Can I use different output transformer taps concurrently?

My guitar amp has 4, 8 and 16 ohm taps, hardwired to four output jacks: 2 x 4Ω, 1 x 8Ω, 1 x 16Ω.

I have a query - can I safely use different output transformer taps at the same time?

I'm toying with an idea: use my current speaker cabs as I typically do.  I'm wondering if, concurrently, I could dedicate an unused output tap for a speaker cabinet simulator device (such as a Two Notes Captor, or Mesa CabClone)?

The short answer is no. Devices like the 2 note actually load the amp just like a speaker and so they dissipate power just like a speaker.  So if you use one AND a speaker you will be tryig to draw roughly twice as much power from the amp which it probably will not be too happy about.

Cheers

Ian

OK, that's good to know.

Thanks for the reply 

you can, it might load your tubes down depending on what you plug in,

what is the impedance of the speakers and the simulator?

Che_Guitarra said:

My guitar amp has 4, 8 and 16 ohm taps, hardwired to four output jacks: 2 x 4Ω, 1 x 8Ω, 1 x 16Ω.

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It's a tad strange; two 4 ohms outputs suggest a resulting impedance of 2 ohms. What is the amp's model? The datasheet mat help us understande that.

I have a query - can I safely use different output transformer taps at the same time?

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The elaborate answer is YES, BUT... For example, if you have a 4 ohms and an 8 ohms output, you can load the 4 ohms with an 8 ohms cab and the 8 ohms with a 16 ohms cab. For more complex combinations, the calaculation is not too difficult, but involves square roots and 2nd order equations.

I'm toying with an idea: use my current speaker cabs as I typically do.  I'm wondering if, concurrently, I could dedicate an unused output tap for a speaker cabinet simulator device (such as a Two Notes Captor, or Mesa CabClone)?

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Do these things have a 16 ohms position?

abbey road d enfer said:

It's a tad strange; two 4 ohms outputs suggest a resulting impedance of 2 ohms. What is the amp's model? The datasheet mat help us understande that.

....


Do these things have a 16 ohms position?

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DIY Princeton/Deluxe type thing.  Classictone output transformer with 4, 8 and 16 ohm taps.  The two 4 ohm outputs: so I can run both my 1x12 speaker cabs at once.  They're both 8Ω speakers.

The cab sim devices:  the impedance is non-selectable (well, not on these particularly basic units), but they can be bought in the impedance of your preference.  I use the four and 8 ohm taps consistently on my amp, so I was thinking to plug it in to the 16 ohm tap like a dongle... of sorts.  To do away with the need for miking up.  It appears the Two Notes option can be used in-line with the speaker, so that might be my plan of attack.

here is what you do, buy the Captor in 16 ohms and plug it into the 8 Ohm jack which presents a load of 16 K to the tubes,

plug your two 8 ohm speaks into the two 4 ohm jacks and you are good to go

total load is now  (8000 * 16000)/(8000 + 16,000) = 5,333 ohms

this is a total mismatch factor of 5,333/8000= 66.6      Pentodes do not care about mismatch as much as triodes, so you are totally ok.

Jerry Garcia loved to use 3 JBL's which has a Z of 5.33 ohms if they are 16 ohm speaks. Said the weird impedance made him sound....weird. 

but we hate the noisy DI outs from speak ports, so next time include a 6N1P inside your amp and attach suitable output xfmr.  ;D

abbey road d enfer said:

It's a tad strange; two 4 ohms outputs suggest a resulting impedance of 2 ohms. What is the amp's model? The datasheet mat help us understande that.

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Perhaps it is just two jacks in series across the 8 ohm tap?

Cheers

Ian

it is two 4 ohm  jacks attached to the OPT 4 ohm tap so that one may plug a  single 4 ohm speaker into 4 ohms, or if more volume is needed, plug two 8 ohm speakers into the two 4 ohm jacks, thus matching two 8 ohm speakers to the plates of he 6V6GT tubes.

ruffrecords said:

Perhaps it is just two jacks in series across the 8 ohm tap?

Cheers

Ian

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CJ knows  8)  It's two jacks in parallel across the 4 ohm tap.  8Ω speaker + 8Ω speaker = 4Ω.