Audio Innovations Alto

I have now removed the front inner panel. It was putting strain on the balance which is mounted on the main pcb (other front panel devices are on leads).
A pair of pliers re-tightened the lugs on the balance pot.

Did I mention high DC offset at speakers as well?
130mv, noticeable plop when speaker relay cuts in & out. Both channels same.

IPA doesn't touch the gunk. It seems rubbery. I'll try acetone.
Only for curiosity to see if this restores function.

I'm convinced the re-purposing is the way to go. A couple of TPA3116 boards would be an easy and cool fit. The case is thermally poor for class AB.

Just trying to figure how to sequence the LEDS.
Volume knob, green for normal operation, red for standby & mute.
Input select, Green indicating source, red for mute & off for standby is one possibility.
 
Alto System (AM1/CT1)

Hi guys,
Recently I bought this system, mint condition, with original stand, both components
intact, stayed in the boxes last 10. years (told by previous owner). Everything working fine EXCEPT high DC offset on left channel, -532mV! Right channel is OK, 4.3mV.
No any sound distorsion or any other bad audible noise, hum, etc. just MJ15015 getting hot...not to hot, but hot!
Service manual is theme for Spielbergs next movie and I hope some "Spielberg" on diyaudio
got service manual or any kind of help to solve this problem!
Thanks in advance!

P.S.
Since 2019. in UK!
 
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Problem sorted without service manual or anybodies help!
Barely visible, track pad between input transistors on the right channel has been broken!
Now, DC offset is 12.2mV! :)
Generaly, PCB in AM1 is disaster...such a awful quality!

I hope this info will be helpful for the owners of AM1!

Cheers
 
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Photo of stripped amp. Note how this 'Richer Sounds' version is totally different to the Mk1 (post #7).
Hi Russc.
I also have a mk2 Alto. It would seem to be quite rare as is any information about it.

I've been trying to find a schematic of the amp but have had no luck in all the usual places.

Have you been more successful than me and, if so, could you post a schematic for me. I'd be most grateful.

Details on the mk1 Alto are easy to find but not the mk2.

Thanks in anticipation. Andy Chapman. Wiltshire, UK.
 
Thanks Russc. Curiosity mainly. I bought it on Ebay years ago and it arrived not working. Two PCB tracks were cracked in the post (?) and I managed to repair it.
I was surprised when I found it did not match the MK1 info readily available but have never found the actual schematic for it.
I'll keep looking.
Andy