Studer A730 advice

[glasgowhifi]

I'm looking for advice on my Studer A730 CD player.

It plays fine, but I have noticed that on longer CDs, it skips as it reaches later tracks, and sometimes eventually gives up altogether.

It plays also plays CDRs fine as well (providing they are burned at a slowish speed), but again exhibits the behaviour above on longer CDRs.

It is also not very tolerant of discs with surface marks that play fine on my other more recent CD players.

I have searched previous posts, but have a few questions that hopefully someone with experience with these machines will be able to answer:

1) Am I correct in thinking that the skipping on later tracks could be corrected by adjusting the radial offset?

2). Is the problem of skipping on blemished discs due to the fact that the error correction is not as complex on todays machines, or could this behaviour be caused by something more sinister?

3). I'm assuming the player could benefit from replacing electrolytic caps. Apart from the power supply, are there any other particular sections of the machine I should be looking to replace electrolytics?

Many thanks in advance. Any help or advice is much appreciated!

Colin

[guido]

Hi,

This is not an easy player to fix. It's quite complicated as it is intended for studio use. So a lot of functions and circuits you won't find on a normal player.

It is based on philips chipset, but it uses a cdm3 transport. And these are very rare. Think it will be difficult and expensive to find one. As for playing a worn disk, this machine should be able to do that. It's designed for studio use and you don't want skipping on the air during a radio broadcast. cdm3 transport quality was mixed, philips had problems getting a constant good quality. Also it was too expensive to produce. MTBF is 4500 hours!!

These transports were selected, the best quality went to sweden (to a company that manufactured test equipment for cd quality measurements). Others went into cd players and even cd-rom equipment. But that list is very small. Studer actually also got better quality ones, as they demanded this.

As for the skipping, i think it is more difficult for a player to read at the end of the disk. From memory it's that the reading goes from the inside to the outside and that at the outside of the disk, the speed of it turning is much faster.

If this is a machine from a studio, it will have been used a lot. So the laser could be worn. On the other hand, on e.g. a cdm2 it is often nothing more than a worn cap. But that is with an older chipset. It's similar to C11 on the decoder board in your machine.

And yes, other caps could also be worn, but i've never encounterded many problems with my own machines. But do check the 5V supply as it is implemented with a switching supply.

I have the manual, but only on paper. And a pdf for the cdm3, but that's in dutch

Be carefull, it's a special machine. Don't touch it if you dont have much experience with this stuff

[Netlist]

Public Studer / Revox manuals.

Might help.

/Hugo

[glasgowhifi]

Just thought I'd post this in case anyone finds it useful. My studer a730 (see previous) had got to the point where it was skipping like mad on track 1 of any cd I threw at it.

I decided to recap the PSU, servo board, and digital sections of the main board. While I was in there I replaced the Varta NiCd as it was beginning to show signs of corrosion.

The result? As good as new. Playing back cds properly, even ones that are pretty scratched.

If anyone else is having similar problems with these machines, it may be worth doing this before assuming that it ust be the rare and expensive CDM3.

Many thanks to everyone that offered advice.

Regards!

GlasgowHifi