Hammond 290BBX Tweed Deluxe Shielded Power Transformer, 710VCT

The 290BBX is a 290 Series replacement power transformer referenced to the Fender amp listed as "DELUEX*" (Deluxe) with Tweed chassis and similar amp part number 6452 (reference only). It is a strong fit for restorers of Tweed-era amps who want a drop in replacement with detailed test data.

The primary is 120V at 50/60 Hz (BLK - BLK). Secondaries are 710Vct @ 115 mA (RED - RED/YEL - RED), 6.3Vct @ 1.65A (GRN - GRN/YEL - GRN) and 5V @ 2A (YEL - YEL). The assembly drawing marks the unit as shielded and made in Canada, with a bobbin winding per the series table.

The drawing's electrical data lists excitation current of 232mA at 120V, 60Hz, and no-load voltages of 759.9V (RED to RED), 6.761V (GRN to GRN) and 5.408V (YEL to YEL), each ± 2%. DC resistances at 20°C are 3.49 Ohms primary, 204.4 Ohms RED to RED, 121 mOhms GRN to GRN and 101 mOhms YEL to YEL, ± 20%. Hipot is 3000V, 60Hz, 1 sec primary to secondary.

Mechanically, the drawing gives a 3.413 ± 0.125" dimension, 3.375 ± 0.064" and 2.813 ± 0.032" footprint dimensions, a 2.40 max dimension and a Ø0.392 diameter callout. The drawing lists the unit weight as 3.90 lbs, and the shipping weight is 4.25 lbs (1.93 kg). The 290BBX is RoHS and REACH compliant, and like all 290 Series parts it was designed to look similar to the original and preserve the stock "tone".