Hi, I'm trying to fix a CA A1 mk1 (creek) amp with a power fault. The 34 v rails seem ok at the output collectors but I'm getting half rail voltage at the emitter and base with and loud hum on one channel. I took out one of the Tip3055 output trans and it was ok so I am thinking a driver fault. I could use a Ingram but can't find it online. Any ideas
Thanks
Monty
Thanks
Monty
There are all kinds of reasons for your described fault.
Here is the service manual index; Cambridge Audio manuals, schematics and brochures - Hifi Manuals
Here is the service manual index; Cambridge Audio manuals, schematics and brochures - Hifi Manuals
Unfortunately, the "Hifi Manuals" site listing does not include Cambridge Audio A series models. A1 Mk1 is the original discrete version, as you say by Mike Creek. Later versions which are easier to find a manual for, are straightforward Philips chip-amp (TDA1514) implementations.
Good luck locating the real A1 Mk1 schematic. However, as for most commercial amplifiers, the matter of finding manuals and schematics has come up here several times already. Searching it would have shown that at least one previous post suggested contacting Mike Creek at Creek Audio.
Good luck locating the real A1 Mk1 schematic. However, as for most commercial amplifiers, the matter of finding manuals and schematics has come up here several times already. Searching it would have shown that at least one previous post suggested contacting Mike Creek at Creek Audio.
My thanks for sending the manual so promptly, Mario. Unfortunately, it is the same manual linked earlier which is for later versions of the amplifier. Those are identifiable as based on chipamps rather than Mike Creek's discrete design. Their schematics are copyright to Cambridge Audio but freely available.
Don't ask me why Cambridge try so hard to confuse us with their haphazard model identifications but it probably has more to do with marketing than service needs.
To nail the design and schematics, this design version is copyright to Michael Creek and will most likely be drawn in the style of Creek Audio - not CA. Other CA schematics designed by Mike or associates like Alex Nitikin (x-pro here), can be found on the web but not this one. As CA in-house designs are identified by their own copyright, this is probably why you can't get technical support for the product. A case of the left hand not knowing what the right should be doing
Don't ask me why Cambridge try so hard to confuse us with their haphazard model identifications but it probably has more to do with marketing than service needs.
To nail the design and schematics, this design version is copyright to Michael Creek and will most likely be drawn in the style of Creek Audio - not CA. Other CA schematics designed by Mike or associates like Alex Nitikin (x-pro here), can be found on the web but not this one. As CA in-house designs are identified by their own copyright, this is probably why you can't get technical support for the product. A case of the left hand not knowing what the right should be doing
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