cathode bias VS grid bias tremolo
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Re: cathode bias VS grid bias tremolo
Assuming that's not a photo of you above, check out Aiken Amplification, GeoFX, Ruby Amplification, etc. to find out the differences. Or, you could buy a copy of The Ultimate Tone for $60 +/- and learn that plus a whole lot more.
I was thinking about cathode bias vs. fixed bias for power tubes. Try searching the Hoffman Amps forum.
Or look at a crapload of schematics over on SchematicHeaven.com. Vibro Champ vs. Deluxe Reverb, for example? Most tremelo circuits are on push-pull amps and the tremelo is inserted onto the control grids between the phase inverter and the power tubes. For single ended amps, the tremelo seems to be applied to the cathode of the last preamp tube.
Learn something new every day. Still got no clue what it would mean in terms of tone/sound.
Chip
Assuming that's not a photo of you above, check out Aiken Amplification, GeoFX, Ruby Amplification, etc. to find out the differences. Or, you could buy a copy of The Ultimate Tone for $60 +/- and learn that plus a whole lot more.
I was thinking about cathode bias vs. fixed bias for power tubes. Try searching the Hoffman Amps forum.
Or look at a crapload of schematics over on SchematicHeaven.com. Vibro Champ vs. Deluxe Reverb, for example? Most tremelo circuits are on push-pull amps and the tremelo is inserted onto the control grids between the phase inverter and the power tubes. For single ended amps, the tremelo seems to be applied to the cathode of the last preamp tube.
Learn something new every day. Still got no clue what it would mean in terms of tone/sound.
Chip
Re: cathode bias VS grid bias tremolo
Bias for a tube is the difference in voltage potential between the grid and cathode of a tube. The difference is usually to make the grid more negative than the cathode. This difference can be achieved in a number of different ways.
I don't understand cathode bias tremolo vs grid bias tremolo. Tremolo is an effect created by periodically varying the volume of the signal. It can be achieved by varying the bias of amplifying stages (i.e. not just tubes).
The ultimate problem in achieving a tremolo is to prevent the low frequency modulation signal from being fed through the amplifier as a separate signal - in other words, you don't want to hear the modulation frequency when you aren't playing.
Bias for a tube is the difference in voltage potential between the grid and cathode of a tube. The difference is usually to make the grid more negative than the cathode. This difference can be achieved in a number of different ways.
I don't understand cathode bias tremolo vs grid bias tremolo. Tremolo is an effect created by periodically varying the volume of the signal. It can be achieved by varying the bias of amplifying stages (i.e. not just tubes).
The ultimate problem in achieving a tremolo is to prevent the low frequency modulation signal from being fed through the amplifier as a separate signal - in other words, you don't want to hear the modulation frequency when you aren't playing.
Re: cathode bias VS grid bias tremolo
Thanks for the help
1.) Tremolo is an effect created by periodically varying the volume of the signal.
Bias is not a volume its a ?
2.) It can be achieved by varying the bias of amplifying stages
If u vary/modulate the ""bias"" then the positive or negative cycles of the wavefore are going to be clipped or waveshaped?
3.) Most fender amp have a bias of (-)48volts do u mean tremolo vary/modulates between -32volts to -56volts?
4.) Vibro champ is grid bias tremolo
Twin or deluxe iscathode bias tremolo
Cathode bias is push pull A/B
Grid bias is Class A
5.)Whats the difference how the tremolo "bias" is varied/modulated
between a Push Pull tremolo VS class A tremolo??
Thanks for the help
1.) Tremolo is an effect created by periodically varying the volume of the signal.
Bias is not a volume its a ?
2.) It can be achieved by varying the bias of amplifying stages
If u vary/modulate the ""bias"" then the positive or negative cycles of the wavefore are going to be clipped or waveshaped?
3.) Most fender amp have a bias of (-)48volts do u mean tremolo vary/modulates between -32volts to -56volts?
4.) Vibro champ is grid bias tremolo
Twin or deluxe iscathode bias tremolo
Cathode bias is push pull A/B
Grid bias is Class A
5.)Whats the difference how the tremolo "bias" is varied/modulated
between a Push Pull tremolo VS class A tremolo??
Re: cathode bias VS grid bias tremolo
Already told you: "difference in voltage potential between the grid and cathode of a tube"
Modulating the bias changes the gain of the tube which then changes the volume of the signal. It is not a means of clipping.
The bias voltage does vary, but not quite as extreme as your example. A couple/few volts maybe.
In the vibro champ, the single output tube is self biased. The bias voltage is developed across a resistor between the cathode and ground. The tremolo modulating signal is applied to the cathode of the driver stage, not the output stage.
The bias method of twins and deluxes varied depending on year. The earlier models were self biased. Later models became fixed biased. Fixed bias is when a negative voltage is provided to the grid of the tube.
There were early deluxe models that modulated the fixed bias voltage to achieve a tremolo effect.
I can't find a model where a twin ever used this method. I believe the 6G8 was the first twin to have tremolo and it was the "harmonic tremolo" that modulated high frequencies separate from low frequencies. This was done in the preamp section. It was dropped because it was too expensive requiring five tube stages for the tremolo effect and it was difficult to eliminate the modulating signal from passing through to the output.
