PCL86 single ended amplifier to linoleum Pleiades Auratone 5C type speaker

Not impressive sound.


Just a Pleiades 2N3055 one transistor amplifier sounds so better


Signal path:


(To have and not to hold - Madonna) - Sony Walkman CD player, one channel - Pleiades PCL86 single ended amplifier with Hammond 1626 output transformer - linoleum Pleiades Auratone 5C type cube monitoring speaker with Tessla 5in drive unit - big room


Very nice treble, somewhat deep bass but somewhat harsh and reasonant midrange.


Then the Zeiss Ikon typ:31-06
Similar


Possible cause:
High output impedance of this pentode output stage amplifier with no negative feedback?