Sorry, not Martin here, so I hope this reponse qualifiesFin said:
...I'm reclocking between SAA7220 and TDA1541A and using a "hybrid" of Tent's /2 and
Tom Napier's version . While I can't say I've heard better -- since this is my first use of a /2 -- I can concur that the combo works (IOW, nothing was touchy or needed to be fine-tweaked).
This is what the SAA7220P/B causes:
http://www.diyaudio.com/forums/showthread.php?postid=1411965#post1411965
SAA7220P/A caused even nastier waveforms. NOS waveforms are perfect (with the same TDA1541A chip).
http://www.diyaudio.com/forums/showthread.php?postid=1411965#post1411965
SAA7220P/A caused even nastier waveforms. NOS waveforms are perfect (with the same TDA1541A chip).
Hi,
Another update (related to the already sort of off topic discussion towards the end of this thread).
I now have a PMD100 running with my TDA1541A. I have a slight issue where I hear some small digital noise artefacts on very quiet passages (I think I need to pay attention to my grounding layout), but other than that, it sounds stunning!
I did it using Guido's circuit, and it works a treat.
It sounds so much better than SAA7220. So much more detail, vocals much clearer (not only hearing things I hadn't before, but sometimes lyrics too!)
Thanks to Guido for the circuit, and thanks to rfbrw for the advice and chip suggestions.
Cheers,
Phil
Another update (related to the already sort of off topic discussion towards the end of this thread).
I now have a PMD100 running with my TDA1541A. I have a slight issue where I hear some small digital noise artefacts on very quiet passages (I think I need to pay attention to my grounding layout), but other than that, it sounds stunning!
I did it using Guido's circuit, and it works a treat.
It sounds so much better than SAA7220. So much more detail, vocals much clearer (not only hearing things I hadn't before, but sometimes lyrics too!)
Thanks to Guido for the circuit, and thanks to rfbrw for the advice and chip suggestions.
Cheers,
Phil
Phil: Congratulations on your success! I have a spare PMD100 and a couple of late-1980s Philips CDPs, so I may Xerox your project.philpoole said:
Are all the troubleshooting steps you took in this thread, or on diyhifi in a topically-similar thread?
Yup -- reclocking makes a difference. CarlosFM posted a very effective reclocker elsewhere, and that's what I use along with Elso KC v.7.
Also Martin's higher-power version of Flea for TDA1541's +/- 5VDC is very low-noise.
I didn't really follow the troubleshooting in the thread (I did read it though). My circuit is essentially identical to the one posted in that thread - except mine is in standalone mode, using 74 logic, and a set of DIP switches, so I can play a bit with the settings.
I did have trouble. Mainly my own stupid fault!
I had pin 9 floating. D'oh! it didn't know if it was to be programmed or if it was standalone bless it (I'm now quite fond of my PMD100 ). Once that was solved, there was quite a bit of crackling noise, which I solved, either by adding some extra decoupling (47uF) near the logic chips, and rearranging the grounds (the oversampler and clock boards had their grounds joined and then sent to the star ground point - now they're both seperated out and only meet at the star). Both fixes fixed the issue - not sure which one was the cure unfortunately.
Other than that, it all worked, as per Guido's schematic. And I didn't have to warm up my scope.
I've heard Martin's regulation on his Naim (well, I didn't really hear it - that's the point). He mentioned he'd put it up on his website. I shall have a look.
Currently, all my digital circuits are just regulated with one LM317 followed by 7805 - each circuit as its own seperate regulation, but my DAC stage and IV stage have LM317/337 followed by TL431, per circuit. I originally had just singular 78xx regulation, and my current layout made a huge difference! I think there is still room for improvement.
Cheers,
Phil
I did have trouble. Mainly my own stupid fault!
