Primaluna 8/4 ohm taps

[ematthews]

Just switched my Primaluna speakers out from 4 to 8 ohm and the bass has woken up on my new Ascend RAAL Towers. How does changing from 4 to 8 ohm out effect everything? I'm not sure how this works.

 

[PENG]

Just switched my Primaluna speakers out from 4 to 8 ohm and the bass has woken up on my new Ascend RAAL Towers. How does changing from 4 to 8 ohm out effect everything? I'm not sure how this works.

The Ascend's impedance between 60 to 90 Hz is closer to 8 ohm so the 8 ohm tap could mean more power transfer resulting in more pronounced bass in that range. That does not always mean the overall frequency response will be better. However, the impedance from 1K to 20,000 range from 6 to 8.2 ohms so I think the 8 ohm taps are probably the way to go but trust your ears as everyone's preference are not the same.

 

[ematthews]

Thanks PENG.

 

[ski2xblack]

As Peng said, it's case specific, but generally I've gotten the most satisfying results using the lower taps with a wider variety of speakers. If I have the correct plot for your speakers, you'll note they are below 5 ohms from 30-60hz, and 110-600hz, so using the 4 ohm taps will optimize power delivery there, with perhaps, maybe softer mids/highs where the impedance is higher. Unless I'm mistaken in my guestimate of your primaluna's output impedance, these tonal shifts should be very, very subtle.

 

[PENG]

As Peng said, it's case specific, but generally I've gotten the most satisfying results using the lower taps with a wider variety of speakers. If I have the correct plot for your speakers, you'll note they are below 5 ohms from 30-60hz, and 110-600hz, so using the 4 ohm taps will optimize power delivery there, with perhaps, maybe softer mids/highs where the impedance is higher. Unless I'm mistaken in my guestimate of your primaluna's output impedance, these tonal shifts should be very, very subtle.

I would use the 4 ohm taps too regardless, but if he likes how it sounds using the 8 ohm taps he just have to be careful with the volume knob. The "nominal" impedance of the RAAL towers over the audible range isn't that low but for the Primaluna the 4 ohm taps are still the safe bet.

 

[AcuDefTechGuy]

Assuming the Primaluna amp is high quality, I wouldn't expect such a significant difference in sound quality (bass) between the 4 & 8 ohms settings.

Also, I wouldn't expect too much bass from the Ascend towers.

 

[slipperybidness]

I also tend to prefer the 4 ohm taps over the 8 ohm taps on my Dynaco ST-70.

If you really want to understand what's going on then you need to read / study:

Thevenin's Theorem, Impedance Matching, and the Max Power Transfer Theorem

 

[PENG]

I also tend to prefer the 4 ohm taps over the 8 ohm taps on my Dynaco ST-70.

If you really want to understand what's going on then you need to read / study:

Thevenin's Theorem, Impedance Matching, and the Max Power Transfer Theorem

Still depend much on the amp, I assume the primaluna has output transformers so what ADTG said may not apply.

 

[slipperybidness]

Still depend much on the amp, I assume the primaluna has output transformers so what ADTG said may not apply.

Being a tube amp, it almost certainly has OPTs for impedance matching.

I'm not sure what you are getting at "depend on the amp"?

Maybe you just randomly hit the reply button?

Thevenin's Theorem, Impedance Matching, and the Max Power Transfer Theorem are general concepts in electronics, independent of any amp.

 

[PENG]

I also tend to prefer the 4 ohm taps over the 8 ohm taps on my Dynaco ST-70.

If you really want to understand what's going on then you need to read / study:

Thevenin's Theorem, Impedance Matching, and the Max Power Transfer Theorem

May as well add Norton, Kirchoffs, Superposition theorem etc. Then you need Laplace and Fourier to help in the analysis.. All depends on how deep one wants to go.

 

[slipperybidness]

May as well add Norton, Kirchoffs, Superposition theorem etc. Then you need Laplace and Fourier to help in the analysis.. All depends on how deep one wants to go.

Yup.

