Yeah, mine wasn't an ornamental issue. Maybe I should have another go some time?
Nice work (and good investigative efforts 🙂 ).
Porcelain and hifi don't really go together. I remember when I was a kid, I unintentionally managed to use my Dad's sub and enough sound pressure to make my mum's porcelain hedgehog thing gently make its way to the edge of a shelf, and plummet to its death. Like a spiky lemming! Thankfully, cunning use of super glue (and the fact that she doesn't use the internet, or this forum) meant that she's never found out.
Nice work (and good investigative efforts 🙂 ).
Porcelain and hifi don't really go together. I remember when I was a kid, I unintentionally managed to use my Dad's sub and enough sound pressure to make my mum's porcelain hedgehog thing gently make its way to the edge of a shelf, and plummet to its death. Like a spiky lemming! Thankfully, cunning use of super glue (and the fact that she doesn't use the internet, or this forum) meant that she's never found out.
Funny tales guys!! So DEM re-clock on /2 is a goer. That's two things that can share a /2 line then. The B-chip is a good thing to use, it's definitely a lot better.
Ian - maybe you already have a C or something and that's why yours won't work. I'd imagine you checked though, right? There seem to be a few versions of this chip, like the 1541.
Simon
Ian - maybe you already have a C or something and that's why yours won't work. I'd imagine you checked though, right? There seem to be a few versions of this chip, like the 1541.
Simon
hi, I know it's a little off-topic, anyone had experience with sony digital filters with tda ? (like cxd1088)
what is the difference in comparison to 7220 ?
btw, regarding pmd100, any sources to buy ? pmd200 is supposed to be better but I couldnt find any retailer...
greetings,
Pawel
what is the difference in comparison to 7220 ?
btw, regarding pmd100, any sources to buy ? pmd200 is supposed to be better but I couldnt find any retailer...
greetings,
Pawel
No too much P;$$ taking so far! ty!
I should have known better really! I too have broken ornaments following a good session in the pub follwed by music till late!
I've removed the headphones circuit but maybe I should reinstate for testing! Excellent idea tubee!
So far asa the B chip goes, I was a little confused. Mine's def a A ver on the decoder board. The B ver wasn't from Lee tho'. It was in the DAC kit i'm building so it's possible its a bit suspect. I did all the usual things like checking it was in the right way round and, checking supply voltage etc. I know Lee's dropped straight in to the same decoder board with no problem and also yours too now Simon. I'll need to have another go.
Philpoole - you should definately have another go at the dem. I've now got a sercal /2 board for the DAC and I use this feed to supply the logic gate to give me the inverted clock for the dem. Check out ecdesigns diagram I posted the other day, its really simple!
Ian
I should have known better really! I too have broken ornaments following a good session in the pub follwed by music till late!
I've removed the headphones circuit but maybe I should reinstate for testing! Excellent idea tubee!
So far asa the B chip goes, I was a little confused. Mine's def a A ver on the decoder board. The B ver wasn't from Lee tho'. It was in the DAC kit i'm building so it's possible its a bit suspect. I did all the usual things like checking it was in the right way round and, checking supply voltage etc. I know Lee's dropped straight in to the same decoder board with no problem and also yours too now Simon. I'll need to have another go.
Philpoole - you should definately have another go at the dem. I've now got a sercal /2 board for the DAC and I use this feed to supply the logic gate to give me the inverted clock for the dem. Check out ecdesigns diagram I posted the other day, its really simple!
Ian
Ah, I tried this earlier version from John (ECDesigns), it uses a counter to divide down BCLK:
DEM reclock
I hadn't seen this new circuit (I'd been distracted from DEM reclocking for a while).
Perhaps worth a punt. I didn't realise you could simply use BCLK, I thought it had to be a bit slower than that.
DEM reclock
I hadn't seen this new circuit (I'd been distracted from DEM reclocking for a while).
Perhaps worth a punt. I didn't realise you could simply use BCLK, I thought it had to be a bit slower than that.
I think it depends on the tolerences of the tda.
John says it should lock up to about 7Mhz. That means you should be OK with the /2 used for bck. You will need yhe /2 non inverted and inverted so you'll need a gate in the way for the inverted feed. Mine's done exactly as per his later diagram that I posted.
The worst case is that you'll need to divide again and use /4.
You could always use a 74hc4040 (12 bit binary counter) to give you multiple clock freq then a 74hc00 (i think) to give you the inverted. That way you'll have all the bases covered for many clock choices!
