Hi,
The most important thing to note is that the PCC88/7DJ8 is just a different heater version of the ECC88/6DJ8.
If you trawled the web for preamps using the PCC88 you could do the same for the ECC88 and dig up a whole lot more.
As I and others already expressed our reservations about the proposed HS circuit, let's point you to something simpler but excellent just the same:
It's pretty much textbook yet it does what you require and with gain to spare.
If you want about half the gain of the PCC88 you could opt for a SRPP circuit, it has low enough output impedance but is a little more complicated.
Cheers,
The most important thing to note is that the PCC88/7DJ8 is just a different heater version of the ECC88/6DJ8.
If you trawled the web for preamps using the PCC88 you could do the same for the ECC88 and dig up a whole lot more.
As I and others already expressed our reservations about the proposed HS circuit, let's point you to something simpler but excellent just the same:
It's pretty much textbook yet it does what you require and with gain to spare.
If you want about half the gain of the PCC88 you could opt for a SRPP circuit, it has low enough output impedance but is a little more complicated.
Cheers,
Attachments
I built a cascode line preamp using the PCC88. Unity gain. I based it on Joe Rasmussen's Ultra Linear Gainclone valve buffer (the full tube CCS and MosFet CV implementation). It was a matter of trial and error to get it working so I would have difficulty drawing up an accurate schematic. Still sounds excellent. The PCC88 which I used was a Miniwatt and it bettered both the Mullard ECC88 and the Sovteck 6922.
Using this tube in this configeration requires a flatline power supply as "any" noise bleeds into the signal, the power supply was more complicated than the actual buffer.
Shoog
Using this tube in this configeration requires a flatline power supply as "any" noise bleeds into the signal, the power supply was more complicated than the actual buffer.
Shoog
Hi,
That's also a SRPP circuit. It still has too much gain which is why the voltage divider is fitted at the input.
The E/PCC88 has much lower noise and higher transconductance,
all in all a better tube for this kind of service.
Ask me an all tube PS and I'll be happy to oblige...
Solid State is not really my thing but if I find anything I'll let you know.
Do you need one for the first circuit?
Cheers,
That's also a SRPP circuit. It still has too much gain which is why the voltage divider is fitted at the input.
The E/PCC88 has much lower noise and higher transconductance,
all in all a better tube for this kind of service.
Ask me an all tube PS and I'll be happy to oblige...
Solid State is not really my thing but if I find anything I'll let you know.
Do you need one for the first circuit?
Cheers,
Hi,
No idea how good this one really is so I hope some of the sand guys will chip (ahem...) in:
MASTROIANNI...NOT THE ACTOR.
Cheers,
No idea how good this one really is so I hope some of the sand guys will chip (ahem...) in:
MASTROIANNI...NOT THE ACTOR.
Cheers,
Hi,
It would be fine: it is indeed a mu-follower meaning that Ao is close to the amplifiaction factor (mu) of the single triode.
If you look closely you'll notice a feedback loop from the output of that stage to the input grid to reduce gain, distortion (which should be very low already) and output impedance (ditto).
Moreover, there's also a voltage divider with a 1/1 ratio at the input formed by the 100K pot and the 100K series resistor in oder to cut the level of the input signal in half.
All in all much added complexity where you, strictly spoken, don't need it.
Cheers,
It would be fine: it is indeed a mu-follower meaning that Ao is close to the amplifiaction factor (mu) of the single triode.
If you look closely you'll notice a feedback loop from the output of that stage to the input grid to reduce gain, distortion (which should be very low already) and output impedance (ditto).
Moreover, there's also a voltage divider with a 1/1 ratio at the input formed by the 100K pot and the 100K series resistor in oder to cut the level of the input signal in half.
All in all much added complexity where you, strictly spoken, don't need it.
Cheers,
If I wanted to learn to make a preamp, I'd look at this schematic:
http://www.triodedick.com/6072_voorversterker.html
You will need to change the heater voltage but that is pretty easy.
rick
http://www.triodedick.com/6072_voorversterker.html
You will need to change the heater voltage but that is pretty easy.
rick
This is the schematic
The thread about it is;
http://www.diyaudio.com/forums/tubes-valves/76602-my-version-vacuum-state-fvp5.html
I would replace the second stage LED with a resistor (whatever sets current to 10mA) as the LED defeats the object of the bottom triode - we learn by our mistakes. Iw ould also probably replace the R4 with a 100K or even 150K.
Shoog
Attachments
HiHi,
The most important thing to note is that the PCC88/7DJ8 is just a different heater version of the ECC88/6DJ8.
If you trawled the web for preamps using the PCC88 you could do the same for the ECC88 and dig up a whole lot more.
As I and others already expressed our reservations about the proposed HS circuit, let's point you to something simpler but excellent just the same:
It's pretty much textbook yet it does what you require and with gain to spare.
If you want about half the gain of the PCC88 you could opt for a SRPP circuit, it has low enough output impedance but is a little more complicated.
Cheers,
What is the gain and that is the input resistance Zout?? this preamplifier of schematic.
Thanks!
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