Tune the sound to the recording, or your mood . . .

[rick57]

What do you think of these three 'tweaks':
It's been said the Pass amp designs have become (I haven't had the opportunity to compare) more 'romantic' & less analytical over time, from eg A40 to later Alephs.
Preferences are partly personal, but it also depends on the music, perhaps mood, and the quality of the recording.

Some rock bands use different amps for different songs. After thinking about this, I was considering having an AKSA and an Aleph as switchable amps - for a cost - your cake and eat it.

This of course isn't audiophile: but since '97 (?) some bands go further and use DSP emulations of different 'classic rock amps'.
http://johnson-amp.com/jstation.htm
has a choice of eg 24 amp "emulations" etc, including Marshall, Vox etc! For $140 on a switchable basis, say a tape loop, maybe would be fun (depends on the subtlety and controllability or otherwise).
In a home sytem, it might do least signal degradation routing digital out from CD into such a beast, doing its DSP, then going into a DAC.
You would probably only do it on mediocre quality rock recordings, but that's many of them.
A wannaabe a studio engineer's dream tweak?

On a more serious note, thoughts on this:
the opinionated objectivist guru Doug Self writes a lot at
http://www.dself.demon.co.uk/ampins.htm
Particularly "Distortion in Power Amplifiers":
http://www.dself.demon.co.uk/dipa.htm

Someone in our local audio club, 'inspired' by Self, suggested:
I think that people who are enthusiastic about SETs are trying in there own way to compensate for the damage done by the preceeding 99% of the audio chain.
There are three popular ways to make the reproduction in your home sound better than the somewhat degraded rendition found on the CD that you bought.
You can reproduce the CD through an amplifier that

(1) adds some 2nd and 3rd harmonic distortion. Adding the 2nd and 3rd HD gives the music a sense of warmth and fullness.

(2) Rolls off the treble a bit. Rolling off the treble helps to reduce the effects of clicks and pops and the harshness introduced by the preceding 99%.

(3) Reduces the attack of notes. Reducing the attack tends to emphasise the tone and decay of the notes. It emphasises the flow of the music and makes the music gentler.

If Douglas Self wants a "niceness" knob to put on a "blameless" amplifier, that should be easy for him or for you. All you need is one stage with local feedback that remains stable irrespective of the level of feedback, and a knob on the front of the (pre) amplifier to control it.

Lowering the feedback will add harmonic distortion, reduce attack (leading edge of the note) in the midrange slam in the bass and roll off the treble all at the same time.

You can turn up the "niceness" for simple music like acapella, quartets and Sade or turn it down for complex orchestral or rock. Turn it up for triode fans, or down for the dry objectivists.

Turn it up when you get home tired from work and want the emotional nourishment that music can provide, and turn it down for critical listening of a guitarists technique.

The point is that some people like "niceness" some or all of the time, it is easy to do, and it can compensate for deficiencies in the other 99% of the chain.

(I think) he was being tongue in cheek, but that appeals to me.
Ridiculous, or some merit?

[Jay]

1. Romantic vs Analytical. I think what amplifier designers do when they just graduate from “school” is to implement the theories they got from their teachers and books. There’s no element of biology and psychology in electronic books I have read. The real life is different. There’s no (yet) physical metrics for fatigue, harshness, depth, involvement, etc.

Tube amp design is the most romantic design I guest. The tube fans are indeed romantic people. Once you get old, you won’t need the hard slams from Sepultura. And your ears may not be able to hear hi frequencies anymore. So that sweet vocals is all you need when you get older.

I wonder how old Mr. Pass is by now. Thirty-nine? But as far as business is concerned, it is not the designer’s preference that is important. But the preference of market segment in target.

2. Having AKSA and Aleph at the same time? I used to have many amps and speakers at the same time, but never done any bi-amping. I did use many speakers in series and parallel (just curious), and they sounded great, but the physical configuration didn’t suit my taste. I want a compact CD Player, a compact integrated amp, a beautiful bookshelf speaker, and they sound just like in a live music show.

3. Yes you can reproduce the CD through an amp (pre-amp to be precise) the way you specified. So you may create this type of CD: DADADADADADAD. The result will surely be nice and warm, but lacks dynamics I guest, something that I believe is more important.

The better way is, you create a reference audio system, document it’s specifications, and create a digital-to-digital converter that alters the original CD to match your reference system.

[rick57]

> I wonder how old Mr. Pass is by now. Thirty-nine?
(Maybe it's the grey hair, but I think he's more 49-59.
Still he's got lot a lot more hair than me)

> Having AKSA and Aleph at the same time?
I . . . never done any bi-amping.

