Incorrect model dating or incorrect tube(s) / semiconductors.

Please read the explanations below the list of errors.

We try to give the correct market introduction date for a model and for tubes or semiconductors it uses. The system automatically checks these dates for consistency. Collectors and admins sometimes make mistakes. If you as a guest notice errors and have solid evidence to recommend corrections, please use the contact form to inform us. The following reasons may be the cause for errors:
1 The model is dated too early (date should be corrected even if it is marked as "uncertain" with ? or ??).
2 The market introduction year for the tube is too late.
3 Schematics or books show later replacements.
4 The model has multiple versions, with different tube line ups.
5 The set (of the uploader) was modified with different tubes.


Schematic collections like Rider, Beitman or SAMS sometimes published schematics years after the market introduction of a model - specially in the early days. As a consequence, they sometimes listed updated tube types that were in use at the time of publication. Example: A set which originally used a UY-224 (224) from 1929 might be later shown with a 24A, an updated version of the tube introduced in 1932. Few people are knowledgeable about these kinds of obscure facts; however as these details become known, we must update model dates, tube types listed for models, and tube dates accordingly.