Yep remove those 4 100uF (Cerefine) and those 2 opamps
You will see U210 U214. Remove these and solder a wire from each to the output sockets to bypass the HDAM and the muting.
Also cut out R651 652 653 654 as the HDAM no longer needs the voltage supply. Oh and remove C655 657 656 658.
Brent
You will see U210 U214. Remove these and solder a wire from each to the output sockets to bypass the HDAM and the muting.
Also cut out R651 652 653 654 as the HDAM no longer needs the voltage supply. Oh and remove C655 657 656 658.
Brent
LOLHi brent sorry to be hard work but when you say run a wire to the output sockets do you mean the phono outputs. And allso does it matter which way round the caps go in
Yes run the wires to the op /phono sockets. You can solder to the back of them.
The caps must be the correct way round. Take note of the ones you take out. The negative stripe will line up with the dot on the pcb.
Brent
The caps must be the correct way round. Take note of the ones you take out. The negative stripe will line up with the dot on the pcb.
Brent
Hi brent just done all the sound deadening on the chassis while i got the board out, Now the hard part i noticed when you turn the board up side down looks like not all the legs on the opamp are soldered so when i fit the new ones do i solder all of them or just the ones that are done on the origonal ones
Hi again if the HDAM circuit as left and right signals does it matter which chanel i bypass it to or do you run one to each
All the pics should be used on the opamps!
Run a wire from the opamps side of U216 to the R ch of the rca and from U217 to the L ch of the rca
Brent
Run a wire from the opamps side of U216 to the R ch of the rca and from U217 to the L ch of the rca
Brent
Hi brent thanks alot for your help i have done it and its not on fire. Had a few pink floyd albums on and it sounds really well it does not sound digital any more it sounds a lot smoother and easeyer to listen to but for some reason i have to turn the amp up more. and i noticed it sounds slower than before. So what do you recon next upgrade should be
Well done 😉
It will sound a little quieter (a good thing) as the HDAM is out of the circuit. The slower and smoother sound is mainly due to less distortion.
The 2 big Brown/gold Silmic capacitors near the transformer need replacing, and as you have a 67 it is ideal to replace these with Mundorf HC 25V max diameter of 26mm. If you drill the holes biggeryou can fit the much better 25000uf or 22000uf HC that are 30mm diameter.
There are also 2 more caps after the 2 regs C805 C806. Rubycon ZA 16v 220uF/470uF work well here. These caps supply the opamps.
Also did you short out resistors R613 614 615 616 just above the opamps
Brent
It will sound a little quieter (a good thing) as the HDAM is out of the circuit. The slower and smoother sound is mainly due to less distortion.
The 2 big Brown/gold Silmic capacitors near the transformer need replacing, and as you have a 67 it is ideal to replace these with Mundorf HC 25V max diameter of 26mm. If you drill the holes biggeryou can fit the much better 25000uf or 22000uf HC that are 30mm diameter.
There are also 2 more caps after the 2 regs C805 C806. Rubycon ZA 16v 220uF/470uF work well here. These caps supply the opamps.
Also did you short out resistors R613 614 615 616 just above the opamps
Brent
HI brent thanks again for your help no i didn't short the resistors i just cut through them and left the 2 short legs stick up. Is this wrong
Just looking at the board brent and the resistors i cut through are R652 653 652 I think there was 4 or 5 in between the ADAM SILVER BOXES i allso removed the 4 caps in between the silver boxes and the 4 caps at the back near out puts
That's correct, you have disabled the HDAM and its psu supply doing that.
The R613 614 615 616 are the voltage supply resistors to the opamps. Cut these legs but leave enough leg sticking up so that the legs can be bent over and soldered together (on top of the pcb). You get a more dynamic sound doing this.
Brent
The R613 614 615 616 are the voltage supply resistors to the opamps. Cut these legs but leave enough leg sticking up so that the legs can be bent over and soldered together (on top of the pcb). You get a more dynamic sound doing this.
Brent
Hi brent so i need to solder the resistor legs together i didn't bother doing that as i thought i had bi pased them with the wires to the cd outputs
Hi brent i will place an order with you for the other caps and bridge the resistors when i fit them as i removed all restors and didn't leave the legs And i cant be bothered taking the board out to get underneath to bridge the resistors. I dont think its poss to bridge them from above is it
Hi brent i will place an order with you for the other caps and bridge the resistors when i fit them as i removed all restors and didn't leave the legs And i cant be bothered taking the board out to get underneath to bridge the resistors. I dont think its poss to bridge them from above is it
If you leave the legs long enough then you can bend them over and solder together from the top.
A bigger higher quality caps offers Lower ESR and better ripple current. This helps keep the power rails cleaner + the larger uF helps with bass and over all soud quality. If you are on a budget then the Panasonic FC 25V 4700uF are pretty good in that location.
Brent
A bigger higher quality caps offers Lower ESR and better ripple current. This helps keep the power rails cleaner + the larger uF helps with bass and over all soud quality. If you are on a budget then the Panasonic FC 25V 4700uF are pretty good in that location.
Brent
Hi again since i have changed opamps and caps and HDAM bypass i have played a fair few cds and i think the midrange is not as good as it was before. Though the bottom end is better trebble is a bit ragged do any of you know were i may have gone wrong. I have just got the caps today for the power supply which i will fitt tommorow
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