Sony scd xa777es vs scd777es


Can anyone enlighten me as to the differences between these two units (other than their confusingly similar names)? Does either have balanced out? Which is considered to be the better unit? I see that one weighs almost twice as the other and is a top loader perhaps indicating better build quality. I am looking for a solid sony product as I have had good luck with my older es player.

Thanks to all
Gene
gwoodall
I knew you understood Chuck,but there were a few that seemed to be a little confused,so I tried to nip it in the bud.Take care,Gary.
Regarding the "balanced" XLR outputs on the SCD-1. The way this is implemented is reasonably well-known, but just in case you are not completely aware of the method, Allen Wright has this to say:
The complex way SONY do the balanced outputs on the SCD-1 has been commented on here before.

To recap:

1/ The digital signals in the SCD-1 (and all the VC24 based players) are in Balanced format

2/ SONY then convert the Balanced analog signal that appears after their "current pulse" DACs into Unbalanced format, using several opamps

3/ They then filter the signal in Unbalanced format, with more opamps

4/ This Unbalanced signal is then output on the RCA jacks of all these players.

5/ But then, in the SCD-1 only, this unbalanced signal is RECONVERTED to a Balanced format and output on the XLR sockets - using even more opamps!


http://www.audioasylum.com/forums/hirez/messages/125857.html

Regards,
Metralla

I am not an electrical engineer but that circuit does not appear to be a very efficent design and one that would seem to degrade from the sonics. This is why the person modding my player (RAM east)wants to eliminate 90% of the output(audio) board with one pair of summing op amps and then into a transformer stage and then directly into the rca's.

There have been several threads on audiogon debating the fact that the Sony's balanced outputs are truly balanced. The person modding my player tells me they are not and explained why, but I can not remember.

Chuck
Chuck,

What modders can do is use high-end parts that are not cost effective for even fairly expensive production units, such as the SCD-1. But I'm pretty sure the engineers at Sony know a lot more about circuit design than whoever is modding your unit. Sony can afford to hire some smart folks. The use of balanced lines is common in commercial applications where long leads are needed. So I'd take the explanation provided by your modder as just more of the mysticism that previals in high-end audio.

db
Unless the signal is balanced throughout, it is not balanced when it comes to the XLR's. There is more to 'balanced' than simply slapping a pair of XLR plugs into a CDP.