Grande Nando
Cá entre nós, VOCÊ vai ter de definir o que quer desse circuito. No começo do thread você disse que não queria características de válvula, mas agora quer. Amplificador pra guitarra não é meu forte, não sei as distorçoes 'desejadas'. Em todo caso a EL34 é uma válvula de potência...
Sorry for the portuguese. It's just needed for two Brazilians to understand each other. That is also why we keep so good when playing soccer - the communication is in Portuguese: that makes us strong an noone can copy it, because noone understands it
!
Nando - try to understand Moamp's recomendations for a safe operation of a hybrid amp. And ask here at diyaudio if someone else has experience in getting the nice distorted valve sound of a hybrid circuit.
Saudações cordiais
Erik
Cá entre nós, VOCÊ vai ter de definir o que quer desse circuito. No começo do thread você disse que não queria características de válvula, mas agora quer. Amplificador pra guitarra não é meu forte, não sei as distorçoes 'desejadas'. Em todo caso a EL34 é uma válvula de potência...
Sorry for the portuguese. It's just needed for two Brazilians to understand each other. That is also why we keep so good when playing soccer - the communication is in Portuguese: that makes us strong an noone can copy it, because noone understands it
! Nando - try to understand Moamp's recomendations for a safe operation of a hybrid amp. And ask here at diyaudio if someone else has experience in getting the nice distorted valve sound of a hybrid circuit.
Saudações cordiais
Erik
That tube is a power output pentode. Not good for your particular application.
If you simply want warmth, then using a 12AX7 at the input, using the first schematic, keeping the IC buffer that is there would do the trick. You get amplification for your guitar pickup, and warm tube sound.
Gabe
If you simply want warmth, then using a 12AX7 at the input, using the first schematic, keeping the IC buffer that is there would do the trick. You get amplification for your guitar pickup, and warm tube sound.
Gabe
Yes ! Big mistake about the EL84 ! I don't want a power tube, this mistake born from a very fast "search", hope you understand me !
This is what I was thinking, if I keep the U5 IC buffer, everything gets much more simple !
So, 12AX7 is the warmest, and the cleanest, what is?
Thank you !
Erik ! Brigadão por responder meu post! É muito bom encontrar alguém que fala a mesma lígua heh ! É como um "alivio"
Bom, não disse que não quero som de válvula, disse que eu não acredito que apenas um buffer valvulado poderia transformar LMs3886 em amplificadores com som de válvulas ! Então, o que eu gostaria é de ter um buffer, para ter um som "more tube like", entende? Algumas válvulas pelo que eu vi tem um som bem "warm" e "sweet" e outras um som bem claro e focado. Gostaria de experimentar as duas, a grande dificuldade é substituir o U5 no esquemático do BPA200 por uma válvula !
Bom, mas se manter o U5 não traz grandes prejuízos, foda-se, ele fica e tudo fica mais fácil ahahahah !
Outra coisa, quero distorção no amplificador também, e logico que eu quero que ela venha das válvulas !
Acho que isso iria fazer uma baita diferença ! Brigadão !!
Thanks !!
Where are you measuring?
If it is the input of the buffer, for all intents and purposes the impedance is 10K. You can increase that to 100K with no problem by changing that 10K resistor to 100K, and use a tube amp with no problem.
If you are measuring the input to the power amps, as Jan already correctly said, the input impedance is 500 ohms. There are certain electronic theoretical reasons for this.
Gabe
If it is the input of the buffer, for all intents and purposes the impedance is 10K. You can increase that to 100K with no problem by changing that 10K resistor to 100K, and use a tube amp with no problem.
If you are measuring the input to the power amps, as Jan already correctly said, the input impedance is 500 ohms. There are certain electronic theoretical reasons for this.
Gabe
As far as inversion goes (with the 12B4 tube circuit), if both channels of your stereo pass thru the same type of circuit, inversion won't matter.
I would avoid connecting the grid directly to a pot wiper with no other DC bias source.. If the pot gets dirty, the grid can lose bias and the tube plate current runs away high. Just connect a 4.7meg or similar value resistor to ground on the grid. That would give the tube grid a DC bias point when the wiper goes open circuit. I did this in an old tube TV I restored so the sound wouldn't pop loudly when adjusting the volume.
I would avoid connecting the grid directly to a pot wiper with no other DC bias source.. If the pot gets dirty, the grid can lose bias and the tube plate current runs away high. Just connect a 4.7meg or similar value resistor to ground on the grid. That would give the tube grid a DC bias point when the wiper goes open circuit. I did this in an old tube TV I restored so the sound wouldn't pop loudly when adjusting the volume.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.