misterwhizzy
Well-known member
I'm new to the whole biasing thing. What are the tonal differences in a hot and cold bias?
The amp is a JCA20H, and I find the 2 EL84 power amp to lack a bit of bloom. The response is immediate--a bit too much so. It really becomes noticeable at higher volumes, which is why I suspect the power section may be coming into play. It's not that there's no sustain; it's almost like there's a spike with the attack that immediately levels off into a plateau of volume. I have yet to pull it out of the chassis, so I don't know if it's hot or cold, but since it was biased at the factory, I am assuming it's on the colder side.
If it is the power section, is rebiasing the right answer? Is replacing the power tubes the right answer? If so, what EL84s have a little darker characteristic? Is it just the nature of the increased volume and the frequency changes that occur there, or is there something else I can do about it?
The amp is a JCA20H, and I find the 2 EL84 power amp to lack a bit of bloom. The response is immediate--a bit too much so. It really becomes noticeable at higher volumes, which is why I suspect the power section may be coming into play. It's not that there's no sustain; it's almost like there's a spike with the attack that immediately levels off into a plateau of volume. I have yet to pull it out of the chassis, so I don't know if it's hot or cold, but since it was biased at the factory, I am assuming it's on the colder side.
If it is the power section, is rebiasing the right answer? Is replacing the power tubes the right answer? If so, what EL84s have a little darker characteristic? Is it just the nature of the increased volume and the frequency changes that occur there, or is there something else I can do about it?
