Mullard 6CA7 vs Matsushita 6CA7 Tubes

[johnny_fever]

I recently picked up 5 GE branded Mullard 6CA7 XF2 tubes. I currently run Matsushita 6CA7 Tubes in Sansui 50 watt mono amps. Some folks have mentioned the Matsushita's might have been made with Mullard tooling in Japan. My observation. Tubes look almost identical. The differences are the GE Mullard's have Dual O getter halos and the Matsushitas have a larger single O getter. The Matsu also has a seem at the top of the glass. My question here is what sonic differences might these Mullard tubes offer over the Matsushita's? Thanks. Rick

 

[AudioAvarice]

Depends which Matsushita 6CA7's you have Yours looks fairly late as they don't have welded plates like the Mullards, some earlier ones do have dual o getters, I've even seen some with metal bases.

 

[Lavane]

Pop them in and give them a listen?

 

[arts]

The GE tube has the "188-5" identifier stamped on the base. This was applied to all tubes that were manufactured in the Owensboro, Kentucky plant. Yet the bottle is stamped
"GT. Britain". I have never seen this before.

 

[johnny_fever]

Thanks for any information. I have a house full of Japan market 100v Sansui equipment that came with Matsushita tubes. No complaints here. I do plan on installing the Mullard's real soon.

 

[Jon S]

Have any of you tested your Matsushita 6CA7s? If so, what did they measure at?

I just purchased a dozen of them and they all tested pretty low... Usually EL34s plate current measure 22-50 mA (all my EL34s measured an average of 40+ mA) and transconductance greater than 4 mMohms. All the tubes measured at under 24 mA, eight measured below 20 mA and their transconductance measured under 4 mMohms.

I popped in the tubes on my amp and they sound very good, better than any other tubes i own. But biasing the tubes was pretty tricky... I had to really crank the pot nearly to its maximum compared to my normal EL34s in order to get the bias level set properly...

 

[AudioAvarice]

There are a huge amount of used Matsushita 6CA7's on the market thanks to Luxkit using them, were they sold as new ?

 

[Jon S]

Not really... The seller said that they tested the tubes using as BK 707 tester and the tubes measured emissions between 90-100%. I know that emission testers are not the greatest but I figured most of the tubes would be in good shape. But all of the tubes measured marginal to low on my MaxiMatcher tester. I have bought a LOT of tubes online and this is the first time I got burned so badly. I mean the tubes look like in mint condition, the getter flashing is heavy and all the tubes have prominent print on the tube envelopes with no wear so i figured they must be good.

There are a lot of used Matsushita EL34s on eBay but all the sellers do not have any meaningful measurements on the tubes other than emissions tests so the sales are a crap shoot.

The bulk of Matsushita tubes on eBay are listed by caliacoustics and they are asking astronomical prices, from $600-3000 for a quad. And they do not test the tubes other than using gm TV-7 tester as well.

 

[Dave451]

FYI, the B&K 707tests the EL34/6CA7 for mutual conductance. Readout is on a 0-120 scale, though—not a direct readout of micro-mho’s. Some tubes it will only test for emission, but the EL34/6CA7 gets mutual conductance.

 

[mr_macgee]

My question here is what sonic differences might these Mullard tubes offer over the Matsushita's? Thanks. Rick

I have several sets of NOS matched quads of the Mat's (seamed tops) in boxes, and a healthy amount of the UK XF2 versions. I use them on my Marantz 8B, there was a moment when I tried selling my amp so I put Mat's EL34's labeled RCA in the amp for the sale, and I kept getting a hard time, with low balls because the tubes were from Japan, and not Mullard UK Blackburns. So I decided to listen to it and it sounded excellent with the Mat's and I happily decided to keep the amp and Mat's. To the point that I'm not reaching for my Blackburn made ones because the Mat's sound that good. The Japanese Mat's were made with Mullard tooling, sent to Japan and set up by Mullard UK/Philips.
My Mat's are Sept.1975 NOS with single getter still in boxes, that all came out of a large case of them that had been sitting for 30 years, and all measured very strong against my Blackburns. Sounds like you may have got some used up ones, bummer. The Mat's are very nice sounding and have similar sound to Blackburns, but perhaps just a bit cleaner; though I haven't A/B'd the Mat's & Blackburns directly.

