Pre amp tubes

jimdgoulding · « **on:** 26 Mar 2009, 10:13 pm »

Of the variety of tubes that are suitable for use in pre amps, an ARC line stage for example, what is the consensus of which type is best? 6922? 6SN7? 12AX7? It's confusing to me. In your discussion, of which I am hoping there will be, what manufacturer then? Can they be purchased thru The Tube Store? If not, how? Thank you in advance. Not having done much experimenting, I think the best results I've gotten has been from Sovtek 6922's. Can anyone compare for me from their experience. Again, thanks sincerely.

Tyson · « **Reply #1 on:** 26 Mar 2009, 10:27 pm »

I've heard good examples of each type, and overall sound will depend on circuit and implementation more than anything else. Having said that, my favorite sounding tube is the 6sn7.

topround · « **Reply #2 on:** 26 Mar 2009, 10:29 pm »

Not that I know much...but in my experience
it depends on your preamp. If your preamp uses 6SN7's then you have to find the best 6SN7 that works in your system, same as 6922 and 12au7.
It depends on your system and how the synergy is working or not working, a fat sounding tube in a lean system is of course best, yet a lean detailed tube in a fat system works best.
In my experience 6SN7's have a full rich sound where the 12au7's have a thinner but bigger wider sound.
This, in my limited experience, I think the smaller tubes have the edge in linearity, but the bigger tubes have it in tone, of course the bigger tubes can be more microphonic.

I know I am rehashing common knowledge, it is common sense, and seems to be true,
but there is always that one piece of gear that defies the laws.

IMO synergy is what makes the system, and synergy comes in many flavors, some unexpected

Mike

cujobob · « **Reply #3 on:** 26 Mar 2009, 10:30 pm »

Prefer 6SN7 myself. 6922 can occasionally sound really nice, too...but have seen some poor implementations.

markC · « **Reply #4 on:** 26 Mar 2009, 11:45 pm »

Horses for courses; to coin a phrase. I agree with Topround in that if your gear uses xxxx tubes, and you like your gear, find the best sounding tube for it. Research, trial and budget will get you as far as you can go with a paticular piece of gear IMO.

jimdgoulding · « **Reply #5 on:** 27 Mar 2009, 03:37 am »

I believe I will go with ARC's recommendation of a particular 6922 tube. Sovtek 6922's are no longer available. Last I checked, they were supplying Electro Harmonix 6922's. I may try a set of JAN-Philips 6922's at some point. Info on the Tube Store site says these are the tubes Bugle Boy sells under their own name. I have tried a set of expensive Russian 6922's and thought they were fuller sounding. I got a feeling based on a clip of a review of 6922's at large from Vacuum Tube Valley's magazine that the J-P/Bugle Boys have that in common with the latter. Thanks, fellas, I believe that I am good to go. Maybe others can benefit from your wisdom. I believe I just have. You da man.

JoshK · « **Reply #6 on:** 27 Mar 2009, 03:43 am »

From my experience, I prefer 6SN7 to 6922. I prefer 5687 to 6922 too.

Still want to hear the 12B4 in preamp and have plans to make an 801A DHT preamp, a PP 6N6P/6H30P preamp and might try out 6T4, 1J1G, 801A and some others in this position too.

Lots of off the beatan path preamp tube to try for those who like to roll their own. Also, for the newbie who want to try to build something tube, preamps are the easiest place to start and very simple to make a good one. Look at the $200 tube preamp Bill just made.

jimdgoulding · « **Reply #7 on:** 27 Mar 2009, 05:37 am »

Quote from: JoshK on 27 Mar 2009, 03:43 am

From my experience, I prefer 6SN7 to 6922. I prefer 5687 to 6922 too.

Still want to hear the 12B4 in preamp and have plans to make an 801A DHT preamp, a PP 6N6P/6H30P preamp and might try out 6T4, 1J1G, 801A and some others in this position too.

Lots of off the beatan path preamp tube to try for those who like to roll their own. Also, for the newbie who want to try to build something tube, preamps are the easiest place to start and very simple to make a good one. Look at the $200 tube preamp Bill just made.

Are you talkin in general, Josh? Have you experience with an ARC pre? I'm genuinely interested in where you're coming from and why you prefer a 6SN7, for that matter, a particular 6SN7, if any, and why?

Captain Humble · « **Reply #8 on:** 27 Mar 2009, 10:04 am »

Here's a link to general characteristics of various tubes and how they compare to one another.

http://vintagetubeservices.com/page18a.html

Obviously it will altimately depend on your gear and room but it isn't a bad starting point.
Hope you find it helpful.
Jeff

Niteshade · « **Reply #9 on:** 27 Mar 2009, 11:44 am »

The 6N1P and 6N2P are good tubes. The shield they employ between the two triode sections is a good idea as well. They have very low, perhaps nonexistent filament/cathode leakage. Microphonics isn't a problem either.

jimdgoulding · « **Reply #10 on:** 27 Mar 2009, 01:52 pm »

Thanks Jeff, Blair. I was heading in the 6N direction but after having read members' earlier replies, it gave me pause to wonder why Audio Research doesn't employ 6N's from the git. I will ask them, of course, but do you have any ideas? Thanks.