But, to answer the OPs original question, Impedance matching and Max power transfer should suffice

And don't forget Faraday!

 

[PENG]

Being a tube amp, it almost certainly has OPTs for impedance matching.

I'm not sure what you are getting at "depend on the amp"?

Maybe you just randomly hit the reply button?

Thevenin's Theorem, Impedance Matching, and the Max Power Transfer Theorem are general concepts in electronics, independent of any amp.

I meant knowing those won't be enough if OPT is involved, one needs to know transformer theories.

 

[PENG]

Yup.

But, to answer the OPs original question, Impedance matching and Max power transfer should suffice

And don't forget Faraday!

Now you answer your own question you asked me a couple posts back. No I did not hit the r button too quick.

Thanks for lengthening my lunch break. Tough to type on the phone for sure.

 

[slipperybidness]

I meant knowing those won't be enough if OPT is involved, one needs to know transformer theories.

OK. I'll give you that one.

But in this case, we are using the OPTs for Impedance Matching. You could understand impedance matching by taking transformers out of the details and replace the word "transformer" with the words "impedance matching device".

Then, if you want to go a step deeper, you will have to study HOW a transformer can accomplish impedance matching.

 

[PENG]

Yup.

But, to answer the OPs original question, Impedance matching and Max power transfer should suffice

And don't forget Faraday!

Faraday? Are you ready to talk to me about field theory now, Got your ee degree yet?

 

[AcuDefTechGuy]

Why is the amp even making the user choose between 4 ohm or 8 ohm? Shouldn't it be automatic depending on the speaker?

I mean a speaker could be 2 ohm - 16 ohm from 20Hz-20kHz.

And no, there's no way in hell I'm reading any engineering documents.

This hobby is for FUN, yes for FUN, not for reading and studying things I avoided in college.

 

[slipperybidness]

Tube amps are a different animal completely.

A tube amp typically has a high output impedance. The way around this is to put Transformers on the Output for impedance matching the amp output to the input of the load (speakers). Some OPTs will have taps to better match 8 or 4 ohm speakers. (And, yes, transformers in the signal path is a lousy idea).

So the taps are for a 4ohm OUTPUT or an 8ohm OUTPUT impedance.

Properly designed SS amps have such low output impedance that we would not be having this discussion (unless we are talking about Mc)

Some people consider reading engineering documents as FUN!

 

[AcuDefTechGuy]

Tube amps are a different animal completely.

A tube amp typically has a high output impedance. The way around this is to put Transformers on the Output for impedance matching the amp output to the input of the load (speakers). Some OPTs will have taps to better match 8 or 4 ohm speakers. (And, yes, transformers in the signal path is a lousy idea).

So the taps are for a 4ohm OUTPUT or an 8ohm OUTPUT impedance.

Properly designed SS amps have such low output impedance that we would not be having this discussion (unless we are talking about Mc)

So you shouldn't use a 2-ohm speaker if there is no 2-ohm tap? Sounds like bad engineering to me.

Some people consider reading engineering documents as FUN!

Yeah, they're called NERDS.

Well, reading a LITTLE bit into Einstein's Theory of Relativity is fun to me. But not too deep.

 

[3db]

Some people consider reading engineering documents as FUN!

Not me..I read just to get me my EE degree.. although truthfully, the 3ed and 4th year material was far more interesting than the first year material.

 

[3db]

Tube amps are a different animal completely.

A tube amp typically has a high output impedance. The way around this is to put Transformers on the Output for impedance matching the amp output to the input of the load (speakers). Some OPTs will have taps to better match 8 or 4 ohm speakers. (And, yes, transformers in the signal path is a lousy idea).

So the taps are for a 4ohm OUTPUT or an 8ohm OUTPUT impedance.

Properly designed SS amps have such low output impedance that we would not be having this discussion (unless we are talking about Mc)

Some people consider reading engineering documents as FUN!

Oh and those output transformers are specially made for audio so that they can track up to 20KHz to minimize hysteris effects on the signal.