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Old 18th July 2013, 07:04 AM   #11
osci is offline osci  Australia
diyAudio Member
Join Date: Jan 2013

I got around to testing the smaller 5watt output transformer last night and I wouldn't recommend using a small tranny sucj as the 5 watt on a circuit such as the GA-8t which is what I've just built.

I found the sound to be quite muffled, no body, and with the volume turned right up there was hardly a trickle of sound coming out, but all in all it was an interesting excersise.

The 40watt PA output transformer however does work quite well with the 16ohm speaker connected to the 4ohm output to achieve the 8k primary impedance, I have no hesitation in recommending this setup for anyone seeking to try it.

again, thanks heaps for all your input in this thread!!

cheers Ron
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Old 18th July 2013, 07:33 AM   #12
djgibson51 is offline djgibson51  New Zealand
diyAudio Member
Join Date: May 2010
Location: Hawkes Bay
Good outcome Ron,

I've got several 6BM8's in the box that will need an OPT some day. I'll keep in mind the need for more than 5 watts.

I'm currently bread boarding some 6AM5 tubes thro a 5 watter, loosely following the Trainwreck schematic.

I found 20 of the 6AM5's when packing for our move from Melbourne to Hawkes Bay - they were in a box under a layer of some other obscure tubes I had been given

Maybe I should move countries more often?

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