6SN7 is one of the best sounding tube ever... You can read many articles defining this tube like mediocre or not good choice, but almost all consider this tube with,
low voltage supply, like 250V...
This tube is capable to accept very high voltages around 400 (take a look at the datas, please...), and on that point reasonable high current...
With these settings the tube is best sounding device.
Actualy 6SN7GT is laboratory device...
Just bear in mind relatively high capacitance, and need to choose 22K pot value for one section use...
You can try to lower the gain which is about 16 in the circuit with lowering value of LOAD resistor You can go with close to the internal resistance value (6800 ohms),
and not affect the distorsion figure at all...
But there is one major disadvantage of one-stage circuits without transformer:
there is phase shift of 180 deg.
So tru to find input transformer (output is welcome as well, but has to be from very high inductanc of primary winding, for proper bandwidth around 200H, or more... that is in praxis almost inposibile).
I suggest input step-down transgormer not higher than 4:1 ratio, and still You will have 4 times amplification of voltage (with a CD of 2V output will be 8V...).
High transconductance tubes like 6922 are not good for sound...
They are easy to implement with lower Va and lower RL...
and aplification is too sufficiant...
thanks
low voltage supply, like 250V...
This tube is capable to accept very high voltages around 400 (take a look at the datas, please...), and on that point reasonable high current...
With these settings the tube is best sounding device.
Actualy 6SN7GT is laboratory device...
Just bear in mind relatively high capacitance, and need to choose 22K pot value for one section use...
You can try to lower the gain which is about 16 in the circuit with lowering value of LOAD resistor You can go with close to the internal resistance value (6800 ohms),
and not affect the distorsion figure at all...
But there is one major disadvantage of one-stage circuits without transformer:
there is phase shift of 180 deg.
So tru to find input transformer (output is welcome as well, but has to be from very high inductanc of primary winding, for proper bandwidth around 200H, or more... that is in praxis almost inposibile).
I suggest input step-down transgormer not higher than 4:1 ratio, and still You will have 4 times amplification of voltage (with a CD of 2V output will be 8V...).
High transconductance tubes like 6922 are not good for sound...
They are easy to implement with lower Va and lower RL...
and aplification is too sufficiant...
thanks
I think that's like asking "how many people have noses". You are probably going to get a boatload of opinions. You already have gotten several in favor of the 6DJ8-oids. Well, here's my "nose" (opinion): I have built several circuits with the 6SN7 family and been very pleased with all of them. They were all musical and very enjoyable to listen to. I have also built a few circuits with the Phillips/ECG 6922s I have and all of them have verified all of the critisisms I have read about this family of tubes: they were harsh, bright, zippy on top, detailed to a fault, "Hi-Fi-ish" etc. In other words, while they were thrilling to listen to for a short while, they were ultimately fatiguing and really didn't sound at all like live, un-amplified music.
I just checked and see Geek has posted about the 6N6P. But since you already have both 6922s and 6SN7s, why not build a decent high voltage supply of about 375 - 400 volts and try both. You can use resistors to drop the voltage for the 6922s so you don't fry them. Use your own ears, they are the ones you ultimately have to please!
Ken
I just checked and see Geek has posted about the 6N6P. But since you already have both 6922s and 6SN7s, why not build a decent high voltage supply of about 375 - 400 volts and try both. You can use resistors to drop the voltage for the 6922s so you don't fry them. Use your own ears, they are the ones you ultimately have to please!
Ken
VS
The Philips/ECG brand is hardly among the best tubes out there. Different brands sound different just as with other tube types. General statements about a tube's sound by simply testing just one brand tube seems unwise to me.
Secondly, the parts quality and design are crucial with this tube. Unless one is well versed in knowing how to use it properly, one won't get optimum sound. General comments about sonic quality then become worthless at best, and misinformation at worst.
To suggest slipping a E88CC in place (lowering the voltages as suggested) of a 6SN7 will Not work as the design considerations for using a E88CC tube are Completely different than using a 6sn7.
The 6SN7 tube is easy to design for, as it is difficult to achieve an overly bright sound because of its limited frequency response. One uses certain resistors and capacitors to optimize the sound for the 6SN7.
An E88CC tube requires alot more design considerations to optimize the sound. Those same parts you used above will not work with an E88CC because the frequency response of the E88CC is much much higher. Your results of top end tiz and zippy are exactly predictable.
There are other differences in design considerations as well.
Hope this helps.
The Philips/ECG brand is hardly among the best tubes out there. Different brands sound different just as with other tube types. General statements about a tube's sound by simply testing just one brand tube seems unwise to me.
Secondly, the parts quality and design are crucial with this tube. Unless one is well versed in knowing how to use it properly, one won't get optimum sound. General comments about sonic quality then become worthless at best, and misinformation at worst.
To suggest slipping a E88CC in place (lowering the voltages as suggested) of a 6SN7 will Not work as the design considerations for using a E88CC tube are Completely different than using a 6sn7.
The 6SN7 tube is easy to design for, as it is difficult to achieve an overly bright sound because of its limited frequency response. One uses certain resistors and capacitors to optimize the sound for the 6SN7.
An E88CC tube requires alot more design considerations to optimize the sound. Those same parts you used above will not work with an E88CC because the frequency response of the E88CC is much much higher. Your results of top end tiz and zippy are exactly predictable.
