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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

Showing 2 responses by larryi

larryi
4,326 posts
 

I agree that zero feedback and single-ended are quite direct sounding.  But, some of the most direct, immediate and vibrant sound can be had from output transformerless tube amps. 

This would be a rough generalization because I've heard some extremely direct sounding push-pull amps too.  Among the very best amps I've heard are the Western Electric 59A (crazy rare and expensive-pushpull), a recently built one-of-a-kind 271a amp (indirectly heated triode-pushpull), and a one-of-a-kind output transformerless amp. 

I own two amps that are not too bad in terms of delivering an immediate and vibrant sound: 1) a modern build of a Western Electric 133a (using vintage parts, including authentic WE input and output transformers and plate-type resistors); and an Audio Note (uk) Kageki (parallel single-ended).

larryi
4,326 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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