หลอดกลางขวาเอามาแทรก ...บอกว่าเป็นMullard EL84 ไม่ใช่ครับ ถ้าใช่รุ่นนี้ต้องมีรูกลมตรงกลางรูเดียวนะครับ ....ยังมีอีก เอาแบบหลอดสองรูกลางมาหลอกอ้างว่าMullard แต่ที่จริงเป็นหลอด Tungsram ฮังการี คนละเกรดกันเลย.....
มาดูTeleกันบ้าง .....รุ่น ทรงเหลี่ยมอย่างไปแตะนะครับ ลองอ่านข้อความนี้แล้วจะเข้าใจชัดผมคัดลอกมาจากเวป Tele USA อีกที
It is not exactly clear which company first introduced the EL84/6BQ5. The 12-watt moderate end pentode was mentioned in the 1953 European Telefunken tube catalog. The EL84 was developed to replace the pre-war and early post-war tubes
the EL11 and EL41.
Most EL84 tubes that didn't meet the 12-watt plate dissipation test ended up as EL82 tubes with specked 9-watt power dissipation. Philips/Valvo followed in 1954 with their version of the EL84, introduced at the London Radio show in September of 1954 under the Philips Mullard brand.
As Telefunken introduced the EL84 in Europe, Tungsol offered the 6BQ5: a beam power tetrode very similar in specs to the Tele EL84. The only difference is that the cathode is connected to pins 1 and 3, whereas the EL84's cathode connects only to pin 3. In the 1960s the EL84 was used in nearly every European class-A table top radio, delivering 5.5 watt single ended or 12.5 watt in push pull at 6.5% distortion.
The EL84 was never considered a high quality tube; due to the economic construction of the electron system, the physical possibilities were pushed to a limit. Placed in the hands of a guitar amplifier designer, the EL84 was destined to write rock history.
Until 1965, Telefunken produced the EL84 in its Berlin factory with its very distinct round plate shape. Later, Telefunken outsourced the tube's production to East Germany because RFT could produce an entire tube for the same cost that Telefunken paid for the raw material.
Telefunken USA is proud to offer a limited quantity of those labeled Telefunken tubes, made in the former east block in the late 1970. An upgrade for any Vox style guitar amp. Not as clean as the original round plate design, but delivers smooth harmonic distortion without equal in NOS or in production tubes.
