Technics integrated sug 700

holmz thank you for your time and expert explanations it is appreciated.

I often read about this amp or that has good headroom. I thought it meant that at loud levels when you are pushing your amp to its limit and the music pushes it over its max it has a reserve that can cover that brief moment of sound without clipping. Now I think it means having enough watts to cover any musical note played at volumes up to and including those which will make your ears bleed before the amp will clip. In short, your ears will clip before the amp.

 

Can someone answer me is this a high current amp it is 70 watts at 8 ohms 140 at 4 ohms? that all they tell you in the manual

At 70W and 8 ohms, then the rails would be at ~ 24V.
Current at 8 ohms would be ~3A and at 4 ohms would be ~6A.

Which doesn’t really matter a lot, as the speaker will define the current it needs. The amp is not shoving current in… the amp is supplying a voltage, and what current that the speaker requires is defined by the voltage and the speaker’s impedance.

Also what is the headroom of this amp? How do you determine headroom if it is not specified by the manufacturer?

I am not sure I understand?

The headroom is high when the volume is low, and it is decreases as the volume is raised.

As you can tell I’m not up to speed on what constitutes a good amp? Is a good just how it sounds to you?

How it sounds is a great start.

Also, I noticed that its THD is rather high for an SS amp at "70 W + 70 W (1 kHz, T.H.D. 0.5 %, 8 Ω, 20 kHz LPF)
140 W + 140 W (1 kHz, T.H.D. 0.5 %, 4 Ω, 20 kHz LPF)" from their manual.

What does .5 THD actually mean in terms of hearing distortion? if it is there I can’t hear it I’m 75 so my hearing sure is not normal far from it. I know it is a measure of distortion but just how important is it and at what % should raise concern

Unless one knows where the distortion is, then the number is somewhat meaningless. (I.e. 2nd harmonic, or higher harmonics, IMD, etc.)

If the THD+N is close to zero, then we do not care as much where the distortion is, because it is low.

Many tube amps have high distortion numbers, but their distortion profile is sonically appealing.

And many speakers can have distortion numbers that are higher than 0.5%

Basically… if you like it, and it sounds good, then I would not fret about it too much about the distortion numbers.
And if it plays loud enough, I would not fret much about the wattage numbers.

However if you play it loud, and your speakers are super low distortion, then the amp can make more of difference. And if the speakers have a really low and difficult impedance, then that also stresses the amp.