Moving the Soundstage; Help.


Looking for advise... I installed new Tung Sol EL34B's in my amp, burned them in, and they sound wonderful. The problem is the soundstage is now forward of the speakers. This has never happened with my system before, even with changes between SS amps, tube and SS preamps, cables. My system has always been laid-back with mid-concert hall seating; now I'm in the first row. Do to room size, I listen from 8 feet away in the near-field.
I'm using triode mode (30W push-pull) with all Mullard NOS small signal tubes. Sonics are textured, realistic, and dynamic with tight bass. Prior to this, I was using new production Mullard EL34's with Brimar input tubes. Sonics were textured, holographic, with a nice top-end, but bass was too light and soft.
 
It's an all single-ended setup with an Atma-Sphere UV-1 preamp using 1950's RCA Blackplates, short bottle. I'm using Gallo floorstanders with Purist Aqueous Luminist cables, all of which produce wide and deep imaging.
 So, my first thought is to try different 6SN7 preamp tubes to move the soundstage. But here's the rub, I don't want to make a change that will increase high-end extension.
Perhaps, changing room treatments? Any help is appreciated.


lowrider57
I don't know anything about your setup and you may have already tried this, but if your speakers are toed-in just try turning them out slightly. Yo may not get the results you're looking for but it's free.
Kenny

Thanks for your your input, @blindjim . All good suggestions.
Here's an update; I have some extra absorbtion panels that I built, so I tried various positioning behind the speakers and on side walls. The minimal approach is still the best for imaging, 2 panels only. I have a tapestry and wall hangings behind me for standing waves. As I stated before, it's a living room.

The Tung Sol did become less aggressive at about 200 hrs, but still a forward presentation. I replaced the Mullard NOS drivers with Brimar cv4003's and soundstage is now wider and deeper, (love them ). I think I can live with this.
Also tried Bugle Boy as input gain, but too much "sting" at the top. The Amperex Orange sound interesting, have never tried them.

As far as PC's, I have all Audience and one PS Audio which are all laid-back. Very happy with them.
I'll look into Orange tubes for preamp or amp input stage, and after next paycheck maybe different EL34s.

well, would you be opposed to putting the LP now, behind the speakers? lol. just a thouhgt. sorry.
I think the orange and Green lable Amperexs were 60s – 70s iterations. Its been a while. Sorry I can’t be more specific.

Rolling tubes is like baking a well, something. It will change depending on what and how much of this or that goes into it or doesn’t go into it. No one can ever really tell what the final results will be until the results are finalized.

My inference on the CED EL34s was meant only to show some 34s do nothing to the geography of the SS, they just affect the sonics.

Elrod is a laid back PC. Or was….

Dampening the area about the LP seems the best tact, albeit, for a true living space, they’ll needs be ‘mobile’. Arranged when listening. Removed when not.

Whatever was about the speakers that did not change needs not be changed now. Possibly something needs be added and in that area, diffusion appears the best path in my EXP.

Albert Von S. told me once how to treat a room cheaply and how much of it to treat. He said 50 – 50. Absorption and diffusion. Season to taste.

One item can be both things. Albert treated an auditorium in my area and used cloth panels. Rugs. Long runners. Hanging them and spacing accordingly… accordingly to your preffs. Or in his case the needs of the room for conveying live music.

I’m never keen on killing or deadening the area about the speakers and prefer a livelier situation up there. Moving back, its different. Absorption sucks up tones. Diff absorption sucks up different tones at different levels. Maybe a pair of absorptive panels at first reflections vs one is now required. Or placing them higher off the floor onto the wall. Can’t say how big they would need to be either. Maybe pretty small. Dunno.

Only one way to find out.

This is pretty interesting IMO. I’d like what happened and not change anything… but that’s me.
Again, all the best….

Some interesting findings today regarding soundstage. I listened to some symphonies without the absorbion panels centered between the speakers and experienced a massive soundstage recessed behind the speakers. Some fatal flaws though, such as lack of overall focus, e.g., string section is not defined, can't exactly pinpoint the oboe or a soloist.

But, I believe this shows that diffusion behind speakers may be effective.
Any ideas how to experiment using diffusion before investing in real panels?

And blindjim, I learned that the Green Label Amperex are late production tubes from the Mullard factory in Blackburn, UK. Might be interesting to hear these.