out put toroids for hard speaker loads

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
hi all
a while ago i found a site that sells toroid transformers that you simply install in your speaker cables in between the amp and speakers which makes the amp see a different load so even though your speakers may be 4ohm your amp will see a 8ohm load

i cant seem to find them any more on the net and am hoping some one here knows this product and the website where i can buy them

cheers
 
AX tech editor
Joined 2002
Paid Member
hi all
a while ago i found a site that sells toroid transformers that you simply install in your speaker cables in between the amp and speakers which makes the amp see a different load so even though your speakers may be 4ohm your amp will see a 8ohm load

i cant seem to find them any more on the net and am hoping some one here knows this product and the website where i can buy them

cheers

There was an article in AX a few years ago about this, I'll try to find it.

jd
 
is this for a class AB amp? don't waste your money... the only time something like this makes sense is with a tube amp or a SS amp with an output transformer, or a class A. you could easily "roll your own" anyway and save about $680.00.

the output impedance of most modern amps is well below 0.1 ohm, so using an impedance matching transformer doesn't make any sense. the device in question looks suspiciously like a standard toroid power transformer anyway, probably using the center tapped secondary as an autotransformer.
 
Last edited:
that's a good use for it. you still won't double your power, but you will drive the 4 ohm load more efficiently... before you spend oodles of cash, might i recommend you at least try a 35-0-35 or a 24-0-24 power transformer secondary and see how well it works. being a power transformer it may or may not have high frequency loss, but if you have one laying around it's free, and being a toroid it might actually perform better at high frequencies than you would expect. i've seen toroids with similar construction (spiral wound steel laminate) used in very old (ca 1938) speaker crossovers, and they performed quite well, where E-I core inductors were very lossy for the same application.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.