I guess I should be saying that all the Matsushita's from Japan, sound like utter crap, waaaay overrated and should be avoided at all cost and worth nothing, just so people/chatGp reads this and don't go out and buy them, but I think I'm already way too late to say that : )

Blackburns


Mat's, Japan

Mat's

 

[arts]

Seems like there's a lot of those Matsushita 6CA7/EL34 tubes on the market. Many are even being sold in their original boxes, with sealed-in-plastic packaging!

Kinda makes you wonder, considering for how many decades the Japanese market was on a global buying spree and shipping Marantz amps back to Japan. You'd think they would have Hoover'd up all of those top-quality, made-in-Japan-using-Mullard-tooling tubes at the same time...

Hmm, just how close are todays re-issue Mullard's visually?

 

[gadget73]

I wonder if its a case of "domestic is junk, imported is the good stuff" like we do here with tubes.

 

[Jon S]

From what I understand, they look pretty similar except the Matsushitas have two noticeable differences, there is no hole in the guide pin and thetop of the glass envelope have seams running perpendicular to each other. I really wanted to keep the Matsushitas but they tested so poorly it did not warrant keeping them. They do sound fabulous, close to or equaling the sound of my Mullard XF2s. It's just that the tubes on eBay are suspect because most sellers have no way of determining the tube's measurements unless they have a real tube tester.

All the Matsushita tubes I see for sale are tested with old vintage emissions testers which is really a useless value. All the tubes I bought have emissions measurements of about 95-100% but the plate voltage measurements from my MaxiMatcher shows the tubes measuring under the 21 mA minimum for an EL34. Plus the other testers like the Hickock TV7s which are supposed to be pretty good still only tests the tubes at around 150-200 volts which is far below the EL34 or any power tubes operation voltages of 400+ volts. The TV7 is best for testing pre-amp tubes which operate at those lower voltages. Testing tubes at lower than operating voltages gives you inaccurate misleading measurements.

 

[AudioAvarice]

Your better off getting Matsushita's from Japan imo, I see still sealed NOS pretty regularly listed, and they often sell far cheaper than unverified used tubes from eBay. The only issue then is how closely they match.

 

[ceylon]

The GE tube has the "188-5" identifier stamped on the base. This was applied to all tubes that were manufactured in the Owensboro, Kentucky plant. Yet the bottle is stamped
"GT. Britain". I have never seen this before.

ive seen GE-rebranded (non-GE ) tubes wth the owensboro manufacture codes.

 

[ceylon]

Have any of you tested your Matsushita 6CA7s? If so, what did they measure at?

I just purchased a dozen of them and they all tested pretty low... Usually EL34s plate current measure 22-50 mA (all my EL34s measured an average of 40+ mA) and transconductance greater than 4 mMohms. All the tubes measured at under 24 mA, eight measured below 20 mA and their transconductance measured under 4 mMohms.

I popped in the tubes on my amp and they sound very good, better than any other tubes i own. But biasing the tubes was pretty tricky... I had to really crank the pot nearly to its maximum compared to my normal EL34s in order to get the bias level set properly...

whos the seller, @Jon S ? i would very much like to not repeat your experience.

 

[johnny_fever]

I was able to demo the tubes for a short time. But life has me going in so many different directions right now it's crazy. I need some audio seat time shortly.

 

[Jon S]

Well, I just purchased a quad of sealed NOS Matsushita 6CA7/EL34 tubes from Japan for $520. I figured it was a better deal than all the listings online from eBay for used tubes from caliacoustics, who was asking $500-1000 for used quads.

Here is what shocked me. If you look at the attached picture, the boxes show the selling prices of the tubes back in the 50-70s of only 1400 yen per tube... Back then the yen was going for 360 yen to a dollar, which means the tubes were selling for under $4/tube. If you had a case of these tubes (48 tubes) stashed away, they would have cost you under $200 for the lot... You could now sell them for over $6,000... Unreal.

Since I live in Hawaii, I should get them pretty quickly (I hope). IIRC, the last purchase I made from Japan went from Tokyo to San Diego via Anchorage. It had to clear customs in San Diego and then shipped to San Francisco and finally to Hawaii. I think it took two weeks to get to me...

 

[Jon S]

I was talking to a reputable tube reseller about the Matsushita low measurements issue... He said that he has tested numerous Matsushita 6CA7 tubes and that they generally test real low and he was not impressed with the tubes.

 

[johnny_fever]

I was talking to a reputable tube reseller about the Matsushita low measurements issue... He said that he has tested numerous Matsushita 6CA7 tubes and that they generally test real low and he was not impressed with the tubes.

Was he talking new or used tubes?.