16 Ohm amp (AC4TV) into 8 Ohm cab

[tot_Ou_tard]

I have an 8 Ohm cab. I'm thinking of getting an AC4TV head which only has a 16 Ohm out.

Will this be OK?

[tunghaichuan]

I have an 8 Ohm cab. I'm thinking of getting an AC4TV head which only has a 16 Ohm out.

Will this be OK?

Generally not a good idea to mismatch impedances. Fender amps are usually OK, but other amps may not fare so well.

Although you might want to check out this document:

http://www.geofex.com/tubeampfaq/taffram.htm

Specifically #16.

Having said that, I like to match impedances.

Weber makes the Z-Matcher (https://taweber.powweb.com/store/zmatch.htm), kinda pricey but it looks like a good product.

[tot_Ou_tard]

Thanks tung.

I always get confused as to which direction mismatch is worse for a tube amp.

From the link in tung's post:


Extended A: It's almost never low impedance that kills an OT, it's too high an impedance.

[tunghaichuan]

Thanks tung.

I always get confused as to which direction mismatch is worse for a tube amp.

From the link in tung's post:


Extended A: It's almost never low impedance that kills an OT, it's too high an impedance.

I can never remember either, I had to look it up. :thwap

[Plank_Spanker]

Greg Germino and the guy that built my Titan frankenstein told me that the amps are OK with a 2:1 mismatch either way. The output transformer will handle it and Greg said I can use the amp's impedance selector to vary the response of the amp..........................but both amps are overbuilt like tanks and I agree that it's best to match the impedance. Currently, I'm running the Titan (16 ohm) into a 8 ohm cab.

Running a tube amp into a considerably higher impedance speaker load can cause flyback (arcing in the OT), and that will kill an OT dead. SS amps can be run into a dead open since they don't use OT's. Running below minimum rated impedance with them will cause current flow to go through the roof on the final amps and they will give it up.

I definitely would not advise mismatching with older tube amps. Time is not on their side and the OT's on some of them are rather delicate.

[kiteman]

Too high an impedance say bye-bye to the OT
Too low an impedance say bye bye to the PT

:french

[Plank_Spanker]

Too high an impedance say bye-bye to the OT
Too low an impedance say bye bye to the PT

:french

Good way to remember it! :dude

[tot_Ou_tard]

Good way to remember it! :dude
Sez you, I know that I'll transpose the endings of the two bye byes.

Or vice versa.


boooOOOOOOOooooommmmmm!!!

Bye bye.