Hi, As its a TDA1541 based player, check out the CD650 thread as well as the NOS 1541 thread.
If it has the SAA7220 filter chip, this responds very well to a decent regulator.
As always, good smoothers on the supply's along with Schottly's or Hexfreds starts to sort things. A sprinkling Rubycon ZA's or Black Gates to decouple supplies to DAC, Filter, Decoder and output stage will give good gains. Also replace the 4 op amps on the output of the DAC (I/V & Buffer) I think they will be singles. This will give a good improvement for not a lot of money.
The expensive bits to start with are a decent clock & good regulators.
Have you managed to find a service manual?
Ian
If it has the SAA7220 filter chip, this responds very well to a decent regulator.
As always, good smoothers on the supply's along with Schottly's or Hexfreds starts to sort things. A sprinkling Rubycon ZA's or Black Gates to decouple supplies to DAC, Filter, Decoder and output stage will give good gains. Also replace the 4 op amps on the output of the DAC (I/V & Buffer) I think they will be singles. This will give a good improvement for not a lot of money.
The expensive bits to start with are a decent clock & good regulators.
Have you managed to find a service manual?
Ian
Smoothers (Panasonic FC's or Mundorf if cost is no issue) and rec's (schottky or Hexfred if cost is no issue) are a good place to start. Don't replace the std regs with decent ones..........
Use dedicated regs. In that player, I'd start with 1 5v SPower (or similar) on the decoder chip (SAA7220) this will give very good gains. Its quite a greedy chip so the reg will need attaching to a heat sink. I'd also replace all the decoupling caps to the supplys on the DAC (3), Filter (1) and op amps(4) with something like rubycon ZA 220uf (let me know if you want to know how to get some) I'd also replace the 4 op amps with LME49710NA (about £5 each) That would do you for a start!!
Next i'd put on a decent clock and poss a devide by 2 for the bitclock (i'd need to check how the oversampling works on that player for the /2) A good regulator for the clock is also a must.
Next I'd sort the regs out on the DAC +5,-5 & -15v. Fairly costly for 3 decent regs!! but again worth it.
Finally if you've got any budget left, you could source a TDA1524 S1 or S2. Definately the finishing touches for that mod though!
Best of luck
Ian
Use dedicated regs. In that player, I'd start with 1 5v SPower (or similar) on the decoder chip (SAA7220) this will give very good gains. Its quite a greedy chip so the reg will need attaching to a heat sink. I'd also replace all the decoupling caps to the supplys on the DAC (3), Filter (1) and op amps(4) with something like rubycon ZA 220uf (let me know if you want to know how to get some) I'd also replace the 4 op amps with LME49710NA (about £5 each) That would do you for a start!!
Next i'd put on a decent clock and poss a devide by 2 for the bitclock (i'd need to check how the oversampling works on that player for the /2) A good regulator for the clock is also a must.
Next I'd sort the regs out on the DAC +5,-5 & -15v. Fairly costly for 3 decent regs!! but again worth it.
Finally if you've got any budget left, you could source a TDA1524 S1 or S2. Definately the finishing touches for that mod though!
Best of luck
Ian
I recently picked up a CD50-SE, and it's an interesting player, I like the sound but i't not a detailed as my CD63-SE.
Anyway, a couple of points:
the opamps are duals, and i replaced then with LME49720's in metal TO99 format. this does sound better but i feel it has a lot more to give.
second point is that the case is fully braced which means you have to remove the PCB to access the OPAMPs, and interestingly it sounds better with the thin base plate removed and sitting on the carpet. This is in contrast to the CD63 where the sound degrades when the covers are removed.
I'm taking a slow incremental approach to modifying this player, and after reading other threads I think improving the decoupling of each of tha major chips is a priority. As they all produce noise, and consume relatively high currents.
This will probalby take the form of separate regulators for each chip, but initially i thought I'd try Ray's simple replacement of resistors with small inductors and see what happens.
Anyway, a couple of points:
the opamps are duals, and i replaced then with LME49720's in metal TO99 format. this does sound better but i feel it has a lot more to give.
second point is that the case is fully braced which means you have to remove the PCB to access the OPAMPs, and interestingly it sounds better with the thin base plate removed and sitting on the carpet. This is in contrast to the CD63 where the sound degrades when the covers are removed.