The idea I’m suggesting is not bi-amping (though this could be done on eg the mid-range amp of eg a three way active system) but “switchability” or “tune-ability” of a system, depending on particular music style being listened to and/ or recording quality:

(1) Being able to switch either ONE of two amps (eg Aksa OR Aleph; or Aksa or say a tube amp) in as the more appropriate working amp; or

(2) Tuning the sound by either
a) adjusting the level of feedback (several tube amps allow this)
I think eg the Pass A75 allows adjustment of feedback, but only via changes component values, rather than a “control knob”

b) the more extreme/ artifical idea of using a DSP 'amp emulator', like an http://johnson-amp.com/jstation.htm

The point is that some people like "niceness/ warmth" some or all of the time, it is easy to do, and it can compensate for deficiencies in the other 99% of the audio chain.

[Jay]

I got your idea as in case (1), and I expressed my “philosophy” that even I ever had the chance (having many amps and amplifiers) to have great sound (e.g. by bi-amping), I still didn’t follow the way. Wouldn’t it be nice to have a small beautiful speaker that rivals MTM floor-standers? Wouldn’t it be awful to have 5 stacks of amplifiers and 4 pairs of speakers but the sound is “average”? (May be because you use only one amplifier at a time). One may disagree, but I know that to most people, the sound is not the only thing.

Creating a remote that can switch amplifiers/speakers is not a rocket science either. Having no-one implement the idea is not because audiophiles are not resourceful, nor because they don’t have the skill. Well, frankly I don’t know why. What do you think?

Having the ability to adjust feedback? How? Changing resistance? How? You will need to create special PCB with “potentiometer” on it, and run a metal bar from it to the knob on the center panel. Or adding small relay on the PCB to switch a series of fixed feedback value? Or run a cable from the PCB (not a good idea)? I cannot see the difference between feedbacks in A75 and tube amps. A sudden change in the feedback resistor may create some form of instability (if the amp is still on). Having a dip switch on the amplifier panel to allow for feedback variation (for industrial consumer) may be useful, not so for the manufacturers. For audiophiles, they should have known the optimum value, and be able to change it when they change their system (e.g. changing speakers).

I just visited the link above (the last dot should not be there ). As far as I can remember, I didn’t read anything else other than a use of multiple amps (and speakers), similar to the previous case (1)

[pinkmouse]

Originally posted by Jay


I just visited the link above (the last dot should not be there )

Fixed

[halojoy]

I believe in using "natural sounds as" as listening reference
This is mainly for to check out the Loudspeaker system.

HIFI is my way.
The reproduced wave ( close to the speaker)
should be in accordance with the the wave of the source.

nowadays CD-players, Preamps(if they are needed) and poweramps
leaves a so low distorted wave at output,
that I call the result
HIFI, High Fidelity (=very true to the source material, ie the recording)
And now we are talking Solid State with normaL amount of NFB.
That is also the closest you can come Hifi.
Because this gives the lowest distortion.
And distortion is the magnitude and quality of difference
from the input signal, source material.

Do not say that HiFi always = enjoyful listening,
But in the most cases this offers the best listening pleasure, as well.

/halo - likes low distortion figures, below 0.1%
- over intire power bandwith

AN HIFI Speaker:
Dynaudio Audience 42

[rick57]

It’s not for the manufacturers, or purist audiophiles, it’s for those who realise that with a lot of material, the purist audiophile approach can limit enjoyment of the music.
These ideas are not meant to be hi-fi. Other things being equal, I like the best fidelity.
(When space allows) I'm intending to build my interpretation of the Linkwitz Phoenix, with PHL mids and ribbon tweeters.

The 3 ideas above are about when other things are not equal - if the recording is lousy. How do we compensate, to best enjoy the music?

How to adjust feedback? I'm not an amp designer so further suggestions are welcome. Instability would need dealing with.
> A separate PCB with “potentiometer” on it, a dip switch or a small relay to switch a series of fixed feedback value?
a dip switch on the front panel with say 2-3 settings could best balance desirable flexibility with need for stability

Maybe there isn't a difference between feedback in solid state and tube amps?
Several tube amps eg some well regarded Manley amps have adjustable feedback.
A different option is adjustable bias, but I don’t think this would “compensate”.

[sam9]

A prior post wrote: " Once you get old, you won’t need the hard slams from Sepultura. And your ears may not be able to hear hi frequencies anymore. "

For the record I'm old and prefer amps that respect me and the recording artist. That means the signal at the output should be as close to the signal at the input (only louder, i.e., with gain) as possible. There are plenty of ways to alter a piece of music if I care to and allow me personal control over the result. What I don't care for is an amp designer that imposes his/her personal taste on me or on the artist.

[sam9]

My scheme for "niceness". Buld two preamps in one enclosure. One is SS one is tube. The tube unit should be the best current practice as should the SS unit. Upstream, put a pot wired as a voltage divider such that the signal can be routed 0%-100% to either unit. Down stream, sum the signals back together. Let the user decide how much niceness he/she wants by adjusting the dial.

[Tube_Dude]

Hi Sam 9!!!!

100% agred with you!!

Is nice to see people that d'ont have lost is way in audio!

Cheers!

Jorge Santos

PS: Is best to invest in some beer than certain magic portions for the best sound on earth!