Hi,
I have been doing some guitar amps with submiature valves.
But are there subminiature valves that can be used in HI-FI?
Kind regards,
Pedro
I have been doing some guitar amps with submiature valves.
But are there subminiature valves that can be used in HI-FI?
Kind regards,
Pedro
Which ones are you using, and do you design the amps yourself?
Would be interesting to see a schematic.
Would be interesting to see a schematic.
6cw4 , a nuvistor, is used in hifi. Som other ones will also work well.
At home I have 6N17B, 6N16B and 6P30B-R.
I'll try to draw some schematic and post it here.
I don't have a schematic yet. I designed the guitar amplifiers myself, based on other amplifiers (all of them are quite similar too). So, my design is just tweaking the sound, not really inventing something completely new. I usually add a bias pot to go from a hot to cold tone and some more little tweaks, but that's it.
I'll try to draw some schematic and post it here.
Basically most guitar amplifier tubes can be used for hifi as well.
It's mostly just what direction you take at the cross section.
Are you going left, for more distortion and conscious tonal quality?
Or are you going right for less distortion and better transparency?
That being said, there are some tubes that maybe distort naturally a bit more for hifi.
Although, in the end, if that is something you're looking for, there is also nothing wrong with that! 🙂
@b_force
But don't you think I have to change the biasing too, to have a cleaner sound?
I thought that, in order to have a cleaner signal, I should pass the load line in the linear part of the curves, but I took a look at the Mullard 3-3 amp and they use a huge 1Mohm load resistor in the pre-amp (this is a pentode though), which puts the valve almost in a starving condition. How can this be good for hifi ?
Let's take the 6N16B, for example. Which one would be best for hifi, loadline 1(top) or 2(bottom)? To me 1 should be better and 2, as it has more gain, would be more prone to distortion. Do you agree with this?
But don't you think I have to change the biasing too, to have a cleaner sound?
I thought that, in order to have a cleaner signal, I should pass the load line in the linear part of the curves, but I took a look at the Mullard 3-3 amp and they use a huge 1Mohm load resistor in the pre-amp (this is a pentode though), which puts the valve almost in a starving condition. How can this be good for hifi ?
Let's take the 6N16B, for example. Which one would be best for hifi, loadline 1(top) or 2(bottom)? To me 1 should be better and 2, as it has more gain, would be more prone to distortion. Do you agree with this?
@pcardoso73
My personal answer is, whatever you like. 🙂
Some people like to go for the lowest distortion possible and bias accordingly.
For me personally, that doesn't make a lot of sense in tube amplifiers, because you want to hear the tube sound.
Also, it kinda depends on the use case as well. Sometimes you need that specific kind of gain or whatever.
But yes, bias can have a big effect on that. I don't know exactly Mullards use case, but I have also seen certain circuits that I have found peculiar.
When very low signals are being used, it's also less likely that you will hear that distortion, since you're far away from "clipping".
So it's hard to say what is "better".
In your example, the second curve will clip much quicker and more uneven.
Not a problem with a small signal input (like a record player). But you will get a bit more gain.
My personal answer is, whatever you like. 🙂
Some people like to go for the lowest distortion possible and bias accordingly.
For me personally, that doesn't make a lot of sense in tube amplifiers, because you want to hear the tube sound.
Also, it kinda depends on the use case as well. Sometimes you need that specific kind of gain or whatever.
But yes, bias can have a big effect on that. I don't know exactly Mullards use case, but I have also seen certain circuits that I have found peculiar.
When very low signals are being used, it's also less likely that you will hear that distortion, since you're far away from "clipping".
So it's hard to say what is "better".
In your example, the second curve will clip much quicker and more uneven.
Not a problem with a small signal input (like a record player). But you will get a bit more gain.
@b_force
Thinking a bit, to avoid clipping I just have to have a higher supply voltage. So, if I go from the 180V on the guitar amp to, let's say, 300V I should have much more headroom and, thus, a clean signal.
As I like the 6P30B-R I think I will go with that one, or with the one you've suggested, the 6AK6. The 6021 could be an option too.
I just have to check the prices. 🙂
Thinking a bit, to avoid clipping I just have to have a higher supply voltage. So, if I go from the 180V on the guitar amp to, let's say, 300V I should have much more headroom and, thus, a clean signal.
As I like the 6P30B-R I think I will go with that one, or with the one you've suggested, the 6AK6. The 6021 could be an option too.
I just have to check the prices. 🙂
Yes, that is also an option! 🙂
Tube will also be more linear as well.
Since you're from the UK, I would suggest an EL95.
Has more oomph than an 6AK6 and is still pretty small 🙂
Only keep in mind that the internal tube resistance is a bit high with these smaller tubes.
Meaning that it's a bit of a challenge running them from 20Hz - 20kHz.
Using UL mode might help with that a little, without losing to much power.
Incl with some feedback, it's possible to run them from around 30Hz or so.
It also all depends on the output transformer that's being used as well 🙂
Last edited:
I would recommend higher supply voltage 200V or greater. The 6021 is a good alternative to the 6SN7 which is how I have used it.
I don't really know what you're planning to do with these tubes?
But I noticed that the mu is only 35, which isn't a lot of gain.
Which can be troublesome in a situation when you want some negative feedback or so.
But I noticed that the mu is only 35, which isn't a lot of gain.
Which can be troublesome in a situation when you want some negative feedback or so.
It's like using the 6N16B as a power amp, we'll never get more than 0.5W single-ended and 1W PP.
But you are right. For HI-FI maybe I will need something more powerful and both the 6P30B-R and EL95 should achieve 8 to 10W in PP.
The 6021 maybe it will be enough for a headphone amplifier.
But you are right. For HI-FI maybe I will need something more powerful and both the 6P30B-R and EL95 should achieve 8 to 10W in PP.
The 6021 maybe it will be enough for a headphone amplifier.
Personally, I love the sound of pre circuits with 6N16B-V. Easy tube to deal with.
If you want more gain, a very rugged little MF is 6S32B (if you can find them). High anode voltage tolerant,
gain as 12AX7 and extremely low microphonic noise.
6S32B
If you want more gain, a very rugged little MF is 6S32B (if you can find them). High anode voltage tolerant,
gain as 12AX7 and extremely low microphonic noise.
6S32B