It works together with the AC negative feedback from the output of the audio transformer to the cathode of EF86. These improvements enhance the flatness of the frequency response and also reduce harmonic and waveform distortion, as well hum and noise.

Sep 6, 2014 · Mullard Single-Ended (SE) EL84 Tube Amplifier Schematic. This is the classic single-ended EL84 schematic from Mullard. The input stage uses a EF86 to drive a Mullard EL84. The power supply uses an EZ80 (6V4) tube rectifier. For more information about tube based power supplies, see the article Power Supply Design for Vacuum Tube Amplifiers.

May 7, 2023 · Just as a point of reference, My small SEPs use an EF86 in pentode mode to drive a pentode-mode 6V6 with a 5K load. Global feedback is about 19dB, and sensitivity is 0.9v input for full output. The 6BQ5 being discussed here exhibits higher gain than the 6V6, but the EF86 can be reduced from X100 to roughly X30 by leaving the cathode unbypassed.

Mar 14, 2020 · I highly recommend trying a CFB SE amplifier. It retains a lot of SE magic (immediacy and intimacy), while having clean, punchy bass and lacks that typical high level SE distortion most amplifiers do (for good). The DF of this current prototype amplifier is 7,8. I can even go higher if needed.

Sep 6, 2014 · Single-Ended (SE) EL34 Tube Amplifier Schematic with EF86 input stage. The power supply is solid state. The filament supply is regulated at 6.3V using a LT1085 voltage regulator.

Aug 20, 2021 · EF86 – 300B XLS SE Amplifier build Here is a very nice build from Dan Kercher on his contraption of the 300B amplifier with auto bias. The driver is an EF86 with SiC diode biasing, the topology is a hybrid mu-follower and a source follower drives the output stage.

The amplifier, which is operated from AC mains, uses three Mullard valves: an EF86, an EL84 and an EZ80. The comparatively high sensitivity of the amplifier (100 mV for 3 W) permits the use of all types of crystal pick-up head and allows, if required, the use of equaliser networks between the head and amplifier.

Jan 23, 2011 · The pre-amp has an EF86 slot in V1 with Merlin's Triode/Pentode Morph control (labelled "Mojo" on top, in case it doesn't work and I have to think of something else to change it to). This is followed by a 5F2A tone stack and Vol and driver stage.

The EF86 is the standard early stage audio pre-amplifier valve. This exhibit was made by Mullard in Great Britain. Mullard designed the EF86 and it took over the frond end stage of audio amplifiers from the octal EF37A .

Low noise pentode intended for use as R.C. couPled A.F. EF86 voltage amplifier, particularly in the early stages of high-gain audio amplifiers, microphone pre-amplifiers and magnetic tape recorders.