance.
An awful lot of woffle for a simple cathode follower, which seems to do little more than improve the LF response (as shown on the scope traces). (I don't mean audio LF response.) With a poor receiver the LF shift could increase jitter, but a good receiver will use a transformer so LF shifts won't be seen by the data slicer.
An awful lot of woffle for a simple cathode follower, which seems to do little more than improve the LF response (as shown on the scope traces). (I don't mean audio LF response.) With a poor receiver the LF shift could increase jitter, but a good receiver will use a transformer so LF shifts won't be seen by the data slicer.
I did try once, on the grounds that there may be nuggets of gold among the verbose woffle, but I gave up. I am patient, but not that patient! I was also put off by the hints of arrogance - very rare on audio sites!!
I'll build it and listen-just curious...
Here is a link to a different pdf. http://tubeclinic.hostingsociety.com/JFET-buffer.pdf
have a look at http://tubeclinic.hostingsociety.com/FETishizator_V2.3.pdf and http://tubeclinic.hostingsociety.com/STC.pdf
Here is a link to a different pdf. http://tubeclinic.hostingsociety.com/JFET-buffer.pdf
have a look at http://tubeclinic.hostingsociety.com/FETishizator_V2.3.pdf and http://tubeclinic.hostingsociety.com/STC.pdf
Last edited:
That is NOTHING there. Just an obssesion with "magic" tubes, a bunch of masacrated CD-players with final stages butchered in order to make those pseudo-improvements that catch the eye of the uninformed people. Gone are the proper filters, gone the proper impedance adaptation and so on.
Sure it looks cool and gives a hint of "I'm different, therefore I must be better".
Sure it looks cool and gives a hint of "I'm different, therefore I must be better".
Guys, the answer is easy:
BUILD the thing-a handful of parts, a few mintes of soldering.
After all, the site shows scope traces that show better square wave performance vs stock.
If it sound like crud after an hour of "optimising operating points", great, move on, there are lots of nice projects out there
BUILD the thing-a handful of parts, a few mintes of soldering.
After all, the site shows scope traces that show better square wave performance vs stock.
If it sound like crud after an hour of "optimising operating points", great, move on, there are lots of nice projects out there
Last edited:
No, there's no indication that the traces are "better," no scale, and no indication of what the signal looks like at the end of the coax with a termination- the schematic shown will guarantee that the impedances will be mismatched which COULD cause a new set of problems. Build it if you want, but don't think that the "designer" has presented ANY data showing that there's any improvement in the transmitted spdif signal (much less in the output of the DAC, which is the only thing that matters).
There are problems worth solving and "problems" that are purely imaginary. I can't fault the Lampizator guy for lacking imagination.
- Status
- Not open for further replies.