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Ed_Dinning · 19th Oct 2004, 5:23 pm

Hi Dave, If the field coild resistance is too high and you are worried about reduced HT you can add a resistor in parallel to bring the equivalent value down, about 1K5 of suitable wattage should do. The train transformer may give poor HF response as it will be made with laminations suitable for 50Hz use. It may also saturate and produce more distortion as the transformer for a single ended output stage was usually air gapped in the core to prevent the (DC) valve anode current from doing this.
Best regards and good luck,

Ed

19th Oct 2004, 5:23 pm	#14
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Bush PB53 Output stage problems Hi Dave, If the field coild resistance is too high and you are worried about reduced HT you can add a resistor in parallel to bring the equivalent value down, about 1K5 of suitable wattage should do. The train transformer may give poor HF response as it will be made with laminations suitable for 50Hz use. It may also saturate and produce more distortion as the transformer for a single ended output stage was usually air gapped in the core to prevent the (DC) valve anode current from doing this. Best regards and good luck, Ed