• Country
• Great Britain (UK)

• Manufacturer / Brand
• Leak, H.J.; London

• Year
• 1955 ??

• Category
• Audio Amplifier or -mixer

• Radiomuseum.org ID
• 162242

Click on the schematic thumbnail to request the schematic as a free document.

• Number of Tubes
• 5

• Valves / Tubes
• EF86 or Z729 6SN7 KT61 KT61 5Z4

• Wave bands
• - without

• Power type and voltage
• Alternating Current supply (AC) / 240 Volt

• Loudspeaker
• - This model requires external speaker(s).

• Power out
• 10 W (unknown quality)

• Material
• Metal case, TUBES VISIBLE

• from Radiomuseum.org
• Model: High-Fidelity Amplifier TL/10 - Leak, H.J.; London

• Shape
• Chassis only or for «building in»

• Dimensions (WHD)
• 11 x 9 x 6.5 inch / 279 x 229 x 165 mm

• Notes

• The TL/10 was introduced as a lower-cost alternative to the famous TL/12 but maintained a distortion rating of 0.1%.

  It was sold with Point One pre-amp featuring the new "Baxandall" feedback tone control circuit published in Wireless World, October 1952, Page 401, and so has continuous control of boost and cut, instead of stepped switches. 

  As with all Leak pre-amps, there are two gain stages each with shunt feedback. The first stage performs any required equalisation, and the second stage performs tone control functions.

  This amplifier was the first Leak amplifier to incorporate the "ultra-linear" output stage configuration (popularised by Hafler and Keroes from the USA in the early 1950s, but earlier proposed by Blumlein), and many consider the TL/10 to be much under-rated these days. Leak certainly did not skimp on the ratings or size of the transformers, as they are identical in size to the TL/12 Plus (and Stereo 20 in the case of the output transformer).

  This amplifier was also the only Leak circuit to use a single, common cathode resistor in the output stage (all other Leak valve circuits used separate cathode resistors for each output valve, which should reduce the DC unbalance in the output transformer). However, some TL/10's were issued with separate cathode resistors, individually bypassed as with other Leak circuits.

  Ten-watt Amplifier

  First introduced for export, the Leak TL/ 10 amplifier and "Point One" pre-amplifier are now available for the home market.

  Like the TL/12, the new amplifier uses a triple-loop feedback circuit with 26db in the main loop. Harmonic distortion. is claimed to be 0.1% at 7.5 W and 1,000 c/s, and frequency response +1 dB between 20 c/s and 20 kc/s. The damping factor is 25 and hum -80 dB referred to 10 W.
  The pre-amplifier, in addition to four fixed compensating channels providing basic correction for most British and foreign record characteristics, is fitted with continuously variable bass and treble tone controls. The main volume control is supplemented by an attenuator at the back of the set, for accommodating the variations in sensitivity of crystal, moving coil, and other types of pickups. An up-to-date feature is the provision of jacks enabling the amplifier to be used in conjunction with tape recorders for both recording and reproduction.
  The price of the two units is £28 7s.
  Wireless World April 1954, page 199.

   

   

• Net weight (2.2 lb = 1 kg)
• 18 lb 0 oz (18 lb) / 8.172 kg

• Price in first year of sale
• 28.35 GB £

• Literature/Schematics (1)
• Allied Supplement 143, 1955, pg. 51

• Author
• Model page created by Emilio Ciardiello. See "Data change" for further contributors.

• Other Models

• Here you find 46 models, 45 with images and 23 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Leak, H.J.; London