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In the Forum: Audio For Dummies ™
In the Thread: SET and speakers: disregard Volume
Post Subject: SET and speakers: disregard VolumePosted by Romy the Cat on: 2/7/2007

Among many outrages foolishness that are so common among the people who going high-end audio one of the most ridicules is use of Single-Ended Triodes and low sensitivity speakers. The people who have db-meters between their ears instead of brain are under impression that compatibility between amplifier and speaker could be described ONLY by power rating and load sensitively. When they consider they have a correct ratio? When they have enough volume for a given listening space. Nothing could be further from truth - volume is hardly in the picture.

I have seen many times when Morons claimed that a given SET was  able to play “even too loud” still the Morons failed to note that the amplifier sounded like it was driving too heavy load. Since most of the people outs there in complete denial about the subject I will give a very brief survival guide for recognition of SET-to-speaker compatibility (here and below it will call it the Compatibility

Mostly, and very contrarily to common practice, disregard the assessment of the Compatibility by looking at LF clipping. Yes, when a SET runs out of power it clips LF. However, different topologies of LF enclosures handle that clipping-sound differently and different output stages behave differently at max power and at max currant in output transformer. So, the observing of bass is not an objective incaution of the Compatibility. BTW, there are few other reasons why bass should not be a target of attention but I will not dive in this article into those reasons.

The most objective indication of the Compatibility is observing the MF. In this area a SET is far always from any saturations in output transformer, the dimension of the room is way less critical and sound is very easy identifiable for own sensitivity-power compatibility. So what to listen while you are listening?

1) Mechanical sound in upper MF. In 90% of all cases if you drive 95dB speakers with 20W SET than it is might be “loud enough” but at the same time the upper MF sound mechanical. Have you head bad turntable setups when tonearms sound mechanical? It would be the same.

2) The “sculpture in wall effect”. The upper MF do not sound as independent sound but rather as relief over the entire range. Any “space” information in upper MF non present.

3) The “Wet Fur Effect”. Arming with “Wet Fur Effect” you will be able after 5 seconds of listening to draw a collusion if a given speaker is “too dead” for a given SET. (In the past a number of “big names”, seeing as I discarded setups after a few seconds of listening, made a conclusion that I was too superficial and did not even listen the playback enough. Well, there are reasons why I consider most of the audio’s “big names” as pathetic Morons)….

Anyhow, what is the “Wet Fur Effect”? Look how the hair of your fuzzy women looks like if she did not wash them long enough. They are not fluffy and if they not feel this way but at least then look greasy. OK, let do not put women in uncomfortable position and let make more politically correct and more illustrative example.  It will be juts for the sake of association.

Take (hypothetically only!) your Cat or if you are less lucky your dog. Dump her in bathtub, wash he with soup. Then dry your pet with towel. Then put your pet on a middle of carpet and looks at her fur. It is wet and it is not stick out as it should. Now begin to dry your pet with hair blower for instance. The dryer the pet’s fur will be the more distinctive and the more spatial each individual practical of hair will be. The very same is with upper MF and SET amplifiers.

Any low sensitively, dead speakers/driver sounds like wet fur in upper MF. In fact in many cases increase of SET power without increasing the load sensitivity DOES NOT improve situation. I do not why but it was what I have observed. Driving a 92dB for instance speaker with 2A3, or 45, or 300B SET makes upper MF sound like your Pet is submerged under bottom of the Marianas Trench…. even though in some cases YOU HAVE ENOUGH VOLUME.  Increasing SET powers to 211, 845 or to 6C33C do improve bass and sound generally but it does not dry out your pet. I’m not well familiar with sound of 50W-100W SET amplifiers and I might not speculate. However, regardless of the speaker class and type, moving speaker up in sensitivity instantaneously removes moisture from the pet’s fur, making the upper MF to sound as they should.

Romy the caT

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