Need advice: replacing a bad ECC88 tube

Brothers and sisters - As it happens, a tube in my Signature preamp blew and, according to the technician who examined my unit, it did so because it had reached the end of its life. There is nothing wrong with the preamp, so now all I have to do is replace its two ECC88 tubes with new ones. Easy but now I have to make a purchase decision based on zero tube knowledge. Could someone help me out by responding to some basic questions? (My amp is a Signature 250.)

  1. I would spend around $150/tube if it were necessary, but would there be an sonic or life-span difference between it and a $20 tube?
  2. Does the manufacturer of an ECC88 tube make the tube any better or worse?
  3. I’ve read that I could replace the two ECC88 tubes with two 6DJ8 tubes without making any adjustments to the preamp. Is that absolutely true?
  4. If a 6DJ8 is 100% interchangeable with an ECC88, would its cost or manufacturer make a sonic or life-cycle difference?
  5. Is there a best place from which I could order the tubes?

As much as I know about music I know as little about tubes. Thank you all in advance for helping me out!

  • Brother Jim

Tubes can be confusing and ultimately disappointing if you buy the wrong ones.

If you want tubes on a budget that are NOS get any organ grade matched pairs usually 6DJ8’s these are usually American made

If to want the best find a NOS Telefunken E88CC or 6DJ8

1 Like

Watchdog recommendations are good.

Couple questions… you are referencing the PS Audio BHK preamp, correct?

Could you share the existing brand of the ECC88 tubes you’ve been using?

If you liked the sound of them, I would consider replacing with the same (or similar) brand as the tonal characteristics change from brand to brand. For instance, I have some Siemens ECC88’s that bring the soundstage near me (like sitting the front row of a concert); I also have Mullards and it’s like sitting in the back 1/3 of the concert hall. Each brand (or group of brands) have a tonal balance that bring you near or away based on their makeup.

As watchdog mentioned, there are several organ grade tube brands that are inexpensive and get you much of what you like. To go that last 5%, there are more expensive options.

I’m sure others will share, however, feel free to share back your interests and the group here can steer you in the right direction.

ECC88 is simply the European designation for the 6DJ8 and yes the two are compatible. The 6922 is a 6DJ8 industrial grade variant built for a life-time of 10,000 hours (at least on paper). The Cca is a hand selected 6922 that was intended for demanding telecommunication applications. There is really too much to cover about the 6DJ8 tube family for an on-line post. One of the best, most comprehensive discussions of this tube type can be found on the Brent Jessee website:

6DJ8 Tubes From Brent Jessee Recording (

There are all kinds of opinions about sonic differences. See the tube rolling threads on this site (the Brent Jessee 6DJ8 page devotes some discussion of SQ). However a caveat about that, the subjective opinions you’ll find about SQ for different brands and NOS/New Production aren’t necessarily consistent and that will be because SQ is a matter of overall system synergy. You can read all the on-line opinion you like, but in the end only you can make the final decision on what to try next. Note I was deliberate there, I wrote try because that is how rolling tubes in valve electronics works. Most of us have collections of tubes accumulated over time, all excellent, all somewhat different sounding and ready to be swapped in or out as our systems change.

There is no ‘best place’ for ordering tubes in my opinion. There are a number of vendors that I personally consider reliable: (New Production/NOS) , (NOS specialist), (NOS specialist), (primarily New Production), (Canada, interesting but limited NOS selection).

Good luck. Education is key to making smart tube purchase decisions. Start with that Brent Jessee page.


In many cases you can sub 7DJ8 for 6DJ8 and never notice the difference. Matsushita National 7DJ8 usually run $50 to $70. It’s a very good tube.