Dynamically Adaptive Output Stage No. Don"t roll your eyes and dismiss this as marketing bullschiit. Our new Dynamically Adaptive output stage allows us to pack almost 6X the output power of Asgard into an amp that runs slightly cooler. (Now, that doesn"t mean it runs cool. If you want a cold amp, you need to look elsewhere.) It works by sensing the current flowing through the output stage, and dynamically reconfiguring from Class-A single-ended to push-pull Class AB. * Roll Your Own Lyr ships with either new-production NOS GE 6BZ7 tubes, but feel free to substitute any 6DJ8, 6922, ECC88, 6BZ7, CV2492, CV2493, or 6N1P type tube, new or old, American or Russian or Chinese. The ability to use different tubes lets you tune the overall sound signature of Lyr to your specific preferences. * 15-Day Satisfaction Guarantee Don"t like your Lyr? No problem. E-mail us for an RA and send it back for a full refund, minus 5% transaction fee, within 15 days of receiving your amp.When was the last time you spent a couple of weeks in an audio store? With your own equipment? Thought so.