Cambridge Audio 640C v1 Mods

[mikesnowdon]

Brent,

I found this but its a bit pricey. Any cheaper recommendations?

[Fidelity Audio]

Buy the Araldite superglue. You mix it together and it sets like a rock. I used it for fitting my oak feet to my cd and amps and it takes some removing.

Brent

[Fidelity Audio]

Here is a pic of the level 2 mods (4X SPower , 1X C1 clock , lots of BG caps and 6x LM4562 opamps + other bits)

PIC

Brent

[mikesnowdon]

Very nice Brent. I'd love to hear it.

Do you have any plans to mod the 640 further and will there be any pics?

[mikesnowdon]

Finnished my first speaker today!

Good results initially. Cant wait to get the CD sorted now!

Cheers,

Mike

[mikesnowdon]

Yep 220uF is fine. But bigger is that little bit better.

Hi Brent.

What about adding 2 x 220uf to the clock supply then? obviously I'd drill the pcb and link the leads underneath, simmilar to how you did the PSU caps.

Mike

[Fidelity Audio]

2X 220uF would work fine. Run it with 220uF first and then at a later date add a bigger cap and see if you notice a difference.

It sounds very good indeed, easily in the £1000 - £1500 region for sound quality. Makes the Naim CD5i we have here sound rather poor.

I'm not doing anymore work on this 640V2, it's one we are selling (brand new with level 2 mods).

Brent

[Fidelity Audio]

I do have a level 3 upgrade in the pipelines. This will no doubt include 2X Spower regs for DAC digital and an additional 30VA transformer to isolate the power rails even further + increasing the VA headroom on the original transformer.

P.S I have this brand new upgraded 640 up for sale if you know anyone who may be interested.

Brent

[mikesnowdon]

Thanks Brent.

If I hear anything I'll let you know.

I installed the new components today.

I have copied your earlier mods exept adding a new clock and PSU Caps. I added 220uF to the DAC supply and a 220uF to the clock supply. Installed the 6 LM4562NA opamps and 10uf decoupling caps.

Initial listening is promising. There is a more 'live' feel to vocals and more detail. The Bass is more tuneful, better controlled. Definate improvements, will report again after a few days burn in.

Had a little accident and broke one of the pcb tracks while fitting an opamp socket. Fixed it by soldering a piece of wire in. Lesson learnt: dont try to force a component in , if it wont go, make sure all the solder is removed!

I will do the main psu caps in a couple of weks and also the remaining 2 DAC caps. Im going to try Panasonic FC, unless someone knows better? If cash is available I'll also fit 2 x low noise regs on the opamp supply.

Thanks for all of you for your help so far.

Pics here: click

[Thomo]

Nice pics. I particularly like the Audio Component Pet, lol.

Defo give the components time to run-in. Also, leave the player switched on even when not in use, Black Gates in particular really benefit from having a constant current running.

Glad you like the sound so far. I called into Brents place today and had a listen to that player he has modded. Sounds very good, great bass and fluid midrange.

Regards, Lee.