Hi all, congrats on 15,000 posts. Finally got some time to sort my 63 out.
OK, to refresh folks, I'm modding a 63 and it now won't play. Discs spin but not being read.
I finally got round to checking my work. On the advice of Ray and Brent, i reversed some work, checked for broken pads, tracks etc. Can't find anything wrong.
I did some mods on the HF amp too. What does this do. Could that affect the discs not reading. I'm simply following Ray's mod sheet. Any ideas, thanks.
OK, to refresh folks, I'm modding a 63 and it now won't play. Discs spin but not being read.
I finally got round to checking my work. On the advice of Ray and Brent, i reversed some work, checked for broken pads, tracks etc. Can't find anything wrong.
I did some mods on the HF amp too. What does this do. Could that affect the discs not reading. I'm simply following Ray's mod sheet. Any ideas, thanks.
Hi grofus,
If the HF amp doesn't work correctly, and the signal has become weak or distorted for some reason, the player won't read any discs.
What exactly did you change on the HF amp? Just C503/504/505 and R505? C505 is critical, it is in series with the HF signal. I once had a bad 2n2 polystyrene in there that made me puzzle for some time. The rest is power supply, you should check if there's power on both sides of R505 and C503 and 504.
Regards,
Ray
If the HF amp doesn't work correctly, and the signal has become weak or distorted for some reason, the player won't read any discs.
What exactly did you change on the HF amp? Just C503/504/505 and R505? C505 is critical, it is in series with the HF signal. I once had a bad 2n2 polystyrene in there that made me puzzle for some time. The rest is power supply, you should check if there's power on both sides of R505 and C503 and 504.
Regards,
Ray
Hi Ray, Yes, I changed all that you mention.
C503 removed
C504 Uprated to 470u / 16v
C505 Uprated to 2n2 PS
R505 to 1mH / 14R + ferrite
Just noticed you recommend C504 to 330u / 16v, will that matter?
OK, checked voltages, C503 ( across pads) 5v, C504 is 5v. No volts across R505. However, when i move the to a different ground point nearby, i get 5v from the + pin of R505. If that makes sense. Does this indicate a broken pad on - side of R505?
Also checked volts across C505 and got 1.83v
Thanks again for the help
Steve
Hi Steve,
470u is fine, the 330u is probably what I had in stock at that time. It's no rocket science. Across R505 the voltage should be around zero, but between ground and either side of R505 5V should be present. The 1.83V across C505 seems a bit high. When you look at the HF amp in the schematic (it's the circuit around the two transistors Q501 and Q502, near the decoder), it says 2.8V at R507 and 2.5V at C507, at the other side of C505. That means a voltage difference of only 0.3V should be present across C505. You can verify this by measuring at both sides of C505 wrt. ground.
Regards,
Ray
470u is fine, the 330u is probably what I had in stock at that time. It's no rocket science
. Across R505 the voltage should be around zero, but between ground and either side of R505 5V should be present. The 1.83V across C505 seems a bit high. When you look at the HF amp in the schematic (it's the circuit around the two transistors Q501 and Q502, near the decoder), it says 2.8V at R507 and 2.5V at C507, at the other side of C505. That means a voltage difference of only 0.3V should be present across C505. You can verify this by measuring at both sides of C505 wrt. ground.Regards,
Ray
Hi Steve,
470u is fine, the 330u is probably what I had in stock at that time. It's no rocket science
Regards,
Ray
OK, I misunderstood. R505 is OK. C505 seems a problem. Across both pins of C505 I get 1.83v. Then with a common grnd, The pin nearest the back of the board is 2.5v and the pin next to the jumper U183 reads 4.34v.
Is the problem with C505? I have rechecked these readings to be sure.
