RichardH
Bodging pleb
"Brilliant! do it immediately.
Thought I'd post the results of swapping out the opamps on my CD3.5 as a follow on as I'm so pleased.
In the end I had 2 ad8610s and 4 ad825s to play with (there are 6 of the orginal opa604s in the cd3.5). However if you investigate the power supplies you find that the 2 analogue stage regulators feed the opamps in such a way that one regulator feeds the 2 closest the output sockets and the other regulator feeds the other 4 opamps and some associated circuitry. It therefore stands to reason that the group-of-2 were the most important and those were the ones I replaced with the ad8610s, being generally regarded as the better opamp. Whole job took about 3 hours from start to finish and the brown dog soic->dip adaptors are a doddle to solder. Only fiddle was getting out the original opa604s which i did by cutting off the legs and desoldering each leg individually. A pain but it can be done. There is no problem with the power rails as the ad825 is rated at +/- 15V and the AD8610 at +/- 13V while the orginal rails give +18.5V so plenty of headroom.
Result? Changes were apparent even on switch-on. Only 3 hours in and to me most importantly PRT and dynamics are much improved. Leftfield and Faithless fairly hurled along. Hifi stuff of bass deeper, punchier and more defined, treble clearer etc also there. But the sound was also much more refined. Gone is that certain coarseness of the 3.5. The sound now has 'elegance'- it just sounds classy is the best way I can describe it.
Oh yeah, the only other mod on the player is it currently has a kwak clock and this mod is easily up there in terms of gains
....
From reviewing other forums, it would appear the ad8610 has a slightly smoother character whereas the ad825 has more 'bite' but the ad8610 is considered superior overall. I've mixed the two out of necessity but the result is pleasing to me so I'm not too worried. Might even give a harmonious blend."
NOTE: The AD8610 are available only in SOIC package, and therefore need the Brown Dog adapters to fit them into the DIP8 socket. They are also fairly difficult to get hold of in the UK.
Source: ced (PFM v1)
Thought I'd post the results of swapping out the opamps on my CD3.5 as a follow on as I'm so pleased.
In the end I had 2 ad8610s and 4 ad825s to play with (there are 6 of the orginal opa604s in the cd3.5). However if you investigate the power supplies you find that the 2 analogue stage regulators feed the opamps in such a way that one regulator feeds the 2 closest the output sockets and the other regulator feeds the other 4 opamps and some associated circuitry. It therefore stands to reason that the group-of-2 were the most important and those were the ones I replaced with the ad8610s, being generally regarded as the better opamp. Whole job took about 3 hours from start to finish and the brown dog soic->dip adaptors are a doddle to solder. Only fiddle was getting out the original opa604s which i did by cutting off the legs and desoldering each leg individually. A pain but it can be done. There is no problem with the power rails as the ad825 is rated at +/- 15V and the AD8610 at +/- 13V while the orginal rails give +18.5V so plenty of headroom.
Result? Changes were apparent even on switch-on. Only 3 hours in and to me most importantly PRT and dynamics are much improved. Leftfield and Faithless fairly hurled along. Hifi stuff of bass deeper, punchier and more defined, treble clearer etc also there. But the sound was also much more refined. Gone is that certain coarseness of the 3.5. The sound now has 'elegance'- it just sounds classy is the best way I can describe it.
Oh yeah, the only other mod on the player is it currently has a kwak clock and this mod is easily up there in terms of gains
....
From reviewing other forums, it would appear the ad8610 has a slightly smoother character whereas the ad825 has more 'bite' but the ad8610 is considered superior overall. I've mixed the two out of necessity but the result is pleasing to me so I'm not too worried. Might even give a harmonious blend."
NOTE: The AD8610 are available only in SOIC package, and therefore need the Brown Dog adapters to fit them into the DIP8 socket. They are also fairly difficult to get hold of in the UK.
Source: ced (PFM v1)