mika, sorry i'm a newcomer here and i can't find info on how you drive your altecs. is it just a shindo EL84 amp or you have another amp for bass.
i'm asking cause i'm also interested in this kind of onken-derived cab for altecs however afaik hiraga and others from paris horn mafia all drove it with SS amps for best results (in fact hiraga 20 or 30 amps).
Gordan.
Speakers: Oris Swing MkII
Amps: Thomas Mayer 300b/ Hiraga La Maison de L'Audiophile 20
Preamp: Silver AVC by eng. Ferenc Lazar
Phono Preamp: Shishido LCR by Solaja Audio
Decks: Garrard 301 Martin Bastin reworked/plinthed with Fidelity Research FR64fx
Garrard 401 in eng Ferenc Lazar solid wenge plinth with SME 3012/2
Cartridges: SPU Spirit/ Koetsu Black revisited by eng. Salai/ Miyajima Shilabe
Step Up Transformers: Tango MCT 999/ Ortofon T-5000/ Lumiere SUT
Digital: Shigaclone by eng. Ferenc Lazar with Lampizator Amber II
Wires: of sufficient length