Audio Magazine

[wrenchone]

Chris - Interesting observation - the picture progressed from the butler type calmly proferring the caps-on tray in the first installment to almost prancing and face-shoving the tray in the second installment. Here! These are polypropylene caps! Take them or else!

 

[Zoran]

Reading the article in the July 1948 issue with the PP 300b amp. They claim a single 300b is capable of 17.8 watts?

No it cant.
Probably it is just calculated with just statiic paper chrs.
AND with higher input signal that forcing tube to step into + grid bias region and from other side of input whave close to the X axis.
Off course it could be done BUT with pure reistive load.
Not with the Output transformer.
Because reactive component of L load will produce elipse at the LF. As F lowering elipse is more fat.
And deforming the shape close to the X axis region...
Inthat case an extra Lp in [Hy] needed to make ellipse undeformed and away from X axes 0mA...
This is not linear relation...
Could be more than 100Hy to keep the things as should be. To not damaging tha LF phase and LF cutt of.
On the other hand that significant increase of turns will ruin the capacitance and other issuec from HF side
...
And even without the reactive load elipse effect at LF distortion are huge when tube going into +Ug region
...
Off course ususl way is to print Watts without any context

from
http://www.vias.org/eltransformers/lee_electronic_transformers_06_10.html
and

 

[StevenOH]

To supplement the discussion of transistors audio amps on the US scene I will add
a useful review of the British DIY scene history - it was sufficiently "international".

http://ukhhsoc.torrens.org/other/Papers/David_Lord_June_2017/History_of_DIY_HiFi_in_UK.html