They're back and it's better.
While I was 'inside', I replaced some of the Panasonic FCs with Elna Cerafines that I had lying around. (the 47uF ones near the DAC and the 220uF)
Can't say I notice much of a difference though.
While I was 'inside', I replaced some of the Panasonic FCs with Elna Cerafines that I had lying around. (the 47uF ones near the DAC and the 220uF)
Can't say I notice much of a difference though.
ozone_stink said:
I know this may seem obvious but I'll say it anyway... perhaps you just revealed problems elsewhere in the player or system.
Have you replaced the psu diodes with Schottky types? These remove mess from the treble. You may also like to filter the incoming mains with 'x' caps, maybe 0.33uF in parallel with 0.033uF, and use chokes in series with L+N. Also use an isolation transformer. If the sound is unpleasant it's probably down to ur psu or the rest of the system.
ozone_stink,
What is the rest of your system? I've just read the thread through and I can't see a mention of it.
I am concerned that there's a bad apple there somewhere, as shorting a dc blocking cap should give a large improvement, not the opposite.
Have you done any 'mechanical' mods to the player yet? A small amount of bitumen damping on the lid helps, as does supporting the player on 3 cones (some say 4) rather than the stock feet (they usually mess the sound up to some degree).
I think I heard this CDP in a hi-fi shop, and it was nice to listen to, but definately a 'hi-fi' sound, rather than actual music - very 'exciting' and peppy. I think removing those bad op-amps was the best thing you could do, so that's a great start.
What is the rest of your system? I've just read the thread through and I can't see a mention of it.
I am concerned that there's a bad apple there somewhere, as shorting a dc blocking cap should give a large improvement, not the opposite.
Have you done any 'mechanical' mods to the player yet? A small amount of bitumen damping on the lid helps, as does supporting the player on 3 cones (some say 4) rather than the stock feet (they usually mess the sound up to some degree).
I think I heard this CDP in a hi-fi shop, and it was nice to listen to, but definately a 'hi-fi' sound, rather than actual music - very 'exciting' and peppy. I think removing those bad op-amps was the best thing you could do, so that's a great start.
Hi Simon,
Thanks for the advice.
I'm connecting the CDP into a Marantz 2285B. -It's been overhauled recently (all caps replaced, pots & relay cleaned, bias & quiescent current adjusted).
It's input impedance is 33 KOhm.
The speakers are home made with Solen passive crossovers, Scan Speak D2905/9300 Tweeters & Vifa P21WO-12-08 8" drivers.
If I had to hazard a guess as to why it sounded so shrill, I would say that it's due to my clock. I suspect that once I replace my Trichord2 with a Kwak clock, I'll be able to jumper those blocking caps with less of an issue. -Somehow I think they are muddling or smearing the sound just enough to mask some of the jitter.
Of course, Jocko seemed to think that the DAC may require the caps. Perhaps they're doing more than just DC blocking.
Since I've really only got about 3 months of messing about with these types of things under my belt, I would almost blindly defer to Jocko's suggestions.
Thanks for the advice.
I'm connecting the CDP into a Marantz 2285B. -It's been overhauled recently (all caps replaced, pots & relay cleaned, bias & quiescent current adjusted).
It's input impedance is 33 KOhm.
The speakers are home made with Solen passive crossovers, Scan Speak D2905/9300 Tweeters & Vifa P21WO-12-08 8" drivers.
If I had to hazard a guess as to why it sounded so shrill, I would say that it's due to my clock. I suspect that once I replace my Trichord2 with a Kwak clock, I'll be able to jumper those blocking caps with less of an issue. -Somehow I think they are muddling or smearing the sound just enough to mask some of the jitter.
Of course, Jocko seemed to think that the DAC may require the caps. Perhaps they're doing more than just DC blocking.
Since I've really only got about 3 months of messing about with these types of things under my belt, I would almost blindly defer to Jocko's suggestions.
ozone_stink said:
Sounds like you have good speakers (certainly impressive looking drivers), which I would assume let you hear things warts and all. Are these 2.5 way or 2 way MTM or just 2 way (one mid/bass)? Do they sound smooth and easy to listen to from other sources e.g. sound card, tuner, etc.?
Do other Trichord2 clock users report similar negative aspects of the sound?
Jitter doesn't necessarily sound 'shrill', just 'confused' I would suggest.
I think you may just be pointing the finger in the wrong place to cure a 'shrill' sound, i.e. with a clock. The 'voicing' of many Rotel products is all about excitement. Other than those OPA2604s I wonder how they achieve this.
What cables and interconnects do you use? Do you use a metal/glass rack?