There are other differences in design considerations as well.
Hope this helps.
Geek said:
How are you using these? My experience with them in a parafeed line stage (SS CCS, Magnequest B7 OPT, Jupiter parafeed caps, LED bias) is that they are syrupy, super warm, and not all that detailed. Other tubes in the same design (5687 which has nearly identical electrical properties, 6922, 8416, 5842, 6688) were all much cleaner. But, could have been my setup.
What I'd like to know is the voltage swing capabilities of the 6DJ8 vs. the 6SN7. I have heard that the 12AX7 is incapable of the required voltage swing to drive KT88s to their full ability and that 6SN7s are preferred for the job. But how about 6DJ8's? Can they adequately drive KT88 grids?
My favorite 6DJ8 became obvious to me when I was rolling tubes through my CD player. When I put the USN 7308s in, the sonic quality was so impressive that stopped right there. They are amazing.
My favorite 6DJ8 became obvious to me when I was rolling tubes through my CD player. When I put the USN 7308s in, the sonic quality was so impressive that stopped right there. They are amazing.
I use PCC88's in a FVP5 variant (of my own design), it took a few years to evolve the design and now it is better than the CCS loaded 5687 preamp I built. It came out favourite in a DIY meet shoot out. No hint of bright tizz, but it took a lot of fine adjustment to get it to that.
As others have said, its how you use these valves that makes the difference, and generalisations are less than useful.
Shoog
As others have said, its how you use these valves that makes the difference, and generalisations are less than useful.
Shoog
I bought a couple of the TFK PCC88 and use them in my clone Audio Research SP-10. It sound so good.
My friend Albert use the same in his Audio Note DAC's SRPP buffer stage. He just loves it.
For 6SN7's, I collected couple boxes of them. I found the Loctal base ones 7N7 has much more open sound than the 6SN7. Possibly the Loctal version were designed for high frequency operation that has lower inter grids capacitance.
Johnny
My friend Albert use the same in his Audio Note DAC's SRPP buffer stage. He just loves it.
For 6SN7's, I collected couple boxes of them. I found the Loctal base ones 7N7 has much more open sound than the 6SN7. Possibly the Loctal version were designed for high frequency operation that has lower inter grids capacitance.
Johnny
Hi all ,
Just in time , one more opinion , Morgan Jones wrote on his book , Valve Amplifiers :
" A total of 529 valves was tested , and the results show that
the reputation of the 6SN7 / 7N7 is well justified .
..... valves from the 6SN7 / 7N7 family are likely to produce the
lowest distortion .
Valves with B9A bases are significantly poorer"
What do you think about that ??
Regards ,
Carlos
Just in time , one more opinion , Morgan Jones wrote on his book , Valve Amplifiers :
" A total of 529 valves was tested , and the results show that
the reputation of the 6SN7 / 7N7 is well justified .
..... valves from the 6SN7 / 7N7 family are likely to produce the
lowest distortion .
Valves with B9A bases are significantly poorer"
What do you think about that ??
Regards ,
Carlos
Hi Folks !
6SN7/7N7/6CG7/6FQ7 can sound quite OK. But only when operated properly ! Menas over 200V Ua and about 10mA current. Then they operate very linear. Sound is typical triode like and not with an exaggerated midrange as a ECC83.
My favorites are high gm pentodes like E55L, E810F, E280F, 12HG7, 12GN7, EL802 etc. I like pentode sound much more than triode sound. More dynamics and natural.
Regards, Simon
6SN7/7N7/6CG7/6FQ7 can sound quite OK. But only when operated properly ! Menas over 200V Ua and about 10mA current. Then they operate very linear. Sound is typical triode like and not with an exaggerated midrange as a ECC83.
My favorites are high gm pentodes like E55L, E810F, E280F, 12HG7, 12GN7, EL802 etc. I like pentode sound much more than triode sound. More dynamics and natural.
Regards, Simon
I would also suggest that you should build both line stage. And be happy with the one that will suit your ears.
Boy oh boy! Plenty of 6sn7s' tube rolling sessions will be undertaken since you haven't mentioned what particular brand of 6sn7 you'll be plugging in on your linestage amp. Each make of 6sn7 tube got it's own unique sonic imprint on every circuit design. And same thing goes with the 6922 tubes.
Boy oh boy! Plenty of 6sn7s' tube rolling sessions will be undertaken since you haven't mentioned what particular brand of 6sn7 you'll be plugging in on your linestage amp. Each make of 6sn7 tube got it's own unique sonic imprint on every circuit design. And same thing goes with the 6922 tubes.
the_manta said:
That's not necessary. Here's a loadline I did for the 6J5. As you can see, this is quite linear with an estimated THD of 0.008%. As this stage was actually used, it would be even better since the gain was a bit too high, and so the cathode bias resistor wasn't bypassed. As this was the first voltage amp, the required output swing wasn't anywhere near the max possible, so that would make the THD even less than the estimate, based on max swing. That also made for a convenient gNFB summing node.
Works just great.
Drawing a heavy current like that would only be necessary if you were using it as a cathode follower driver for Class AB2 grids. (And then you'd be better off using a MOSFET source follower to get that Zo even lower than that of any hollow state device.)
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