Ian
John says it should lock up to about 7Mhz. That means you should be OK with the /2 used for bck. You will need yhe /2 non inverted and inverted so you'll need a gate in the way for the inverted feed. Mine's done exactly as per his later diagram that I posted.
The worst case is that you'll need to divide again and use /4.
You could always use a 74hc4040 (12 bit binary counter) to give you multiple clock freq then a 74hc00 (i think) to give you the inverted. That way you'll have all the bases covered for many clock choices!
Ian
B filter again delivers more odd harmonics, as TDA1451 A does compared to plain 1541
But my cd 880 is capable of some extra fidelity, more low level detail silence is more black compared to the cd304mk2 with plain dac and non B filter. Could be the S1 and B filter, but output differs too as other periferal circuitry.
But my cd 880 is capable of some extra fidelity, more low level detail silence is more black compared to the cd304mk2 with plain dac and non B filter. Could be the S1 and B filter, but output differs too as other periferal circuitry.
Just a quicky on the valve buffer stage which has replaced my DOS.
Mudorfs 0.22uf arrived today! What a difference. It ended up being pretty expensive (about £50 worth of caps and diodes etc) but worth it. I already had supreme 4.7uF on the output so I guess its about £115 in total (kit, tx and upgrades (without the 4.7's)) comparable to the DOS with decent components.
Its got a relaxing easy going sound but with an enormous amount energy when needed. It seems effortless to produce very big dynamincs (which is poss why I say relaxing). As expected, acoustic guitars and female vocals are to die for! Thats valves for you!
Next in will be the B chip. I got another today so I'll try that sometime next week. I'd better give this latest round of upgrades a chance.😉
Ian
Mudorfs 0.22uf arrived today! What a difference. It ended up being pretty expensive (about £50 worth of caps and diodes etc) but worth it. I already had supreme 4.7uF on the output so I guess its about £115 in total (kit, tx and upgrades (without the 4.7's)) comparable to the DOS with decent components.
Its got a relaxing easy going sound but with an enormous amount energy when needed. It seems effortless to produce very big dynamincs (which is poss why I say relaxing). As expected, acoustic guitars and female vocals are to die for! Thats valves for you!
Next in will be the B chip. I got another today so I'll try that sometime next week. I'd better give this latest round of upgrades a chance.😉
Ian
Hi Ian,
Is the valve stage now the one to go for? This could be something for me to strive for.. when the player goes on plywood.
Simon
Is the valve stage now the one to go for? This could be something for me to strive for.. when the player goes on plywood.
Simon
Hi Simon,
I think its a question of taste! I love the sound that valves make (It goes back to my QuadII's).
I'd definately say its better than the DOS now as its certainly not behind in detail!
The basic kit is about £45 delivered so it not mega bucks to start but its not that good, std.
Also, it'll depend on what you're running now? I already had a Burson doing the I/V and Supreme 4.7's decoupling the putput so I had a head start.
The 1st mods to the Valve stage are pretty cheap, 10 FC's & 5 Schottky's start to tighten it up.
The 4 0.22uF in the audio path are what made this stage really sing.
Not easy (almost impossible) to fit in the player, but on a wood base, you've got all the room you need!
If you want valves, this is a good entry as it uses low voltage HT.
I'm still fairly sure, I can get more out of it! I'm trying to be as balanced in my approach as possible but I must confess I've always fancied a valve output stage (even in my CD63!).
😀
I think its a question of taste! I love the sound that valves make (It goes back to my QuadII's).
I'd definately say its better than the DOS now as its certainly not behind in detail!
The basic kit is about £45 delivered so it not mega bucks to start but its not that good, std.
Also, it'll depend on what you're running now? I already had a Burson doing the I/V and Supreme 4.7's decoupling the putput so I had a head start.
The 1st mods to the Valve stage are pretty cheap, 10 FC's & 5 Schottky's start to tighten it up.
The 4 0.22uF in the audio path are what made this stage really sing.
Not easy (almost impossible) to fit in the player, but on a wood base, you've got all the room you need!
If you want valves, this is a good entry as it uses low voltage HT.
I'm still fairly sure, I can get more out of it! I'm trying to be as balanced in my approach as possible but I must confess I've always fancied a valve output stage (even in my CD63!).
😀
Sounds like the perfect chance to get some TOOBZ into my system! I'm running standard IV/output with LM4562! Been concentrating on the real problems before the tasty icing.
