New tubes for MV60SE

[AnotherJohnson]

As explained in that other thread …

Buy from CJ to support CJ.

Buy from Upscale to save some money without compromising quality.

Buy from others, possibly to save even more money, or to scratch some other itch.

There are happy customers in most camps.
.
I am comfortable buying from either CJ or Upscale, but I usually choose Upscale because their tubes are excellent, they’re easy to buy from, and the price is good for what you get. Fast, well packed shipping too. CJ is more expensive, and harder to buy from (no web ordering and difficult phone ordering). But you get good quality and good shipping.

I’ve bought from local stores, MojoTone, Tube Doctor, and several others. At this point, I buy ALL of my guitar amp tubes from Upscale. I buy most of my audio system tubes from them too. If I’m making a BIG order (20+ tubes) it is always Upscale for me these days.

[JoshT289]

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?

Hi Rubicon15,

I have had luck calling CJ right when they open at 11:00 a.m. ET, or between then and noon. I've also heard from others who say it's when they are most likely to pick up. I've not had luck with them returning voice messages until after making initial contact. I think they're just very busy.

I don't think you can go wrong with CJ, Kevin, Jim McShane or Brent Jessee. They all check the tubes they sell carefully and are knowledgeable and have stellar reputations online. You certainly cannot go wrong with CJ, aside from probably paying a bit more than otherwise.

Have fun. Regardless of what you choose, it would be nice to get an update on how things go, what you picked, and how the MV60SE sounds.

Josh

[Joe Appierto]

Although my experience with tube vendors is 10+ years out of date, AJ and Josh have recommended some of the best in the business. You'd be well served using any of their services and as AJ has pointed out while CJ may be more expensive than most and as Josh says they aren't always at the other end of the phone because they're so busy especially during these times, I've never heard anyone complain about the quality of CJ's tubes.

Now that I made that last statement there may have been here and there a tube which didn't survive transit to the buyer, etc. but those are, I think, few and far between and it'll happen to any vendor especially when the tubes are shipped by air.

In my time dealing with these recommended vendors I can think of only one instance where I received a tube that wasn't up to snuff. That was a single cryo'd KT-120 out of a matched octet from Upscale that just wouldn't bias. This was a good 15 years ago and when I called Upscale and spoke to Kevin (not sure if that counts as lucky on my part or not) although he wasn't happy about it, he made good and replaced the tube.

[Rubicon15]

I was finally able to talk to a sales rep at CJ. Unfortunately, they were not that knowledgeable. CJ now recommends Tung-sol 6550’s, Mullard 12AX7A’s, and Electro Harmonic 6SN7 tubes. This is a complete set from CJ for a whopping $475. When I asked the rep, the person answering the phone, about the use of the different manufactures, she didn’t know if it was a supply chain issue or just the preferred pairing. Unfortunately, she didn’t have any background information or knowledge. I can purchase a complete set of Tung-Sol from Upscale for $353 - Kevin’s grade. Your thoughts and knowledge regarding this matter will be greatly appreciated!

[JoshT289]

Rubicon,

If it were me, I'd buy from Kevin or Jim McShane.

Regarding power tubes, if you stick with 6550 tubes, I would consider the Sovtek 6550WE over the Tung Sol version based on advice from Jim, the lower price, the fact that ARC uses them as replacements for its 6550 amps these days, and user reviews that are very positive. But I have not compared the two. You might also reconsider the Tung Sol KT120. There are lots of positive posts about that tube in CJ amps, and I just read a post in which Big Dog said they transformed the sound of his MV60SE.

For some reason, I'm curious about the Gold Lion KT88 reissues at some point in my 11A, but I'm just throwing that out there in case you want even more things to ponder on, lol!