I'm taking a slow incremental approach to modifying this player, and after reading other threads I think improving the decoupling of each of tha major chips is a priority. As they all produce noise, and consume relatively high currents.
This will probalby take the form of separate regulators for each chip, but initially i thought I'd try Ray's simple replacement of resistors with small inductors and see what happens.
Hi Symon,
I was going off the schematic and missed the fact that the op amps are dual and only 2! (same number of amps overall!)
I agree with your opinion of the dual HA's (tin hats) they are much much better than the std DIL package.
Depending on how far you want to go with this player, I'd seperate the I/V stage (1st opamp) and Buffer stage (2nd opamp). I've got a Burson discrete doing my I/V and Rays DOS off the 63/67 thread for my buffer and they are awesome together. As I say that may be a little too far????
I'm quite familiar with the filter chip and would definately recommend getting it onto its own reg at least (much better with a low noise version). I'm pretty sure it'll draw upwards of 300mA so def sink it!
Ian
I was going off the schematic and missed the fact that the op amps are dual and only 2! (same number of amps overall!)
I agree with your opinion of the dual HA's (tin hats) they are much much better than the std DIL package.
Depending on how far you want to go with this player, I'd seperate the I/V stage (1st opamp) and Buffer stage (2nd opamp). I've got a Burson discrete doing my I/V and Rays DOS off the 63/67 thread for my buffer and they are awesome together. As I say that may be a little too far????
I'm quite familiar with the filter chip and would definately recommend getting it onto its own reg at least (much better with a low noise version). I'm pretty sure it'll draw upwards of 300mA so def sink it!
Ian
Well I replaced a few of the resistors with small inductors so the power to SAA7220 and TDA1541 have better HF filtering.
This simple change seems to have improved the sound a lot, so confrms the view that the first thing to do is improve power supply. And provide clean supply for all the main chips.
This simple change seems to have improved the sound a lot, so confrms the view that the first thing to do is improve power supply. And provide clean supply for all the main chips.
Hi Andy,
I've actually followed this and a number of other sources of information on the TDA1541/SAA7220 chip set.
But rather than jumping in and making lots of changes I'm taking an incremental approach to see which changes have the most significant effect. So while this has been done before, it's interesting to see how far I can get with the simplest of changes. HereWeGoAgain noted that he made a number of changes to his CD50 then removed most of them ...
One of the nice things about hte CD50-SE is that is has lots of space so separate power supplies etc can easilty be added.
Another is that the chassis is very stiff and braced.
A bad thing is that the metal covers are way too thin and seem to pick up every vibration. Which is why I think this player sounds better with the covers off ...
back to wook now
I've actually followed this and a number of other sources of information on the TDA1541/SAA7220 chip set.
But rather than jumping in and making lots of changes I'm taking an incremental approach to see which changes have the most significant effect. So while this has been done before, it's interesting to see how far I can get with the simplest of changes. HereWeGoAgain noted that he made a number of changes to his CD50 then removed most of them ...
One of the nice things about hte CD50-SE is that is has lots of space so separate power supplies etc can easilty be added.
Another is that the chassis is very stiff and braced.
A bad thing is that the metal covers are way too thin and seem to pick up every vibration. Which is why I think this player sounds better with the covers off ...
back to wook now
Leeuwarden said:
I did look at the site and was very impressed with it to the extent I have spent over £150.00 at farnells for loads of parts to make a Lampizator !
I will start with the de coupling caps first then I will try the snipit mods that miss out some op amps before I get too carried away. Watch this space
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Hi, def as Andy says, seperating the noisy SAA7220 onto its own regulator is an excellent place to start with very good gains. Its quite greedy so it'll need sinking!
Another freeby mod recently documeted is to seperate the clock feeds.
As std the clock is connected to the 7220 and it in turn feeds the 7210 with its own x1 clock. If you feed the chips directly from the clock individually, you'll get a gain for nothing.
Also, the system clock should feed pin4 on the tda1541. You should also feed /2 clock to pin2 on the tda1541. All this for free!
You'd definately get even more by using a decent clock to all the places described above.
Lots of info on the cd650 thread (including a cheap copy Musial Fidelity tube stage!)
Another freeby mod recently documeted is to seperate the clock feeds.
