Music slows down!! - Cambridge CD4SE

[Sonusthree]

Hi,
I own a Cambridge CD4se with an intermittent fault.
The music slows down and then distorts.

The story so far:
It has been modified with super regs for the digital section and another Audiocom specifically feeding the clock. Other mods are the usual dampening and Black gates..... blah blah.... you get the idea.

The VAM1202 that I was using had it's problems. It was sometimes very picky about which tracks it would play and was quite temperamental. The transport was not very old (14 months) but I cleaned and re-greased it with no real change. The problem was just something I put up with until recently when the music would crackle and sometimes come to a halt. I always suspected a mechanical problem because I could hear the transport 'grinding' occasionally.

Anyway, Enough was enough and I replaced the whole transport last night and it now finds any track with ease.
Great, but intermittently, the music slows down as if there is a pitch control. It makes the music sound as if it is trying to drive up a steep hill. So far it has not stopped but it sounds as if it nearly does and then gets back up to speed.

I'll be checking the voltage going to the clock from the Audiocom reg later but that's about the extent of my expertise for now.

What do you reckon? I reckon it's got to be the clock or spindle motor but I only know a little theory (from reading this forum) and not the practice. What can I do?
It's all SMD parts in this player so I really need some help before I dive in.


Thanks in advance,
Martin.

[GJF]

I've experienced this to a small degree with some Sony transports and it was the magnetic puck not seating correctly on the top of the disc and spindle motor.
End result is a poorly clamped disc that can slip when the motor spins up and it 'hunts ' to find the correct speed.

[Sonusthree]

Thanks for the reply.

I hadn't thought of that! I'll have a fiddle and see if it helps. I had noticed before (with the previous transport) that the disk seems to vibrate alot.
This was especially obvious when looking at the disk clamp.

I'll investigate and report back,
Thanks again,
Martin.

[Sonusthree]

Hmm, no luck yet.
The disk clamp seems fine. So far it appears to be related to the time that is running for. ie probably heat?

Perhaps alot of these mechs are a dodgy? But I don't want to buy another just in case.

I'll keep trying but this SMD stuff is fiddly.

Cheers,
Martin.