JoshK · « **Reply #11 on:** 28 Mar 2009, 06:40 pm »

Quote from: jimdgoulding on 27 Mar 2009, 05:37 am

Are you talkin in general, Josh? Have you experience with an ARC pre? I'm genuinely interested in where you're coming from and why you prefer a 6SN7, for that matter, a particular 6SN7, if any, and why?

I am only referring to my experience with the few preamps I've heard using said tubes. Never heard the ARC pre. 6SN7 has less gain and IMO that is a good thing for a preamp. Already 6SN7 is way too much gain for a SS amp.

That said I heard the Blue Circle preamp Galatea MKIII iirc. That was a very nice preamp using 6922s. I didn't get to hear an A/B. I just remember my 6SN7 preamps like Mapletree's as being more lush, which I like.

jimdgoulding · « **Reply #12 on:** 28 Mar 2009, 09:50 pm »

Thanks, Josh.

Steve · « **Reply #13 on:** 30 Mar 2009, 02:14 am »

As Tyson mentions, alot depends upon the implimentation. Design, associated passive parts all play a role. Some passive parts that were extremely close to accurate are not sold anymore due to lack of demand, so the full potential of a particular tube cannot be achieved unless one can special order those parts.

Hope this helps.

JoshK · « **Reply #14 on:** 30 Mar 2009, 02:43 am »

Quote from: Steve on 30 Mar 2009, 02:14 am

As Tyson mentions, alot depends upon the implimentation. Design, associated passive parts all play a role. Some passive parts that were extremely close to accurate are not sold anymore due to lack of demand, so the full potential of a particular tube cannot be achieved unless one can special order those parts.

Hope this helps.

Absolutely!

mgalusha · « **Reply #15 on:** 30 Mar 2009, 05:42 pm »

Quote from: jimdgoulding on 27 Mar 2009, 01:52 pm

Thanks Jeff, Blair. I was heading in the 6N direction but after having read members' earlier replies, it gave me pause to wonder why Audio Research doesn't employ 6N's from the git. I will ask them, of course, but do you have any ideas? Thanks.

One thing about the 6N1P is while similar to a 6DJ8/6922 they are not the same. The one often mentioned is heater current requirements, which is about double. What is not often mentioned is that a 6N1P really needs more plate voltage than a 6922 to perform it's best, so if the circuit is optimized for a 6N1P then 6922's likely won't be happy.

sturgus · « **Reply #16 on:** 30 Mar 2009, 09:00 pm »

Jim, What model ARC preamp are you using ? I agree with most of the comments here that it is circuit dependent. That being said i think the Siemens/Sylvania 7308 sound a lot better in my ARC than the Sovteks. I think you can still get these for around $20 from http://www.halfin.com/shop/ . I also think the 6922 Matsushita from Tube Monger are even better for about $10 bucks more.
http://www.tubemonger.com/Matsushita_Japan_6922_E88CC_Mullard_Tooling_NOS_p/591.htm
Sturgus

Steve · « **Reply #17 on:** 31 Mar 2009, 02:54 am »

Quote from: mgalusha on 30 Mar 2009, 05:42 pm

Quote from: jimdgoulding on 27 Mar 2009, 01:52 pm
Thanks Jeff, Blair. I was heading in the 6N direction but after having read members' earlier replies, it gave me pause to wonder why Audio Research doesn't employ 6N's from the git. I will ask them, of course, but do you have any ideas? Thanks.

One thing about the 6N1P is while similar to a 6DJ8/6922 they are not the same. The one often mentioned is heater current requirements, which is about double. What is not often mentioned is that a 6N1P really needs more plate voltage than a 6922 to perform it's best, so if the circuit is optimized for a 6N1P then 6922's likely won't be happy.

Hi Mg,

Very true Mg, and the plate resistance is quite a bit higher as well vs the 6922, which translates to much lower high frequency response vs a 6922. Kinda in between the 12ax7 and 6922.

Starchild · « **Reply #18 on:** 4 Apr 2009, 08:28 pm »

My preamp is a Margules sf220r. It takes 4-12au7s and 1-6dj8/6922. Interestingly enough the dealer told me that using a 6es8 instead of a 6dj8/6922 would make my preamp really sing. I tried it, loved them and I've never looked back since. Due to the prevailing opinion that the 6es8 is not a good tube, they're dirt cheap (typically $5-$8/ea). I'd be interested in an unbiased opinion of why this tube works so well. Happy listening.

Mike

JoshK · « **Reply #19 on:** 4 Apr 2009, 08:41 pm »

Quote from: Starchild on 4 Apr 2009, 08:28 pm

My preamp is a Margules sf220r. It takes 4-12au7s and 1-6dj8/6922. Interestingly enough the dealer told me that using a 6es8 instead of a 6dj8/6922 would make my preamp really sing. I tried it, loved them and I've never looked back since. Due to the prevailing opinion that the 6es8 is not a good tube, they're dirt cheap (typically $5-$8/ea). I'd be interested in an unbiased opinion of why this tube works so well. Happy listening.

Mike

6ES8 works great as a buffer but not good for gain. Your dealer probably realized that your preamp used the 6dj8 as a buffer so then he knew that the 6ES8 would work. 6ES8 is a variable gain tube, so it won't work for audio gain stage, but as a buffer (no gain) it will work just fine. That is also partly why they are cheap.