ARC SP16 vs SP8

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.