Marantz CD-50 and CD-60, TDA1541, CDM4/19

[Mayday]

Yes between output and non inverting ( - ) input

Still trying to wrap my head around this, maybe I'm slow or something lol.

Which pins does the R+C connect to?

 

[AndrewGM]

Still awake ?
Me too !!
I just finished something and I'm sitting here admiring it !!
Did I mention sleep once to you ?
I owe you an apology !
btw....your work looks nice - bravo

 

[Mayday]

Still awake ?
Me too !!
I just finished something and I'm sitting here admiring it !!
Did I mention sleep once to you ?
I owe you an apology !
btw....your work looks nice - bravo

I'm afraid so
Will go to bed soon though, just been up reading the schematics for the CD-players and figuring what to put where etc.
So far:
Sanyo OsCon SEPC or similar: 470uF/16V 2612,2607,2632,2634
Silver-Mica (as low tolerance as possible) 250pF 2636
Rubycon ZLH 470uF/16-25V 2670,2672,2674,2675,2704,2714,2708,2712
Remove 2673,2700 and put 4,7uF MKP's to L & R Out(RCA's)

Still to figure out:
From where to where does the yellow(bypass) wires in the top of the pic connect?

Thanks for saying that btw, I do try

 

[Mayday]

Still trying to wrap my head around this, maybe I'm slow or something lol.

Which pins does the R+C connect to?

Ment to write RC filter...

 

[Mayday]

What did you finish Andrew?? *curious*

 

[Mayday]

Is this a correct schematic of the shunt reg tubee(I think it was) posted?
Can I feed it from basic LM317 regulated PS?

 

[Mayday]

Put 1uF Wima's on the MSB's

Put 470uF Rubycons around the opamps.

Removed the PCB for variabel output.

 

[Mayday]

Not been playing for more then maybe 10min or so, but I allready like the latest mods
Better dynamics and better highs is what pops to mind already.

 

[AndrewGM]

Last night I was just doing the boring stuff - 13 new fast / soft diodes and cap changes to a main board. I was admiring the way it worked out and the fact I never lifted any tracks through overheating with my iron !

If you think your machine sounds good now then a real treat is still coming.
When you eventually power the 7220 and the 7310 ( 7210 in your case ? ) and do an advanced re clock you are going to be absolutely astonished.

Just doing the 7220 brings a huge ( and I mean HUGE ) gain in every area of it's performance.

Not far to go for you now

 

[josha]

Hi Mayday - good work! The RC filter goes across pins 1 & 2, and pins 6 & 7 assuming you are connecting the DAC output to the inverting inputs (pins 2 & 6), pins 3 & 5 should then go to ground.

Hope this helps

 

[Mayday]

Thanks Andrew and Josh!

I did manage to lift two pads this time, but it was easily fixed w silverwire to closest connection point. Been a while since I diy'd, but I've built a few amps, pre-amps etc.
It'll come back w some more practice

 

[Mayday]

It's been playing non-stop now since the latest mods.
Just turned up the volume again and it's really starting to settle and the improvements are obvious
I find myself playing "airdrums" lol

Looking forward to hear what the next mod will bring

 

[Mayday]

Any idea where I might find a cap to lock clock frequences(DEM)?
1% tolerance silver mica or similar, one of the values below:
350pF,318pF,300pF,260pF,250pF,203pF,180pF,145pF,122pF

 

[josha]

I got a 1% 180pf Silvered Mica from here they quote in US and Euro.

I can also confirm that this is great little mod! I'm still trying to get the DEM reclock working from BCK with a NOR gate but in the meantime this little cap soldered straight onto the 1541 makes a big difference!

I also tried no cap all together, it still plays but you get a bit of noise with the music, not much but enough to 'muddle' (technical term) the sound.

 

[Mayday]

Thanks! Page bookmarked

Btw, the smd under the pcb needs to be removed right? I'm sure that's the case, asking to be 100%

 

[josha]

No probs - yes remove the smd underneath, a bit fiddly but worth the effort. I've read that every mm counts when connecting up the DEM capacitor so I soldered it straight onto the 1541.

Another little mod while your there is to connect a 10uf 25v Oscon across pins 15 & 26 of the 1541 (+ve to pin 26), Andrew pointed this out to me but I think it's detailed on the 'ultimate 1541' thread IIRC. Rapid sell this part but when I ordered they said 'while stocks last'.

Cheers

Almost forgot - the oscon also needs to be soldered directly to the 1541, or as close as you can get it!

 

[Mayday]

No probs - yes remove the smd underneath, a bit fiddly but worth the effort. I've read that every mm counts when connecting up the DEM capacitor so I soldered it straight onto the 1541.

Another little mod while your there is to connect a 10uf 25v Oscon across pins 15 & 26 of the 1541 (+ve to pin 26), Andrew pointed this out to me but I think it's detailed on the 'ultimate 1541' thread IIRC. Rapid sell this part but when I ordered they said 'while stocks last'.

Cheers

Almost forgot - the oscon also needs to be soldered directly to the 1541, or as close as you can get it!

Thank you again Josh.
I'll look into the mod you suggested after I've done the one's allready planned,

 

[Mayday]

Another question for you guys, how hot do you set your solderstation when de-soldering part from this PCB? I use a desoldering pump to remove solder and with a rather hot solder iron it tends to lift solderpads of the pcb(happend twice on this pcb, but I managed to solve it easily/luckily). I'm crappy with de-solder wick, never really learned how to use it I guess.

 

[Mayday]

Another little mod while your there is to connect a 10uf 25v Oscon across pins 15 & 26 of the 1541 (+ve to pin 26), Andrew pointed this out to me but I think it's detailed on the 'ultimate 1541' thread IIRC.

Regular OsCon or SEPC? And what does it "do"?

 

[Mayday]

Hi Mayday - good work! The RC filter goes across pins 1 & 2, and pins 6 & 7 assuming you are connecting the DAC output to the inverting inputs (pins 2 & 6), pins 3 & 5 should then go to ground.

Hope this helps

Opamp:

Schematic for opamps etc: