A friend has offered me a stereo Preamp based on the 6N3 valve.
the problem I have is I only want to use a single channel.
Stupid Question 1, can just use a single channel and leave the other channel un connected?
Stupid question 2: Can I use left channel as preamp, feed outpu into passive Tone Control and then feed output into right channel?
Of course I don't have to accept it but am keen to try a valve preamp for my bass guitar amp. ( OPS is SS)
Is there a recommended Preamp I should try and ditch my friends offer? I am not scared of soldering.
the problem I have is I only want to use a single channel.
Stupid Question 1, can just use a single channel and leave the other channel un connected?
Stupid question 2: Can I use left channel as preamp, feed outpu into passive Tone Control and then feed output into right channel?
Of course I don't have to accept it but am keen to try a valve preamp for my bass guitar amp. ( OPS is SS)
Is there a recommended Preamp I should try and ditch my friends offer? I am not scared of soldering.
1: yes
2: you can do that. It might give a very interesting effect.
Getting a bass pre might be a way better idea than using a stereo pre.
Moving to I&ADepending on the amount of gain in your bass power amp, you might need the extra gain of feeding the first channel into the second channel, especially if you put any kind of passive tone control in. You will have some signal loss from this, so you will need to make up signal from this loss.
Also, since according to the data sheet the amplification factor of this tube is only 35, this also supports the idea of using both halves of the tube. In comparison, a 12AX7 has an amplification factor of 100.
Also, since according to the data sheet the amplification factor of this tube is only 35, this also supports the idea of using both halves of the tube. In comparison, a 12AX7 has an amplification factor of 100.
Hello !
Admitting that you have received the gift of your Friend, I'll try to answer your [not] stupid questions...
On the purely electronic level, it may be interesting and quite easy to built a bass preamp from the two canal of a stereo preamp. The needs in bandwidth and dynamic of a bass guitar are close to what is expected in quality HiFi... And tube technology is well suited to this case.
There will be additional components to add: I think of a Tone control... 3 knob Fender or Marshall type, 2 knob Baxandall... You'll have to choose one of this classical passive filters, and I'll give you schematics and advices.
The main work will be to reorganize the two stages : no more in parallel but now in series, with the tone control inserted between them. This would consist of the following sequence:
Instrument input > Input preamp > Tone Control > Preamp output > Volume control
Some presets or commutation can be inserted on preamps and controls.
The moderate gain of 6N3 or 6N3P will be enough for this sequence, if you want that your preamp has to provide an instrument signal level (100 to 500mV). The attenuation (about 12dB) caused by the tone control will be largely rebalanced by the second preamplifier stage. Should there be an excess output level, the logarithmic potentiometer will lower the output volume level to a normal value.
I do not think that the gain of this tube (35) can overdrive the preamp itself. However its output level should be able to overdrive the preamp on your amplifier if you set high the output control of your preamp.
This is basic on paper, but this can be more difficult in terms of material realization : remove what must be, install new components (which mount ?), Rewire the new set ... Do you feel yourself motivated and able ?
I would be happy to go on study this project with you. Just ask.
Guitar Poppa
Admitting that you have received the gift of your Friend, I'll try to answer your [not] stupid questions...
On the purely electronic level, it may be interesting and quite easy to built a bass preamp from the two canal of a stereo preamp. The needs in bandwidth and dynamic of a bass guitar are close to what is expected in quality HiFi... And tube technology is well suited to this case.
There will be additional components to add: I think of a Tone control... 3 knob Fender or Marshall type, 2 knob Baxandall... You'll have to choose one of this classical passive filters, and I'll give you schematics and advices.
The main work will be to reorganize the two stages : no more in parallel but now in series, with the tone control inserted between them. This would consist of the following sequence:
Instrument input > Input preamp > Tone Control > Preamp output > Volume control
Some presets or commutation can be inserted on preamps and controls.
The moderate gain of 6N3 or 6N3P will be enough for this sequence, if you want that your preamp has to provide an instrument signal level (100 to 500mV). The attenuation (about 12dB) caused by the tone control will be largely rebalanced by the second preamplifier stage. Should there be an excess output level, the logarithmic potentiometer will lower the output volume level to a normal value.
I do not think that the gain of this tube (35) can overdrive the preamp itself. However its output level should be able to overdrive the preamp on your amplifier if you set high the output control of your preamp.
This is basic on paper, but this can be more difficult in terms of material realization : remove what must be, install new components (which mount ?), Rewire the new set ... Do you feel yourself motivated and able ?
I would be happy to go on study this project with you. Just ask.
Guitar Poppa
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