Thanks, Steve
A bit off topic but.... sometimes we have to step back to see the forest from the trees (lousy metaphore I admit) I have had my 67' for a long time and it is now about a third of the way towards Brent's uber machine (no doubt in great part due to Ray's DOS.)Until now I was convinced but not overwhelmed to be honest. Each upgrade brought an improvement but...there was always a but. Until...I had my amp recently re-tipped (joke) with a total array of Blackgates and the new Vishay S-foil resistors. After a fairly painless but rather boring 100 hours of burn-in, it suddenly snapped into bloom (and there are still some 400 hours to go I'm told) and I finally got to hear what has really been done to the Marantz. I wouldn't bore you with the details but believe me I never had a TT that sounded like this or for that matter, never had a system sound so musical and convincing. the amp is stellar, the CDP is not far behind and even my modest TL speakers are singing like never before. I believe there are better players, for a whole lot of money, and some have modded other ones with different dacs and topology and maybe they do sound better but I am both pleased and greatfull to have benifited from all the hard work and thought that has gone into this project. Long may it last.
Absolutely, that's why it's the player from my point of view in an "efficient" money-wise audio gear & set-up.
There are better everything around but when it's about money/musicQ ratio then it's a winner. As for me it's a 120€ machine inc. player. No need to say that no cdp, even modded, beat it in decent price (let you figure what is a decent price for a 1000€/monthly worker, again, point of view). The attemp with CD951 and CD40 were more expensive and needed more work even if they can be taken further. Same about amp and speakers (TK2050 Tripath and MJK's open baffle) and you are in the twilight zone. By twilight zone I mean the "other world" when you can't compare thing for there is so much difference than nothing can explain it beside... twilight zone. Last time I went to a "famous" shop I heard a 1400€ speakers set and Marantz xx5004 stuff: crap! It sounded like my alarm clock, or a bit better. And it's legal to sell these prices?
C505 is working fine, it is blocking DC and keeping those two voltages separated. But the 4.34V is too high, according to the schematic it should be around 2.8V. Could you confirm by measuring directly across R507?
Ray
Hi Shep,
Good to hear your player can finally show what it is capable of. There was clearly a bottleneck in your system... You should also consider to try some new interconnects. Now that your system is playing at a higher level, the present ones may be holding things back a bit (depends on what you have right now of course).
Ray
Good to hear your player can finally show what it is capable of. There was clearly a bottleneck in your system... You should also consider to try some new interconnects. Now that your system is playing at a higher level, the present ones may be holding things back a bit (depends on what you have right now of course
).Ray
Actually I have very good cables so the bottleneck was the amp. I would love to hear some cables in the 500 euro range but sadly...What ever happened with that "add-on" for the DOS Ray? Worth doing or not? I'm making my wish list for Brent for the next time I ship to him. More S'regs, resistor change and anything else I've forgotten. I would ask for suggestions but I don't even know any more what has been done. We haven't heard from Romeister in a while. He must be very busy. I haven't been near a hi-fi shop for years. It's better that way. anyway the nearest is Toulouse and they would probably not let me in the door!
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I think the add-on for the DOS is great. I haven't heard it yet, but Steve got very good results with it. The theory behind it and the simulations I did tell me it's an upgrade over the existing DOS circuit, so I think it's worth doing it. One of Steve's nice boards and most of the parts are waiting here to be assembled and fitted in my SA8400. No time yet... But I have two weeks off at the end of the year, and i'm hoping to work on my player then.
If you have some spare time, take two PNP transistors and the few needed resistors and adapt the DOS to the new circuit, i'm sure it will be an improvement.
Ray
If you have some spare time, take two PNP transistors and the few needed resistors and adapt the DOS to the new circuit, i'm sure it will be an improvement.
Ray
Yes, I know... It is also an encouragement for others
Well...seems I have to order BC560s (any brand recommended?)
Any feedback on the sonical bonus of having this tweak?Shepp, so there also doors open if you look like bankable cutomer? HiFi stands for High-Finances there...
Yes, 4.34v across R507. Also measured the pins from Q502. The pin that feeds R507 was, of course 4.34v and the others were at 4.9v and 5v.
Looking at the schematic the pin with 4.9 is right, the others are not.
Is this the problem ? (he asks hopefully)
By the way, how is the proud owner of the pink soldering iron doing. Still providing joy, smiles and sleepless nights?
Steve
Hello Everyone,
Well I'm still the only one with this CFP-DOS circuit in my players. I think it is a fantastic circuit! I've sold boards, given some away, even sold a completed module, but nobody else has yet put this circuit in their player. Eventually someone will get one together and into a player. Then we will see just how good the circuit really is.
Steve