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What makes an amp sound more direct ?

In our hifi journey we have probably all heard amps with different topologies and implementation. Most of these amps would have an implementation which is a combination of one of these:

1. Single Ended
2. Push-pull
3. Balanced
4. Differentially Balanced
5. Class A, A/B, D
6. High/Low Damping factor
7. Zero Negative Feedback (global & local)
8. Low/Medium/High Negative feedback
9. 2/3/4/multiple gain stages

There will be more such items that can be added to the list. My curiosity arises from the fact that some amplifiers (or even preamplifiers) sound much more direct than others. The ones that does this trick generally seems to do the "they are here" trick very well. While the components which sound relatively indirect cast a sound scape which gives the perspective of "we are there".

Just from my observation, single ended and zero feedback designs sound much more direct than balanced designs especially ones with high negative feedback. Is this a coincidence or is there a valid reason behind this ? 
pani
pani OP
1,219 posts
 
jmcgrogan2, it is not exactly a soundstage phenomenon per se. Immediacy...yes. Direct sound is a bit self-explanatory already, the way the sound is directed to the listener. The listener actually feels a touchy-feely with the instruments in the room as if they are being played "for him". Even if the stage is behind the speaker, the way the notes are formed is like looking through a lens whose focus on the objects are spot-on. Sometimes it becomes difficult explain these phenomena even though it is ubiquitous.

Larryi, I had a couple of 300B SETs at home and also the famous Tenor Audio OTL 75 amp (its a push-pull). It was very clear that the Tenor did not have the directness of the SETs but it was clearly faster with wider bandwidth. Interestingly Naim amplifiers have a very direct sound though not in the same league SETs, still...
Similarly the Nelson Pass Firstwatt amps also sound more direct than most of the other typical SS amps including the Pass XA.8 amps.

Recently I heard some SS amps which were very well built, with very high damping factor. Even though they were tonally nice (not SS dry) they clearly sounded "indirect". 
unsound
7,336 posts
 
IME, this directness you speak of usually has more to do with the recording technique than anything else.
pani OP
1,219 posts
 
unsound, I am talking about directness of a system. If you have listened to some horn speakers you will relate to it. They may not sound forward but horn speaker have a way to convey the music in a very focussed way. That aspect also happens in the electronics side. 
mapman's avatar
mapman
22,532 posts
 
I'm not sure its possible to associate "directness" inherently with any electronics.   Speakers and room acoustics would seem to be the main factors.   Some speakers are more directional than others ie more sound firing directly at you versus other directions.   Room acoustics will determine how much reflected sound reach your ears compared to direct.

It may be that many zero feedback and SET amps tend to sound this way in that they tend to work best with higher efficiency speakers many with horns or waveguides that in fact direct more sound towards you, which in genral means the system is more efficient in taht more of the sound produced reaches your ears directly rather than via reduced volume reflections that travel further and are hence not as loud as the direct sound.
larryi
4,135 posts
 

Pani,

I think we are in agreement on what is lively and immediate sounding.  I had a friend's Firstwatt amp in my system for two weeks and it sounded very good.  It was very lively, immediate and could hold one's interest in the music for a very long time, just like very good tube amps are good at doing.  The only slight negative for me was the slightly artificial "edge" or hardness to the initial attack of notes.  With that edge can make things sound fast and exciting, after a while, if it is pervasive, the sound becomes "mechanical" (sameness to the presentation) and I lose interest.  I find that to be much more the case with Naim amplifiers than the Firstwatt amp I had in my system and I certain could easily live with the Firstwatt amp (one of the best solid state amps I've heard, and not very expensive too). 

I personally did not like the Tenor OTL 75 amp I heard.  It really did not deliver the kind of liveliness and immediacy which is the raison d'etre of OTL amps.

Most of the higher powered solid state amps I've heard sound dull and lifeless unless they are being used to really pump up the volume level.  These things do not play well at lower volumes.  But, if one needs high power, solid state may be the way to go; most higher powered tube amps sound hard and glassy and unpleasant.  Give me low-powered amps, and speakers that play well with them. 

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