When you installed sockets for your op-amps, did you place any psu bypass caps at the sockets' psu pins? I would recommend Panasonic FC 33uF or so at this location - they sound nice and will not add any shrillness or harshness, but will improve things all round if you've not done this yet.
Just some things to think about there anyway, others can probably offer better advice than me, especially WRT the CD player.
Hello,
I got plenty of questions too. I'm not sure if you still use the active filter or not. In both cases: the DAC needs to be AC coupled (can be on Marantz side also.... but I don't have a schematic).
Do you still have the 330pF from the center of your RCA to ground? These togheter with the cable's capacitance and the input capacitance of the Marantz may account for max. 1nF (wild guess).
The PCM1732 is a voltage output DAC and needs to see an AC load of minimum 5kOhm @all frequencies. If it sees directly the 1nF this may explain the shrill sound you're describing.
Does the mute still function? <-> Bad cliks between tracks.
If so is the OpAmp still in the socket? (ouch...) Had to ask...
And finally one question... if you can check this for me. I'm just curious to find out what values R707(708) and R705(706) actually have. They set the gain for the first opamp.
I got plenty of questions too. I'm not sure if you still use the active filter or not. In both cases: the DAC needs to be AC coupled (can be on Marantz side also.... but I don't have a schematic).
Do you still have the 330pF from the center of your RCA to ground? These togheter with the cable's capacitance and the input capacitance of the Marantz may account for max. 1nF (wild guess).
The PCM1732 is a voltage output DAC and needs to see an AC load of minimum 5kOhm @all frequencies. If it sees directly the 1nF this may explain the shrill sound you're describing.
Does the mute still function? <-> Bad cliks between tracks.
If so is the OpAmp still in the socket? (ouch...) Had to ask...
And finally one question... if you can check this for me. I'm just curious to find out what values R707(708) and R705(706) actually have. They set the gain for the first opamp.
sidiy said:
too wild.....
80pF per meter is a good average for coaxial type cables
The input capacitance of an amp differs, usually 47pF or 100pF
best
Hi, I'm just using the internal DAC in the player.
The 300pF caps were an experiment for the Swenson mod that's no longer connected/active.
At the moment, my Rotel is stock with the following exceptions:
Clock:
Original Crystal (& associated bits) and HCU04 removed from circuit
Replaced with Trichord2 -clock out goes to two resistors feeding DAC and 'big chip'
Caps:
Replaced the following Panasonic FC caps with Elna Cerafines of the same value:
C665 & C666 (orig. 10uF 50V, new 10uF 100V)
C651, C661 & C662 (orig. 47uF 50V, new 47uF 100V)
C601, C963 & C965 (orig. 220uF 25V, new 220uF 100V)
C717 & C718 (orig. 100uF 25V, 100uF 100V)
C667 & C668 (orig. 4.7uF 50V, 4.7uF 100V) - DC blocking (I may eventually replace with film&foil of same value....waiting for better clock first)
Well, sorry to have caused some confusion before.
Cheers.
🙂
The 300pF caps were an experiment for the Swenson mod that's no longer connected/active.
At the moment, my Rotel is stock with the following exceptions:
Clock:
Original Crystal (& associated bits) and HCU04 removed from circuit
Replaced with Trichord2 -clock out goes to two resistors feeding DAC and 'big chip'
Caps:
Replaced the following Panasonic FC caps with Elna Cerafines of the same value:
C665 & C666 (orig. 10uF 50V, new 10uF 100V)
C651, C661 & C662 (orig. 47uF 50V, new 47uF 100V)
C601, C963 & C965 (orig. 220uF 25V, new 220uF 100V)
C717 & C718 (orig. 100uF 25V, 100uF 100V)
C667 & C668 (orig. 4.7uF 50V, 4.7uF 100V) - DC blocking (I may eventually replace with film&foil of same value....waiting for better clock first)
Well, sorry to have caused some confusion before.
Cheers.
🙂
Hello,
For Guido: Indeed 1nF was too much....
For O-Z: First I really hope that your mods will succeed. For shure a good clock will put things in perspective... just one caveat.... it is easy to notice that Rotel had implemented the PCM1732 in Hardware mode (probably you knew this already...) This means that the performance had to suffer a bit...more precisely the MSB. HDCD scaling is done digitally by default. You can compare the specs on page 3 of the datasheet.
That's why B-B wrote on the first page of the datasheet: "mid to high grade applications" ...and I still keep my helmet handy from the previous posts....
IMHO you have to work hard to bring this chip on a par with 'normal' DACs. Hope you'll prove me wrong....
