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.!


#231

Hi

I recently tried Valvo E88CC red label in my BHK250 . I would say they sound very close to the amperex 6922 PQ
If I had to compare them I would say that the valvo give a slightly better image and especially depth, and on the other hand loos a little of the amperex warmth. The price I paid was similar to the amperex (around 100euros for the pair).
Very good tubes


#232

$15 off those beautiful-sounding Mullard E188CCs!

https://www.thetubestore.com/mullard-e188cc-7308


#233

Hi again,

this time I tried philips miniwatt SQ E188CC. Compared to the valvo red label, they have fuller bass, richer medium (more harmonics) and similar highs.
The bass are not as much controlled as the siemens cca but to my ears everytnig else is better.
Compared to the valvo and amperex, they are in the same family but do eveything a little better, which at the end of the day changes everything.
These tubes are the most balanced and the closest to life that I have tested. I listen to some of my favourite tracks tonight and one could see the smile on my face…
I think the miniwatt will be hard to beat.


#234

I concur on your opinion of the Miniwatt’s. I have a quad of the Philips Miniwatt 7308’s that I currently have in my BHK 300’s. They are now my preferred tube for the amps. Unfortunately, these are getting harder to find as quads.


#235

So would either the Philips Miniwatt 7308’s or the Philips Miniwatt SQ E188CC work in the BHK 250?


#236

7308 and E188CC are the same/equivalent tube. I use them in BHK 300’s so they are perfect for a BHK 250. I never cease to be amazed at how good they sound. I have 5 quads of other tubes and the Miniwatt 7308 are the ones that I always come back to.


#237

Where did you purchase them from. They seem to be in short supply.


#238

I had a “want to buy” on a Canadian audio forum. A dealer in western Canada approached me about a quad that he had. I bought them without a thought. Still glad that I did.


#239

The E188CCs that are NOT in short supply are the mentioned-just-above Mullards, MY favorites–detailed, spacious, slightly warmly balanced…just YUMMY!
https://www.thetubestore.com/mullard-e188cc-7308


#240

Thank you


Lots of Buzz Here About Tungsram PCC88's?
#241

I own a BHK 250 amp since July 2016. I soon replaced the Gold Lion tubes by PCC88 Tunsgram. Not the best in terms of microphony, background and triode balance because I could not find them in Europe and Upscale Audio does not sell to Europeans. I found the result musically more involving than with the Gold Lions. But after a few weeks, I replaced them by Mullard E188CC/7308 tubes of the 70’s followed by two generations of RTC E188CC. These tubes brought some more refinement and transparency with respect to the PCC88. However, the lifetime of these 3 pairs of NOS tubes never exceeded 6 to 6.5 months. Initially, I thought I had been fooled with the Mullard’s that would have been used rather than real NOS tubes. But it turned out that whatever the tube pairs in use, their life spans were the same. I have not used the PCC88’s long enough to know their lifetime.

I estimate my listening time at 10 hours per week on average (540 hours per year). However, I often leave the tubes on while I do not listen to music during the day. Do I have to take this time into account, too? The BHK booklet recommends changing the tubes every one to two years. Clearly, I am not in this scenario. Has anyone had a similar experience? Do I have to worry about my amp? Now I went back to the PCC88’s. We’ll see if they last longer.