Sould a bypass/loop box be active?

[Phorhas]

Helllo guys

DO you think that a bypass box or loop box (even a sonic annahilator) should be active (i.e. bufferd) or are short hardwired connection eanogh for good tonal attributes?

[Mike Burgundy]

For tone hardwiring is fine.
Passive boxes *might* cause major problems in the groundloop department though.  If your setup allows for hum-free looping, great. If not, try active (wqith electronically isolated ground) or transformer-isolated or both.
RG has a good article on this.
Active electronics always do "something" to your signal, so keep a couple of things in mind: High input impedance, low out, full range audio, good quality caps, good quality actives, metal film resistors, and make sure there's ample headroom.
Build a passive looper and see what it does. You need the switches anyway, so adding electronics can always be done later.
Be aware that different locations (another stage, different room, etc) might present different problems all of their own with passive boxes.
hih

[Phorhas]

thanx for the advice, I'll give some designs a shot

[Mark Hammer]

Buffered, etc., is great for anticipating more diverse operating circumstances (e.g., running long cables out to a rack and back), but fully passive can be completely sufficient for a great many situations.  Depends on your context and needs.

If you want to go one step further, sometimes it's useful to have send/receive attenuation/boost to compensate for the signal-level needs of different outboard devices.  For instance, the return jack can have a buffered attenuator to accept things which only know how to output line-level signals (or operate better when doing so).  Similarly, the send jack can have some modest boost and a level attenuator to be able to provide optiaml signal levels to whatver you want.  If sending to something that is easily overdriven, you can pad down, and then crank up on return.  In such instances, you can also use the loop itself as an impromptu booster by simply running a patch from send to receive or by usin "normalized" closed circuit jacks that patch send directly to reeive if nothing is plugged in.

But again, this is not REQUIRED. If it were me, I'd make myself a passive loop selector first, leaving space which I felt might accommodate a board and pots in the future, and then make the leap to active/buffered when it seemed right.  Either way, you'll have something that works, without necessarily having to wait long.

[Khas Evets]

I'm planning to build one of these soon, and I've decided to add a buffer with an on/off switch. I'm not sure it's necessary, but it could be useful if I'm bypassing everything and have long cable runs.

[Phorhas]

Can I do it passively by sticking an audio-line Xformer in the "In" jack and "Send" jack?