Anyone: Are there some workarounds? Like increasing the order and the cutoff frequency (simultaneously) of hthe analogue filter?
For Guido: Indeed 1nF was too much....
For O-Z: First I really hope that your mods will succeed. For shure a good clock will put things in perspective... just one caveat.... it is easy to notice that Rotel had implemented the PCM1732 in Hardware mode (probably you knew this already...) This means that the performance had to suffer a bit...more precisely the MSB. HDCD scaling is done digitally by default. You can compare the specs on page 3 of the datasheet.
That's why B-B wrote on the first page of the datasheet: "mid to high grade applications" ...and I still keep my helmet handy from the previous posts....
IMHO you have to work hard to bring this chip on a par with 'normal' DACs. Hope you'll prove me wrong....Anyone: Are there some workarounds? Like increasing the order and the cutoff frequency (simultaneously) of hthe analogue filter?
Oops
I forgot to state that the op-amps which were originally OPA2604 were swapped out for AD8620s with Brown Dog adapters too.
I forgot to state that the op-amps which were originally OPA2604 were swapped out for AD8620s with Brown Dog adapters too.
Hi SIDIY
I noticed that Rotel uses two of these DACs in their top-end RCD1072.
Do you think this is to redress the issue of using them in HW mode?
On a completely different note, a friend of a friend is an engineer with Hydro Quebec. She claims that the mains in Montreal (most of Quebec too) are vastly superior in terms of 'the ideal' to the rest of North America and thus (especially) Europe.
Have you heard this too? I'm still planning to build myself a felicia balanced power conditioner , but I also wonder if we in Montreal have to worry as much as other folks do about mains nasties.
I noticed that Rotel uses two of these DACs in their top-end RCD1072.
Do you think this is to redress the issue of using them in HW mode?
On a completely different note, a friend of a friend is an engineer with Hydro Quebec. She claims that the mains in Montreal (most of Quebec too) are vastly superior in terms of 'the ideal' to the rest of North America and thus (especially) Europe.
Have you heard this too? I'm still planning to build myself a felicia balanced power conditioner , but I also wonder if we in Montreal have to worry as much as other folks do about mains nasties.
I heard the mains in UK was the best in the world and thus much better than Canada 😀 😀 😀
Seriously now, I'd advise putting a large cap across L+N - I use 10uF to good effect. Remember to use a bleed resistor to discharge it - don't kill anyone!
Also use the correct type, e.g. motor run or lighting cap.
Don't use anything in series other than a nice big isolation transformer, mmmmmm, sounds sweet!
You've reminded me now - it was the 1072 I heard in a shop. Was quite nice to my ears, with standard hi-fi gear.
Seriously now, I'd advise putting a large cap across L+N - I use 10uF to good effect. Remember to use a bleed resistor to discharge it - don't kill anyone!
Also use the correct type, e.g. motor run or lighting cap.
Don't use anything in series other than a nice big isolation transformer, mmmmmm, sounds sweet!
You've reminded me now - it was the 1072 I heard in a shop. Was quite nice to my ears, with standard hi-fi gear.
For the mains issue: it is important what you have connected on the same fuse (the local circuit in your home). If you have the fridge + computer + microwave & stuff like that on the same circuit with your gear generally it is not a good idea. We can imagine that in a huge province like ours with only 4 mil population (another wild guess) the grid should be cleaner than say... NY. But again the local consumer(s) and the industrial neighbours have the biggest influence....
I had a quick look at the line conditioner. Good layout, just a bit too compact.... Also you have to evaluate your power needs before starting and if possible place it in a grounded metallic enclosure. If not you're trowing all those nasties through the door and they enter through the window 😉
I have to look for some info on the RCD1072...
I have to look for some info on the RCD1072...
Hi O-S,
Seems also that RCD1072 is not a good 'test platform' for a diy-er : comparing the specs with RCD-02 it looks that inside it's the same story - single PCM1732 in hardware mode.
Many of us found here refuge from reviewers...anyway I googled a good one:
http://www.hifichoice.co.uk/review_print.asp?ID=2751
In that group test it scored negative by a good margin in all measurements and the listening tests are not very enthusiastic either. In fairness it was the least expensive from the group but a S/N of 88.7dB A-wtd is waaay too low.....hard to iron out.
Hope it helps.
Seems also that RCD1072 is not a good 'test platform' for a diy-er : comparing the specs with RCD-02 it looks that inside it's the same story - single PCM1732 in hardware mode.
Many of us found here refuge from reviewers...anyway I googled a good one:
http://www.hifichoice.co.uk/review_print.asp?ID=2751
In that group test it scored negative by a good margin in all measurements and the listening tests are not very enthusiastic either. In fairness it was the least expensive from the group but a S/N of 88.7dB A-wtd is waaay too low.....hard to iron out.