Josh

[Rubicon15]

I’m going to double check and verify what tubes are currently in my MV60SE. I believe, I’m running all Tung-Sol with the 6550’s. What are your thoughts regarding the use of three different manufactures? From my limited research and talking to a CJ tech a few years ago, using the same manufacture for the input and output tubes were recommended. In this case, if CJ has a supply issue, I can find matched, tested, and graded tubes at Upscale. I still hope a tech from CJ returns my call. Based on the conversation I had with the person answering the phone at CJ, I feel more comfortable purchasing tubes through Upscale at this point. CJ could not tell me if they approved the use of KT120’s. Note: I would easily spend an extra hundred dollars if CJ provided a higher level of service. At this point, they have sadly been no help whatsoever. Back to the use of three different manufactures? Good idea, bad idea, not recommended??? Thoughts

[AnotherJohnson]

Technically all manufacturers are building to the specs of the tube type, within tolerances.

If all three manufacturers are “close enough,” or if all three have synergistic variances, or if your system is forgiving, or if your system isn’t particularly revealing, it should be fine.

Buy ‘em ‘n try ‘em.

[Rubicon15]

Follow up question seeking very candid feedback. I understand the technical aspects of manufacturing. I have a technical background. However, based on the efforts (testing & grading) vendors go through like Kevin at Upscale, all tubes are not created equal. Just like other industries, the question is, is using three different manufactures considered a best practice? In this situation, I can easily find all of the tubes manufactured by the same manufacturer.

[AnotherJohnson]

Since CJ amps allow individual tube biasing, it’s not as big a deal as it might be for AR.

If it were me, I would replace them all with new high quality of the same brand. To advise otherwise would be considered quackery by most.

Could you tell the difference? I dunno … it depends on a lot of other factors.

Platinum grade from Upscale is what I would buy for myself.

I would not waste money on cryo treatment.

[AnotherJohnson]

If you’re asking about mixing one brand of small tubes with another brand of power tubes, that’s fine. No one would flinch at that.

[Rubicon15]

I love the quackery comment and totally agree. I think I will pull the trigger and order tubes from Upscale. According to their website, all Tung-Sol 6550’s are platinum grade. I think I will order “Kevin’s Stash” grade for the 4 input tubes unless the other guys on this thread think I’m crazy or have a better idea based on their experience and knowledge base.

[AnotherJohnson]

I’ve never gone for the “stash” upgrade. You’ll have to report on your impressions.

[Joe Appierto]

Totally agree with the quackery comment regarding output tubes although as usual there's at least one exception to the rule. The very first tube amp I owned was a Class A SEPP (Single Ended/Push Pull) design. It was the kind where changing the bias on one tube affected the others in that channel. Anyway, it used 5881/6L6GC tubes. I found using all Sovtek 5881 (this was back in the 90s) lead to a kinda laidback sound but using all SED 6L6GC tipped the frequency up too high for my taste yielding a "hot" sound. After some experimentation the happy medium for me was 2 Sovtek and 1 SED per channel.

But that was the only amp with which I ever tried this mix'n'match approach.

[Rubicon15]

Quick question regarding compatibility and sonic qualities of tubes I currently have in my Upscale online cart. Just to verify, the 6SN7 is exchangeable for the Tung-Sol 6SN7GTB, and the 12AX7A and 12AX7 are also interchangeable. This would hold true for 99% of the applications for these tubes. Are the sonic qualities also the same?

[AnotherJohnson]

Totally agree with the quackery comment regarding output tubes although as usual there's at least one exception to the rule. The very first tube amp I owned was a Class A SEPP (Single Ended/Push Pull) design. It was the kind where changing the bias on one tube affected the others in that channel. Anyway, it used 5881/6L6GC tubes. I found using all Sovtek 5881 (this was back in the 90s) lead to a kinda laidback sound but using all SED 6L6GC tipped the frequency up too high for my taste yielding a "hot" sound. After some experimentation the happy medium for me was 2 Sovtek and 1 SED per channel.

But that was the only amp with which I ever tried this mix'n'match approach.

It was that elusive serendipitous variance with some help from Messrs Fletcher and Munson.

[AnotherJohnson]

Tubes don’t really have sound on their own. The sound is dependent on the specific system.

