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ARCAM 8 Power AMP fault?

To all who have experience with power amps....I have recently attempted to connect my Arcam Mosking to my existing ACAM CD 72, ARCAM 8 (Pre amp) setup.  I connected the CD 72 to the 8 (pre) as normal, connected the 8 pre (SP 1) ports to the hi frequency ports on the back of the AE AEGIS 3 sepakers, connected the 'pre-amp' outputs to the power amp inputs, and connected the power amp SP1 ports to the Low frequency speaker ports.  (I also removed the coupling on the speakers).   When playing CD, I only got sound on the hiher frequencies (the pre amp part).  No bass (no power amp output). 

When I removed the connnection from the pre-amp to the speakers, and put the coupling back on the speakers, i could not hear anything from the speakers unless I turned it up max- in which case I could faint hear high pitch beat of the CD. 

Assuming cables are all fine (which they are), what does this sound like to you guys?  Is the Mosking broken or what? Sad Dont wanna pay for 'fix' if it is bust, and dont wana pay for fix if it is me being a 'knob'.  Thanks!...

 

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RE: Headphones, etc.

If its any consolation it doesn't sound like your being a knob !

When you turn the poweramp on can you hear the relay click after a couple of seconds ?

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RE: Headphones, etc.

I assume that when you turn the Mosking on the light comes on (green I think), and when you just use the 8(pre) connected to the speakers you get full range music.  then either the cable between the amps is broken (unlikely that left & right would break) or the Mosking is broken.  Couls be anything fuse?, output transistor.

 

You could try using the sp2 outputs to rule out the connections.

 

Chris

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RE: Headphones, etc.

Hi egg-  I can hear the click, after about 4 or 5 seconds.   Green light, all signs positive....but still no sound.   Ive tried SP2 ports as well.  

Anonymous
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RE: Headphones, etc.

thanks chris-  you know if those kind of faults fixable at a worthwhile cost?

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RE: Headphones, etc.

If the relay is clicking then the power stage hasn't blown as it would go into dc offset. Arcam's generally only have one fuse on the primary side of the transformer so it is unlikely to be fuse related.

Strange one ! I haven't got a schematic to hand at present but will have a look tomorrow to see if there is anything obvious. It does make you wonder if the signal is getting out of the preamp. Do you have a 6.3mm jack to RCA lead ? You could try running the power amp off the headphone out just to see if it springs into life.

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RE: Headphones, etc.

Do you have another source to try, maybe an ipod with a 3.5mm-2 rca cable, going straight into the Mosking (missing the pre).

 

I know its a long shot but have you tried plugging the cable into the "link output" of the Mosking instead of the input?  I believe they are just linked inside.

 

Chris

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RE: Headphones, etc.

Genius- the iPOD works directly plugged into the 8P.  So its not the amp itself thats bust.  Which leaves only weak link....the Pre-Amp output sockets on the 8R.  I will try changing the RCA cables just in case, but I think they are ok.  IS there any way to avoid using the Pre-Amp outputs?  Thanks for sstaying with this... Smile

Anonymous
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RE: Headphones, etc.

Egg,  I think you have pre-empted the question I have asked chris below.  I will try that and I think we might  have a solution.  Thanks...!....

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RE: Headphones, etc.

looks like your getting close to solving this.

 

I suspect that the pre amp output is not working, could be a loose connection inside the amp, i doubt that its just the cable as both channels are not working.  but stranger things have happened. 

 

The pre amp board may be broken (or just not in properly) , you should be able to find one cheap and replace yourself, one was on sale on ebay but has gone.  only £30.  http://cgi.ebay.co.uk/Arcam-Alpha-Amplifier-PreAmp-Out-Upgrade-Kit-/250835929684?pt=UK_AudioTVElectronics_HomeAudioHiFi_Amplifiers&hash=item3a66fc8a54

 

chris

 

Chris

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RE: Headphones, etc.
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