Hope it helps.
Well, thanks for that.
I guess I'll do what I can and sell when I'm done.
Prior to this I had a Marantz CC-48 5-disc. -The sound difference between that other player and the RCD-02 are night and day (as one could imagine)
What you are saying about the DAC and the 1072 leads me to believe there's room for even further improvement.
Cote St. Luc, eh? That's not too far from the Pte. St. Charles.
Perhaps you could drop my Rotel into your system and A/B so that I could hear what a 'real' cd/dac sounds like sometime 😉
Cheers. 🙂
I guess I'll do what I can and sell when I'm done.
Prior to this I had a Marantz CC-48 5-disc. -The sound difference between that other player and the RCD-02 are night and day (as one could imagine)
What you are saying about the DAC and the 1072 leads me to believe there's room for even further improvement.
Cote St. Luc, eh? That's not too far from the Pte. St. Charles.
Perhaps you could drop my Rotel into your system and A/B so that I could hear what a 'real' cd/dac sounds like sometime 😉
Cheers. 🙂
You guessed it right...presently my main source is a DAC (chipset DIR1701, SRC4192, CS4397) fed by a Marantz CD6000 (with the whole kit: re-clocked, re-worked S/PDIF, separate supplies for the clock and the analogue section of the decoder chip). It's either good or I'm getting too self-sufficient 'cause we're living in harmony for way too long (like almost 2 years without menacing screwdrivers or hot irons pointed @ the combo)
Sounds inviting?...scary maybe? 🙂 ...watch your e-mail
Sounds inviting?...scary maybe? 🙂 ...watch your e-mail
Kwak Clock 6 installed!!
So, thanks to Elso's help, I have replaced the Trichord 2 with the Kwak Clock 6.
There's really nothing anybody could have said to me to prepare me for the difference this has made!!
I've been hounding anybody in these forums who'll listen with PMs and emails pleading for their help to get my gear to sound as good with CDs as it does with vinyl.
Well, this has just catapulted my system forward in that direction.
When listening to Muse's Absolution CD, track 2 'Apocalypse Please' sounds like there's a guy in my living room wailing away on a piano...before it's always sounded like a machine making noise somewhere inside my speakers!!
Right now I'm listening to Rodrigo Leão's 'Cinema' and quite enjoying the goosebumps!! 😎
If you are one of the few who are considering this mod, don't think. Just do it. It's that good!! 😀
I can't stress enough how helpful / supportive / patient Elso is! -Even if you're a DIY n00b/moron like me, he'll get you there in the end!!
What else can I say? This mod is better than replacing the op-amps.
So, thanks to Elso's help, I have replaced the Trichord 2 with the Kwak Clock 6.
There's really nothing anybody could have said to me to prepare me for the difference this has made!!
I've been hounding anybody in these forums who'll listen with PMs and emails pleading for their help to get my gear to sound as good with CDs as it does with vinyl.
Well, this has just catapulted my system forward in that direction.
When listening to Muse's Absolution CD, track 2 'Apocalypse Please' sounds like there's a guy in my living room wailing away on a piano...before it's always sounded like a machine making noise somewhere inside my speakers!!
Right now I'm listening to Rodrigo Leão's 'Cinema' and quite enjoying the goosebumps!! 😎
If you are one of the few who are considering this mod, don't think. Just do it. It's that good!! 😀
I can't stress enough how helpful / supportive / patient Elso is! -Even if you're a DIY n00b/moron like me, he'll get you there in the end!!
What else can I say? This mod is better than replacing the op-amps.
Excellent, I'm pleased to hear you've got a good result here. I wonder what was wrong with that Trichord 2.
And what's next on the cards? 😉
And what's next on the cards? 😉
The only thing I could do next is modify the clock into a Kwak Clock 7. However, this would also involve building an unregulated PS with +/- rails.
The Rotel's raw digital supply only has +ve rails. Elso's clock works best on raw non-regulated supply. As one would expect, it's not a good idea to use the analogue suppy with your clock.
Seems like a lot of trouble to go through for ver. 7. However, who knows...it's not like that's stopped me before. I think what I'm worried about is that it sounds really good right now and I don't want to break it.
The Rotel's raw digital supply only has +ve rails. Elso's clock works best on raw non-regulated supply. As one would expect, it's not a good idea to use the analogue suppy with your clock.
Seems like a lot of trouble to go through for ver. 7. However, who knows...it's not like that's stopped me before. I think what I'm worried about is that it sounds really good right now and I don't want to break it.
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