#6dj8

[takmiblog]

6DJ8 Mini Watter (ミニワッター) アンプ：その後編

6DJ8 Mini Watter (ミニワッター) アンプですが、完成して2週間ほど使っています。 聞き込んで見て分かったのですが、感覚的な表現ですが、「大人のアンプ」です。地を這うような低音や、ナイフエッジの様なシャープさはありませんが、音を正確に鳴らします。そこに、各真空...

[audio-luddite]

New(ish) tubes.

A package arrived yesterday.  A set of 5 Tesla E88CCs or are they Ecc88s or are they really JJ counterfeits? I popped the full set in the AR and started a burn in.  You just have to let it run.  I played a familiar album, and yes it sounded a bit different. Was it the fact they had to burn in, or the fact that these were better / worse?

The story is stupid complex.  JJ brand bought the machines to make tubes from Tesla.  They set up a plant and make them.  The design is the same the difference is the article of faith that the old factory just made better stuff.  These tubes may be NOS (New old stock) from the real Tesla factory. Or they may be knock offs.  Or they may be JJs labeled by an unsavory person to get more money for them.

I figure my risk is low.  Of the several alternatives most indicate they should be no worse than my old set of JJs.  I figure its a win that they work fine so far.  They do look oldish judging from the patina on the pins.  The rest is shiny.

My AR preamp has five tubes.  They are the only active signal gain devices in the device. That is really simple you know.  The AR SP9 mk3 has 13 active devices in the signal path two of which are tubes.  Some of these wall wart preamps have 2 tubes and maybe some transistors.  Those being too simple.

The phono section uses three, two for gain and one as a buffer interposed with the line section as I understand it.  Some preamps like the old dynaco  PAS3s had no buffer so theoretically not as good?

So the records are playing, sound comes out. First step we are OK.  Just have to do more of that then play the usual suspects.  Gotta get familiar all over again. 

I have said it many times, but it really is silly that different tubes sound different.  It adds needless complication to an already complex hobby.  Still the music sounds good.

[audio-luddite]

Vacuum Tubes

In the Olde Country they call them thermionic valves. I think that is charming and actually a good clue to how they operate.

A vacuum Triode for example has 3 component features.  A source of electrons, a receiving anode plate with a grid of wires between.  It is wonderfully mechanical.  The electron source is a glowing filament just like in an old light bulb.  The target is the Anode plate and the flow of electrons from the filament to the anode is controlled by the charge on the grid.  It works exactly like a valve.

The differences between one tube type and another is the construction and arrangement of these bits.  A given type is pretty much the same from any source.

Those with an irrational love for these things in audio equipment often say that tube equipment is perfect or almost so.  Solid State is nasty and solid statey. Yet they will enthusiastically admit that different brands even different production runs of a single tube type sound very different from one another.  I have said many times before that if they were as good as so many believe this should not happen.

The golden age of tubes was in the1950s to 1960s.  TVs and radios and audio equipment had many choices of manufacturers and types.  They used them in computers and supersonic jets.  When transistors bulldozed along the tube factories were shut down and the equipment sold off, scrapped, or worse.  In most places.

In China and behind the Iron Curtain factories kept making them as they still used them in computers and in fighter jets right up to the 90s.  By then the Audiophile world fully embraced them and kept production going.

Today if you want to buy new made tubes for your classic or newer tube amplifiers and preamplifiers you are going to buy from Russia, China, or Slovakia or there abouts.  If you have a tube machine as I do it needs to be fed glass. Tubes will last a few years in most cases. My preamp takes 6DJ8s also known as ECC88 and E88CC and 6922 depending of where it is made and to a degree the quality.  The better ones qualify if that is the word to be called 6922.  Arguably if they work OK they should do the job in a circuit consistently.  They really should not sound different, but they do.

I check prices and keep an eye out for deals.  The 6DJ8 can cost as little as $13 to as much as $200 Each!  The really expensive ones are 60 year old New Old Stock (NOS) made in the USA or in Europe by big electronic brands of the day. Personally I would not buy a 60 year old vacuum tube as well they do leak from time to time and can you be sure they were treated gingerly for that entire time? That and they are stupid money.

I was on a tube vendor site and was reading the buyer comments.  That led me to a guy who did a review of about a dozen different brands and labels of this type. He has a tube preamp that was a kit I am not familiar with.  He fed it sets of tubes and commented on his observations.  The interesting thing was how different the tube sets sounded.  I believe he was being honest and really heard these things.  What was not clear to me was why.

If you do not know already the sound of a given component depends as much on the components around it as the thing itself.  A phono cartridge can sound radically different depending on the input impedance of the preamp.  Every stage in the chain will react in some way to the bits it is plugged into.  Kit equipment is simpler and less subject to testing and such than big gun manufacturers so if this guy was hearing subtle things it could be for reasons other than the physical tube he was using.

Cut to the chase.  The reasonable price tube this guy likes was the JJ brand made in Slovakia.  It did nothing poorly and most things OK to fine.  That was good cuz that’s what is in my SP12.  A bunch of fairly expensive NOS tubes did not do so well.  The ones he liked better than the JJ did things really well.  Still stupid money.

But.  He was doing his tests in a line stage listening to CDs. He did not review a phono stage. I could not find what his cd deck was.  So how valid was the whole process?

I guess what he did succeed at was to demonstrate that things that should work exactly the same inside the same machines do not.  So are reviews of big name golden ears handicapped by the tubes the manufacturer chooses?  Can even a big player like Audio Research afford to test and burn in full tube sets?  I know at least one model of AR device got an “upgrade” that was mainly switching the source of the tubes.

This unicorn hunting involves a lot of rabbit holes.

[osamub]

#tubeamplifier #amplifiers #headphoneamp #6dj8 #6n23p #ヘッドホンアンプ #真空管アンプ #mobile #ポタアン

[osamub]

#tubeamplifier #mobile #headphoneamp #6dj8 #6n23p #tubeamp #amplifiers #handmade

[vtubeaudio]

Details 4 Philips USA 6922 Premium Sound Audio Tubes All testing above 100% Gm for this ty

(via Philips 6922 6DJ8 ECC88 JAN Philips ECG Quad (4) Vacuum Tubes VTC)

[reallyclever-blog]

Tubes and LED bokeh

Tubes and LED bokeh

Two vacuum tubes: one Telefunken EL86/6CW5 (left), and one Hewlett-Packard 6DJ8/ECC88 (right).

Lit from above camera left (about 90 degrees to the shooting position) with a clamp reflector lamp and a 23W daylight-balanced CFL bulb, plus a foamcore reflector camera right. Background lights are LED Christmas lights off in the distance.

Nikon D5000 AF Nikkor 50mm f/1.8D

Posted by Richard Wintle on…

View On WordPress