No one actually knows how to lculate what speaker cable they need

Mr. glupson

DF is an amplifier design and making matter that may advertised whatever they felt its right.

The high DF is all about controlling the speaker. In electronics, the common idea about it is: the more the better. (Just the opposite of THD or noise: which is the less the better). However, some likes better the sound of amplification with higher THD and very low DF: tubes. That’s Ok too.

The new kind of D-class (digital amplifiers, using direct DAC as PWM) have DF of 5000! Even thou those need to be related more like a DF of 1000 (way of calculation).

I'm not into say what amp is better for you (it might be another thread) but I do say, for the amp you already own, what would be the best speaker cable.

Mr. flapjack

What could be better than a dual purpose cable?

If you would read my thread, you could already know that tube amplification have a very low DF, so you could practically borrow your line phone cable and use it for your speakers. If that would be also a long one, you could use it in between listening to your tubes and speaking on the phone, to hang your wet laundry.

Looks like you have altered your exell sheet. Your original spreadsheet had 3 participants your game, you have deleted Willson and now only have conradnash & keppertup on the latest version. It looks like the satisfaction level has dropped a half point too, from 9 to 8.5. You also removed keppertop's cost for the project. What's up with that?

https://imgur.com/a/dPO2o1p

Mr. stevecham

Your post is way off the subject and your attitude is rude. But I'll clear a few facts about your Manley Neo 250 with your speakers. https://www.manley.com/hifi/n250/

At a DF of 14.8 / 17.2 (output resistance = 0.5 Ohms) and a 4 Ohms load @ 218W, 1/8 or 12.5% of that power is dropping on the amp's and 7/8 on the speaker. So you are wasting 27W of the 218W. This is way the cable in your case has no significance. I really would care, if I would you, in such case about the DF.

At the time tube amplification first introduced, the amps had very moderate power: 10W-20W. At that time the DF was the same and it was not a problem. Some designs looked into tube as "what was missing is more power", made it to deliver a 250W but over looked all other aspects.

Your speakers demand way more than 1W. They are very demanding on impedance and low efficiency. So why would you bring up the 218W power, if you think you need only 1W? It is true that as close as you get to 0W, all problems are gone!

The spec. defines 1.5% THD (it's a lot!) and I can't hear it because I'm 10,000 miles away. But anything above 0.2% is audible. 1.5% is a bad figure for today amps.