Heathkit W4-AM Tube Amplifier
Archived listing from the original vintage-amplifier.com. Prices, seller details and purchase links have been removed; this page is a reference record, and nothing here is for sale. About this archive.
The tubes lit up as they should when plugged in. I pulled the tubes, It does not come with tubes. It has a capacitor can with a cracked base.
About this model
The W4-AM was one of Heathkit's Williamson-type kit amplifiers. The Heathkit Virtual Museum rates it at 20 watts, with push-pull 5881 output tubes and a Chicago Standard output transformer built to Heath's specification; dealer listings give the rest of the tube complement as two 6SN7s and a 5V4G rectifier. Radiomuseum puts it around 1957.
This example was sold without tubes and with a cracked base on its capacitor can, which is the part to replace first anyway. A kit amplifier's value depends on the original builder's work, so look at the solder joints before anything else.
| Maker | Heath Company (Heathkit), USA |
|---|---|
| Model | W4-AM |
| Type | Williamson-type mono power amplifier (kit) |
| Rated output | 20 W (Heathkit Virtual Museum) |
| Output tubes | 2 × 5881, push-pull |
| Other tubes | 2 × 6SN7, 5V4G rectifier |
| Era | About 1957 |
Questions collectors ask
What tubes does the Heathkit W4-AM use?
Two 5881 output tubes in push-pull, two 6SN7s and a 5V4G rectifier.
How powerful is the W4-AM?
The Heathkit Virtual Museum gives 20 watts.
Is the W4-AM a Williamson amplifier?
It is a Williamson-type design, following the push-pull, high-feedback approach D.T.N. Williamson published in 1947.
Sources: Heathkit Virtual Museum: W4-AM; Wikipedia: Williamson amplifier; Wikipedia: Heathkit.