Hi Simon,
If you're running dual op amps, its prob worth spendng time to get them to singles. You'd need to do this in order to play with the output stage seperate to the I/V anyhow. Could poss make sub boards on vero with 4 singles? Could even cater for better decoupling caps before you start on the output stage!?
My DAC board had 4 singles to start with. I used a dual Burson but just wired the input to both DIL sockets for the I/V.
Like you say, perfect chance to get some TOOBZ in!
Ian
If you're running dual op amps, its prob worth spendng time to get them to singles. You'd need to do this in order to play with the output stage seperate to the I/V anyhow. Could poss make sub boards on vero with 4 singles? Could even cater for better decoupling caps before you start on the output stage!?
My DAC board had 4 singles to start with. I used a dual Burson but just wired the input to both DIL sockets for the I/V.
Like you say, perfect chance to get some TOOBZ in!
Ian
Lee's also been on at me about trying just one half of the op-amp... I'll look into it!
Thanks,
Simon
Thanks,
Simon
Dual regulation in analog section
Hi Guys,
You should read this:
From Stereophile nov 1991 by Corey Greenberg
Aunt Corey's Homemade Buffered Passive Preamplifier
Psychedelic dual regulation, that's where it's at
Hoo boy, have I saved the best for last, After putting the Penny & Giles volume pot back in, after installing the high-speed rectifiers, after rewiring the innards with Kimber KCAG, I was seriously digging the new clarity shining out of my preamp. It was certainly no slouch before the mods, but the sum total of all these tweaks made for a very real and significant improvement to the sound, and I was finally satisfied that I'd wrung all the performance out of the design that I could.
John Curl called me with what turned out to be the most important mod I ended up making to Aunt Corey's Homemade Buffered Passive Preamp; seems he'd read my original article, and it reminded him of when he built the piece of gear that put him on the high-end map in the first place: the Mark Levinson JC-1 preamp. He (and everyone else at the time) thought it was just about as good as it got, but one of his friends told him that he got much better sound by using two JC-1s, used as "mono" preamps for each channel. John tried it, and sure enough, the soundstaging got better! After he went back and looked at the circuit, John found that because both channels were fed by the same power-supply regulators, the two channels "talked" to each other; what happened in the left channel affected the right, and vice versa. By giving each channel its own dedicated regulation stage, John was able to isolate the two channels sufficiently to where the JC-1 sounded as good in stereo as two did in mono.
"Dual regulation," John advised me. "That's where it's at!"
Well, when John Curl talks, I listen. After fishing out a couple more Linear Technology LT1033/1085 regulators from my parts drawer, I completely rewired my entire power supply; using single solid-core legs of AudioQuest's Type 4 speaker cable for the DC rails, I basically duplicated everything after the rectifiers. In other words, where before each of the two rectifier bridges fed a single regulation stage, now it feeds two. Connect the input of the second positive regulator to the positive terminal of C1; that of the new negative regulator to the negative terminal of C8. Once you finish wiring the supply up, each BUF-03 should be powered by its own pair of LT1033/1085 regulators. Go on, spoil the li'l buffers.
I really tried to lay the wiring out neatly this time; no more Squiddly Diddly retardo mess. And in a nod to the Chicken Littles who wrote all those letters about my use of 18V DC rails in the original article (footnote 10), I sighed and brought them down a bit to a safe and happy ±15V DC by changing the value of R2 and R4 in the original schematic (Vol.14 No.11, p.101) from 12.9k to 10.5k. Real men run their BUF-03s at max supply voltage, but I guess such a brazen display of machismo is unwelcome in this time of male rebirthing and Wildman gatherings. I need a hug.
Because the current demand on each LT regulator is halved when you go for dual regulation, I lowered the value of the bleeder resistors across each supply rail to ground, R7 and R8, to 750 ohms/0.5W. This gives an additional 20mA current drain per regulator; the LT chips need to work a bit before they get their mojos workin', and the new resistor values keep the regulators nice and warm.
Lather knows best
You want lather? I'll give you lather; when I changed the Alps pot out for the Penny & Giles, the preamp sounded more open on top. When I installed the high-speed rectifiers, the low-level detail became much clearer and the slight grain through the mids was banished. When I rewired the audio circuit with Kimber silver wire, the sound became even more alive.
