mwl168

Apologize if you already ruled this out - could it be the cable instead of the driver that actually died?

Did you check if the values are in stock with other brands like KOA, Xicon, etc.?

You have not idea how relieved I am to hear this. Thank you Santa!

May be better to post a picture to be sure but if the 8N80C you have are encapsulated then there is no need to use an insulator/plastic washer when mounting to the heatsink.

Happy Birthday Soren!

Thanks everyone for your patience. I did not realize so many of you have yet to receive the package. I sent the packages out in a few batches and usually 6 - 7 at a time. I am at a loss making sense why some of the packages arrived so much later than others.

The sad thing is that it appears that the Mouser delivery to me in USA takes longer than the delivery to a different continent.

@hhobeika The secondaries spec should be fine. You can dial back the current on the 15vac, 100mA ought to be enough for the Carbon front end which draws less than 20mA IIRC. B+/ B- draws around 80 mA both channel combined. 250mA should provide ample headroom. Where are you located? If you are in USA, you can check out Antek transformers which are well built, reasonably priced and sized.

Since I started trying different tubes on my SRX Plus I've noticed that, while the amp is dead quiet with some tubes, some tubes will result in audible hum with no input signal present. After some reading and experiment I decided the hum is most likely caused by leakage current between the heater and cathode of the input tubes. I decided to elevate the input tube AC filament supply. The photo below shows the filament elevation circuit I added this morning. The 12.6vac filament is elevated to about + 56VDC reference to ground. The amp with the same set of tubes went from a bothersome hum to dead silent (knock on woods)!

A very nice, different take of "The boys of the summer". Well recorded too.

Cut all the round holes myself with a table drill. The AC socket hole and the ventilating slots came standard on the chassis.

Cased my SRX Plus last weekend at long last. Finally got down to adjust and test it last night. The PSU inside is the Kerry design from the recent GB with a high tension supply timed delay.

I was warned by the USPS about possible delays when I sent the packages but did not expect the delay to be so extensive. Thanks for letting me know guys! I'll sleep a little better tonight.

I have both the Clear and Elear. Going by memory, I bought the Elear two years or so before I bought the Clear. They are more similar than different but I like the Clear much better. I feel the Clear has better resolution and top end and, again, better tonal balance compared with the Elear. Even though the differences are relatively small, all thing combined, I consider the Clear a better headphone all around. YMMV!

I agree with most of what catscratch described about the Utopia and Clear. For me, Utopia's resolution and clarity are very impressive and clearly better than the Clear. I bought the Clear new for $1K US but the best deal I could find for the Utopia is over $3K. I do not find the Clear fatiguing in my system. I also wonder how much factor the system synergy/matching plays. Even though I read the Focal headphones are very easy to drive I do believe the amps make a significant difference. I listened to the Utopia in a store driven by a Chord Dave DAC/amp. I primarily listen to my Clear driven by full balanced SuSy Dynahi and Kevin's Current Feedback CFA.

I may not be answering your main question. The Utopia does do many things extremely well. And, for me, if the Utopia sells for the same price as the Clear then, given their own strength and weakness I may lean for the Utopia. But the decision is made easy when Utopia sells for 3 time the price of a Clear.

I own the Clear and have only brief experience with the Utopia under an unfamiliar surrounding equipment so take this with a large grain of salt. The Utopia does something very well and better than the Clear but overall I feel the Clear is a better tonally balanced headphone. There are a few flaws of the Utopia that I consider too severe for me to justify the high cost.

I had the good fortune to have listened to the Beast driving a pair of Nelson’s own DIY Lowther speakers at the 2011 Audio DIY show held in San Francisco. It left an impression!

Did it just arrive today?

Kevin designed multiple PSUs for Stax amps over the years. I believe the board shown in matthew-levi's post is what's called BH mini PSU. It's the simplest, lowest cost to build PSU. The schema show in decoherent's post looks like the GRHV psu. Either PSU will work but the GRHV is much more stable and much lower noise but also much higher cost and larger in physical size.

Going by memory, the only obsolete part on the KGST is the 2SK170 JFET which is still available at BDent. Stay out of eBay, etc. - most advertised out there are fakes. I personally do not consider KGST the golden standard of Stax amps but it's easy and low cost to build. One other easy to build Stax amp that uses all current parts is the all solid state electrostatic current feedback amp.

Hi Ben: I have the GRLV boards. will PM you.

Agreed, And if "flagship" product refers to the most expensive model in the line, my experience is that it does not guarantee that the more expensive model necessarily outperforms the less expensive ones. I have both the 007 and 009 on hand, I like them both. Each has its merits and faults. In addition to the music genre, I pick which one to listen with based on my mood-swing and sometimes the alignment of the moon and sun.

Thanks for letting me know John! Hope all will receive your packages soon. I have no clue how much time the packages take to reach different countries/recipients based on past experience - there seem to be quite a bit of variance. Sometimes the customs plays a part and I was also warned that the COVID pandemic may cause some delay as well.

One vote for the CFA/GRLV.