Some good work going on there Ian! I want to know every step taken... don't want to miss a trick 😀
Yes James, I bet Philips never really envisaged that 20 years later so many people would be spending good time and money tweaking these old beasts into something truly special.
Simon
Yes James, I bet Philips never really envisaged that 20 years later so many people would be spending good time and money tweaking these old beasts into something truly special.
Simon
jameshillj said:
The forum is entirely responsible. I'd still be reading What Hi-Fi and lusting after ever more expensive but ultimately cr@p products if it weren't for the information freely shared on here. Long may it continue.
Simon
SimontY said:
Indeed! That was me 3 months ago! I did have a MF A5.5 on home dem (paid for in full) It sounded nice and I was drawn to its warm sound but something was missing. I took the lid off to find some nice work in the PSU (but still using cr@p regs) average caps, cr@p opamps and the cheapest microphonic valves you could buy! Original retail price tag £2k! It also uses the VAM1201 transport the same as the cd63's (well the cheapo chineese version)!
My 960 would eat it up and spit it out whilst laughing at it and shouting bring it on!!
Indeed we are subject to some less than desirable content in new so called "high-end" players!
Happyness!
Given the fact that I'm smiling like the cat with the cream this morning, I'd thought I'd share this.....
Here's what I've done so far
PSU
5v Hexfreds into 2xFC 4700uf 16v in parallel, std 7805 into ZA 200uf 35v decoupling
+/- 12v FC4700uf 25v and Audiocom Qpower regs into 200uf 35v decoupling
Filter & Decoder
I've got 2 5v SRegs on the heatsink side by side. 1 for the Filter and 1 for the decoder. They are fed direct from the unregulated 5v supply smoothers (about 8v). The decoupling on the decoder and filter board are Os-Con 10v 100uf (nothing additional just replaced the original caps on the board) I cut the track on the board to give me 2 seperate supply lines. Both chips are covered in copper tape and grounded. The Trichord Clock 4 is connected via minature Co-ax. This is currently fed via a seperate supply into a std regulator (not for long me thinks).
DAC
Decoupling with ZA 220uf 35v (3 of them on the various rails).
PSU fed from std TX into Hexfreds, 15000uf mundorf, SReg direct to seperated 5V supply. The cap on 16&17 is 680 as std.
Output stage
LME49710NA (copper foil covered) decoupled via BG std 220uf 35v
+/-15v supply (6800uf 25v elna for hifi & discrete reg as std)
This supply also supplied the headphones circuits which are completely removed.
Mundorf supreme 4.7uf DC decoupling
Didn't realise how much I'd done! lol
I've still got a few more bits available, another 5v SReg, 2 x TX and the DOS (all robbed from my 63 which has been somewhat unmodified!)
The latest additions were the SRegs and they have made a terrific difference to the clarity and dynamics. I cannot recommend these highly enough.
Clever chap that Brent gezer!
If anyone can see any obvious things that I may have missed please let me know
Ian
** Tubee the regs are from Brent (rowemeister) on the forum.
Given the fact that I'm smiling like the cat with the cream this morning, I'd thought I'd share this.....
Here's what I've done so far
PSU
5v Hexfreds into 2xFC 4700uf 16v in parallel, std 7805 into ZA 200uf 35v decoupling
+/- 12v FC4700uf 25v and Audiocom Qpower regs into 200uf 35v decoupling
Filter & Decoder
I've got 2 5v SRegs on the heatsink side by side. 1 for the Filter and 1 for the decoder. They are fed direct from the unregulated 5v supply smoothers (about 8v). The decoupling on the decoder and filter board are Os-Con 10v 100uf (nothing additional just replaced the original caps on the board) I cut the track on the board to give me 2 seperate supply lines. Both chips are covered in copper tape and grounded. The Trichord Clock 4 is connected via minature Co-ax. This is currently fed via a seperate supply into a std regulator (not for long me thinks).
DAC
Decoupling with ZA 220uf 35v (3 of them on the various rails).
PSU fed from std TX into Hexfreds, 15000uf mundorf, SReg direct to seperated 5V supply. The cap on 16&17 is 680 as std.
Output stage
LME49710NA (copper foil covered) decoupled via BG std 220uf 35v
+/-15v supply (6800uf 25v elna for hifi & discrete reg as std)
This supply also supplied the headphones circuits which are completely removed.
Mundorf supreme 4.7uf DC decoupling
Didn't realise how much I'd done! lol
I've still got a few more bits available, another 5v SReg, 2 x TX and the DOS (all robbed from my 63 which has been somewhat unmodified!)
The latest additions were the SRegs and they have made a terrific difference to the clarity and dynamics. I cannot recommend these highly enough.
Clever chap that Brent gezer!
If anyone can see any obvious things that I may have missed please let me know
Ian
** Tubee the regs are from Brent (rowemeister) on the forum.
Attachments
Decent mods there. Lots to do though 😀
Does your Philips have the decoder on its own supply? What did you find when you upgraded the decoder supply? I'm dying to know because I've not touched mine yet. I don't even know which IC it is (will need to review the service manual...)
edit: nice pic!
