6922 vs 6SN7

[henryp]

I'm fixing to build a tube line stage and have some 6922's(Siemens CCa) and nos 6sn7's and would like to know which tube is best for this application in terms of sonic quality?
Thanks for the help and opinions.

ph

[SY]

Start by defining your requirements and the best tube will suggest itself. Gain? Output impedance? Worst-case load? Required swing? Signal-to-noise?

[Zoran]

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

[sasaudio]

"High transconductance tubes like 6922 are not good for sound"

Depends on the design, parts, and which brands are used. If designing an invisible sounding preamp (tested VS a "straight wire") the JJ E88CC beats the 6sn7 hands down.

Steve

[arnoldc]

"High transconductance tubes like 6922 are not good for sound..."

What is your basis for this?

On the contrary, I never liked (as hard as I want to) the 6SN7. I have found other tubes, some with high transconductance, that blows away the 6SN7. Hey, it's my ears

[powertriode]

I've never been overly impressed with the 6SN7. It's somewhat overrated; rather like the 300B.

[Geek]

I'm surprised no one has yet mentioned a 6N6P (6H6pi), dang linear at low voltages, similar plate dissipation and high Gm.

[wa4htz]

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

[sasaudio]

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.

[dsavitsk]

Originally posted by Geek
I'm surprised no one has yet mentioned a 6N6P (6H6pi), dang linear at low voltages, similar plate dissipation and high Gm.

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.