As std the clock is connected to the 7220 and it in turn feeds the 7210 with its own x1 clock. If you feed the chips directly from the clock individually, you'll get a gain for nothing.
Also, the system clock should feed pin4 on the tda1541. You should also feed /2 clock to pin2 on the tda1541. All this for free!
You'd definately get even more by using a decent clock to all the places described above.
Lots of info on the cd650 thread (including a cheap copy Musial Fidelity tube stage!)
Dual regulation in analog section
I make a seperate regulation for left and right. You don''t believe what this cheap mod does with your CDplayer.
Just 4x 1000 uF50V Cap parallel a 1uF mkt
then 2x 7815 or 7915 and then 4x 1uF MKT and a resistor of 1k5 to pul 10mA.
Opamp is OPA2134 (only one halve is used with 1k5 and parallel 1nF (from the second opamp)
Of course NOS an a lot of OSCON's
I make a seperate regulation for left and right. You don''t believe what this cheap mod does with your CDplayer.
Just 4x 1000 uF50V Cap parallel a 1uF mkt
then 2x 7815 or 7915 and then 4x 1uF MKT and a resistor of 1k5 to pul 10mA.
Opamp is OPA2134 (only one halve is used with 1k5 and parallel 1nF (from the second opamp)
Of course NOS an a lot of OSCON's
Attachments
At long last, I have managed to complete the Lampizator. The mods to the CD player are minimal, no new caps, regs or supply diodes, just the Snipit mods to start with.
The Snipit mod was easy to do and the results are very good, the sound was on a par with a Naim CD3 unmodified.
I stole the signal coming out of the first opamp just before the series resistor to the second half of the opamp and used a big fat Poly cap from Maplin as the de coupler.
The jump in sound quality is amazing to say the least and all for a couple of hours and £30.00 for parts.
I made the lampizator free standing and self contained as I want to try it with a variety of players, so it has RCA in and out.
The output from the snipit mod was too much for the lampizator and it does not clip very nicely so I had to take the plunge and take the output direct from the 1541.
The take off point is on the underside of the PCB where you can trace the track to a small distance away from the Dac. I chose a jumper point and a resistor point.
I took the signal to the RCA sockets with a 92 ohm resistor across it for iv conversion, connected it up and got next to nothing coming out !
The I realised that the circuit is still connected to the first opamp for iv conversion leaving not enough signal for the lampizator. Out with the snips again and a knife to cut some PCB tracks.
Much better now with amazing weight and detail to the sound, percussion sound more live like with cymbals regaining their fluid sound.
I will have to start looking at the power supply now because although the detail and resolution is very good, it does show up a bit of harshness that is probably regulators and caps that need upgrading.
I will play with them later as I am enjoying the player too much to pull it apart for a while.
I will now lampizate my Naim CD3 player as it has very good regulation as standard.
Thanks again for all your suggestions, I am enjoying revisiting the hobby of my youth.
The Snipit mod was easy to do and the results are very good, the sound was on a par with a Naim CD3 unmodified.
I stole the signal coming out of the first opamp just before the series resistor to the second half of the opamp and used a big fat Poly cap from Maplin as the de coupler.
The jump in sound quality is amazing to say the least and all for a couple of hours and £30.00 for parts.
I made the lampizator free standing and self contained as I want to try it with a variety of players, so it has RCA in and out.
The output from the snipit mod was too much for the lampizator and it does not clip very nicely so I had to take the plunge and take the output direct from the 1541.
The take off point is on the underside of the PCB where you can trace the track to a small distance away from the Dac. I chose a jumper point and a resistor point.
I took the signal to the RCA sockets with a 92 ohm resistor across it for iv conversion, connected it up and got next to nothing coming out !
The I realised that the circuit is still connected to the first opamp for iv conversion leaving not enough signal for the lampizator. Out with the snips again and a knife to cut some PCB tracks.
Much better now with amazing weight and detail to the sound, percussion sound more live like with cymbals regaining their fluid sound.
I will have to start looking at the power supply now because although the detail and resolution is very good, it does show up a bit of harshness that is probably regulators and caps that need upgrading.
I will play with them later as I am enjoying the player too much to pull it apart for a while.
I will now lampizate my Naim CD3 player as it has very good regulation as standard.
Thanks again for all your suggestions, I am enjoying revisiting the hobby of my youth.
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