Upgrade or sell ARC LS-15 ?

You should be able to get a LS-25 for $2000-$2500. I would go this route, personally. I've gone the mod route before, and although it does make an improvement, you won't recover as much of your money should the upgrade bug bite again. Generally speaking you're lucky if you get back 25 cents on the dollar for the cost of the mods. That's not a sound investment. If I really wanted a modded GNSC LS-15, I'd wait for one to pop up on AudiogoN and buy it for about $1750 or so.
As always, YMMV.

Cheers,
John

Mbonn-

I was in your situation not too long ago. I concidered the GNS with the Reference upgrade for my 15 and called Steve at GNS. We spoke at length and he basically said that even with the upgrade, the 15 will not be as good as an LS5 MkII or III. for example and may or may not be the equal of the 25, but wont be "better" than the 25.in his estimation. I ultimately decided to sell the 15 for a MkI 25 with the variable gain of 6,12 or 18db. and put Siemens 7308's ( now British Ediswan CV5358's)) tubes in it. I think this may be a better choice.Better PS regulation and just more pre amp in the 25. In fact, I would seriously think about a used LS5 MKII or III for about the same price. Most will agree this is the superior pre amp sonically. -Ken :)

Thanks for your responses. They are quite helpful.
Ken - I had not considered the LS-5 before, as I was unfamiliar with it. In researching it, I see it accepts only balanced inputs. My sources are a PH3-SE and an Arcam FMJ CD-23T cdp, both of which have only single-ended outputs. Doesn't this rule out the LS-5 ?

Good Boy Ken!

No not at all. Pick up the Cardas rca-xlr adapters readily available. They are a high quality adapter that wont degrade the signal in the laest IMO and will allow use of the 5. You may need a pair for your output to your amp also.(XLR-RCA config) They ususally go for about $50 pair..it's still cheaper than changing all your cables or components. Well worth the cost to be able to use the LS5. Alot of folks are intimidated by the all balanced in/out of the LS5 or figure its not worth changing their whole set up. IMO this pre amp IS definately woth building around it, The Cardas adapters will allow you to have your cake. :) Ken