Any tricks to increase Quickie gain?

[machinehead]

Thanks Paul, I take it, that it won't filter frequencies?

Also I bought the PJCCS I take it that I should not use it in conjuction with a choke?

Thanks.

[Dr. Toobz]

If the output impedance is doubled using a current source or choke (I've used both, and am using the PJCSS right now), does that mean that the coupling cap values could/should be changed to a more ideal value? Or does this not matter?

[Paul Joppa]

For raw frequency response, the cap size depends on the input impedance of the following device. Usually 2uF is enough for a load of 10K or more (-3dB at 7Hz).

Larger is better because it keeps the impedance of the interconnect line lower so it is less likely to pick up interfering hum and noise from the environment. The point of diminishing returns is when the reactance of the capacitor becomes less than the source impedance. That in turn depends on what frequency you specify. For example, if 60Hz hum is the issue then you would use that frequency. This is my usual practice for line-powered devices like Seduction and Foreplay. For Eros, being a higher-end product, I doubled the output capacitance to get a tradeoff point of 30Hz.

Of course, larger means pricier, heavier, and often lower sonic quality, so it's a tradeoff. The optimum actually depends on the electromagnetic environment in your particular system, including that inside the system (the power amp for instance). If you want to use a different value, experimentation is your friend, all those internet gurus are not. (That includes me!)

[machinehead]

Thanks Paul.

Something I have question about.  You doubled the capacitance, you said which usually can reduce sonic qualities, but you also stated was a higher end product.
Did this just work better in that particular product?

[Paul Joppa]

No, we used a better quality capacitor. Sorry that wasn't clear. For the most part, capacitors of a given design (dielectric and conductor) will be similar in sonic qualities. But in general, the best materials often result in physically larger and/or very expensive capacitors, which at some point forces you to use a smaller/cheaper capacitor of lesser quality for purely practical reasons. This leads us to over-simplify and think "smaller value capacitors are better" - sloppy thinking, and I apologize for indulging in it.

The above is the reasoning that leads some to bypass a large value capacitor (often an electrolytic) with a small value, high quality capacitor (usually a film cap). In my experience, this often does not work because the interactions between the caps do more harm than the bypass does good, but sometimes it does help.