6922 vs 6SN7

[Salas]

You can use 5U4G also in the PSU.

[Salas]

3 were built. A test platform with tube regulated PSU, a narrow wooden and perspex one (used to carry 6SN7s), and this one (mine) which used to carry 12AU7s. It is current sourced for heaters. One more to come. No one of my DIY mates cares for their 6SN7s anymore. This circuit dawned on me when I had some 6v6s but already had a more powerful amp. Use GT type for lowest microphonics and no self noises.

[anatech]

Hi Salas,
Thank you. It looks simple to wire up and modify (play with). Your constructed preamp looks really nice! Good job.

What is your total current draw? I'm thinking that a 6CA4, or maybe one per channel might work out well. There is no sense in using a large rectifier if it isn't needed. Think of the power savings in heater current alone.

If you like bottles, stick a gas regulator in for each channel. Now that would look cool! It would also regulate your stage a little tighter. Not that you really need this.

-Chris

[jlsem]

Back to the original poster's inquiry: Based on personal listening experience as well as agreement among my fellow audiofile friends, the 6SN7 makes an excellent linestage (especially with CCS plate loads - I recommend a choke for the novice) while 6DJ8's are best left to phono stages.

If someone claims he can hear differences of 6mhz in amplifier bandwidth there is either something wrong with his hearing or he's wearing a tinfoil hat.

My polemic,
John

[anatech]

Hi John,
I might agree with you, except that I have heard some really good line stages based on both the 6922 and 6SN7 (and a few more). There seems to be no clear winner in my mind as I think execution may be more important than the schematic some times. I can't say one way o the other.

Since the world is completely full of schematics for the 6922, our O.P. may be more comfortable going that way. It really depends on the circuit he wants to try.

No shortage of PC boards floating around either.

-Chris

[Salas]

Originally posted by anatech
Hi Salas,
Thank you. It looks simple to wire up and modify (play with). Your constructed preamp looks really nice! Good job.

What is your total current draw? I'm thinking that a 6CA4, or maybe one per channel might work out well. There is no sense in using a large rectifier if it isn't needed. Think of the power savings in heater current alone.

If you like bottles, stick a gas regulator in for each channel. Now that would look cool! It would also regulate your stage a little tighter. Not that you really need this.

-Chris

About 45mA.
The big rectifier charges up big caps without choking and it sounds far more relaxed than small ones in this circuit. It has been chosen on performance grounds vs small bottles.
I avoided gas regulators bcs they have isotopes inside. You never know.

[rdf]

Hi salas. Speaking of choking, why not one as plate load?

[Zoran]

The power pentodes in triode mode,
could deliver a great sound, just like we have an example with 6V6...
Also the lower value for Rload could be applyed, because we have few volts of signal
at the input of pre-amplifier... Sometimes even lower than Ri of the tube, but with preserved low distorsion and dramaticaly increse of sound quality...
Pentodes in triode mode have a lower amplification factor up to 6, which can be accepted,
against 6922 tube with A=35 that overloads input of the amplifier hardly...
But one thing is common, preampifiers with Rload inverting the pahase to 180 deg.
like in example with 6V6 here, and almost every design we can find...
That is not acceptable.
So the proper design have to incude input, output or booth transformers, to be considered like valid.
Not to forget, 6SN7 is much better device for sound implementations then 6922...
But 6922 can be used for rectification in PS section of RIAA pre-preamplifier...
Thanks

[Positron]

"Pentodes in triode mode have a lower amplification factor up to 6, which can be accepted,
against 6922 tube with A=35 that overloads input of the amplifier hardly..."

But using a higher gainstage allows one to use fewer overall stages. So the net gain is one stage to distort the music. One could then rid of the extra stage, say in the amp (integrated).

"But one thing is common, preampifiers with Rload inverting the pahase to 180 deg.
like in example with 6V6 here, and almost every design we can find...
That is not acceptable."

"Why not simply invert the speaker leads?"

"Not to forget, 6SN7 is much better device for sound implementations then 6922..."

How does one know which is best since all of us have different tastes? Some like accurate, some like lean, some like fuller, some like syrupy. I thought there were no absolutes?

If one likes accurate, which some state, how do one know what is accurate? Does one have a way of testing?

If one likes accurate, one doesn't want to use a 6sn7.
Just doesn't cut it. Now if one likes flavoring, a personal choice, the tube is good. And where is one going to get one and how much?

How does one know the parts one is using are actually the 'best' and are not flavoring the sound to ones liking?

How does one know you have the best design?

How does one know if one of the components, say cartridge/phono, is accurate or whether the 6sn7 is compensating for X? Does that make the 6sn7 better?

How does one know if one could not get better, with a different design, parts, tube?

How much experimentation has one perfomred? Is ones testing accurate?

6922 good for rectification in power supply for phono stages? I thought the rectifier made a sonic difference? So why us an inferior rectifier instead of a good one, like a 6sn7?

Just something to think about.

[Salas]

Zoran

We can always reverse the polarity again on the speaker terminals...

Rdf

I just did not have one proper choke for anode handy. Maybe it will sound fantastic, maybe it will tighten the sonic flow. Hey guys, make one, I wanna know!