For sale is a single ended stereo el-34 amplifier based on a no-name Chinese kit amp.I have modified the circuit to use a SRPP 6sn7 tube input into the single EL-34 power tube. A full schematic of the power supply and signal section will be included with the sale. Most of the circuit has been modified, and I am happy with the sonic results. I used the kit power transformer, output transformers, chassis and power entry module. I also used one of the power capacitors, but essentially all else are parts I substituted. The steel chassis is 14.25 x 9 x 3 inches and has a bottom plate with rubber feet. It has wood side panels, which I lined with copper shielding tape for better overall shielding. There are gold plated rca input jacks, and plated brass 3 way binding posts, as well as the IEC connector with fuse on the back. The speaker binding posts are small, and work best with bare wire, banana or pin terminals rather than spade terminations. The On-Off toggle and stereo volume pot are on the front. 5 ceramic octal tube sockets are mounted as shown. The circuit is all point to point, no circuit boards. Input wiring is shielded to the 6sn7 tubes. All other wire used that is not coming from the transformers is teflon insulated silver coated mil-spec copper wiring. There is a smoothing choke and multiple capacitor filter sections. The circuit is tube rectified by the slow turn on 5V4GA tube. The voltage to the power tubes is about 390 vdc. The EL-34 tubes are pentode connected with filtered screen supplies and are cathode biased, making a measured 6.5 watts output at clipping. Plate dissipation is 82% so the tubes should have good life expectancy. All heaters are AC, with separate windings to each el34. The heater winding to the RCA matched 6sn7 tubes is elevated about 76 volts for decreased hum. The coupling capacitors are CDE 940 types which have a nice sound. Overall, this is a nice, quiet single ended amplifier of about 7 watts, with good frequency extension and a relaxed presentation. It has been reliable in use, runs a bit warm, and has been a pleasant surprise as to how it all came together. I will sell with the included NOS testing rca 6sn7gtb tubes, matches EH el-34 tubes and the GE 5V4GA tube. Shipping will be via insured ground shipping. I will ship to the Continental USA only. Sale is final, as for all older or DIY electronics.
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