Recently I finished my design of a (tube) headphone amplifier and I decided to include a tone (transistor) control
with the possibility to bypass it, so I did.
The amplifier has two inputs: Phone and Auxiliary, the Auxiliary input is for connecting a CD player.
It it still possible to activate the tone control circuit when the Auxiliary input is used.
But in fact it isn't necessary when a CD is playing is it?
The opinion of the forum members is highly appreciated.
with the possibility to bypass it, so I did.
The amplifier has two inputs: Phone and Auxiliary, the Auxiliary input is for connecting a CD player.
It it still possible to activate the tone control circuit when the Auxiliary input is used.
But in fact it isn't necessary when a CD is playing is it?
The opinion of the forum members is highly appreciated.
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Probably not necessary (other than for using the tone controls), since the gain is unity,
and the output impedance likely won't change.
and the output impedance likely won't change.
Tone controls are as much to correct source material inconsistencies as they are to correct for personal taste , so yeah they can be for any source
All right, thanks for your responses so far.
But adding some more : my personal opinion is that, when playing a CD (using the AUX), normally there is no need for any audio correction in contrary to when playing vinyl (using the Phono input). So I want so prevent that someone is playing a CD and accidentally overlook that the tone control is still active.
So my idea was that when AUX is selected the tone control is made inactive automatically.
But is it worth the effort?
But adding some more : my personal opinion is that, when playing a CD (using the AUX), normally there is no need for any audio correction in contrary to when playing vinyl (using the Phono input). So I want so prevent that someone is playing a CD and accidentally overlook that the tone control is still active.
So my idea was that when AUX is selected the tone control is made inactive automatically.
But is it worth the effort?
If the tone is bypassed, your unsupervised guests and children can't turn the bass all the way up.
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All right, but in my opinion bass is not to be tuned "way up".
Just listen to that CD recording because the recording is much more sophisticated than a recording on vinyl.
But I can imagine that, when listening to a vinyl recording, due to the quality of that recording, one want to adjust some tone control.
All right. So it is wise to just let listeners decide what to do: yes or no fiddling the tone control.
The idea is that if they can't engage the tone controls, they can't turn the bass up all the way and
damage your speakers. Some actually do that. But maybe this isn't a problem for your situation.
damage your speakers. Some actually do that. But maybe this isn't a problem for your situation.
Ok, then your question is, if it gives better sound to select the CD before the tone stage?
Possibly, since there will be fewer switch contacts and less wiring in the CD signal path.
Unless you feel the need to correct the tonal balance of CDs often.
Possibly, since there will be fewer switch contacts and less wiring in the CD signal path.
Unless you feel the need to correct the tonal balance of CDs often.
Yes, that is exactly the case at this moment. But in my next design I wanted to decouple the tone control possibility from being independently from source.
Just the possibility activating tone control when selecting the phone input.
It needs some clever switching but is is possible anyway.
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Very simple. The phono stage connects directly to the tone stage.
The selector switch selects either the CD player or the tone stage output.
The tone stage can still have a bypass switch if you want one.
Or you can have a three position selector switch only, and no bypass switch.
One position for CD, one for the tone stage output, one for the phono stage output.
The phono stage always feeds the tone stage, whether or not the tone stage is being used.
The selector switch selects either the CD player or the tone stage output.
The tone stage can still have a bypass switch if you want one.
Or you can have a three position selector switch only, and no bypass switch.
One position for CD, one for the tone stage output, one for the phono stage output.
The phono stage always feeds the tone stage, whether or not the tone stage is being used.
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Thanks rayma. The only question left is: is it worth the effort to make that possibility switching on/off the tone control or just leaving it as it is now: tone control possibility on/off independently from source.
What would you do?
What would you do?
Think I would leave it as-is, and just use it for a while. If you feel a need to change it later on,
you still can. Personally, I've never felt the need for tone controls. See how often you use it.
you still can. Personally, I've never felt the need for tone controls. See how often you use it.