One of my favourite hobbies is to collect pre-amp audio tubes of ECC82, ECC83 and ECC88 family series. The reason why I go for these series is very simply, my amplifier, DAC and pre-amp are all using these types of audio tubes.

Though this hobby of mine has been going on for some years, by now my collection is still considerable small. Why? My answer is simple; I always have budget constraints when buying new stock. Being a father of 2 kids, my priority for spending money is always family first followed by individual necessities and hobbies last.

So, I am sorry to tell you that I do not have those expensive and antique NOS (New Old Stock) tubes, whichever you name it. For hobby sake, I have collected a variety of low to mid-price, new and NOS audio tubes of different brands. If you are interested in my pathetic collection, please carry on reading.

My first encounter of audio tubes could be traced back to seven years ago when I bought a Unison Research Triode 20 integrated amplifier. This Triode class A amplifier uses one ECC83 tube at input, two ECC82 tubes at output and four EL34 tubes for power.  As “two” means “easy” in Cantonese, I choose ECC82 family series to begin my tube collection.

ECC82

As learned from some Hi Fi magazines, audio tubes coded ECC82 is of the same family as other tubes coded 12AU7, 5184, CV4003, M8136, 6189 and 5963. In other words, these tubes are inter-changeable for use in audio equipments. Out of curiosity, I spent some efforts on getting 1-2 pairs for each of the named codes for my collection. This was how I started my tube collection hobby.

Code “ECC82” is widely used by tube manufacturers in Europe, whereas American manufacturers commonly use “12AU7”.  What do I have in my collection?

Mullard ECC82

Mullard ECC82

One pair of ribbed plate tubes manufactured by Mullard of Great Britain. It has a small shield logo but without the word “Mullard” inside. Some said that the tubes of such logo were made at the latest production stage of Mullard in early 70’-80’.

The earliest Mullard tubes had the word “Mullard” inside of a big shield logo. The tubes of later production had the same logo of smaller size for differentiation. 

Telefunken ECC82

One pair of smooth plate ECC82 labelled Telefunken of Germany.

Original Telefunken tube has a diamond shape molded onto the bottom of the glass for identification. But, my pair does not have such diamond identification.

Telefunken ECC82

By looking at its plate design, I suspect that the tubes were manufactured by RFT (also in Germany) for Telefunken and released in markets under Telefunken label. On the another hand, I remember, one Hi Fi magazine ever said that in 70’-80’ Mullard  manufactured tubes for Telefunken as per their specifications. These tubes were printed with the unique date codes and logo of the original Telefunken except for no diamond mark at the tube bottom. So, are these genuine tubes or fakes? 

Mullard ECC82 Vs. Telefunken ECC82 (no diamond mark)

The Mullard ECC82 tube is superior in sound when compared with any one of those new tubes (12AU7) made in Russia and China. It also easily beats the old RCA 12AU7 grey plate tube of America, no sweats. But surprisingly, when comparing Mullard ECC82 with the suspected “fake” Telefunken ECC82, I found the latter one sounded more harmonic and musical, closer to my personal preference. On the other hand, the Mullard ECC82’s sound is inferior to its elderly brothers coded CV4003 and M8136 in my collection.

In general, the original Telefunken tubes are usually praised for their superb rich and well-balanced sound stage, but they do not have mid range charm of the Mullard tubes of early days’ production. Nevertheless, both are excellent tubes in great demand at high prices today.

RFT ECC82

Original Grade RFT ECC82

Let’s look into my collection again.  I have another two pairs of ECC82 made by RFT of Germany. The left photo below shows an ordinary grade one whereas the right photo below shows a military grade ECC82 .

The military grade tube was coated with word “RFT ECC82” in white colour. The ordinary one comes with logo and coated “RFT ECC82” in yellow colour. Both are almost of identical sound quality, which gives detail, balance and wide sound stage.

Military Grade RFT ECC82

Both RFT ECC82 have outstanding analytical treble but lacking in rich mid range and bass. Otherwise, it would be a good all round tube highly recommendable.

When time allowed, in my next article I shall continue with my collection of tubes coded 12AU7, 5184, CV4003, M8136, 6189 and 5963 that are of the same family as ECC82.