Feb 26, 2017 · I've been thinking about using a 4P1L in pentode mode to drive a 300B, sort of like a WE91 but with a directly heated pentode as the driver tube. Anyone tried this?

Russian audiophile 4P1L tube with direct heating & lowest anode voltage. The pentode is fine up to 100 Mc/s. Equivalent to the 4L1S / 4LS1. Copy of RL2 / 4P6 Wehrmacht tubes. New, old stock OTK stamp (State quality control) Svetlana factory, Saint Petersburg.

Russian audiophile 4P1L pentode tube with direct heating and lowest anode voltage. Great sound! Equivalent to the 4L1S, RL2, 4P6.

Russian audiophile 4P1L tube with direct heating & lowest anode voltage. The pentode is fine up to 100 Mc/s. Made by SVETLANA plant. Equivalent to the 4L1S / 4LS1. Copy of RL2 / 4P6 Wehrmacht tubes. Name: 4P1L; Type: pentode; Application: oscillation and power amplification up to 100MHz; Cathode type: oxide,direct heating; Envelope: glass;

I’ve started to experiment with the Loctal DHT 4P1L pentode many years ago. 4P1L is greatly praised for its awesome tonality and great linearity in triode mode. This is single amplification stage, direct coupled input, filament bias and line output transformer coupled preamplifier.

Jun 29, 2012 · Looking at the specifications, the key points to highlight are: Maximum operating voltage 250V anode or screen. I became aware of this valve when Anatoly (a.k.a. Wavebourn) recommended the 4П1Л directly heated pentode which was used in military transmitters. It is very popular now among Russian audiophiles.

This is a Soviet copy of Wehrmacht RL2/4P6 tubes and probably last DHT pentode ever made. Couple sweet spots can be found at anode voltages of 160V and 240V – ideal for pre-amp and amp operating points. This tube definitely needs more investigation.

Tube 4П1Л or Röhre 4П1Л ID19676, Vacuum Pentode, Loctal-8, B8G (Sylvania, 1938) and Power/Output shown. Radio tubes are valves.

Feb 17, 2011 · Improved Pentode driver by adding a parallel resistor to the gyrator output and managed to halve distortion: THD=0.27% @ 200Vpp, 4P1L is a great driver candidate indeed! Is there an advantage of a DHT pentode, vs a 6c4pi ? I guess I always considered the little space tube as being a better driver.

The 4P1L Pentode is designed for oscillation and power amplification up to 100 MHz. The 4P1L is a Very Good choice for Audio Applications.