Just bought a (non digital readout) Radio Shack a month or so ago & it works fine.

It displaced an expensive Ivie that had developed too much internal noise to use for room correction. A friend is going top look at repairing it for me but the parts are packed in so tight it is a nightmare to work upon. However, even after nearly 25 years, the manufacturer still exists and sent me a circuit at no charge. They no longer make this smaller unit.

John