16 Ohm Speakers

[danielwritesbac]

or in series
VA(watt) rating comes out the same anyway
its always the total of the whole trafo
Ampere rating is each secondary

Thank you for the unconfuse!
I was accustomed to buying EI-core center tap (always secondaries series), but the Antek toroid dual secondaries datasheets (always secondaries paralleled) baffled me since their test conditions never match my application.

P.S.
A possible chip amp for 16 ohm speakers is bridged TDA7265 monoblocs, and these can run from $9 19vdc laptop power pack. However, the datasheet bridge application's gain setting looks like a misprint. I think I'd use the non-bridge schematic, change the feedback resistors to 27k and then apply simple one resistor bridge. That plan makes only about 11 watts to 16 ohms though. That is a very effective 11 watts if one adds about 1000u series to the + amplifiers output (DC block, speaker protect, current drive) and adds resistors to the - amplifiers output with the value matching or greater than the ESR of the + amps output caps. Sort of an inexpensive current drive setup that way, and minimal loss too. Would be a non-shouty chip amp. Some people enjoy that chip for mids-n-treble amp in bi-amp systems.

 

[sreten]

based on more ampere for low imp speaker load,
I would say reality is mostly the opposite in general
you will have to lower VA rating to achieve this

Hi, the reality is you are mostly wrong, rgds, sreten.

Work out the VA ratings for an amplifier
that does 50W/8ohm and 80W/40hm.

 

[sreten]

... here is a different option for current drive at only the bass ...
... Carefully chosen roll-off has a current drive effect potentially useful for bass extension ...

Hi,

No it doesn't. Simple capacitor coupling outside the feedback loop is the
same as capacitor coupled speakers* (so called third order speakers),
and the effect is very speaker dependent but can work well.

rgds, sreten.

* Numerous models from Kef, Goodmans, Wharfedale etc.
The capacitor needs to match the speaker properly.