This is the Pioneer SX-1000TD which is one of Pioneer’s first all solid state receivers. There were a couple other similar models in the SX-1000TW and SX-1000TA. I believe the TA model actually had one tube in the tuner section while the all solid state TD version was a European release and the TW was sold in the U.S. Still, it also looks like the SX-1000TD was rebadged and sold as an Allied receiver in the U.S. as well.
The SX-1000TD is a 50 watt per channel receiver and has a great lates 60’s vintage look to it. It measures 15 15/16″ X
13 3/4″ X 5 3/8″ and weighs roughly 23 pounds.
The TD and TW models look very similar on the outside. Here is the TW model in a wood case:
The TA version on the other hand looks very different:
As I mentioned above, the TA version has a tube in the tuner section as well as two Nuvistors which are actually tubes as well so there are really 3 tubes in the tuner section. The Nuvistors were used in some RF applications during the mid 60’s because transistors were still hard to produce and were less than reliable. So, the TA version of the SX-1000 is a hybrid design and was probably produced before the TD and TW versions. Once Pioneer decided to go all solid state they quit making the TA and switched to the TW and TD instead. Obviously they redesigned the front panel as well as some of the circuitry as well. I’m not sure of the output of the TA version. I’ve seen most quote it at 50 WPC but I’ve seen others claim it is 20 WPC.
Another thing you may notice about the SX-1000 series is that they have strange speaker plugs on the back panel. The TD model shown above has an adapter plugged into the main speaker outputs. The adapters look like this:
You’ll need these to hook up speakers to your SX-1000 model receiver. They can usually be found on eBay.
Here is a really nice SX-1000TW in a wood case. As you can see it looks essentially identical to the TD version.
All of the Pioneer SX-1000 versions are in demand from collectors and enthusiasts. The restored TW version above sold for $335.00 which is about the top end for the SX-1000’s. A decent working unit without a wood case would bring about $80-$100 while a nice unrestored unit in a wood case would bring $100-$200.