I had pin 9 floating. D'oh! it didn't know if it was to be programmed or if it was standalone bless it (I'm now quite fond of my PMD100
). Once that was solved, there was quite a bit of crackling noise, which I solved, either by adding some extra decoupling (47uF) near the logic chips, and rearranging the grounds (the oversampler and clock boards had their grounds joined and then sent to the star ground point - now they're both seperated out and only meet at the star). Both fixes fixed the issue - not sure which one was the cure unfortunately.Other than that, it all worked, as per Guido's schematic. And I didn't have to warm up my scope.
I've heard Martin's regulation on his Naim (well, I didn't really hear it - that's the point). He mentioned he'd put it up on his website. I shall have a look.
Currently, all my digital circuits are just regulated with one LM317 followed by 7805 - each circuit as its own seperate regulation, but my DAC stage and IV stage have LM317/337 followed by TL431, per circuit. I originally had just singular 78xx regulation, and my current layout made a huge difference! I think there is still room for improvement.
Cheers,
Phil
Hi Cosme,
Not sure what you mean.
It worked fine for me, although I didn't use a PIC and I knocked it up using TTL logic, not a PAL, which would have made it a bit more interesting.
The only problems I had were errors I'd made.
You can find a whole thread discussing it on 'the other forum' - as its so lovingly referred to around here.
Cheers,
Phil
Not sure what you mean.
It worked fine for me, although I didn't use a PIC and I knocked it up using TTL logic, not a PAL, which would have made it a bit more interesting.
The only problems I had were errors I'd made.
You can find a whole thread discussing it on 'the other forum' - as its so lovingly referred to around here
.Cheers,
Phil
Hi
from TDA1541A 's datasheet ,its max of BCK is 6.4MHz .
But PMD100 can Output 32bit wordlength only.
that is ...overclocked?
but I have found some CDP of NEC (cd-10 and so on) may be using TDA1541A overclocked.
their DF is YM3414. its output is 24bit wordlength and glued some logic board or logic array IC.
I modded it before make sure , but DF1704 is well working with BCK 8.4MHz.
from TDA1541A 's datasheet ,its max of BCK is 6.4MHz .
But PMD100 can Output 32bit wordlength only.
that is ...overclocked?
but I have found some CDP of NEC (cd-10 and so on) may be using TDA1541A overclocked.
their DF is YM3414. its output is 24bit wordlength and glued some logic board or logic array IC.
I modded it before make sure , but DF1704 is well working with BCK 8.4MHz.
Couple of questions...philpoole said:
You noted earlier having used Guido's ckt. Did you implement Guido's DEM re-clocking, too (see schema here; DEM ckt inside rectangle)? If so, any issues here?
Not using PMD100 yet, but I do reclock all lines between 7220 and 1541A. This means I have to use a /2 ckt (with 11.2xx MHz Kwack Clock). If I do ditch the 7220 for a PMD100 in 8x mode, I wonder if I'll then have to further divide the BCLK (e.g. to /4)?philpoole said:
Hi,
No I didn't do DEM reclocking. I might have a go at it one day. I tried a long time ago with little success, so I think I'm better off looking for gains in other places at the moment.
I assume by /2 you mean BCLK? If so, no you keep it the same because it uses two data lines, so the bit clock stays the same. BTW, if that wasn't the case, then you wouldn't be dividing the clock further, you'd keep it at MCLK (8xOS increases the data rate). Anyway, to confirm, you don't need to do that, because BCLK = MCLK/2.
Cheers
Phil
No I didn't do DEM reclocking. I might have a go at it one day. I tried a long time ago with little success, so I think I'm better off looking for gains in other places at the moment.
I assume by /2 you mean BCLK? If so, no you keep it the same because it uses two data lines, so the bit clock stays the same. BTW, if that wasn't the case, then you wouldn't be dividing the clock further, you'd keep it at MCLK (8xOS increases the data rate). Anyway, to confirm, you don't need to do that, because BCLK = MCLK/2.
Cheers
Phil
Success ... sort of
Phil:
I also note "digital noise artefacts on very quiet passages". Not sure I concur that this (or my) implementation of the PMD100-1541 ckt is better than my 7220-1541A (other than on HDCDs). Then again, I had the 7220-1541A fine tuned to sing, and that was a labor of love. Also, as rfbw suggests, the PMD100-1541 may not be ideal partners, despite the fact that they can be made to work together.
