New tubes or new preamp?

Buy 4 tubes or a preamp that costs more than double the price of your current preamp is an amusing question. I think NOS tubes have become extremely overrated. If you want your LS-15 to sound its best you should send it back to ARC for a complete checkup and fitted with tubes selected by ARC. If you want an upgrade buy the LS-27.

I cannot comment on Modwright products.

I got a set of tubes from ARC and they were so microphonjc I Sent them back. Really want to know if spending money on an older per is worth it versus a new one.

There's more to a preamp than just the tubes. For me, the preamp is the most important piece in the system. (Providing you don't mess up matching your other components.) Get the LS-27. Its a big upgrade.

A set of good old stock tubes will change the presentation of your LS-15. I have tubed rolled a few LS-15 and LS-25 WITH VERY NICE RESULTS but if it is a major improvement you seek you should consider moving up to a better preamp of which there are many to look at.
Dennis
PrimeOne Media