Cambridge Audio A3i repairs and mods

[x-pro]

Originally posted by tiefbassuebertr
Are you also the developer of the SRPP phono RIAA head amp module for the A1 and Atac3 ?
This is one the best MM phono modul, that I have ever heard. Together with a Mark Levinson JC-1 (MC head Amp) it sounded better for me as the Linn phono preamp " Linto".

Hi,

Thank you for interesting feedback!

Yes, the phono module in A1, same as the phono stage in A3i and some of the later Cambridge Audio amps, used my circuit designed originally for Creek Audio OBH-8 stand-alone phono pre-amplifier. That circuit was published by me in 1998 in the "RadioHobby" magazine.

Alex

[Puffin]

Alex. Some years ago I remember seeing the innards of a Cambridge amp in Richer Sounds window in Brighton. It was the one with the R-Core transformer. The PCB was stamped Mike Creek Audio.

Which model was it and was it any good?

[x-pro]

Originally posted by Puffin
Alex. Some years ago I remember seeing the innards of a Cambridge amp in Richer Sounds window in Brighton. It was the one with the R-Core transformer. The PCB was stamped Mike Creek Audio.

Which model was it and was it any good?

With R-core that was most likely A3i.

Alex

[Puffin]

Thanks.

[fisherc6]

I would just like to say that I love this thread. I think I will print it and keep it in my A3i box, with the original owner manual.

[niles300z]

Sorry for the late add. I too have come across the A3i and have fallen in love with its warm and detailed sound. I noticed the LED issue crop up, but have bent it a bit to avoid having to solder just yet. Alex, any interest in doing some mods on this thing? I sure wouldn't mind if one of you pros wanted to tinker a bit. I can't imagine what a real power cord and a few updated parts might do.
The internals say Creek. I am not surprised. I have considered this piece better than an NAD 2200 and B & W Pro 5 combo, except for the power of course.

[homemodder]

Originally Posted by niles300z

Sorry for the late add. I too have come across the A3i and have fallen in love with its warm and detailed sound. I noticed the LED issue crop up, but have bent it a bit to avoid having to solder just yet. Alex, any interest in doing some mods on this thing? I sure wouldn't mind if one of you pros wanted to tinker a bit. I can't imagine what a real power cord and a few updated parts might do.
The internals say Creek. I am not surprised. I have considered this piece better than an NAD 2200 and B & W Pro 5 combo, except for the power of course.

Hi, Havent seen Alex around but there is a thread where he shows some mods made which lower distortion considerbly, just basic mods anyone with some electronic knowhow can do, do a serch for cambridge A3.

[tiefbassuebertr]

Originally Posted by x-pro

Hi,

Thank you for interesting feedback!

Yes, the phono module in A1, same as the phono stage in A3i and some of the later Cambridge Audio amps, used my circuit designed originally for Creek Audio OBH-8 stand-alone phono pre-amplifier. That circuit was published by me in 1998 in the "RadioHobby" magazine. Alex

Schematics are to find about
How convert Creek OBH-8 to MC cartridges?

[tiefbassuebertr]

Originally Posted by x-pro

I've designed that amp more than 12 years ago. I attach the schematics of A3i power amp section and two graphs - on the left is for the unmodified amp (THD = 0.002&#37 and on the right is after modifications (THD = 0.0005%).

The use of the p-channel MOSFET ZVP3306A (Diodes, formerly ZETEX) at this place I have never see by other brands. If I remove this one and shorted the gate-drain, then I get a folded cascode.
Which advantages provides now the introduced ZVP3306A?

The Creek integrated amplifier circuit 5350 MK-II are also your signature of creating. Because I have difficult to understanding the schematic, I start the follow thread:
Creek 5350MK2 (5350-II 5350 Mark 2 5350-MK2) - circuit descr. arround Q12a wanted

Thank you very much for your comment.

[amber]

Hi alex, hope you keeping well,any chance of a cicurt digram for the cambridge a3i. Im an ex audio service now retired, but still keeping hands on repaires,

thanks, amber