Transformer for impedance matching?

wilrecar77 · Post by **wilrecar77** » Sat Jul 10, 2010 3:00 am

I know there are many many impedance questions on this forum, but I had an idea that I'd like to either get proved or shot down by someone with more know-how than me.
Anyway, would it be possible to correct an impedance mismatch by using a transformer? I can't see any reason why it couldn't, aside from the fact that having two transformers between a tube amp and speaker might affect the tone. Being that I'm using a SS transtube bandit with a 4 ohm output and an 8 ohm Swamp Thang I don't think it would negatively affect the tone, and I've been itching to run it at 100 watts (as opposed to 75-ish).

Post by **Doog** » Sat Jul 10, 2010 8:36 am

I'd personally steer clear of such major electronics work for something so minor. It's really not going to make a massive difference to your output volume or headroom, plus it'll damage your resale value.

Far better to sell off your existing speaker and pick up a 4 ohm version. Or use another 8 ohm cabinet in parallel to create a total 4 ohm load for your amp.

George · Post by **George** » Sat Jul 10, 2010 8:48 am

And picking a new speaker is fun

Though I can imagine the market is mostly flooded with 8 or 16 ohm speakers only

wilrecar77 · Post by **wilrecar77** » Sat Jul 10, 2010 10:56 am

I've definitely been thinking about the extension cab idea, but aside from cost and difficulty, is there any reason that a second transformer would NOT work?

Julian · Post by **Julian** » Sun Jul 11, 2010 4:17 am

Get another swamp thing, then wire them in parallel

Post by **Doog** » Sun Jul 11, 2010 12:24 pm

Julian wrote:Get another swamp thing, then wire them in parallel

I'm guessing we're talking about a 1x12 combo here, I don't imagine there'd be room for a second speaker..

wilrecar77 · Post by **wilrecar77** » Sun Jul 11, 2010 2:17 pm

You would be correct about the 1x12 combo part. I'm not interested so much in getting a full 100 watts, if I was to get an extension cabinet it would be purely for volume (there is a limited amount of air one speaker can push, regardless of wattage). I am still wondering why I have never seen a second transformer used for impedance matching reasons. Considering the cost of a transformer (or the cost of making one yourself) it would seem like a cheaper alternative to buying a new cabinet or speaker. I would trade weight for cost if I had an amp and speaker that sounded good together but are not matched in a safe way. (this is all hypothetical, I have no real reason to do this or problem related to mismatched impedances.)

George · Post by **George** » Mon Jul 12, 2010 11:35 am

Bit of a sidetrack but certainly not deserving of a new thread... when buying a new output transformer could you use a transformer with a higher wattage?

e.g. say I put a 50w output transformer in my 30w amp, would it work or blow up etc? My expectation that it wouldn't be a problem, it would just leave 20w untapped so maybe more headroom or less break up to a degree?