[quote author="Peter A"]I'm not sure what to make of it. Does the test sugest to much hf roll off from the Edcor transformers ??[/quote]
the test shows too much hf roll off in this circuit, in my opinion.
but this is only measuring - may be the sound is right, or the combination with an output transformer, or while compressing :grin:
too many options to measure all combinations.
take this charts just as an idea what each part can do.
choose what ever you think it fits your need (on paper, or sound-wise)
anybody is welcome to post his result and opinions after the build :thumb:
I have measured:
Edcor XSM10K/600, Edcor WSM600/10K backwards, an original NOS Haufe AÜ V74 and a (Altec) Peerless 15095. there have been a few others under test, but the circuit seams not to be sensitive to the output transformers.
anythings in the range of 10K:600 (4:1) will do.
forgot to take a photo, and lost the THD curves, sorry
but nothing special there.
[edit: the 100R in the gif is 600R, of course]
no input transformer,
Output Potentiometer = 100%, Input Potentiometer set for +12dB gain without transformers.
Generator Level = 0dBu
Zout 15Ω, Zin 600R / 100K
no Zobel networks etc used, just the transformers
Kubi was kind enough to send me this photo of his finished D-AOC, Frontpannel removed:
He already used it for tracking and mixing, loved it on Acoustic Guitar and Choirs.
Compared to the LA2A Kubi says the D-AOC is more inconspicuous and inaudible.
While mixing he missed his second D-AOC :green:
[since Kubi is in vacation he asked me to post this for him]
Thanks Bernd for the explanation. But where can I find some?
I could not find them even on the Lundahl official website.
I am just curious about their cost, the XS1100 look to have similar
curve and are cheap so Lundahls might be a nice option also but
it depends on the price.