Similar to your experience, perhaps, I can’t seem to make DEM re-clocking work with PMD100, despite Guido’s success. Not sure why yet. Guido did note that he’s using Henk’s design, not his own, in the default PMD100-1541 you and I built. Speaking of DEM, you noted success with DEM earlier. Was this with the 7220 filter or NOS?
Thx for any light you can shed!
Phil:
I’ve implemented the PMD100-1541A ckt, sticking mostly to Guido’s design, but added a reclocker between decoder and PMD100 (the 7210 decoder is supposed to be jittery).philpoole said:
I also note "digital noise artefacts on very quiet passages". Not sure I concur that this (or my) implementation of the PMD100-1541 ckt is better than my 7220-1541A (other than on HDCDs). Then again, I had the 7220-1541A fine tuned to sing, and that was a labor of love. Also, as rfbw suggests, the PMD100-1541 may not be ideal partners, despite the fact that they can be made to work together.
Similar to your experience, perhaps, I can’t seem to make DEM re-clocking work with PMD100, despite Guido’s success. Not sure why yet. Guido did note that he’s using Henk’s design, not his own, in the default PMD100-1541 you and I built. Speaking of DEM, you noted success with DEM earlier. Was this with the 7220 filter or NOS?
Thx for any light you can shed!
Attachments
Hi Hollowman,
Yeah, I noticed you've been busy with PMD100 and TDA1541A recently on the other forum. Glad you've got it working.
All my DEM reclocking (mis?)adventure has been with SAA7220 (and I think maybe NOS as well).
My initial thoughts, and hence that post, were that it was an improvement, when really it was just different (and not for the better). It seemed brighter, and further listening, especially with headphones, revealed this horrendous hash, and that actually, it was of no improvement at all.
It became apparent to me that actually my DEM reclock circuit was useless and was equivalent to not having anything there at all. This was reinforced by the fact that the hash vanished as soon as I replaced this circuit with the standard 470pF cap. Hohum.
I think these digital artefacts you hear are either due to similar issues I had with DEM reclocking, or perhaps poor grounding (I discovered great improvements in reworking my ground return paths a bit). I don't think it's related to the PMD100, or the TDA1541A selection, as rfbrw suggested. I have 10 TDA1541As and I've not noticed any sounding the lesser in this current setup I have (although I haven't needed to try all of them). The TDA1541A is still working within its rated limits (8x oversampling).
I think, since I've improved my layout and grounding a bit, I may well return to attempt DEM reclocking. However, I'm in the middle of implementing a new I/V and Bessel filter for it instead.
Cheers,
Phil
Yeah, I noticed you've been busy with PMD100 and TDA1541A recently on the other forum. Glad you've got it working.
All my DEM reclocking (mis?)adventure has been with SAA7220 (and I think maybe NOS as well).
My initial thoughts, and hence that post, were that it was an improvement, when really it was just different (and not for the better). It seemed brighter, and further listening, especially with headphones, revealed this horrendous hash, and that actually, it was of no improvement at all.
It became apparent to me that actually my DEM reclock circuit was useless and was equivalent to not having anything there at all. This was reinforced by the fact that the hash vanished as soon as I replaced this circuit with the standard 470pF cap. Hohum.
I think these digital artefacts you hear are either due to similar issues I had with DEM reclocking, or perhaps poor grounding (I discovered great improvements in reworking my ground return paths a bit). I don't think it's related to the PMD100, or the TDA1541A selection, as rfbrw suggested. I have 10 TDA1541As and I've not noticed any sounding the lesser in this current setup I have (although I haven't needed to try all of them). The TDA1541A is still working within its rated limits (8x oversampling).
I think, since I've improved my layout and grounding a bit, I may well return to attempt DEM reclocking. However, I'm in the middle of implementing a new I/V and Bessel filter for it instead.
Cheers,
Phil