Horrible thread. Bias is simply voltage, e.g. a difference in electric potential, required to make a circuit or component function. A transistor requires a bias voltage to function properly. But so does a diode. And that is specified according to the manufacturer, freely available on datasheets. It's not something to tweak. Vacuum tube bias / biasing for guitar amps is frequently required when changing tubes and some players may prefer to tweak the bias to make the tubes run 'hot'. This can however shorten the life of the tubes and in extreme cases melt any PCB is it near. Guitar tube amp biasing tweaks are NOT for audiophile situations. Guitar tube amps are designed to be pushed quickly into breakup and harmonics and feedback, audio tube amplifiers are not. I just changed tubes and biased my guitar amp. The EL84s were 81mv average but I changed brands and the new tubes read around 60mv which is more in spec. so I didn't adjust anything. When any tubes are changed, the bias may need adjusting, but its not something you tweak to a room. And bias can drift. So, for any tube amp, guitar or "audio", biasing may need periodic adjusting within a specified range...but an "audio" amp shouldn't be "biased" to produce a particular sound. That IS what tone controls are for, if you need those or want them in the signal path. Biasing can be done in a closet. Biasing an amp in a particular "setting" to tune the amp is just garbage if someone is claiming that. A "room" does not determine circuit design and unless you seek distortion, leave dials on the circuit boards where they are.
I've Just Learned What Amplfier Bias Is...
I’ve just learned what amplifier bias is and want to share what it is, especially to us newbies out there. Here is an email I sent to Klaus Bunge of Odyssey Audio this morning:
I’ve written this on behalf of all of us newbies out here who are constantly trying to learn in this Hi-Fi thing. And by all means you experienced Hi-Fi Heads out there please chime in.
This is NOT to say there is anything wrong with tone controls, DSP, EQ or any other form of tuning your system, it’s just I’ve learned a new way of getting there.
It reminds me of my stubbornness NOT to use my systems room correction so I’m constantly upgrading my systems peripherals by ear.
For example just last week I’ve decided to order Duelund Double Strand Pair w/KLEI banana plugs DCA12GA or what is commonly referred to as Double Shotguns w/KLEI banana plugs of DCA12GA for my front speakers as I’m always looking to upgrade and with this simple upgrade I’ve managed save some coin as I already use single strand pair Duelund DCA12GA for my front speakers and can reuse.
Hi Klaus,
Bare with me here as I’m a newbie and am just learning about asking YOU the right questions, before I give you a call as I just read the 12/10 six moons review of the Odyssey Kismet Monos along with the 11/10 audiocircle forum of Kismet vs Extreme:
https://6moons.com/audioreviews/odyssey2/1.html
https://www.audiocircle.com/index.php?topic=88089.0
So to make a long story short. So far I (think) would like to purchase a lightly USED from you Khartago Stereo Extreme + biased to every conceivable variable you can think of that I may need for my particular system and room specifics.
Am I ready to buy now, no but I’m working on it.
One of the interesting facts is this morning I’ve spent about three hours trying to figure out why and how folks with high end audio gear use components WITHOUT tone, treble and bass control in the sound chain.
What I’ve read this morning and come to understand is it’s because it’s best to get the amplifier manufacturer or DIY biasing of the amplifier for the best resolution, soundstage, imaging, speed, fidelity, tonal balance, holographic three dimensionality, neutral and dynamics - spot on - in the listening room itself and completely compatible with my gear.
Bare with me Klaus, I’m getting there.
I’ve written this on behalf of all of us newbies out here who are constantly trying to learn in this Hi-Fi thing. And by all means you experienced Hi-Fi Heads out there please chime in.
This is NOT to say there is anything wrong with tone controls, DSP, EQ or any other form of tuning your system, it’s just I’ve learned a new way of getting there.
It reminds me of my stubbornness NOT to use my systems room correction so I’m constantly upgrading my systems peripherals by ear.
For example just last week I’ve decided to order Duelund Double Strand Pair w/KLEI banana plugs DCA12GA or what is commonly referred to as Double Shotguns w/KLEI banana plugs of DCA12GA for my front speakers as I’m always looking to upgrade and with this simple upgrade I’ve managed save some coin as I already use single strand pair Duelund DCA12GA for my front speakers and can reuse.