Aric Audio Systems Unlimited Preamp

Thanks! As far as relay-activated- that wouldn't be prudent to the design as it goes against the "completely hand-wired" and no solid state components in the signal path. Generally a relay is "PCB architecture". This has a manual switch, and the volume control is manual as well. A digital preamp, I could see a relay input selector on. 

Thank you Aric for the explanation. I figured there was a good reason for avoiding such complexity otherwise you would have considered it in your design.  

While the Transcend and Special SE's have enough guts to drive most speakers (even my older 89 db 1W efficient speakers), I'm still thinking that careful design of a single-chassis push-pull amp that has less to the signal path can be the answer to lower sensitivity speakers. I'm working out a couple of proto-types currently, and so far- the results are very good! I've got a set of KT88's being driven from a LTP 6SN7 with a single 6SN7 gain stage in front of it. Listening has been on-going for about 10 hours now and I'm so far not wanting to change a thing! Best, Aric

Just an update. Further testing of the new push-pull amplifier using some pretty inexpensive Electro-Harmonix KT-88's has been very positive! This new circuit is producing the best of both worlds- the smooth, cohesive realism of a single-ended, and the additional power and "slam factor" of a push pull. Less is more in this design, and I'll be working on the second draft of the prototype next week. 
Aric

Just another follow up: This "less is more" circuit is what I believe if giving me the magic I'm hearing with this new PP design. There are only two coupling capacitors per channel in the entire amplifier- which greatly lessens the chances of "phase" issues in each stage. It also ensures the balance between output tubes will be tighter and they'll operate more cohesively. It's generally thought that Push Pull sound too "clean" or too close to solid state, but that is definitely not the case here. There will be two models listed- the "Transcend" version (which will use very reliable, and excellent "bang for the buck" components), and the "Special" version, which will be a no holds barred version using an exclusive film capacitor power supply, "True Copper" coupling capacitors- and many other upgrades! Stay tuned.