Internal Phono-stage Bypass/Replacement ?

[CheeseofBorg]

I have been troubleshooting a problem with the internal Phono-Stage of my Kenwood Eleven III, but I have also been wondering if it is possible to replace/bypass the internal phono stage while still using the phono input selection on the receiver? I have been trying to avoid using the AUX input for an external phono stage for compatibility reasons. There seems to be enough room inside the receiver for a small board (such as something from the TC line or something I make myself). If the phono stage simply amplifies and equalizes the phono signal to line level, should it not be possible to redirect a phono in (or just snake an RCA cable directly to the new board) and then have the out for the new phono stage go into the main board replacing the "out" from the internal phono stage? I can see this having an additional benefit of being able to use an independent power supply for the Phono-Stage and therefore being able to leave it on. An other "option" I can think of is to use an external Phono-Stage in its normal configuration, but the "out" of the Phono-Stage going into the casing of the Kenwood and bypassing the internal Phono-Stage as mentioned above.

Is this at all possible? Or is it a crackpot idea?

 

[Chip Chester]

Certainly possible. How practical it is depends on how tightly integrated the physical construction is. Often, pulling up one end of the first "in-line" component is enough to re-use the existing pc-mounted input jack for other internal circuit board uses. Likewise with the last component before the selector switch. Schematic would be quite helpful here. Taking the input jack straight to the selector switch (or duplicating the aux circuitry) would be pretty straightforward.

Make sure to document by labeling outside, and placing a notecard inside the device to give the next guy a clue about what was going on.

But I've gotta say that it seems like less work to replace every component in the phono preamp.

Chip