Newbie question.
I am running my TL2 (Troels Gravesen The Loudspeaker II) using Line Magnetic LM-216IA valve amp. Great amp, wonderful speakers... but!
Is there any sonic adventage/ difference/problem/risk connecting this 8ohm rated speakers to the 4ohm output?
Thanks, and if your start throwing tomatoes at me, please make sure thery are overripe 🙏🍅
I am running my TL2 (Troels Gravesen The Loudspeaker II) using Line Magnetic LM-216IA valve amp. Great amp, wonderful speakers... but!
Is there any sonic adventage/ difference/problem/risk connecting this 8ohm rated speakers to the 4ohm output?
Thanks, and if your start throwing tomatoes at me, please make sure thery are overripe 🙏🍅
Hi
If you look at the internet page of the Troels you can see that the woofer is driven by class D so the issues aren't present because the major changing in modulus of the loudspeaker are in the bass range.
I don't see the complete spec of the model ; with the graph of the modulus and phase will be possible to have a better idea.
But is possible to say that the the other three ways aren't a heavy load
In every case a little check is possible to do, the amp will work and you can understand if the results is good for your ears.
Walter
If you look at the internet page of the Troels you can see that the woofer is driven by class D so the issues aren't present because the major changing in modulus of the loudspeaker are in the bass range.
I don't see the complete spec of the model ; with the graph of the modulus and phase will be possible to have a better idea.
But is possible to say that the the other three ways aren't a heavy load
In every case a little check is possible to do, the amp will work and you can understand if the results is good for your ears.
Walter
For the valve amp, it should halve the impedance reflected back to the primary of the OPT from the secondary.
With any tube amplifier there is no risk/danger to connect 8 ohms speakers to 4 ohms output. The situation is the same when connecting 4 ohms speakers to 8 ohms output.
It's interesting that in some speaker reviews eight ohms output was claimed to sound better, even though the load was near or below four ohms for much of the bandwidth. I wonder what the reviewers were hearing as "better"?
If you put an 8 ohm speaker on the 4 ohm outputs you are doubling the reflected impedance on the primary. A higher primary impedance gives you less power and less distortion. The opposite is also true. It can be audible and either good or bad depending on how much power you need it can be an issue. Try it, you might like it!
Try all taps available and pick the one that sounds best. No harm to the OPT. On my SET the one I thought would sound best didn't. I am glad I put a switch in to have all the choices available vs. taping some off.
I'll give it a try! BTW, after going from SS to PP AB class configuration I am very tempted to try a SET amp. Line Magnetic have the LM-805iA which is a SET Amp delivering 48watt! Sounds somehow dangerous does it 🤔... are you in any case familiar with high output SET'S?
A 48 watt SET amp would use deadly high voltages or have several tubes in parallel. Parallel tubes in SET kind of defeats the idea of Single in SET. There is no way to perfectly match two tubes well enough not to mess with the idea of the whole concept. They must be eye wateringly expensive too. I love all my SET amps I’ve built and prefer them over PP amps with more power. They have something special that is hard to quantify. I call it the sound of one tube clapping! With very efficient speakers 10 watts is plenty but with 90db or less it’s not really enough to rock the house.
I'm having 95db... biwiring the beefy 18inch BMS 18N862 with clas D.
SET is very tempting indeed...
If you don't need all the power of the 8R tap, choosing the 4ohm one will lower your noise floor by 3dB, a worthwhile improvement.
Since my 100wpc Rogue Atlas is out of warranty I may try a heavy duty DPDT to switch between the 4 & 8 ohm windings; otherwise the top chassis plate must be removed to change transformer wires to the binding posts.
I'm using the 4 ohm output now because the connected Paradigm Studio 100v2 speakers dip below 4 ohms in the "power" region of the bass. This tower speaker has two 8" bass drivers with a large inductor and capacitors for their bass crossover. Perhaps I shouldn't have assumed the amp's 4 ohm output would be more suitable just because the speaker reviewers recommended it. That suggestion may have been intended more for SS amps.
Presently, the bass is quite articulate and 100+ dB SPLs are attainable, without audible distortion, using the 4 ohm amp output. I wonder if I'd lose some bass with the 8 ohm winding?
I'm using the 4 ohm output now because the connected Paradigm Studio 100v2 speakers dip below 4 ohms in the "power" region of the bass. This tower speaker has two 8" bass drivers with a large inductor and capacitors for their bass crossover. Perhaps I shouldn't have assumed the amp's 4 ohm output would be more suitable just because the speaker reviewers recommended it. That suggestion may have been intended more for SS amps.
Presently, the bass is quite articulate and 100+ dB SPLs are attainable, without audible distortion, using the 4 ohm amp output. I wonder if I'd lose some bass with the 8 ohm winding?
In practice about 2 dB assuming SET amplifier does not utilize GNFB.
If GNFB is used, then there is no difference.