New tubes for MV60SE

[Rubicon15]

Unfortunately or fortunately it’s time to replace the tubes in my MV60se. From what I’ve read on this forum and others, the KT120’s appear to be on the top of everyone’s list. I’ve done a few quick searches to check on pricing etc. Is it best to purchase replacements directly from Conrad Johnson or a different seller? Any recommendations regarding the best brands and sellers will be greatly appreciated.

[AnotherJohnson]

There are quite a few threads on this.
Look at the “active topics” list. There is a fairly current thread near the top of the list.

https://www.conradjohnsonowners.com/vie ... 314#p14314

[Rubicon15]

I was really looking for advice regarding the different manufactures, sound quality, life expectancy, etc. Are Tung -Sol tubes better than Millard’s?

[AnotherJohnson]

Are you looking for KT120s manufactured by Mullard?

[Rubicon15]

I honestly don’t know if Mullard makes a KT120. I know Tung-Sol makes them. I would also like to hear thoughts regarding mixing manufacturers- output V5-8 one mfg. and V1-4 another or should I use the same brand for all eight tubes? I’m looking for a set of great sounding tubes that are dependable.

[AnotherJohnson]

Tung Sol is the only KT120 manufacturer.

There is no incentive to mix brands … especially for the power tube complement.

If you browse around this site, you will find countless opinions. As Groucho said, if you don’t like these opinions, we collectively have others.

[Rubicon15]

Please correct me if I’m wrong. It appears the majority of people prefer Tung-sol tubes in older CJ amps like the MV60SE. Is is worth purchasing the tubes directly from CJ or are all tubes/sizes equal. For example, I would be interested to know if CJ tubes are more reliable and if higher quality than purchasing tubes from those mentioned in a few post. Thoughts?

[AnotherJohnson]

It’s all in that thread I offered you.

Buying from CJ is generally more expensive, but they do burn in and evaluate the tubes. CJ has historically been a reliable supplier.

Upscale Audio is an intermediate cost supplier but they also burn in, evaluate, and grade the tubes. They have historically been a reliable supplier.

There are many other suppliers out there. Some are less costly, some have their proponents as suppliers.

As for tube life, no one can pick up a tube and predict it by eye.

Tube failure is to some extent random. If you have 100 tubes, 5 may die in the first 200 hours (infant failures), 10 may die during the next 1800 hours (constant hazard rate regime), and nearly all of the rest will die in the next 400 hours more or less following a Weibull distribution (wear out regime). These numbers of hours or numbers of tubes are not bad estimates, but failure is stochastic, so they’re not strictly exact.

[AnotherJohnson]

If you want a fairly honest and unbiased (in my opinion) tube education, I would recommend browsing Kevin Deal’s FAQ videos on the Upscale Audio website.

Kevin does have a vested interest, so he’s not completely neutral - but his experience base is huge, and his most valuable selling commodity is honest customer care which leads to repeat customers.

FWIW, I think CJ and Upscale are both worthy of support. I’ve been happy with both.

Once you’re an Upscale customer, you can get a 15% discount.

[Rubicon15]

Thank you for the candid feedback. I read the information posted on Upscale’s website. I’m waiting on pricing from CJ. I will definitely consider Upscale as well. I’ve read that the smaller tubes last almost as twice as long as the output tubes. Should I consider just replacing the output or all 8 tubes?

[Rubicon15]

I forgot to mention that I currently have Tung-sol. If I go with the KT120, all tubes will be made by the same manufacturer.

[AnotherJohnson]

The small tubes do tend to last longer.
When small tubes fail, they tend to make noise.

More hiss. Maybe even intermittent crackles or pops.
If none are noisy, just replacing power tubes is generally fine.

[roberto]

AJ,
With much respect, only super wisdom you have! That's exactly what they do. Also when they are double triode, one could might have lower gain than the other.

Happy listening!

[Rubicon15]

No snap, crackle or pop. I will ask CJ and Upscale the same question and see what they recommend. I can see the logic in replacing all of the tubes at the same time. Thank you for taking the time to respond to my questions. I sincerely appreciate your feedback and advice. Have a great week!

[AnotherJohnson]

Some of the regular denizens have firm opinions about the sound of this tube or that. Joe Apierto, Big Dog RJ, Roberto and others may chime in. You may try PMing them.

All opinions, including my own, grow out of our own experience with different systems and rooms. Mine may be overly influenced by my background as an engineer and as a music listener rather than as a sound listener.

When your system really seems transparent, and when it can resolve all the musical threads present, I recommend leaving it alone.

[AnotherJohnson]

AJ,
With much respect, only super wisdom you have! That's exactly what they do. Also when they are double triode, one could might have lower gain than the other.

Happy listening!

Yes, that can happen. Even with new twin triodes. That’s a major point in favor of buying from a supplier that tests and grades their inventory.

[JoshT289]

I agree with everything AnotherJohnson wrote and the link he sent you provides opinions on your questions.

I have a Premier 11A, which many consider to be about the same as the MV60SE. Or put another way, many consider the MV60E to be the effective replacement to the 11A. I bought the amp used with some fairly high hour SED winged C 6550s, and when I replaced the tubes a few weeks ago, I decided to stick with that tube type because I got a great deal on some very, very low hour ones, and I like the sound of that tube in the Premier 11A.

As you likely know, CJ recommends and supplies the Tung Sol 6550 tube for the 11A these days (and, I assume, for the MV60SE). But when I told Jeff Fischel at CJ that I had access to low hour SED winged C versions, he flat out recommended I go for them instead of the Tung Sols. For what it's worth, Jim McShane does not like the Tung Sol 6550 and recommence the Sovtek version for those looking for newly issued 6550s.

THAT SAID, if you have decided you want to try the KT120s, then yes, Tong Sol is the only show in town. I would say most people are doing that, though certainly some are sticking with 6550s or trying KT88s. If it were me looking for KT120s, I'd go with Jim McShane or Brent Jesse because they both have excellent reputations and seem a bit more laid back than Kevin, lol. But Kevin is obviously a rockstar with a lot of fans.

I have a Rogue Audio Cronus Magnum II with the KT120s in it, and that is also a great sounding amp. I'd say the KT120s are more neutral and extended on the bottom end, but the SED 6550Cs are a bit more lively and detailed. I think it's a fun tube! I have not yet swapped tube type between the two amps, however, because the Rogue is down in Florida at our winter place and the CJ is up here in Boston. I'm looking forward to doing so in the future.

[AnotherJohnson]

I agree that Kevin is a showman. Sometimes you have to wade through his wake.

All the successful audio companies have at least one fairly strong personality at the helm.

[AnotherJohnson]

One of the reasons we have different opinions is that we hear things differently. Fletcher and Munson studied this and published a paper on it about 90 years ago.

If you google Fletcher Munson Equal Loudness, you will find links to help you understand this. Their work showed that you can’t really argue about differences without also knowing who is doing the listening. Human hearing depends on the human.

[Rubicon15]

Everyone has certainly given me sound and candid advice. I am not sold on the KT120’s. CJ has not returned my call yet. If they recommend the 6550’s, I will probably stay with what is recommended by the manufacturer. After all, CJ definitely knows their product line. After I finalize my selection, the final question is who test and offers the highest quality Tung-sol tubes for example. Does CJ or Kevin?