The power transformer supplied in DH-220 amplifiers sold in the lJSA is intended for 120 volt, 60 Hz operation only. For use in other countries, a multi-voltage transformer is available at higher cost. It has dual tapped primary windings which can be arranged in various series-parallel combinations for 100, 110, 120, 200, 220 and 240 volt 50 or 60 cycle AC mains. The schematic diagram details the wiring combinations which are represented pictorially here.
Note that a separate 2-lug terminal strip is required when the multi-voltage transformer is used. This is supplied in kits which include the special transformer. If the amplifier is operated with
200to 240 volt tines, the 7 amp line fuse which is supplied should be replaced with a 4 amp Slo-Blo type fuse.
VOLTAGE CHART
measured with 120 volt line, no signal. with respect to the ground buss between the two capacitors in the power supply.
| E | B | c | Q 8 | E | B | c | | s | G | D |
Ql | 62.6 | 62.1) | 0.88 | 63.0 | 62.0 | 1.54 | Q401 | 0 | 1.0 | 65.4 |
Q2 | -62.6 | -62.0 | -0.37 | Q 9 | -1.27 | -0.6 | 1.54 | Q402 | 0 | 1.0 | 65.4 |
Q3 | -0.32 | 0.22 | 61.8 | QlO | -63.0 | -62.0 | 0 | Q403 | 0 | -0.8 | -65.4 |
Q4 | -0.32 | 0.22 | 61.8 | Q11 | -63.0 | -62.0 | -1.35 | Q404 | 0 | -0.8 | -65.4 |
Q5 | 0.8 | 0.22 | -62.0 | Ql2 | 1.0 | 1.54 | 65.0 | | | | |
Q6 | 0.8 | 0.22 | -62.0 | Q13 | -0.8 | -1.35 | -65.0 | | | | |
Q7 | 63.0 | 62.0 | 0 | | | | | | | | |
