I guess I will walk into the Lion's den!
All kidding aside a new user here looking to jump on the Stax gravy train. Last year I jumped back into headphones after a 15 year absence - mostly spent with my 2 channel system which takes most of my time. I put together a tight system with the Utopia headphones and the new Sony Signature series Z1R/WM1Z and their TA-ZH1ES Dac/Amp. I am now looking to start with a small stand alone Stax system - partly because Stax is so highly regarded in my 2 channel world (Naim/Linn) and also because of a demo I had at my first CanJam last year of the 009/Blue Hawaii at the HeadAmp booth. I still cannot get that demo out of my mind one year later.
With that said I do not want to jump full blast in (like I did with my Utopia's) and have been thinking about a stand alone Lambda system. I visited the Woo audio booth on Saturday at CanJam and had the opportunity to demo a 300 Anniversary and 500L through the 353 Anniversary amp. After that they were able to get their pair of 700's which were on loan at another show booth for me to demo - however the time I was able to spend with those was extremely short - just a quick few minutes.
My first listen to the 300 anniversary's impressed me quite a bit however when I stepped up to the 500's I felt that everything improved. Better bass foundation and more realistic timber to the instruments as well as a more "mature" sound - and a bit less strident.
My brief few moments with the 700 did not leave me thinking it was a step up. Bass was stronger however a bit muddy and it tended to cloud the out of head soundstage and airiness.
The 353 amp was quite nice with all three headphones.
For some reason I came away thinking the 500L was the sweet spot of all three. Better than the anniversary - and without the increased bass which I felt muddied things up.
Looking to get some feedback here. I would have thought the 300 Anniversary would have been the sweet spot of the line considering it utilized certain parts of the 700? How is the 500 considered by people here?
PS the only thing which clouds the issue is that I forgot to look at the 300's I was demoing to confirm they were 100% the anniversary edition (with the gold Stax tag). I emailed Woo and they said that hey were - however for some reason I am just not sure. The person at the booth was not the most knowledgeable and provided several bits of inaccurate information. They looked a bit beat up to be a brand new model!
After running the amp for over an hour, bias was 14+mA, so right where I want it to be.
I thought it might be interesting to create a table or spreadsheet showing different users biasing and results, so I made a Google sheet, here:
Go ahead and fill in your info if you like so this is available for all to see. Note: this is the first time I've created a Google sheet, so let me know if you can't edit it and I'll try to figure it out
Heatsinks: I've been looking for some. The ones that @mypasswordis mentioned from ebay don't seem to be available any more, and I'm having a hard time finding any that appear to be suitable size. There are some I almost pulled the trigger on that were 50mm x 25mm, but the 25mm would leave the end transistors half covered. I could get the Fischer SK81/37.5/SA from TME and cut them in half, but I'm trying to avoid that if possible. I'd need enough for 3 amps.
EDIT: Found these, 45 x 35 x 18mm on ebay https://www.ebay.com/itm/263051780518?var=562054192200