Looking for 5AR4 rectifier tube most like solid state

I think that Cary may have give you some bad information. I agree with @rhtowson; there is no reason why you can't run solid state rectifiers in your preamp. While I prefer the sound of tube rectification, there have been situations when I have used plug compatible solid state alternatives. To be honest, while rectifier types and quality (tubes) will make a difference, it's generally not a huge difference. And SS "tubes" last longer and don't change much with use.

Lots of good advise here. Try swapping tubes and/or SS devices and see what sounds and works best for you.

Yes, I was a bit surprised when they claimed that changing the rectifier would require a complete power supply redesign. I've designed power supplies for many solid state amps myself. SS rectifiers have a lower voltage drop, so the rectified voltage would be higher. Consequently, the smoothing caps would have to accommodate the higher voltage.

I guess that higher smoothed DC voltage would be passed along to any regulation circuits, and potentially require more heat dissipation. (I have no idea what's in place in the SLP-05.) If there is no regulation, then the higher voltage would be passed along directly to the rest of the circuitry.

Therefore, I wouldn't feel comfortable trying a SS rectifier without the blessing of Cary.

Therefore, I wouldn't feel comfortable trying a SS rectifier without the blessing of Cary.

Understand. But the tube plug-compatible SS rectifiers are designed to be direct replacements. I have tried them in many amps and never had a problem. They run much cooler than any tube and I haven't noticed any voltage differential, compared to the compatible tube. But maybe the Cary circuit is more sensitive???

Thanks, @br3098 . I haven't had a chance to try the Mullard yet. If I'm still dissatisfied with that, then I'll ponder whether to try a plug compatible one, or to start looking for another preamp.