Hi Gibosi and kvtaco17,
Having spent a little more time with the Japanese Raytheon 6GC7/6FQ7 I must say that it grows on you. After spending time listening to a 1953 Tung Sol 6SN7GTB tube you have to adjust to next tube type - it takes a little time to get a settled opinion. While the TS 6SN7 is more musical and has a round fat bass, the Jap Raytheon is more detailed with a gorgeous wide forward sound stage with a fantastic timbre and exquisite high end and clarity, although the bass is not as tactile. Both tubes are really excellent.
Again, these are early impressions, subject to change. But, the wow factor is there...Man, I just smelled the breath of the trumpet player I am listening to LOL!
Thanks to Oskari (remember the mystery of Siemens Foreign tubes?) we now know that Raytheon had ties with Toshiba and that they used Philips sourced manufacturing equipment. The tube could also have been made by Hitachi.
Anyhow, I got this little bargain voltage regulator with a digital readout. There were many sellers of what looked like the same item, so I picked one seller of several who had the same low price of $4.33 incl. shipping. I picked a company with over 100.000 feedbacks and well rated. Unfortunately the shipping took a full 30 days, which I feel is too long. I have gotten stuff from China in 5 days, but usually it takes around 14 days. Maybe the end of year volume slows things down.
The voltage regulator is adjusted with a little brass screw, but I cannot adjust it exactly. Either I get 6.27V or 6.43V - nothing in between. Checking the voltage with my Sears multitester I get a readout of 6.30V when the voltage regulator reads 6.27V.
Which value should I trust? (The Sears tester is a cheap $20 unit)
Happy tube rolling!