Arcam Alpha 5 Plus CD Player.

Umberto

Member
2005-05-16 5:56 pm
uk
Please Help.

I have distorted audio output when playing my CD's, i've checked the lazer to see if it was dirty and it seems to be ok. After some further investigation I've also manged to check the +/- 25ve rail and they both seem to be ok. I susupect it's a problem with the D-A circuit.
Has anyone experienced the same fault?
 
Umberto

I have here the complete boards out of an Arcam 5 player. The only fault: main tranny burned and no transport.

I got it to scavenge and to build my own external DAC...

So, what seems most suspect on this board, what I would check in your case: the two nonpolar 100uF caps near the output jacks on the smaller board. They sit fully in the signal path and they could be aged.

Should you receive a service manual, could you send it to me per mail? ([email protected], please subject "Arcam" or something like this (Spamfilter).

Should you not succed with the reparation, I could offer you my boards, but take it as your second chance :D

Kind regards
Franz

/Edit: I realized to late: my boards are not from the plus version and I don't know about the differences. I am very sorry! But I am quite sure, you will find the two grey caps, I mentioned. Check them!
 
Umberto

Here a picture of the DAC/Audio Board showing the mentioned caps (red arrows).

After looking at the schematics, this is the most possible reason for your problem!

After isolating the problem (you can try a lower value than 100uF, possibly loosing some bass, but the distortion should disappear), you could check, if the attached device (pre- or integrated amp) has some input caps.

If yes, you dont need the output caps in the player and you can replace them by a wire.

In this case, I may suggest you also to remove the output mute transistors (Q2/Q102) and the output resistors (R14/R114). See blue arrows.
 

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O.K. O.K., I agree! :D

Today, I spoke to the local high-end service shop: He remembered this problems in the Arcam Alpha 5 are often caused by some electrolytics failure in the audio/mute PSU.

So, I suggest to check C406, C407 and C416 near the power connector.

Kind regards
Franz

P.S.
C415 is not an electrolytic and therefore seldom object of failure.
 

hujanus

Member
2009-05-31 1:55 pm
Hi,
I am having a similar problem. I have replaced the audio board and still have distortion. Read this thread and replaced C416, still have distortion. Replaced all the 1000 and 3300 capacitors and still have distortion.
What should I check next?

Any help apreciated.
 
O.K. O.K., I agree! :D

Today, I spoke to the local high-end service shop: He remembered this problems in the Arcam Alpha 5 are often caused by some electrolytics failure in the audio/mute PSU.

So, I suggest to check C406, C407 and C416 near the power connector.

Kind regards
Franz

P.S.
C415 is not an electrolytic and therefore seldom object of failure.

I'm fixing a distorting Arcam alpha 5 plus CD at the moment and have found a dead C416 (470uf 25v) & replaced it, but haven't tried it yet to see if the problem has gone! I'll leave it untill tomorrow. Just wanted to say thanks for the pointer!:cheers: