I recently purchased a Marantz DV7600 and the DIY'er in me has to try and improve it. I lost my complete novice status by doing most of the recommended mods on my CD67SE so I'm going to try and apply similar prinicples to this new universal player.
My first stop is the primary supply for the audio portion of this player.
Based on my CD67 experience I have the following ideas:
D928 and D929 will be replaced with a FairChild 600V/4a Stealth diode. Although I have to reread some posts to see everyones thoughts on the MUR's.
C929 anc C930 will be replaced with a Rubycon ZL 1000uf 50volts.
As far as the +/-8v regulators go I have ordered ALWSR's to replace them.
And last but not least I am considering replacing C931 and C932 with some BG FK 100uF 100v caps.
I'm always interested in different points of view so feel free to offer your opinion.
Regards,
Dan
My first stop is the primary supply for the audio portion of this player.
An externally hosted image should be here but it was not working when we last tested it.
Based on my CD67 experience I have the following ideas:
D928 and D929 will be replaced with a FairChild 600V/4a Stealth diode. Although I have to reread some posts to see everyones thoughts on the MUR's.
C929 anc C930 will be replaced with a Rubycon ZL 1000uf 50volts.
As far as the +/-8v regulators go I have ordered ALWSR's to replace them.
And last but not least I am considering replacing C931 and C932 with some BG FK 100uF 100v caps.
I'm always interested in different points of view so feel free to offer your opinion.
Regards,
Dan
gbyleveldt said:Hi Dan,
Do you have the schematics for the DV7600??
Wow, if possible, would you care to forward it to me? I've been itching to tinker with mine as well, but wouldn't even consider it without the schematics.
I made the attempt and hope the 14.6M file size doesn't screw things up.
That aside, I've learned some interestings things about our player already. SMPS power supply, 12.288Mhz audio clock, discrete output stage (yahoo! no opamps!).
Let's start some interesting threads about modding this player for the benefit of all.
Regards,
Dan
dantwomey said:
Heh, I doubt that will work. Any idea on where you got hold of it? Maybe I can try that way. Otherwise maybe break it into smaller chunks and send it that way, if possible.
dantwomey said:
Yup! I was going to get the DV6600, but after checking the specs on the DV7600, I decided to go for that rather
My reasons were
a) HDAM II (Marantz JFet Discrete output stage)
b) 6 CS4398 DAC (Crystal's flagship DAC)
c) Discrete 6 channel analogue outputs. I have my own 5.1 preamp and the various amps. I think this is the cleanest signal possible without going through some fancy DSP and noisy environment in a normal AV amp.
I'm quite curious to see the schematic. That'll be the only way to decide what to upgrade
Cheers
Gert
Hi Dan,
There's another option which will obtain an excellent result - install a separate complete power supply for analog section. Check the analog circuitry - you could probably leave this power supply ON all the time. This is the best, easiest option that will give the most in return. You could also feed this current from your new analog power supply via high quality cables (!) straight to where it is needed and avoid connectors completely.
SMPS are difficult to work with and are usually carefully designed to obtain optimal results. Any component replacement could possibly lead to extra heat dissipation / current “drive capability” loss. The only SMPS section you could improve without any danger is the input bridge rectifier and decoupling cap. I use RURP3060 and costly Black Gate high voltage cap - but to be honest, the "bang for the buck" factor is not that great... but it can be easily noticed as an improvement!
As for the parts you mentioned you'd like to replace, try Black Gate Non Polar type 50V 100uF (which is fantastic cap for "post-decoupling"). 1N4937 diode can be replaced with one of the excellent glass - passivated fast switching diodes from the Philips range.
Good luck,
Boky
There's another option which will obtain an excellent result - install a separate complete power supply for analog section. Check the analog circuitry - you could probably leave this power supply ON all the time. This is the best, easiest option that will give the most in return. You could also feed this current from your new analog power supply via high quality cables (!) straight to where it is needed and avoid connectors completely.
SMPS are difficult to work with and are usually carefully designed to obtain optimal results. Any component replacement could possibly lead to extra heat dissipation / current “drive capability” loss. The only SMPS section you could improve without any danger is the input bridge rectifier and decoupling cap. I use RURP3060 and costly Black Gate high voltage cap - but to be honest, the "bang for the buck" factor is not that great... but it can be easily noticed as an improvement!
As for the parts you mentioned you'd like to replace, try Black Gate Non Polar type 50V 100uF (which is fantastic cap for "post-decoupling"). 1N4937 diode can be replaced with one of the excellent glass - passivated fast switching diodes from the Philips range.
