biasing is a p.i.t.a!

[glassjaw7]

So, to me the idea of pulling a chassis out of a headshell and biasing an amp is just a pain in the ass and it seems silly to me that external bias points and adjustment knobs/dials aren't a standard thing in this day and age. I really appreciate the fact that some builders do this like Fortin and Diezel(until legal restrictions stopped him from doing so).

I'm sure some of you guys, if not most of you are not bothered by this inconvenience and maybe you view it as regular tube amp maintenance, but to me it is a real drag. A lot of builders put shitloads of options on amps when most of them are worthless and could be replaced with useable features such as bias points / midi switching, etc...

Now this may be a dumb question since I don't know jack about building amps, but if certain amps like THD amps and the Diezel Schmidt don't have to be biased due to being cathode based or whatever, then why aren't all amps built this way? Would it drastically change the sound of the circuit? I'd love to understand more about how amps work, but for now I just want to drive the car, not be the mechanic under the hood. Thoughts?

 

[~Abstract~]

I generally like the tone of fixed (adjustable) bias amps over cathode biased ones.


fwiw

 

[glassjaw7]

I generally like the tone of fixed (adjustable) bias amps over cathode biased ones.


fwiw

How is it different? I would never know if certain components within the circuit or the cathode bias was causing the difference in tone.

 

[Motorpud]

So, to me the idea of pulling a chassis out of a headshell and biasing an amp is just a pain in the ass and it seems silly to me that external bias points and adjustment knobs/dials aren't a standard thing in this day and age. I really appreciate the fact that some builders do this like Fortin and Diezel(until legal restrictions stopped him from doing so).

I'm sure some of you guys, if not most of you are not bothered by this inconvenience and maybe you view it as regular tube amp maintenance, but to me it is a real drag. A lot of builders put shitloads of options on amps when most of them are worthless and could be replaced with useable features such as bias points / midi switching, etc...

Now this may be a dumb question since I don't know jack about building amps, but if certain amps like THD amps and the Diezel Schmidt don't have to be biased due to being cathode based or whatever, then why aren't all amps built this way? Would it drastically change the sound of the circuit? I'd love to understand more about how amps work, but for now I just want to drive the car, not be the mechanic under the hood. Thoughts?

I couldn't agree more man, bias times a BUMMER for me. The external bias points should be something every tube amp has

 

[~Abstract~]

I generally like the tone of fixed (adjustable) bias amps over cathode biased ones.


fwiw

How is it different? I would never know if certain components within the circuit or the cathode bias was causing the difference in tone.

They feel "dull" to me. IDK...I bet there are plenty out there that I'd love. I just haven't found em yet.

 

[SuperFlyinMonke]

I swapped and biased tubes in my Hydra a few days ago and it took all of 10 minutes. External adjustable bias is great.

 

[Tawlks]

Eh?

#


... Really though I do agree, my 5150 II has 'bias points' which measure the wrong type of bias aswell, at what point of designing the amps did they decide to put that feature in? I'm sure Eddie Van Halen would have known better? I can't comment over which sounds better as I don't have enough experience.

My amp is a fixed (adjustable) - (That doesn't make sense, right?) bias amp, is the 5150 the same or is it fixed like a THD?

 

[Buckeyedog]

That's why I love Egnater amps. Bruce always makes it so easy to bias. Takes like 3 minutes to bias my Mod 50. Sorry, just had to chime in.

 

[Death by Uberschall]

It doesn't bother me to do it, but I'm a "tinkerer" and enjoy checking out what's going on inside an amp.

In most cases it might be 2 or 4 grille screws and 4 chassis screws. Shouldn't take more than a couple of minutes to have the chassis out.

 

[fek]

Biasing is one of the many reasons why I love the Randall/Egnater amps. Biasing is simple and I can put just about any type of power tubes in them. I do also like Mesa's fixed range idea and incorporating a EL34 or 6L6 switch.

 

[LP Freak]

It doesn't bother me to do it, but I'm a "tinkerer" and enjoy checking out what's going on inside an amp.

In most cases it might be 2 or 4 grille screws and 4 chassis screws. Shouldn't take more than a couple of minutes to have the chassis out.

+1

 

[~Abstract~]

Biasing is one of the many reasons why I love the Randall/Egnater amps. Biasing is simple and I can put just about any type of power tubes in them. I do also like Mesa's fixed range idea and incorporating a EL34 or 6L6 switch.

But then you're required to purchase tubes from them (at a premium)...or find another vendor that can supply tubes manufactured to a certain spec.

 

[SwampDonkey]

Pay a tech!

$50 to get it biased by a pro is worth it if it causes you that much frustration.

 

[Ventura]

Pay a tech!

$50 to get it biased by a pro is worth it if it causes you that much frustration.

I don't trust techs, typically speaking.

Personally, if one could simply have the bias pot available somewhere on the outside of the chassis, then using a Weber BiasRite would be the bomb. Just plug in the new glass, stick the Webers in there, and grab a screw driver - done. I don't really HATE having to pull a chassis, flip the fucker upside down, watch my books used to elevate the whole enchilada, but the deal is - there has to be a smarter and easier way overall.

Peace,
V.

 

[Erock]

the easiest amp I've owned to bias is the ENGL SE. It has 3 LED's, yellow for too cold, green for just right, and red for too hot. There is a button to test each tube, and 2 bias adjustments, the main one and a fine tuner. All you do is make sure each tube tests in the green. Really handy to use, since I can check the bias after an hour of playing with new tubes, just to see if it's drifted out of range, without having to open the amp. Just turn the master down, press the buttons, and look at the LED's. Would be nicer if it had a readout of what the actual current is, but still the easiest amp I've biased.