Which Preamp - Modwright or Joule-Electra?

The forums can be your friend.

Its a shame that the internet can be a useful tool for such things as this, but instead people want answers now with out doing research.

I wish I could guide you, but truth be told, what I or anyone else likes ,isn't necessarily going to be what you like. Your options are virtual auditions reading as many reviews as you can, Or listening to one trusted friend or knowledgble person Best of all listening for yourself.
It is tough when polling people. I found one person's opinion about a warm sound was very analytical and crisp to me. Go figure, the best way is to listen for yourself with your own gear in your room. That means buying and selling until you hit the right one for you. This can be very expensive and frustrating.
I ran into my favorite because I wanted a pre amp that used 6SN7s. It was cheap~ $350 and very responsive to tube rolling. That turned out to be near perfect for my needs and preferences. So you know, it was a used AES-AE3 made by Cary and still available from Upscale Audio but new and jazzed up a lot, making it $1200 min. I hope to buy an SLP-05 or whatever comes out using 6SN7s from Cary in the furure.
It was pure luck maybe that will happen to you. I spent a lot of money along the way, so it wasn't as cheap as it seems plus the tubes I use are really good and also expensive.

With all my due respect to great work Dan Wright does - these two line stages are in two different classes.

This is (very biased) opinion of the owner of LA-300 Platinum and I auditioned many, many preamps and even owned REX by BAT (also great preamp but with different sonic signature). Jud Barber equipment "forces" me into the music as no other pre- or power amp I know (well, except LA-450 ME which I cannot afford at the moment...)

All The Best in Your Search

Rafael

Dob- OP is asking for comparison btwn LS100 and LA-150. The Joule LA-300 is in a different league price and quality wise. It would only be fair to compare it to the Dan Wright's more expensive (LS 36.5??) two piece unit. I've owned both the LS 100 and either the LA-100 or 150 (not at the same time). I'd say that the Modwright is a value leader that is very neutral and perhaps closer to a ss sound. The Joule tended to be a bit slower, fuller, more tubey sound and was good at conveying emotional impact. If I wanted to add a tube sound to a system w ss power amp I'd probably pick a Joule product. If I had a tube amp and wanted to stay w tubes while maintaining speed and neutrality (whatever that means) I'd go w the Modwright. but you need to compare statement or near statement pieces to each other, not basic to statement. My $0.02, YMMV.

"I'd say that the Modwright is a value leader "

I agree.

FYI, I have listen to all J-E preamp I could find, starting from LA-75... and LA-150SE of course.

The sound of LA-150SE is very, very close to that of LA-300ME. The biggest difference is that LA-300ME has different (better?) power supply.

Sonic difference between LA-300ME and LA-300 Platinum is much wider then that between "150SE" and "300ME".

That's my biased opinion.

Ooops, "slow", you mentioned. I used Still Points ULTRA-5 vibration control under my preamp (and before that ULTRA SS and before that ultracheap Yeil). No, not slooooow, not in slightest, so sorrrry. Lightingly fast I would say. Also, I use interconnects and power cord which also effect sound, I been told....

I respect you methods of matching equipment you described in your post but I have my own. I buy ONLY equipment which, IMO (biased of course) has "musical soul" in it. I am grown-up and can improve bass, speed, imaging, this and that (e.g. all kind of accessories exist to choose, different capacitors, resistors etc) One think I can do nothing about: substutute designer and give "soul" to this equipment

All The Best