Is it feasible to make a voltage divider at the input of a tube amp by using the grid leak resistor and another resistor forming a voltage divider to reduce input signal voltage ?
A bandage I suppose for a preamp with a bit too much gain.
A bandage I suppose for a preamp with a bit too much gain.
I have tried really hard to come up with a need for a preamp but failed. Even starting from a 0.15mV pickup and still manage to endup with too much gain.
It would be better to send schematic to help others. The preamp output is better for reducing the signal amplitud
There is no need. A device called "potentiometer" is invented and can be used as an adjustable level control. Add one
at the input and you are all set.
Because it’s a sharp cutoff pentode, designed for limiters and detectors. See the datasheet.
It's been used as a audio voltage amplifier by highly competent designers since the 1930s. The EF86 is a sharp-cutoff pentode too. I suppose Mullard was all wrong to employ it in their revolutionary three-stage feedback amplifier. The designers at Leak were nuts to build a preamp around it! Seriously, the 6J7 is a perfectly good tube for audio. From the Valve Museum:
Although originally designed as a detector, it's linear characteristic and good internal shielding...made it a natural choice for audio.
That's a message from the universe.
Most present day power amplifiers can be driven to full power with less than a volt of input signal. Some just half a volt, or even less.
Most digital sources put out up to 2 volts of signal.
Even RIAA phono preamps put out as much as 2 volts (peak) audio signal.
In these systems, all commonly used sources can drive the amp past clipping.
In these systems, you need signal attenuation, not gain.
Over the years, many people have complained that a system with a 'passive preamp' sounds flat, uninvolving, sterile, bland, unexciting, etc. etc. Often the claim is made that using a preamp with gain makes the sound more dynamic, more alive, more vivid, etc. etc.
Technically speaking, a passive preamp using a 10k ohm potentiometer or stepped attenuator should be absolutely fine as long as all your music source devices have low output impedance (1k ohms or lower).
A stepped attenuator is exactly that. Or a potentiometer.
Basically just a volume control.
