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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.


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Showing 6 responses by lowrider57

lowrider57's avatar
lowrider57 OP
5,397 posts
 
Thanks, great idea. Yes, microdynamics are terrific and I'm hearing everything.

But still wondering if more/less absorbtion will make a difference.
lowrider57's avatar
lowrider57 OP
5,397 posts
 
@stevecham ,
yes, diffusion might be more effective. Don't know since I've never used any.
 I'm in a living room, very well treated, and I have 2 DIY absorbion panels on the wall between the speakers. They've been very effective for focusing the image.
lowrider57's avatar
lowrider57 OP
5,397 posts
 
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.

lowrider57's avatar
lowrider57 OP
5,397 posts
 
Thanks Kenny, speakers are toed-in, and I'll play with position some more.
lowrider57's avatar
lowrider57 OP
5,397 posts
 
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.

lowrider57's avatar
lowrider57 OP
5,397 posts
 
Thanks, @blindjim .
I removed the 2 vertical absorbion panels from the wall, and placed one panel centered between the speakers; this creates some reflection points. The soundstage now extends from the face of the speakers back to the wall. Very nice since it also provides a focused image.
I also placed a vertical panel on each side wall which adds a concert hall shape to the soundstage for classical music. I'll listen to this setup this week to see if works.
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