But when I installed the dual-regulated power supply, the preamp was transformed. Bass lines just bounced out of the BUFs, deeper and tighter than I'd ever heard them over the mighty Muse subwoofer; the sense of increased "slam" was amazing! I mean, this preamp BOOGIED! And the sense of recorded space on purist recordings like the Cowboy Junkies' Trinity Session and JA's piano cut on the first Stereophile Test CD was just incredible; so much better than the original prototype, I could hardly believe this was the same preamp. The increased sense of bass boogie made music sound much more rhythmically exciting, even slow blues like Stevie Ray Vaughan's "Tin Pan Alley." Is this what real hi-fi critics like Mr. Martin Colloms mean when they talk about "pace"? If it is, boy, then "pace" is IT!
John Curl, thank you; dual regulation transformed my preamp from a very good piece of gear into a serious monkeybone muh-cheen. Yeah, it was a pain in the butt to go back and rebuild the power supply, but the improvements it wrought are on a par with installing dedicated AC lines in my listening room. It's that dramatic, and I'm that ecstatic!
I did this to my Marantz CD40 and I agree with Corey. The player is transformed into a new player. I used 7815 and 7915 with red 1uF MKT caps and a resistor of 1k5.
Peter
Hi Guys,
You should read this:
From Stereophile nov 1991 by Corey Greenberg
Aunt Corey's Homemade Buffered Passive Preamplifier
Psychedelic dual regulation, that's where it's at
Hoo boy, have I saved the best for last, After putting the Penny & Giles volume pot back in, after installing the high-speed rectifiers, after rewiring the innards with Kimber KCAG, I was seriously digging the new clarity shining out of my preamp. It was certainly no slouch before the mods, but the sum total of all these tweaks made for a very real and significant improvement to the sound, and I was finally satisfied that I'd wrung all the performance out of the design that I could.
John Curl called me with what turned out to be the most important mod I ended up making to Aunt Corey's Homemade Buffered Passive Preamp; seems he'd read my original article, and it reminded him of when he built the piece of gear that put him on the high-end map in the first place: the Mark Levinson JC-1 preamp. He (and everyone else at the time) thought it was just about as good as it got, but one of his friends told him that he got much better sound by using two JC-1s, used as "mono" preamps for each channel. John tried it, and sure enough, the soundstaging got better! After he went back and looked at the circuit, John found that because both channels were fed by the same power-supply regulators, the two channels "talked" to each other; what happened in the left channel affected the right, and vice versa. By giving each channel its own dedicated regulation stage, John was able to isolate the two channels sufficiently to where the JC-1 sounded as good in stereo as two did in mono.
"Dual regulation," John advised me. "That's where it's at!"
Well, when John Curl talks, I listen. After fishing out a couple more Linear Technology LT1033/1085 regulators from my parts drawer, I completely rewired my entire power supply; using single solid-core legs of AudioQuest's Type 4 speaker cable for the DC rails, I basically duplicated everything after the rectifiers. In other words, where before each of the two rectifier bridges fed a single regulation stage, now it feeds two. Connect the input of the second positive regulator to the positive terminal of C1; that of the new negative regulator to the negative terminal of C8. Once you finish wiring the supply up, each BUF-03 should be powered by its own pair of LT1033/1085 regulators. Go on, spoil the li'l buffers.
I really tried to lay the wiring out neatly this time; no more Squiddly Diddly retardo mess. And in a nod to the Chicken Littles who wrote all those letters about my use of 18V DC rails in the original article (footnote 10), I sighed and brought them down a bit to a safe and happy ±15V DC by changing the value of R2 and R4 in the original schematic (Vol.14 No.11, p.101) from 12.9k to 10.5k. Real men run their BUF-03s at max supply voltage, but I guess such a brazen display of machismo is unwelcome in this time of male rebirthing and Wildman gatherings. I need a hug.
Because the current demand on each LT regulator is halved when you go for dual regulation, I lowered the value of the bleeder resistors across each supply rail to ground, R7 and R8, to 750 ohms/0.5W. This gives an additional 20mA current drain per regulator; the LT chips need to work a bit before they get their mojos workin', and the new resistor values keep the regulators nice and warm.
Lather knows best
You want lather? I'll give you lather; when I changed the Alps pot out for the Penny & Giles, the preamp sounded more open on top. When I installed the high-speed rectifiers, the low-level detail became much clearer and the slight grain through the mids was banished. When I rewired the audio circuit with Kimber silver wire, the sound became even more alive.