The bias method of output stages has no effect on it's class of operation. Example: A class "A" operation can be achieved with either self or fixed bias.
By class A I'm assuming you mean a single output tube. The answer is essentially none.
It works best with a push pull stage - since the same tremolo modulation signal is applied to both output tubes, most of it will be canceled. With a single output tube, you might get the modulation signal coming through the speaker.
Already told you: "difference in voltage potential between the grid and cathode of a tube"
Modulating the bias changes the gain of the tube which then changes the volume of the signal. It is not a means of clipping.
The bias voltage does vary, but not quite as extreme as your example. A couple/few volts maybe.
In the vibro champ, the single output tube is self biased. The bias voltage is developed across a resistor between the cathode and ground. The tremolo modulating signal is applied to the cathode of the driver stage, not the output stage.
The bias method of twins and deluxes varied depending on year. The earlier models were self biased. Later models became fixed biased. Fixed bias is when a negative voltage is provided to the grid of the tube.
There were early deluxe models that modulated the fixed bias voltage to achieve a tremolo effect.
I can't find a model where a twin ever used this method. I believe the 6G8 was the first twin to have tremolo and it was the "harmonic tremolo" that modulated high frequencies separate from low frequencies. This was done in the preamp section. It was dropped because it was too expensive requiring five tube stages for the tremolo effect and it was difficult to eliminate the modulating signal from passing through to the output.
The bias method of output stages has no effect on it's class of operation. Example: A class "A" operation can be achieved with either self or fixed bias.
By class A I'm assuming you mean a single output tube. The answer is essentially none.
It works best with a push pull stage - since the same tremolo modulation signal is applied to both output tubes, most of it will be canceled. With a single output tube, you might get the modulation signal coming through the speaker.
Gearjoneser
Gear Ho
Re: cathode bias VS grid bias tremolo
Re: cathode bias VS grid bias tremolo
Thanks LJ King for the help
1.) Fixed bias is when a negative voltage is provided to the grid of the tube.
Self bias is the same thing it has a negative voltage to the grid of the tube right? (but its variable)
2.) Whats the difference between Self bias VS fixed bias?
3.) Whats the difference between Self bias tremolo VS fixed bias tremolo?
Thanks LJ King for the help
1.) Fixed bias is when a negative voltage is provided to the grid of the tube.
Self bias is the same thing it has a negative voltage to the grid of the tube right? (but its variable)
2.) Whats the difference between Self bias VS fixed bias?
3.) Whats the difference between Self bias tremolo VS fixed bias tremolo?
Fresh_Start
New member
Re: cathode bias VS grid bias tremolo
Look, I'm not going to post any cartoons, but please look at the sites I suggested earlier to learn about fixed/cathode bias, etc.
Chip
Look, I'm not going to post any cartoons, but please look at the sites I suggested earlier to learn about fixed/cathode bias, etc.
Chip
Pink Unicorn Horsey
Megä Pöny Rÿdr
Re: cathode bias VS grid bias tremolo
What's the difference between cathode bias and Len Bias?
Is Len Bias the inspiration behind Celtic Amps?
If you blow a fuse, is it like doing too much blow like Len Bias?
What's the difference between cathode bias and Len Bias?
Is Len Bias the inspiration behind Celtic Amps?
If you blow a fuse, is it like doing too much blow like Len Bias?
wixedmords
New member
Re: cathode bias VS grid bias tremolo
Don't make me think about Len Bias and Reggie Lewis and what might have been KG.
I am feeling a little emotional tonight.
Don't make me think about Len Bias and Reggie Lewis and what might have been KG.
I am feeling a little emotional tonight.
Pink Unicorn Horsey
Megä Pöny Rÿdr
Re: cathode bias VS grid bias tremolo
Ugh! I forgot about Reggie Lewis.
If Len Bias and Reggie Lewis got married, would they be Len and Reggie Bias?
Is it okay to have a Len Bias and a Reggie Bias?
Is Len fixed? Is Reggie a cathode?
If I use cathode biasing, does it turn my tube into a cathode ray tube?
Ugh! I forgot about Reggie Lewis.
If Len Bias and Reggie Lewis got married, would they be Len and Reggie Bias?
Is it okay to have a Len Bias and a Reggie Bias?
Is Len fixed? Is Reggie a cathode?
If I use cathode biasing, does it turn my tube into a cathode ray tube?
Fresh_Start
New member
Re: cathode bias VS grid bias tremolo
http://aikenamps.com/ see Tech notes
http://paulamps.com/index.html see Tech Info
http://www.geofex.com/gtramps.htm
http://www.tone-lizard.com/
http://www.schematicheaven.com/index_FLASH.htm
http://195.178.227.103/ax84/media/ax84_m35.pdf great intro to which does what to whom in a tube amp
Chip
P.S. this info provided for any forum brothers who got this far in this lame thread, not necessarily for someone too lazy to use Google.
http://aikenamps.com/ see Tech notes
http://paulamps.com/index.html see Tech Info
http://www.geofex.com/gtramps.htm
http://www.tone-lizard.com/
http://www.schematicheaven.com/index_FLASH.htm
http://195.178.227.103/ax84/media/ax84_m35.pdf great intro to which does what to whom in a tube amp
Chip
P.S. this info provided for any forum brothers who got this far in this lame thread, not necessarily for someone too lazy to use Google.
