Gregss
New Head-Fier
Hello,
Have the SA-8004 and am pretty well pleased with it. Headphone output was a little lacking though (overly smooth or sweat) in my opinion. Did the following mods to the audio board and believe got it quite a bit better (more accurate) IMHO.
Replaced the (+/-) supply caps with Panasonic FC 460uf / 35volt caps to try to make sure the supply wasn't limiting things especially when using lower impedance headphones.
Replaced the four Silmac (spelling?) silk caps in the output of the headphone amp feeding the headphone jack. Silmac spec sheet on these caps says in the english version that these caps smooth things out. Only way I can think of these smoothing things out is to add in even order harmonics. Spec sheet proudly states 3d order harmonics are way down, but completely says nothing about even order ones...
Replaced them with Panasonic SU (bipolar) 220uf / 35volt caps. Sound seemed to much more what was on the CD and not smoothed over anymore. These caps are in series with the headphones, so carrying some current and do seem to make a distinct change.
Also, the output has two 100 ohm resistors in series with the outputs to the HP jack. Replaced these two resistors with 10 ohm 1/8 watt ones. These two's job is to prevent problems if the jack or the headphones have a short. But - really decreases the damping factor for the headphones. 10 ohms isn't a great output impedance, but still much better.
Anyway, I really like the change this work made. See what you think.
By the way, be very careful with the ribbon cables in these units. Marantz USA tech support tells me that Marantz Japan will not even give them a part number for these ribbon cables, much less supply them if you should bend them any.
Regards,
Greg
Have the SA-8004 and am pretty well pleased with it. Headphone output was a little lacking though (overly smooth or sweat) in my opinion. Did the following mods to the audio board and believe got it quite a bit better (more accurate) IMHO.
Replaced the (+/-) supply caps with Panasonic FC 460uf / 35volt caps to try to make sure the supply wasn't limiting things especially when using lower impedance headphones.
Replaced the four Silmac (spelling?) silk caps in the output of the headphone amp feeding the headphone jack. Silmac spec sheet on these caps says in the english version that these caps smooth things out. Only way I can think of these smoothing things out is to add in even order harmonics. Spec sheet proudly states 3d order harmonics are way down, but completely says nothing about even order ones...
Replaced them with Panasonic SU (bipolar) 220uf / 35volt caps. Sound seemed to much more what was on the CD and not smoothed over anymore. These caps are in series with the headphones, so carrying some current and do seem to make a distinct change.
Also, the output has two 100 ohm resistors in series with the outputs to the HP jack. Replaced these two resistors with 10 ohm 1/8 watt ones. These two's job is to prevent problems if the jack or the headphones have a short. But - really decreases the damping factor for the headphones. 10 ohms isn't a great output impedance, but still much better.
Anyway, I really like the change this work made. See what you think.
By the way, be very careful with the ribbon cables in these units. Marantz USA tech support tells me that Marantz Japan will not even give them a part number for these ribbon cables, much less supply them if you should bend them any.
Regards,
Greg