BHK Signature 250 or 300 Tube Rolling


#1

I understand PS Audio’s tube selection is limited to new tubes. I, however, just purchased three different sets of quads: (1) Siemens ECC88 (6DJ8); (2) Amperex 6922 (Holland) and (3) Amperex ECC88 Bugle Boys with the Halo Getter.

Does anyone have experience with these tubes? How long do you have to burn in a tube before listening to them to determine which ones sound better? Any other thoughts on tube rolling?

Mark


BHK amp or preamp tube rollers
BHK amp or preamp tube rollers
#2

I have experience with all three in the 12AT7/ECC81/6201 variety. IME tube burn in is very subtle is small signal tubes. You get most of the way there after an hour or so, with the rest catching up within a day or two or normal playing. I assume these are NOS tubes? If so (or even if not) do you have a way to check at least for gas and shorts?


#3

Has anyone rolled the tubes in the amps? What results?


#4

I have 2 weeks ago changed the tubes to Philips 6DJ8 NOS 1960 in the 250 BHK the only difference I could hear was the Bass was a little more deeper and the sound when listening to quitter sound tracks they had more depth to them .


#5

In developing the upcoming BHK SignaturePreamplifier, Arnie Nudell & I early on decided the Tungstram PCC887DJ8 was superb in the preamp. Being a NOS tube, we couldn’t ship the preamp with those. Subsequently, in searching for a tube we could use, we came upon the Psvane 12AU7. This tube sounded as good or better than the Tungstram PCC88. So, since I now had the pair of PCC88s available, it was suggested that I try the PCC88s in the amp. Whoa! That was a wonderful increase in resolution, detail, & musicality. So, tube rolling in the amp can definitely yield sonic benefits. Note that the 12AU7 won’t work in the amp as it is wired to only supply 6.3V to the heaters on tube pins 4 & 5.


#6

Do I understand correctly that the Tungsram PCC88/7DJ8, the 7 volt version of the 6DJ8, will work?

Yes, even though the heater voltage is about 10% low, it works just fine and sounds sublime!

BHK


#7

I found Tungsram ECC88/6DJ8 and Tungsram 6922.

Those would be interesting to try but I have no experience with them. Perhaps you could try one or both and report on your findings.

BHK


#8
Mark A. Larsen said Do I understand correctly that the Tungsram PCC88/7DJ8, the 7 volt version of the 6DJ8, will work?

Yes, even though the heater voltage is about 10% low, it works just fine and sounds sublime!

BHK


Thank you. I will try them.

#9

One of the best sources of information for a comparison of tubes is “Joe’s Tube Lore” and Upscale Audio.


#10

Yes, Kevin at Upscale Audio has always provided me with excellent advice.


#11

I suppose I should try my Telefunken ECC88’s I got from Upscale audio before my BHK arrived. But before that happened, I noticed one of those tubes had the exact same date stamp with gold letters that the guy at Jacmusic.com had that bought similar ECC88’s earlier than Kevin. His batch was bad. I suspect that most likely what happened was there was a big batch of used TFK ECC88’s in Eastern Europe, so these guys relabeled them and stuffed them into new boxes. Jacmusic’s tubes were worn out, so the sellers just tested theirs and picked out the good ones, so Kevin (I suspect) has those for sale. (There was a way the TFK embossed logo on the base of the tube could be faked, also, per the Jacmusic site)

So I never put in the ECC88’s.

But I did put in a pair of PCC88’s into my BHK, and WOW, the detail improved a LOT. I got more dynamics and more detail (MartinLogan Spire electrostatic speakers)

And the PCC88’s are cheaper, to boot!

–SSW


#12

Streets, I have a B&K 707 tube tester. If you’re curious about those tubes and want them tested, shoot me a PM.


#13
tony22 said Streets, I have a B&K 707 tube tester. If you're curious about those tubes and want them tested, shoot me a PM.
Tony,

Kevin at Upscale Audio tested them. And finds matching pairs. He even listens to them on headphones after running them through the tester. They test just fine. That’s not the problem.

The issue is that I feel I got hoodwinked. Snookered. (But then again, so did Kevin) And I did buy them more than 90 days before the BHK 250 was shipped to me, so I can’t return them. So I just feel bummed. I bought two pairs, so that’s over $600 down the rabbit hole for what amounts to used tubes. So I’m just reluctant to use them.

But I will say the PCC88’s are FANTASTIC in the BHK250. There are details in the mid-highs that I didn’t get with the factory Gold Lions. It really opened up.

Enough that I don’t regret not getting the monoblocks now. Paul tested the 300 mono’s a week after I got the 250 stereo and made me feel bummed that I didn’t get the additional detail. But with the PCC88’s I’m guessing a LOT of that detail is now present, so now there’s NO regrets for the stereo BHK 250 whatsoever.

–SSW


#14

SSW, I read your post about the ECC88’s yesterday and was horrified that I might have bought those tubes, but I looked at my recent order to Upscale and discovered they were, in fact, the PCC88 that you like so much and were recommended by BHK. Whew! Now I’m curious if the Tungsram ECC88’s are the tubes Kevin Deal refers to as the “super-expensive, impossible to find 6DJ8”. $300/tube is expensive, especially when they are used. I would try contacting who you bought them from to make sure they aren’t willing to understand the circumstances. As for the PCC88’s, mine arrive Friday so maybe this weekend I can hear the difference.


#15
pmotz said SSW, I read your post about the ECC88's yesterday and was horrified that I might have bought those tubes, but I looked at my recent order to Upscale and discovered they were, in fact, the PCC88 that you like so much and were recommended by BHK. Whew! Now I'm curious if the Tungsram ECC88's are the tubes Kevin Deal refers to as the "super-expensive, impossible to find 6DJ8". $300/tube is expensive, especially when they are used. I would try contacting who you bought them from to make sure they aren't willing to understand the circumstances. As for the PCC88's, mine arrive Friday so maybe this weekend I can hear the difference.
Actually, I got 2 pairs of them at $165 each, but still.

Yeah, by all means give the PCC88’s a try and let me know what you think. I’m really liking mine!

–SSW


#16

There are obvious confounding factors in tube rolling. Are the quads compareable? Are the amps broken in? Of the five sets of quads, in my system, I like the Siemens. The Siemens have a noticeably clearer midrange.


#17
Mark A. Larsen said There are obvious confounding factors in tube rolling. Are the quads compareable? Are the amps broken in? Of the five sets of quads, in my system, I like the Siemens. The Siemens have a noticeably clearer midrange.
Pardon my ignorance, but what are the "quads" mentioned above?

BHK


#18

(1) Siemens ECC88 (6DJ8); (2) Amperex 6922 (Holland); (3) Amperex ECC88 Bugle Boys with the Halo Getter; (4) NOS 1971 Tungsram PCC88 7DJ8 tubes; and (5) Genalex Gold Lion.


#19
Mark A. Larsen said (1) Siemens ECC88 (6DJ8); (2) Amperex 6922 (Holland); (3) Amperex ECC88 Bugle Boys with the Halo Getter; (4) NOS 1971 Tungsram PCC88 7DJ8 tubes; and (5) Genalex Gold Lion.
Well, Mark, that is an interesting and informative list of tubes to consider BUT, it did not answer my question as to what the word "quad" meant in your previous post!

#20

Bascom, in this usage I believe he’s referring to a set of four closely-matched tubes. Pair for 2, quad for 4, octet for 8…