Good luck,
Boky
Extreme_Boky said:
A separate power supply is an excellent suggestion but I'm going to try and improve the SMPS for two reasons. First, this player is in a compact case so space is at a premium. Looking ahead I can already see some issues in fitting the ALWSR boards and the NewClassD Audio clock I have planned.
And secondly, with SMPS being alittle more complex and less tinkered with I think I'll enjoy the challenge of upgrading it.
Referring to Percy Audio's parts list I see the Blackgate WKZ caps are VERY expensive. If I get the chance I'll send you a copy of the SMPS schematic and we'll discuss some ideas.
Regards,
Dan
Hi Dan,
Thanks again for the schematics.
OK. On the SMPS front. I would be REALLY careful messing with it. Most caps in an SMPS are very low ESR types, required for the high frequencies involved. The SMPS in the DV is one of the simpler varieties. When I get the guts, I'll rip open my DV and measure how much of the HF gunk ends up in the audio chain before merilly changing out parts here. What might be a suggestion is to replace the regulators after C929 and C930 on the SMPS board. Otherwise, after we know what happens on the power lines, we can try inductors in line to filter out some of the *possible* HF noise.
One the audio side, the upgrade should be done in stages. Firstly, it would appear as if Marantz has made a pretty decent attempt at improving the muting circuit around the audio outputs. I'm not sure what kind of impact these have on the audio, but it might be a good idea to replace these with reed relays. Also, the only cap in the audio chain is the 220uF cap after the HDAM circuit (C716). Initially I would replace these with a back to back pair of 470uF YXF Rubicon caps (or Blackgates if you mortgage the house).
As a side note, I would like to study the schematics of the Classe CDP300. These use the same CS4398 DACS (and they sound incredible!!) as on our DV. It would be interesting to see how they approached the design of their analogue section.
Anyway, this is what I can think of for now. I'll probably hold off any mods on my DV till the warranty expires. Or maybe not... Heehee
Cheers
Gert
Thanks again for the schematics.
OK. On the SMPS front. I would be REALLY careful messing with it. Most caps in an SMPS are very low ESR types, required for the high frequencies involved. The SMPS in the DV is one of the simpler varieties. When I get the guts, I'll rip open my DV and measure how much of the HF gunk ends up in the audio chain before merilly changing out parts here. What might be a suggestion is to replace the regulators after C929 and C930 on the SMPS board. Otherwise, after we know what happens on the power lines, we can try inductors in line to filter out some of the *possible* HF noise.
One the audio side, the upgrade should be done in stages. Firstly, it would appear as if Marantz has made a pretty decent attempt at improving the muting circuit around the audio outputs. I'm not sure what kind of impact these have on the audio, but it might be a good idea to replace these with reed relays. Also, the only cap in the audio chain is the 220uF cap after the HDAM circuit (C716). Initially I would replace these with a back to back pair of 470uF YXF Rubicon caps (or Blackgates if you mortgage the house).
As a side note, I would like to study the schematics of the Classe CDP300. These use the same CS4398 DACS (and they sound incredible!!) as on our DV. It would be interesting to see how they approached the design of their analogue section.
Anyway, this is what I can think of for now. I'll probably hold off any mods on my DV till the warranty expires. Or maybe not... Heehee
Cheers
Gert
gbyleveldt said:
As I mentioned previously I'm considering replacing C629 and C630 with Rubycon ZL's. I've already ordered the respected ALWSR regulator boards to replace the aforementioned 7808 and 7809. After that I'll put some sort of BG in to finish things off.
Since there is only one cap per channel it won't cost that much for the two BG's to do the FL and FR channels for a start. I'm really looking forward to seeing what kind of impact Lars new precision clock has since in my opinion the two channel performance is already very good!
Regards,
Dan
As a side note, I would like to study the schematics of the Classe CDP300. These use the same CS4398 DACS (and they sound incredible!!) as on our DV. It would be interesting to see how they approached the design of their analogue section.
Anyway, this is what I can think of for now. I'll probably hold off any mods on my DV till the warranty expires. Or maybe not... Heehee
Cheers
Gert
Hi Guys,
You can download the schematic from the link below. It'll only be there for another day or two, so hurry, hurry
http://www2.sendthisfile.com/d.jsp?t=OIutiewOWxIAnCXd5kMfy4dW
Cheers
Gert
You can download the schematic from the link below. It'll only be there for another day or two, so hurry, hurry
http://www2.sendthisfile.com/d.jsp?t=OIutiewOWxIAnCXd5kMfy4dW
Cheers
Gert
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