When I inserted an SCE Harmonic Recovery System black box between CDP and amp, there was a performance increase. Since there are no controls to adjust, it can be considered as a part of the signal optimizing circuitry which manufacturers have not seen fit to include when they make provision to let you omit a formal preamp stage.
You can check out its reviews, one of which is on the positive-feedback.com website. If you see it used on Audiogon, well worth adding to your system when you go direct from CDP to amp. Strangely, by adding an extra box with its interconnect (going less than direct) you get better sound. Opposite to what our intuition tells us.
As an aside, it also works even if you use a preamp, since the SCE signal transfer optimization ideas go beyond what is built in to most components.
You can check out its reviews, one of which is on the positive-feedback.com website. If you see it used on Audiogon, well worth adding to your system when you go direct from CDP to amp. Strangely, by adding an extra box with its interconnect (going less than direct) you get better sound. Opposite to what our intuition tells us.
As an aside, it also works even if you use a preamp, since the SCE signal transfer optimization ideas go beyond what is built in to most components.