First tubes in 30 years

😎

Thanks for the kind words.

Now I have to decide whether to sell my XA60.8s. These are great amps, and are a nice "reference" to have to compare my DIY projects. But they are pretty big and heavy, so a little hard to tuck in a corner, and I have way too many amps at this point (is it possible to have too many amps 😁?).

Nice. Transformer coupled? Heater kit boards?

You used honest to goodness Western Electric 300Bs...  From their website, a matched pair is $1,500 dollars, and you have monos so times two...  Well, good stuff doesn't come inexpensively.  As for selling your Pass XA60.8s, don't do that; those are some very fine amplifiers.  If you're using a Pass preamp, I bet that sounds pretty astounding.  In my experience, Pass amps are "picky" when it comes to that "just right" sound.  I went through a few preamps before I picked up a Pass and boy oh boy, I wish I had done that sooner.  Nice job on your SETs.  

@noromance - I'm using a Jensen input transformer for the balanced inputs. The driver stage is coupled to the 300Bs using a c-core interstage transformer. Then another c-core transformer for the outputs. 

The 300Bs each have a Tentlabs filament supply (voltage controlled current source). The driver tube (6SH7) has a Pete Millet regulated heater supply. I'm also using a Neurochrome 21st century Maida regulator. 

@lucky_doggg7 - yeah the WE tubes don't come cheap. But right out of the box, they were very clearly superior to the Linlai tubes I started with (mostly because I didn't want to risk damaging an extensive tube when I was first checking out the amps). 

I'm using a DIY preamp which I'm pretty happy with. This is my second DIY preamp build. You can see details on my virtual system page. 

At this point, it's unlikely I'll buy another commercial product. I am really enjoying the whole process of building my own. So far, I have primarily been using subassemblies designed by others, but I'm starting to experiment with my own ground-up designs as well.