BHK Signature 250 or 300 Tube Rolling


#222

I had already stocked up on some NOS tubes in anticipation of the delivery of the amps . So when I received the amps, I ran the OEM Gold Lions for a few days for a break in period. My recollection was that they were good sounding tubes. You could easily live with them if you had not tried other tubes. Fortunately many people have gone down the rabbit hole and have tube rolling experiences to share.


#223

i agree as the stock tubes were pretty good. have been using an old set of tungstrum that had been used in the preamp. now i am going to try the new telefunken tubes. i like changing tubes on the amp as it is so easy.
the preamp requires more effort including unhooking it and taking it out of the rack, so not as easy to play with. what a great hobby and what great gear from PS


#224

I purposely put the Preamp on the top rack for easy access. Swapping takes a few minutes.


#225

great idea of course. sadly the TV sits up there.


#226

I am currently using the Tungsram PCC88 in my BHK250. Can you guys share your thoughts on which tube gives you the best SQ in female vocal? Many thx!


#227

Most of my listening is Female vocals and I have BHK 300’s, so similar. My favourites in my power amps are Phillips Miniwatt 7308’s seconded by Siemens E88CC’s.


#228

I have not heard the philips miniwatt 7308, which is described as the “holy grail” and is hard to find. I love the Sieman E88CC.


#229

I’ll see if I can find the article, but I’m sure I read somewhere that Phillips, Miniwatt, Amperex, Mullard and some other names were all made by Phillips; the names varying by world area factories for areas served.


#230

From Brent Jessee web site…

7308:

This is probably the ultra 6DJ8 type tube commonly available. It has all of the features of the 6922, but the triode sections are also matched to each other, and the tubes all fit within very tight specifications. Therefore, any 7308 should match any other 7308 within the same brand. The Amperex versions were again made in New York, complete with gold pins, and often have a number etched into the side of the glass. Amperex made these for industry as well as the military. The Amperex versions have the PQ label, the military type usually is labeled “USN-CEP”, but I have seen versions made for Stromberg-Carlson and Hewlett-Packard, with white ink labels. These all had the numbers etched into the glass, and all are the same tube. The USA made military white label types have been rated “Best of All”, over other 7308, 6922 and even Cca tubes, in several well-documented 6922/7308/Cca listening tests. Therefore this particular type is becoming scarce and prices are rising. There were a few of these made in Holland, but most were made in the USA, therefore the Holland tubes are RARE and usually command a higher price. The Holland PQ versions have the PQ with stars on either side of the letters, and the words “Premium Quality”, where the USA types have the PQ inside of a shield logo. Again, there are some nice vintage USA made standard pin military and industrial types available from Raytheon and Sylvania, just to name a few, and these are quite good at a price currently far below the European vintage labels. Finally, Philips (the parent company of Amperex) owned a number of tube brands, and many were never seen outside of Europe. Most were actually made in the same Heerlen, Holland factory that turned out the Bugleboy 6DJ8 and PQ 6922 Amperex. Watch for tubes labeled E188CC with brands like Valvo, R/T, RTC, Miniwatt, Dario, Philips, and Adzam. These tubes are identical to the Amperex PQ and Philips SQ (Special Quality) types more often found in America, and are perfect if the Amperex label is not available. Also rare in America are these same brands made at the Philips-owned Mazda factory (La Radiotechnique) in Suresnes, France. These usually have a capital “F” in the second line of the date code. They are sweet like the Holland tubes, with a bit better detail and punch at the top end, and still have nice balanced warmth. We are one of the very few worldwide tube dealers to offer these rare NOS French Philips tubes. Finally, watch for Siemens or Telefunken German made 7308 tubes, most having the E188CC label in white, with the Telefunken having the distinctive diamond shape in the bottom glass. Siemens are usually more plentiful, and a huge savings over their Cca tubes.!