Simon
Does your Philips have the decoder on its own supply? What did you find when you upgraded the decoder supply? I'm dying to know because I've not touched mine yet. I don't even know which IC it is (will need to review the service manual...)
edit: nice pic!
Simon
SimontY said:
Unfortunately in my attempt to get in front of my 63 performance with this, all the above mods have gone over the last 5 days so I didn't get a chance to take in the differences.
The decoder and filter are up on that vertical board on the side. Lee was insistant that I fed it on its own regs. I seperated the supplies and fed from std seperate regs to start with. This was the first thing I did. It changed it into horrible (but with known potential) into listenable. (remember I'd changed nothing else from std at this point)
I'd say for £1.50 for a std reg, its worth doing.
My Decoder chip in SAA7210 and filter is SAA7220
Which reminds me I also uped the TDA to an "A" version
Ian
I presume the decoder in the CD650 is also the SAA7210, though from memory I think it's printed with something different.
Looking at the datasheet it takes 200mA, like the 7220! Again I want to use an Audiocom reg as I have some, but it won't like it. They can push 300mA but they're not well heatsinkable as far as I can tell. Brent has suggested swapping the (D-pak) output device for something beefier. This would make it easier to heatsink and more durable (and better?)
Simon
Looking at the datasheet it takes 200mA, like the 7220! Again I want to use an Audiocom reg as I have some, but it won't like it. They can push 300mA but they're not well heatsinkable as far as I can tell. Brent has suggested swapping the (D-pak) output device for something beefier. This would make it easier to heatsink and more durable (and better?)
Simon
Hi Simon,
You prob know what I'm gonna say......
Seperate SRegs!!!
I've got both of mine on the same heatsink. I had to drill new holes to mount them side by side. They are on top of the DAC!
SRegs are small neat and from what I can hear bloody good.
You'd def want to heatsink those Audiocom devices. There must be a way. Have you got any pictures of them?
Ian
You prob know what I'm gonna say......
Seperate SRegs!!!
I've got both of mine on the same heatsink. I had to drill new holes to mount them side by side. They are on top of the DAC!
SRegs are small neat and from what I can hear bloody good.
You'd def want to heatsink those Audiocom devices. There must be a way. Have you got any pictures of them?
Ian
Attachments
Hi Ian,
I agree there must be a way but I don't know how. S-powers are easy to heatsink (and better).
http://www.referenceaudiomods.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=RAM&Category_Code=SR
Simon
I agree there must be a way but I don't know how. S-powers are easy to heatsink (and better).
http://www.referenceaudiomods.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=RAM&Category_Code=SR
Simon
mmm a bit more tricky to mount!
I think I'd try finding some clips.
My old Philips CD850 had spring clips holding the regs to the heatsink. It clipped through vertical slots in the sink and pinned the device to it. I don't know if something similar still exists could be used?
Failing that you could use the hole and carefull pack washers to the same thickness as the reg on the board (a little more difficult to get spot on though!).
Ian
I think I'd try finding some clips.
My old Philips CD850 had spring clips holding the regs to the heatsink. It clipped through vertical slots in the sink and pinned the device to it. I don't know if something similar still exists could be used?
Failing that you could use the hole and carefull pack washers to the same thickness as the reg on the board (a little more difficult to get spot on though!).
Ian
Attachments
I just had another look at this and I see what I need to do...
http://www.referenceaudiomods.com/images/products/audiocom/sreg.jpg
I need to insert a spacer/washer and use the hole to bolt the 'sink to the transistor.
Seems obvious now! Might give it a go this evening.
Simon
http://www.referenceaudiomods.com/images/products/audiocom/sreg.jpg
I need to insert a spacer/washer and use the hole to bolt the 'sink to the transistor.
Seems obvious now! Might give it a go this evening.
Simon
Simon saw on a picture you have the pre saa7220 with other marking, but it is the same, have it in my cd304mk2 too.
Ah thanks Jan, that helps. I've been scouring a CD640 manual and printing some block diagrams to help me realise what should be or could be done.
CD640 has 680pF across pins 16 & 17 of the "TDA1541P". Maybe mine has this too and I just added to it?
Or maybe CD640 was more recent and came with TDA1541A (I've no idea what that P means, but every day I learn of a new version of this legend).
Simon
CD640 has 680pF across pins 16 & 17 of the "TDA1541P". Maybe mine has this too and I just added to it?
Or maybe CD640 was more recent and came with TDA1541A (I've no idea what that P means, but every day I learn of a new version of this legend).
Simon
P is just the regular non- a version afaik. The non-a 1541's sound some more coloured btw, the A dacs can give more odd harmonics, compared to the R version (non-a) they have more even harmonics. Bernard found that out with spectrum analizing his dacs.
The CD640 uses 680pF as dem cap indeed. Remove the ceramic and add a 470p polystyrene cap, or do the dem-mod in time 😉 Remember with a cap you will be AROUND 200 kHz, so not in pace with the clock.
The CD640 uses 680pF as dem cap indeed. Remove the ceramic and add a 470p polystyrene cap, or do the dem-mod in time 😉 Remember with a cap you will be AROUND 200 kHz, so not in pace with the clock.
tubee said:
Whats the reason for the change in value? I've not changed this cap yet. Should I cahnge from 680p to 470p?
Ian