I have an SP16 in my system and I can assure you that imaging is not an issue. I have not heard the SP8 so I can't say whether it would be an upgrade.
I can say that one the biggest upgrades I made was the purchase of my Benz glider. Again I can't say whether there would be biggest difference between it and your sumiko.
One final point, a big determinant of imaging is your room and equipment placement. If I were you I would start there. I hope this helps...
I can say my SP-15 is a great linestage and phono.
The Sp-15 two box preamp, is all solid state with ust a three tube phono section.
If you use primarily LPs for source, it is a great preamp.
Better if with a good power conditioner.
I got mine four years ago for $1,400. mint.
It is an underrated gem.
What's the rest of your system? Just about any piece in an audio system can mess up imaging. I've never cared for the SP-16, myself, but I wouldn't necessarily say that its the cause of your problem.
As far as your analog setup goes, I don't think thats your problem. Even with modest equipment, records image very well. When people either get back into analog or try it new, for the 1st time, their first remark is almost on always how good the imaging is.
Nick, you make a great point, i might have my speakers too close to eachother. I will try to space them further apart. My room is small which is why i bought magnepan mc1 on stands with a sub for the low end. They are about 4 feet from the wall. Im gonna space them out about 5 1/2 to 6 feet apart. I had them about 4 feet apart. I usually sit 6 feet away from the speakers. The sub is behind the right maggie in the corner which sounds really good.
Elizabeth, 1,400 for a 15 is steal if its anything like the 10 or 11. I paid more for the 16 lol. If i ever see that pre amp for that price im all over it. I also use a ps audio duet which at first was really bright but calmed down over time. Im not sure if it improved my system, but i havent removed it.
Oh yea as far as cables are, i use tara labs prime m2 from the turntable to the preamp, tara air 2 from the preamp to amp, audioquest rocket 88 speaker cables, and shunyata venom power cords.
I've found the imaging of the SP16 to be quite precise and capable of a very wide soundstage. I'm at a loss as to why you would find it "too mono".
Just read your followup - sounds like speaker positioning may be your issue. Might be difficult to achieve a wide soundstage under those circumstances. Speaker positioning and proximity to walls etc will have a greater effect on imaging than (competently designed) electronics.
Yea im starting to think that even 6 feet apart is still not enough, im gonna have to live with it. Im not sure how far i should sit from the speakers.
Good imaging usually starts with a set up of a triangle. Seat perhaps 10 to 15 percent further away from the speakers than the speakers are apart from each other. An equalateral triangle is a great place to start. FWIW.
Agree i bought the Sp-15 here on Audiogon.
I was able to compare the Sp-15 to a SP-10mk2 and the Sp-15 was better all around than the Sp-10 I had on hand (with cheap tubes).
The Sp-15 never had a great review, mostly due to it's huge price increase. So it was 'damned with faint praise' as not being really worth $6,000. list.
It follows the other two two box preamps the SP-10 and Sp-11. And is a great preamp.
I have to say, some folks would prefer the sound of the Sp-10 with great tubes in it, over the Sp-15.
I am in the precision over warmth club. so i love the Sp-15 way more than the SP-10.
I do not need to keep the SP-15, but I love having it around, so mine is not for sale!
It is one of those 'keepers'.
Honestly from what i heard about the 10, the cost to retube it is alot. What i do like about the 16 is how neutral it is, im not sure if i would like a warmer coloration. I think the 16 is more closer to the sound of your 15 than the 10, but mabey not as detailed or as front row.
The SP-8 was just below the SP-10 in the product line. It is an expensive proposition to keep the SP-10's phono stage in low noise tubes. The SP-8 had a tube regulator and was more tube sounding than the SP-16. The SP-16 is more accurate and is a really good preamp. Crosstalk should not even be an issue unless there is a problem with it. You could have a noisy regulator in it. When was the last time it was retubed?
Barruch, I don't mean to sound critical here but I believe too many people waste money changing gear when a better system set up might give them what they are looking for. If you were 6' away with speakers spaced 4' apart I'm not surprised if it sounded like mono.
Now no one can tell you exactly how to set up your speakers because there are too many variations with room interaction. But some basic guidelines can help. I agree with Newbee that an equilateral triangle between speakers and listening seat is a good place to start. If your room allows you to be a little more than 6' from the speakers I'd try that. Then, whatever that distance, I'd experiment starting with the same separation between speakers as listening distance, then incrementally reduce the separation between the speakers up to an 80% of the listening distance. Hopefully somewhere within that range will optimize your room.
If you haven't seen a copy, Jim Smith's book "Get Better Sound" will offer far more information on all this.
Not sure how much plugging and unplugging of left and right channel cables you have done lately, but you may want to be sure all of your right to right and left to left connections are correct.
Thank you everyone for your help. I think im gonna keep the preamp and work on speaker positioning. Moving them around as wide as i can get has helped. I also tried tilting the speakers slightly downward because the stands made for the mc1 are 24 inches high, making the speakers 70 inches tall. My seat is 16 inches high. I think that was part of the problem. Hifi geek, i do hear noise in the power supply, i did recently retube it with arc's west germany tubes from arc.
Wow i gotta say with the speakers 6 feet apart, 4 feet out into the room and sitting 8 feet back, the system is much more stereophonic. Fantastic actually you guys nailed it and i was looking at the preamp. The speed of the sp16, vs110 and maggies is jaw dropping.
The SP-8 MKII is an amazing preamp. Think single chassis SP-10.
I have the SP-16 with Vandersteen 3A Sigs, Red Dragon M-500 Mono Block Amps. Speakers are 8 1/2 feet apart and I sit about 10 feet away. Soundstage is wonderful. Imaging is first rate. The SP-16 is a very nice preamp and can be tuned with different tubes in the positions nearest the inputs. You should be fine with that amp/pre combination and experimenting with speaker placement, seating position and room treatment.
I heard the SP-8 many years ago when I had an SP-6b. The SP-8 was part of an amazing system that a friend had consisting of a Quicksilver tube amp and modified Quad ESL speakers. The imaging and sound (esp. female vocals) was nearly the best I have ever heard. You have to leave a light on in the room or you will freak out thinking that you are not alone. The SP-8 and vinyl is a knockout combination. The only drawback is incompatability with low output MC cartridges.
I had an SP-6B as well and the SP-8 was a better sounding preamp. The SP-6B had a bit of a lumpy low end. I now run an SP-3C. Much better preamp.