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I'm building the Castanet as a linestage preamp: it has a lower output impedance - look at it's specs in the catalog. Pictures soon folks - I am building it with way cool green anodized panels that came in this week, silver knobs, 4 inputs, selectable record out, and some of those magic teflon bypass caps...Matt
Basically, just build a bigger box, add enough input chassis RCA's for your needs, then run these to a switch and feed the output to the pcb.The Castinet provides a high and low impedence output option. The gain is pretty low on this critter. So hopefully you have decent source voltages to deal with.Cheers!
I have used my Castanet with amps with approximately the same gain (AKSA 55 and Muse 100s) as yours. Because I was in test mode I set up a small switch in a separate box. I also use a Transformer volume control. With my speakers (about 94 dB efficient) it works really well. You could keep the low impedance for your headphones and use the high impedance for the amps. I can't find it right now but Jim either commented on this in his blog or in the forum. The Castanet is a great product.
You won't get more gain out of a CASTANET unless you use different output trannys. The 3k of the CLARINET might sound high, but in practice it drives most anything. Adding a cathode follower might mess it up a little, unless you decouple the supplies and use a constant current sink. And even then, you'll be in the range of 500 ohms.It really depends a lot on the amplifier it will be driving. Some can be difficult. I would think a Pass amp as a demanding load.jh
If you were to plug in your cd player or other source directly to your amp, and it was as loud as you'll ever need (and you don't launch the coils out of your speakers), you wouldn't need more than unity gain (0db). Another way to look at this is if your source outputs 1.4 v and your amp takes 1.0v to meet max output power, you wouldn't want gain. Most of the time one is attenuating with a preamp. The advantage with low gain is that you can run the volume pot fairly wide open, with less degredation to source signal. Until the Castanet is buttoned up, I am using a passive control on my bel canto amp, and I can barely turn the the thing a degree or two before it's too loud. I selected the Castanet for these reasons: Selectable impedance output, headphones, the ability to use it as a 1/2 watt SET amp, very low noise floor, choke PS, ability to float ground on the output trannies, single tube design, great design and success building previous kits, the total kit integration and flexibility, and I found I would never need more than unity gain.Matt