But when I installed the dual-regulated power supply, the preamp was transformed. Bass lines just bounced out of the BUFs, deeper and tighter than I'd ever heard them over the mighty Muse subwoofer; the sense of increased "slam" was amazing! I mean, this preamp BOOGIED! And the sense of recorded space on purist recordings like the Cowboy Junkies' Trinity Session and JA's piano cut on the first Stereophile Test CD was just incredible; so much better than the original prototype, I could hardly believe this was the same preamp. The increased sense of bass boogie made music sound much more rhythmically exciting, even slow blues like Stevie Ray Vaughan's "Tin Pan Alley." Is this what real hi-fi critics like Mr. Martin Colloms mean when they talk about "pace"? If it is, boy, then "pace" is IT!
John Curl, thank you; dual regulation transformed my preamp from a very good piece of gear into a serious monkeybone muh-cheen. Yeah, it was a pain in the butt to go back and rebuild the power supply, but the improvements it wrought are on a par with installing dedicated AC lines in my listening room. It's that dramatic, and I'm that ecstatic!
I did this to my Marantz CD40 and I agree with Corey. The player is transformed into a new player. I used 7815 and 7915 with red 1uF MKT caps and a resistor of 1k5.
Peter
Attachments
Pedja Rogic mods to 304 MKII
For those who did not read the story of Pedja.
I'm sorry to say but I did have a CD650 for 20 years but the Marantz CD40 does sound better after moddding.
The SAA7310 is better.
Peter
For those who did not read the story of Pedja.
I'm sorry to say but I did have a CD650 for 20 years but the Marantz CD40 does sound better after moddding.
The SAA7310 is better.
Peter
Re: Pedja Rogic mods to 304 MKII
Hi Peter, very interesting read indeed!
Do you have copies of Pedja's diagrams refered to in the document? The embedded links don't seem to work for me!
Many thanks
Ian
PAM said:
Hi Peter, very interesting read indeed!
Do you have copies of Pedja's diagrams refered to in the document? The embedded links don't seem to work for me!
Many thanks
Ian
Re: Pedja Rogic mods to 304 MKII
😕 Better at what? Getting the bits from the disk? I don't think that's the case. If the 7220 is kicked out and the master clock is connected to the 7310, then maybe less jitter towards the dac. Another thought would be less powersupply demands from a (cmos) 7310. But still, define better and why is the difference between the players down to the 7310?
A cd40 is nothing special. cdm4 without hall motor. R1 DAC (had a cd40 once), allthough the A version, were a 650 is without. One microcontroller (iirc for the cd40 instead of three in the 650); less noice on the powersupplies. But still the entry player at the time.
Probably it comes down to the mods to explain the difference.
PAM said:
😕 Better at what? Getting the bits from the disk? I don't think that's the case. If the 7220 is kicked out and the master clock is connected to the 7310, then maybe less jitter towards the dac. Another thought would be less powersupply demands from a (cmos) 7310. But still, define better and why is the difference between the players down to the 7310?
A cd40 is nothing special. cdm4 without hall motor. R1 DAC (had a cd40 once), allthough the A version, were a 650 is without. One microcontroller (iirc for the cd40 instead of three in the 650); less noice on the powersupplies. But still the entry player at the time.
Probably it comes down to the mods to explain the difference.
Dual regulation.
Yes. When I built my second DAC, I used dual regulation, and it made a huge difference. My first DAC just used simple 78xx style regs, but I then moved on to LM3x7 style followed TL431. It really helped.
I'm interested in replacing with opamp based regs (Using three dual opamps, I can regulate 2 TDA1541As 🙂 ), but I have no time at the moment, and I also want to design a better reconstruction filter (well I've sort of designed it, need to buildit), do DEM reclocking again, stuff like that. The list never ends.
Yes. When I built my second DAC, I used dual regulation, and it made a huge difference. My first DAC just used simple 78xx style regs, but I then moved on to LM3x7 style followed TL431. It really helped.
I'm interested in replacing with opamp based regs (Using three dual opamps, I can regulate 2 TDA1541As 🙂 ), but I have no time at the moment, and I also want to design a better reconstruction filter (well I've sort of designed it, need to buildit), do DEM reclocking again, stuff like that. The list never ends.
I did a couple of little mods on my CD650 this evening. One was to swap the little 47uF ZA I had on the SAA7220 for an Os-con 220uF / 20V. This has certainly had the effect of widening the stereo image, as well as generally tightening things up. So far so good. Will do more soon!
Simon
Simon