[digitalmind]

Nothing special, but I took some pictures along the way and figured it'd be fun to post them here.
I bought this player a couple months ago with what the seller called extra balanced outputs.

There were extra outputs but they weren't balanced, they bypassed the output stage. They were terminated with Coax connectors, so I reterminated them to Cinch a week ago. I didn't like the results, it's more detailed but also harsher, not something a Grado needs. I prefer the regular outputs and since they were using NE5532's as opamps I decided to roll in OPA2132's or OPA2107's. I replaced the opamps with sockets for easy rolling in the future, and am using 2132's but truth be told, I don't hear a difference (yet?).

I wasn't expecting to hear much of a difference (if any) since I did some designing on an audio amplifier a year ago for a school project. I used 5532's then and they sounded and measured fine.

I opened up the player earlier and noticed that it was also reclocked, but I never found out with what clock since it was wrapped tightly in tinfoil and tape. I unwrapped it today and to my surprise it is a Trichord Research Clock 4 (http://www.trichordresearch.com/acatalog/Clocks.html) relative (A clock 4b?)!

Anyways, here are some pictures, I figure they might come in handy if anyone plans to bypass the outputs of this player or reclock it, or just wants to see some insides. The components are of good quality but placed fairly badly, bent here and there -- though soldered well on the bottom side.

If anyone wants them, I have more pictures and high res versions.

Top off, nice clean layout. Shiny things with random audio sentences.

Output board.

The bypass, Red is right, Yellow is left, Black the ground.

One socket in place, other opamp removed and waiting for socket.

Both of them in there.

OPA2132's in there.

The Trichord Research clock upgrade.

Working again! On my test amp -- I don't want to fry my Mapletree but I don't care all that much for this thing.

 

[zanash]

Try changing the bipolar dc blocking caps for ...well almost anything !

say 10uf 200v paper in oils ...

or 10 stacked 1uf 63v wimas

you'll be amazed at how much those nastycaps are emasculating your output.

 

[rain_uk]

nice! Ive never dared or needed to open my 640c v2 up as yet, but its nice to catch a glimpse of whats under the hood. Is that modded one a v2 or standard 640c?
Have you not noticed any improvement after rolling the op's? Is it worth doing in your opinion..im only thinking of when my warranty runs out though..not touching it before..

 

[digitalmind]

Quote:

Originally Posted by zanash /img/forum/go_quote.gif Try changing the bipolar dc blocking caps for ...well almost anything ! say 10uf 200v paper in oils ... or 10 stacked 1uf 63v wimas you'll be amazed at how much those nastycaps are emasculating your output.

Yes, this will be the next thing I'll do. It's a comon mod and I'll definitely try it out.

Quote:

Originally Posted by rain_uk /img/forum/go_quote.gif nice! Ive never dared or needed to open my 640c v2 up as yet, but its nice to catch a glimpse of whats under the hood. Is that modded one a v2 or standard 640c? Have you not noticed any improvement after rolling the op's? Is it worth doing in your opinion..im only thinking of when my warranty runs out though..not touching it before..

It's a V1, the standard 640c. I haven't noticed an improvement to be honest, so I wouldn't recommend it. However, alot of people do notice improvements when rolling opamps so it could just be me -- or not. There are OPA2132's in there now, I have a pair of 2107's so I'll swap them in this weekend. I would really like to hear a stock unit so I could tell if the done mods have had any real effects. If the superclocks sell for that much they have to do some good.

Warranty was non existant for me anyways, I got this player secondhand. One thing is for sure though, I've been trying to get the official Service Manual and noone, from the dealers to the distributor is willing to cooperate with me because I bought this player secondhand. I don't really get why -- I can understand not wanting to give service to what could possibly be a grey import player, but I'm willing to pay for the Service Manual and they still turn me down. I can understand not wanting to distribute a service manual but that doesn't seem to the problem, just that they don't know where this player came from.

 

[Goover]

Quote:

Originally Posted by zanash /img/forum/go_quote.gif Try changing the bipolar dc blocking caps for ...well almost anything ! say 10uf 200v paper in oils ... or 10 stacked 1uf 63v wimas you'll be amazed at how much those nastycaps are emasculating your output.

Done.

I'll post pictures in a bit but first impressions are that there is indeed an improvement! Even on my test amp, a chinese solid state I noticed a slight improvement. Going to grab something to eat now, will do some more serious listening later tonight.

 

[digitalmind]

Quote:

Originally Posted by Goover /img/forum/go_quote.gif Done. I'll post pictures in a bit but first impressions are that there is indeed an improvement! Even on my test amp, a chinese solid state I noticed a slight improvement. Going to grab something to eat now, will do some more serious listening later tonight.

Haha, crap, that's me at a friends pc... forgot to log in under my own name.

Quote:

Originally Posted by digitalmind /img/forum/go_quote.gif

Something changed

Also, this player has made a scratching noise when playing cd's since I've had it. It's audible when I use my Grado's at a low volume, and very annoying. So, I destroyed two mousepads and got rid of that. Not the neatest of all, but quite effective. It presses on the transport unit and gets rid of the noise.

Overall this has proven to be a VERY worthwile mod. The sound has improved by alot, I can't believe that a simple cap upgrade could yield such results. There is more detail, but not in a sharp way. Guitar strokes have more texture, there's a vibration in them that was missing before. High hats are sharper, quicker.

I actually had this player for sale on some local hifi boards, but I've taken it off. The way it sounds now paired with the riddance of the scratching noise means I'll be keeping this player.