Audio Research D150

I just bought a Audio Research D150 tube amplifier, can any one tell me any history of the Audio Research D150? what brand tubes sound best? 
There’s a website with all of their legacy products, including updates. Here’s the link: [url][/url]

And here’s a link to the manual if you don’t have it: [url][/url]

I still have my Dual 75a amp that I bought new in around 1975. It’s not in use right now, but i kept the packing, have the original manual, such that it is, along with a period era price list. I owned several pieces of their gear in the ’70s and ’80s and remember a friend who had the D-150. Quite an amp for its time. No idea how it stands today or what it would involve to bring one up to spec or better. I know that there are some folks that upgrade and restore old ARC. Perhaps someone else can chime in on the tubes- I bought a fresh set of the big tubes from ARC for my D75a before the company got sold. I used to have constant calls with Leonard in service-- a pleasant, somewhat laconic man-- when I owned an SP 10 mk ii. That rascal was a fabulous preamp for its day. Plagued by tube microphony issues. You own a piece of history.
A classic from the mid-70's when ARC was the only game in town - and a favorite of JGH and HP! Still competitive with today's big-buck gear and worth keeping! I have its brother the D75 (along with an SP6)! Tube sound for the connoisseur!
Where do I start?  The day it came into my shop we were thrilled, if not ready to go to the hospital for trying to lift it out of its crate.  Some amp!

We hooked it up to our SP3-A1 pre-amp and the Maggies that were out at the time...I forget whether they were C or D models...and let 'er rip.  It sounded like the D76A x two, which, in fact, it probably was. Finally drove those speakers with one amp.

To this day I have not heard a better amp that isn't tens of thousands of dollars. Have it gone through by someone who understands what it took to get it to that level.  Caps dry out over the years, so make sure the person contacts or has contacted AR to see what they suggest these days for replacements. 

Back then, each component was chosen by hand by people who measured each item supplied to AR by their various sources.  Many items were sent back as not meeting specs even though specs were specified to the supplier.  They only chose the "best of the best" parts back then.  No idea what they do today now that Bill J. is gone (RIP) and the company has been bought out by whatever.

It came with GE 6550's, which I don't think are around any more.  Get the best ones AR recommends as replacements and follow the biasing and burn-in instructions.  Make sure the rest of your system is high quality and I don't think you will be disappointed.  If you are, I am sure I know someone who will want it (hint)!