2. amps-preamps
  3. 192205-171531

I hate to say it, but now I think maybe I like my amp in ultralinear mode versus triode

It's a Cary V-12; it features a dozen EL34s and each pair has a switch in between them that configures that pair to either triode or ultralinear. In full triode Cary listed in the specs that it makes 50 wpc and in full ultralinear 100 wpc.   For most of the twenty three years that I have owned this amp I have always felt that I preferred triode except for the occasions that I wanted to full out blast (it has literally been many years since I've felt the need to full out blast).

However, today I experimented with a couple of things in my system, and after listening to the same "Jazz Essentials" (compilation) red book CD a couple of times all the way through, the next thing I experimented with was switching to full ultralinear.

Maybe there was more "PRaT"?  (Which is a term I am still not sure that I completely grasp.)  Maybe . . . but what I do feel I noted for sure was that the imaging (particularly the imaging in the center) had more weight (meatier?) and was presented more forward, which I actually like.

I put a few more hours in (one more time with Jazz Essentials, Holly Cole/It Happened One Night, Dave's True Story/Sex Without Bodies, selected tracks from Rebecca Pigeon/The Raven and Once Blue/self titled and Norah Jones/Feels Like Home) after switching to ultralinear.  (No booze during this session, just coffee.) The jury is still out on this, but I do have some CDs in mind that I want to listen to over the next few days as I continue to evaluate.  

immatthewj
mulveling's avatar
mulveling
1,912 posts
 

Regardless of what we each think of the term "UltraLinear", and its alignment on the good-versus-evil spectrum, I found the following diagram most succinct and easy to digest. It’s from a web search that hits el34world dot com.

Note the wiring in the orange boxes (these would be easily controlled with switches), and the "UtraLinear" taps coming from the transformer primary, to the right - these UL taps are the legs that are positioned (symmetrically) between the 2 outer taps (each tied to their corresponding push/pull tube’s anode plate) and the center tap. These particular taps are disconnected in triode and pure pentode modes. They are connected to the corresponding tube screen grid in UL mode.

I assume the exact % of the UL taps’ positioning between outer taps and center tap is what’s at issue for "optimal" UL loading to a given output tube type - as circuit gurus like Ralph have pointed out.

In pentode mode, both tube screens are tied to the center tap. In triode mode, each screen is tied to its own tube's anode plate. 

immatthewj OP
2,023 posts
 

Thank you, @mulveling !  I have printed that as well.

You asked for a diagram, @emergingsoul , it appears as if your wish has been granted a couple of times over.

viridian's avatar
viridian
5,043 posts
 

Circuit topology of appliances sexy? I would not want to clean your Roomba. 

immatthewj OP
2,023 posts
 

Circuit topology of appliances sexy? Someone needs to go on a date....with a human.

@viridian , going on about 25 years ago I was buying some 12AU7s and 6922s for a preamp and amp I had, from Andy from Michigan. I probably made two or three phone calls to get the deal done, but in the course of those calls and conversations, Andy got off the topic of the tubes he was selling me and got to talking about a push pull amp he had recently restored or built (I wish I could still remember his exact words) but it was just a massive amount of class A wpc and when he said something about ". . . liquid fire coming out of the . . ." his tone of voice was almost orgasmic.

Your post made me think of that.

viridian's avatar
viridian
5,043 posts
 

Andy Bouwman, Vintage Tube Services? Have not heard that name in decades. Thank you.

More to discover