Zero Autoformers

Please see here for full description of function but basically they enable you to increase the impedance of speakers to better match your amplifier.

http://www.zeroimpedance.com/Zero-New.html

Review here: https://www.tnt-audio.com/accessorie...oformer_e.html

Essentially you put them between your amp and speakers and can raise the impedance seen by the amp by 2x, 3x or 4x depending on which wires you use. Apparently very effective with OTL amplifiers but the testimonials on the website show that they can work with a wide range of amps. I tried them between my twin Eikona speakers, wired in parallel so giving a 3 ohm load, and my Leema Pulse SS amplifier. In truth I found marginal differences but you may find a bigger improvement. I have since rewired my Eikonas in series to give a higher impedance so even though they made a bigger difference when using my Ming Da Piccolo single ended amp I no longer need them.

https://i.imgur.com/LT8rhu5h.jpg#gWPQG

https://i.imgur.com/oEN8qj4h.jpg#gWPQG

https://i.imgur.com/1LzcdXBh.jpg#gWPQG

https://i.imgur.com/9mpK0TCh.jpg#gWPQG

Cup for scale only, not included in sale!

I paid Roger (TheMooN) £250 + £26 postage back in November so would like something near this please. Happy for you to collect or meet not too far away if you want to save postage.

Thanks, Ian

I.imagine they would work well for valve amps that don't have the right taps. Could they also be reversed so a 4 ohm speaker can be run of an 8 ohm tap?

Re OTL amps, it seems a bit silly to buy an OTL amp and then put transformers across the output taps but I've seen crazier things. Given the importance of transformer quality to the sound, buying a cheaper OTL amp and using these would probably sound better than an amp with lower quality transformers built in, so it's a good upgrade path in that sense.

Hi Lawrence, thanks for input. Apparently you can run them in reverse. Your example is how they normally work but in reverse you could for example, run a 8 ohm speaker into a 4 ohm tap.

I should add my comments are based purely on logic with no experience of using these, but I've heard good things before.

Sold subject to payment.