This link makes an effort to explain it.

http://aeaaudio.com/why-does-changing-t ... the-sound/

If you take 100 samples of a particular brand and model tube, tolerances and manufacturing differences are real. If you stick them in a McIntosh, conradjohnson, Prima Luna, Audio Research, or other brand, which of the 100 you like best will vary.

The tubes are also called valves by the Brits because they control the flow of electrons from the power supply to the load. The power supply and the load impact how the tubes sound too.

Most of your questions will only have definitive answers for your ears and your system.

[AnotherJohnson]

Actually, the sound of a tube is often a negative artifact. Hiss. Snap, crackle, pop. Microphony. Imbalance between twin sides.

I think that’s why Upscale, CJ and others listen to their tubes.

The best tubes are silent partners, neutral valves, following the volume control, adding nothing.
Tubes are not supposed to be tone controls. I’ve often wondered if what often passes for the difference between one tube and the next is actually just variations from linear performance that someone finds pleasing, or differences in gain response.

People explain that tubes overload more gracefully than solid state, favoring even order harmonic distortions over odd.

How often do you really want your amp to be driven into distortion?

Tubes are fun. Tube gear can sound great. It does give you a warm and fuzzy feeling … but the music should be neither warm nor fuzzy unless it was the intent of the original artist.

[Rubicon15]

Today, I verified that CJ was recommending three different manufactures (1 for power tubes and 2 different for the input) do to supply issues. I decided to stick with one manufacturer, Tung-Sol for all 8 tubes. I pulled the trigger and placed an order with Upscale. I upgraded the 4 inputs to Kevin’s Stash. The 6550’s were only available in their platinum grade. I will let everyone know how they sound after I get a few hours on the tubes.

Thanks again!

[Big Dog RJ]

Yes, when I did have the MV60SE it came fitted with 6550C tubes from SED (Svetlana Electron Devices) for those who don't know what SED stands for. The 6SN7 tubes were from EH (Electro Harmonix) and the input tubes were also from EH. It was mighty fine driving Quads, Maggie's and a pair of refurbed Apogee's until...

It was time for an output tube change. I'd never tried KT120's before. Always used to 6550C's and KT90 type back during CJ's hey day of their Premier 8A monoblocks and the big Manley Labs reference 350's using 16 KT90's.

Only after a decade or so was I recommended to try these new KT120's from Tung Sol, and so I did! It definitely transformed the overall sound of the MV60SE to such an affect that it sounded way more powerful than a 60w rated stereo tube amp. Apart from the extra detail in soundstage depth and the presence in finesse plus that better control factor it has over transients, it was basically a much fuller sound. The LF was just fantastic, it had a much more solid thump to it compared to the 6550's.

However, as AJ very importantly pointed out, the tube itself may not add significant improvement, rather it's the type of system it's installed in that delivers the most significant improvement. Whether or not there's an improvement is another factor that needs to be determined. So at the end of the day, it all depends on the primary owner if he/she actually prefers this new type of sound.

The good thing with the MV60SE is such that it was built on CJ's Premier standards, which included fine input & output transformers that could handle higher current requirements. Therefore, putting in KT120's was no issue. Also, the MV60SE tube cage was designed in such a way that it can accommodate the much taller and larger KT120's compared to other amplifiers, where their tube cages touch or aren't high enough... anyway, I guess this is not an issue since Rubicon has already placed an order for 6550's.

Let us know how it goes and what improvements you come across. Cheers, RJ

[Rubicon15]

I installed the new tubes a few days ago. I have less than 10 hours on them. The tubes definitely have more power. The volume can be set to a lower setting with a similar output level. The soundstage has improved slightly. The amp sounds a bit cleaner or more transparent if that makes sense. I’m going to have my old tubes tested to see how much life they have left in them. Based on the limited information still visible on the power tubes, they were made in Russia in 1949. Since I purchased the amp used several years ago, I don’t know how many hours any of the old tubes have on them.

I’m looking forward to getting more hours on the new tubes and listening for subtle changes.

Different topic. What is the best way to clean the aluminum plates on CJ equipment? I routinely use a swifter for dusting but I would like to clean the faceplate of my DV-2b without damaging the unit.