Since my first BHK 300 thread got sort of hijacked, here's mine on evaluating tubes

A partial update on tube evaluation. Here’s part of a blurb (edited) I posted on AVS forum.

"…and I’ve spent lots of time and WAY too much money on 6DJ8-type tubes. A few weeks ago, a friend and I did a first session of evaluating and culled the Tungsram 7D8s lots of people love and also the inexpensive Soviet-era 6H23ps. This first time thru, the British-Mullard-made, R.T.C.-labeled E188CCs won. These were rather expensive at $420 per set, and then I bought two more sets! I’ve added a few more candidates including two sets of Seimens, West-German-made PCC88/7DJ8s and a set of Mullard-labeled, British-made E188CCs. It’ll take another couple weeks to get all of these run-in (four days per set of tubes)*, and then the ‘fun’ begins anew.

  • It’s AMAZING–it actually takes FOUR entire days to get 4 days of run-in on a set of tubes! " … :smirk:

So it’ll be all-three sets of RTC-labeled Mullard E188CCs, the Mullard-labled E188CCs, and two sets of Seimens PCC88/7DJ8s…and maybe another set of Mullard E188CCs, these used and significantly less expensive. Jeez! One would think I didn’t have a life! … :persevere:

BTW, I’m running all this stuff–DP, preamp, two poweramps–24/7.

I have two quads arriving today. One quad of Telefunken Ecc88, tubes and another of Siemens E88cc. I can’t wait to see what they do. I’ve gone neutral on the Tungsram tubes, They are OK but I’m not where I want to be soundwise.

I’ve installed the Telefunken tubes with the Diamond in the glass base and I’ve let the amps play for a few hours. My first impressions are positive. More bass with good bass resolution. Trebles and mids are very good. Some nice “sparkle” for lack of a better term. The Siemens quad will have to wait. I was sent one slightly different tube from the other three. I’ve already called about a replacement and it’s being sent to me tomorrow. I should have it in a week or so.

I have the LAST new set in their 2-day run-in; starting tomorrow afternoon, I’ll start 1-day runs of each of the five sets–

  1. Two sets of Siemens-branded, West-German PCC88s (AKA 7DJ8s),
  2. Mullard-branded British-Mullard E188CCs (AKA 7308s),
  3. The second set of RTC-labeled British-Mullard E188CCs,
  4. Another set of Richardson-branded Japanese Matsushitas, this time 7DJ8/PCC88s, and
  5. The third set of RTC-labeled British-Mullard E188CCs. The first set of these ‘won’ the first comparison.

I also have a set of used (and inexpensive at less than $170 delivered) Mullard-branded, British-made E188CCs on the way. That’ll be set number 13. … :roll_eyes::smirk:

I seem to prefer the sounds of the best of the Mullards–a bit recessed and NOT forward-sounding, a somewhat-warm tonal balance with great bass, and above-average sense of space around the orchestra. I believe the latter comes from higher-overall transparency.

What’s are the latest returns in your adventure, jeffreybehr, with all these tubes?

One thing I know–I have WAY-too-many tubes to evaluate! Doing so would be easier if I were indeed a golden-eared audiofile, but I’m not–and I’m especially NOT good at quick evaluations.

To try to unconfuse many of us (including myself until a few months ago) on American/European 6DJ8-equivalent labels…the original tube was the ECC88/6DJ8. The (AFAIK) first variant of that is the slighly-heavier-duty, closer-tolerance E88CC/6922. The last (AFAIK) variant is the E188CC/7308, made, allegedly at least, with still better materials and closer tolerances.
But I digress…

Just to make sure I’m organized, I’ll summarize what I have passed by (rejected).
A. NOS Tungsram PCC88/7DJ8s–a bit thin(1) sounding.
B. British-made, Amperex-labeled, A-frame-type 6DJ8/ECC88s–a bit forward; otherwise good to very good. Pop-music and jazz fans probably would love these.
C. Inexpensive Soviet-era Vokshod 6H23Ps–a tad thin and also slightly harsh.

Making the 1st cut were British-made Mullard 6DJ8/ECC88s, Japanese-made National/Matsushita 6DJ8s, and the winner with excellent detail, warmth, and depth-of-image, British-Mullard-made, RTC-labeled E188CCs.

Added to these, besides additional sets of the RTC/Mullards, are (by my tube-set numbers):
8 and 12) Made-in-West-Germany Siemens PCC88/7DJ8s,
9 and 13) Mullard, Gt. Britain-made E188CCs (having the later-style Mullard shield [visible immediately right of the powercord in the pic] and labeled with only that tube number), and
10) National/Matsushita 7DJ8/PCC88s.

