Tube saturation

rubin

I've read that the harder you drive tubes,the better they'll sound.So if I were to reduce the input on my ss amp and then increase the gain on my tube pre,would that drive the preamp tubes more and improve (that tube sound) or not neccessarily?

organ

From my understanding, it is very circuit dependant. Those who design circuits that run the tube hotter is in the minority. It usually involves the output (power) tubes more than signal tubes. But there are those who run signal tubes a little harder like some BAT equipments.
Don't forget that running tubes harder will shorten their lifespan.

As to your question, I doubt anyone could tell you what the outcome would be unless they have a very good understanding of your pre and amp's circuits and how they interact with eachother. To increase your gain, you will have to add more voltage at the plates which would require mods (and will likely increase noise level). If your PS can't handle it, it would need an upgrade.

Is there something about the sound you're not fully satisfied with? Why not just tube roll?

rubin

organ wrote: »

From my understanding, it is very circuit dependant. Those who design circuits that run the tube hotter is in the minority. It usually involves the output (power) tubes more than signal tubes. But there are those who run signal tubes a little harder like some BAT equipments.
Don't forget that running tubes harder will shorten their lifespan.

As to your question, I doubt anyone could tell you what the outcome would be unless they have a very good understanding of your pre and amp's circuits and how they interact with eachother. To increase your gain, you will have to add more voltage at the plates which would require mods (and will likely increase noise level). If your PS can't handle it, it would need an upgrade.

Is there something about the sound you're not fully satisfied with? Why not just tube roll?

Thanks for the info.I can't afford tube amps so I'm gathereing all the information I can to get the best sound possible with what I have. I'm reading web articles about this and thought I could pick the brains here on CP also. I've done tube rolling with some success. Preamp mods is another option,but is expensive($1,000 or more)

heiney9

The phenomenon you are talking about is really for guitar amps and wanting to get different tones. It's tube and circuit dependent and sometimes it deals with rectifier tubes as well.

Tubes in general have a slower more linear break-up characteristic when the signal starts to clip. It's more pleasing to the ear and contains more 2nd order harmonics, which is also more pleasing to the ear.

As far as "over driving" tubes in pre-amp, it's not an issue and unless you know how the rest of the circuit will react I'd leave it alone. You're liable to ruin caps, chokes and tubes if you mess around too much.

I have a tube pre that uses a tube rectifier and I could put a "hotter" rectifier and higher gain tubes in it; but I'd probably ruin some caps, resistors and tubes in the process and most likely the power supply.

Guitar amps are completely different animal and the over-drive is what can give, say a Gibson, that really fat, nasty tone. Home audio tube gear is different and designed for a different purpose.

H9

rubin

heiney9 wrote: »

The phenomenon you are talking about is really for guitar amps and wanting to get different tones. It's tube and circuit dependent and sometimes it deals with rectifier tubes as well.

Tubes in general have a slower more linear break-up characteristic when the signal starts to clip. It's more pleasing to the ear and contains more 2nd order harmonics, which is also more pleasing to the ear.

As far as "over driving" tubes in pre-amp, it's not an issue and unless you know how the rest of the circuit will react I'd leave it alone. You're liable to ruin caps, chokes and tubes if you mess around too much.

I have a tube pre that uses a tube rectifier and I could put a "hotter" rectifier and higher gain tubes in it; but I'd probably ruin some caps, resistors and tubes in the process and most likely the power supply.
Guitar amps are completely different animal and the over-drive is what can give, say a Gibson, that really fat, nasty tone. Home audio tube gear is different and designed for a different purpose.

H9

Thanks H9 that really helps! Your knowledge surpasses mine.I'd like to pm you to further discuss this topic. What tube pre-amp ru using?

organ

I agree with Heiney. You're probably better off leaving it alone.

The EL34 tube could handle 800V+ at the plates, but pretty much all the designs have 400-500V on them.

$1000 is a lot for mods. What kind of mods are you looking at?

rubin

organ wrote: »

I agree with Heiney. You're probably better off leaving it alone.

The EL34 tube could handle 800V+ at the plates, but pretty much all the designs have 400-500V on them.

$1000 is a lot for mods. What kind of mods are you looking at?

I was looking on line at Underwood Hi Fi level 1&2 mods for my Jolida envoy preamp. United home audio warns against any mods, except tube rolling.That's interesting!

organ

I'm not farmiliar with their mods. But a lot should be done for 1k.

rubin

I think I'll go along with H9 and you organ (leave it alone) Maybe I'm just chasing ghosts.

heiney9

rubin wrote: »

I think I'll go along with H9 and you organ (leave it alone) Maybe I'm just chasing ghosts.

That's a good idea. The pre is designed to work with what it's given as far as how the manufacturer designed it. Your original idea really comes from rectifier tubes in a guitar amp. While the idea of the tube guitar amp and tube pre and amp being similar in the end they are executed differently and totally opposite purposes.

That's not to say there aren't upgrades/mods available. Just not specifically to introduce tube saturation.

H9

comfortablycurt

heiney9 wrote: »

The phenomenon you are talking about is really for guitar amps and wanting to get different tones. It's tube and circuit dependent and sometimes it deals with rectifier tubes as well.

Tubes in general have a slower more linear break-up characteristic when the signal starts to clip. It's more pleasing to the ear and contains more 2nd order harmonics, which is also more pleasing to the ear.

As far as "over driving" tubes in pre-amp, it's not an issue and unless you know how the rest of the circuit will react I'd leave it alone. You're liable to ruin caps, chokes and tubes if you mess around too much.

I have a tube pre that uses a tube rectifier and I could put a "hotter" rectifier and higher gain tubes in it; but I'd probably ruin some caps, resistors and tubes in the process and most likely the power supply.

Guitar amps are completely different animal and the over-drive is what can give, say a Gibson, that really fat, nasty tone. Home audio tube gear is different and designed for a different purpose.

H9

Very well said Brock.

I have a tubed guitar amp that I've been using for about 4 years now...a Mesa/Boogie Dual Rectifier. Tube amps aren't ideal as practice amps, because of what Brock discussed above. They need to be driven hard to really get the best sound out of them, so they're not going to sound as good at practice volumes.

What a lot of guitarists use are tube heaters. I got one about a year and a half ago, and I don't know how I lived without it before. What it does is heat up the tubes so that they're being run hotter, but the input is still kept at a lower volume, so they can be used at lower volumes and still have a nice rich, full sound.


This is why a lot of guitarists have both tube amps and solid state amps. I've had several solid state amps over the years, and I've never been able to find the tone I was looking for until I got the Mesa/Boogie.

dorokusai

It's not rocket science...just a tube.

reeltrouble1

but a rocket is a tube......no??????

RT1

rubin

dorokusai wrote: »

It's not rocket science...just a tube.

But the military uses tubes for their rockets !!!!!