15 Watt Push-Pull 2A3 Amplifier XP15940, XP15952

• alternative name: Wholesale Radio

This new model Lafayette Push-Pull 2A3 Amplifier is the ideal unit to use wherever moderate power with outstandingly fine tone quality is desired. Its power output is such as to particularly fit it for use in the average medium sized dance hall, theater or other gathering place. It is for these reasons the most popular unit of this popular line, and it adequately fulfills the demand for an amplifying unit that can be depended upon for satisfactory day-after-day performance in installations of this character.

The circuit used is of the direct coupled type, which is superior in both gain and frequency response, but which is rarely used in amplifiers at anywhere near this price, because it is more expensive to build due to the high voltage required. It is only because a ready consumer acceptance makes possible quantity production that we are able to offer an amplifier of this type at this price. A 57 pentode is direct coupled to a pair of 2A3 triodes in push pull. A 5Z3 high vacuum tube is used as rectifier. An exceptionally high gain of 80 db. with an output of 15 watts (18 watts peak) is obtained. This gain in the majority of cases eliminates the need for pre-amplification when a carbon microphone is used. 

The frequency response of the amplifier is particularly good due to the unique method of neutralization employed. The maximum variation, from the average level of 80 db. being only one db. plus or minus from 40 to 10,000 cycles. It is impossible, due to the limitation of space, to ilustrate the actual curve obtained, however, this curve is shown in our "Sound Manual".  Field supply for four 1500 ohm or two 3000 ohms fields (7 watts each) can be obtained from the amplifier, thus eliminating the need for separate field exciters and thereby considerably reducing the cost of the complete installation. 

Input impedance of the amplifier is 500,000 ohms and permits the direct connection of high impedance phono-pickups without the use of matching transformers. Two models are available —one with, and the other without, output transformers. Output impedances with the transformer are 2, 4, 8 and 15 ohms for speaker voice coils. Also 250 and 500 ohms for line transmission application. When supplied without the transformer the output impedance of the amplifier is that of the plate loads required by the tubes—5000 ohms. 

All components used in the construction of the amplifier are considerably oversize and will safely carry far greater loads than will ever be placed upon them. The chassis is of steel and is finished in black crystalline lacquer, both inside and out, for protection against rust. 

XP15940 — Lafayette P.P. 2A3 Amplifier less tubes and output transformer.  $26.50 USD.

XP15952 — Lafayette P.P. 2A3 Amplifier with output transformer, less tubes  $29.95 USD.

Kit of Matched Tubes  $3.00 USD.

Here you find 2018 models, 1876 with images and 425 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Lafayette Radio & TV Corp; New York (NY)