With multiple sets of a few of these, I still have ten sets of six-different tubes. I have the last set–#13–still running in*. I run them for four days each, and including set #13, I have five sets with only two days on them, each of which will get two more days.

Maybe we’ll get them evaluated the WE of April 28.

  • Seems I’ve been running in tubes for years in my BHK 300s. :roll_eyes:

(1) = lacking in upper-bass/lower-MR energy/richness, the power region of an orchestra.

My experience so far in order of preference:

  1. Siemens Halske E88CC gold pins (Very good, my favs)
  2. Telefunken E88CC gold pins, diamond imprint in base (VG)
  3. Tungsram 7DJ8, (good)
  4. Amperex Orange Globe “A” frame (good)
  5. Gold Lion OEM (good)

The bottom three are all good just slightly different. That’s what makes this hobby fun but expensive.

I’m going to order the Mullard E188CC RTC’s. is a local not too far from me.

So far I could easily live with the Siemens tubes.

Watch, e-mail me (jeffreybehr[at]cox[dot]net) if you’d like to save 30% on those RTC E188CCs; I don’t need three sets. They’ll be broken-in, too.

I’ve finally tired of listening to tubes instead of to music and have selected my favorite tubes(s), being…the Mullard E188CC. I have FIVE sets including the RTC-labeled versions, and I can’t distinguish any differences among them.

These Mullards, relative to all the tubes I heard, sound slightly warm (something that’s important to me), are never hard or strident, and are highly resolving of musical detail including soundstage and instrumental image. I’ve ‘retired’ all the other 6DJ8-type tubes I have and will be offering them for sale at attractive prices. Do understand that only two of the 13 sets ever sounded slightly unattractive and that the six sets in between sounded slightly different but never bad.


Looking forward to your sale.

[quote=“jeffreybehr, post:29, topic:5424”]
I’ve finally tired of listening to tubes instead of to music and have selected my favorite tubes(s), being…the Mullard E188CC.

I admire your tenacity ! You have put in the hours… If you were to grade all the tubes - where would you place the standard ( Gold Lion ) tubes ?

I hear you on that. I had an Ayon tube DAC and I never had the slightest interest in tube rolling. Listening time is too precious to be wasted on distraction. But I do like reading all the above posts whilst I go about enjoying my all digital listening.

I hear you. I had an Aesthetix Calypso preamp that I truly loved but it forced me to do lots of tube rolling, looking for quiet tubes. If the tube wasn’t perfect–in what way I don’t know–it just had this unpleasant noise floor. My wag was that it was because the preamp had an awful lot of gain.
My BHK fixed that problem and 3 tube types later, I’m good with 7308’s.

…and the 7308 is the US equivalent of my fave, the European E188CC.

I really don’t much enjoy most of the rigmarole of tube rolling. There is inevitably a burn-in time before you can seriously listen to them. They wear out insidiously, so you don’t really hear it happening until the process has crossed a threshold. And an identical set of replacements is not guaranteed to give the same sound. All these things combine to make comparing different tubes a real PITA unless you happen to have multiple sets just lying around … which a few people here seem to do!

Anyway, that all said, I thought I’d just list my own personal experiences with different tube sets on my pair of BHK 300 monoblocks. In order of preference, they are:

  1. JAN-Phillips 6922. Smooth and dynamic, rich sound. Short life. Liked them a lot. Too expensive, especially considering the short life.
  2. Golden Lions from PS Audio. 2 different sets. Sonically similar to the JAN-Phillips, but slightly brighter and rougher round the edges. Nice when new, but sound quality seems to drop off progressively with age.
  3. Tungsram PCC88/7DJ8. Beguiling, but darker tone. Deeper, but oddly narrower stereo image. Lacking in power for orchestral music.
    I have now ordered a set of Reflektor 6N23P-EV, and am waiting to see how they will pan out. I am intrigued by the prospect of longer service life, assuming the sound quality makes keeping them worthwhile.

Have you bought and tried the Reflektor 6N23P-EV/6922 tubes?

Love your systems!

Hi my system has evolved considerably since then. I haven’t tried the Reflektor tubes from PartsConnexion. I chose to stay with my Telefunken 6922 tubes. One word of caution on the Refektor’s, there are some horrible sounding versions out there. I have a pair from a bulk tube purchase and it’s amazing how bad the ones I have sound.