So ..just can't resist undoing the screws and taking a peek. Having done so and established it has a switch mde psu [not fans of]...... The opamps are sighted under the board holding the input and output connections. So first as the case rings like a bell I've damped with bitumen both case and lid. Effect noticable clarity slightly fuller sound. Then swapped the 1000uf supply cap in the switched mode psu for panasonic fc 1200 63v ...effect bass where did that come from ? Looked at the processor board and swapped the majority of the 10uf 16v caps for a mix of starget and panasonics ..stargets near the chips and the panas round the regulators. effect more bass ...geez where is it coming from ? extra delicacy in the top and mid. But now ....I could attack the caps on the opamp board ...but not certain theres much milage here ? any thoughts......?