Audio amp question

Thread Starter

phil patterson

Joined Mar 25, 2015
24
Well thats what my impression was as well, but I think that since in the beginning amps started out with tubes, I think that that might be the best way to start...
 

AnalogKid

Joined Aug 1, 2013
12,128
Relative to "equivalent" solid state designs, I've always found tube audio to be somewhere between inconvenient and a real pain, primarily because it has, well, tubes. The kit you've selected looks like a good starting point.
I think that since in the beginning amps started out with tubes, I think that that might be the best way to start...
Umm ... no. I'm not being snarky here - this is a real question: did they make you learn how to ride a horse in driver's ed? -- OK, that was a bit snarky.

100% of the signal system concepts are easier to learn in solid state circuits, and 100% of the biasing gorp has no value except in other tube circuits.

ak
 
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Audioguru

Joined Dec 20, 2007
11,248
I quickly looked for a "clone" amplifier kit that uses the excellent modern LM3886 IC that is not a Chinese kit sold on ebay. I couldn't find one but instead found an antique solid state amplifier kit designed in England in the '70ies. This Naim Nap-140 kit is made by companies in England, America, Canada and China and is $34.00US but without a power transformer and heatsinks. I found a schematic but no spec's.

Soldering some parts together does not teach you anything about electronic circuits. A course will teach you but I am not a student or a teacher so I don't know of any good courses.
 

Thread Starter

phil patterson

Joined Mar 25, 2015
24
I’m starting to think that some of this tube vs solid state is generational....When I grew up in the 50’s, most things were tube, and crystal radio kits were also popular (as was shortwave in the 60’s...DIY’ers were mostly those nerdy ham guys)...I witnessed as the very first ‘mystical’ transistor pocket am radios begin to hit the market...6 transistors were considered a top of the line status symbol !!....They were a big hit and quite extravagant because they could be carried in ones shirt pocket - prices eventually dropped as they went mainstream...Boy, the things we now take for granted!!...I feel very lucky to have lived in the 50’s and for having to wait in anxious anticipation for the radio tubes to warm up to a point where they’d glow, or to tirelessly search for a distant am signal on a ‘wireless’ batteryless crystal set - lol..... Admittedly waxing romantically here, theres an upside and downside to everything - as electronics has changed (in every way for the better??), Oh so has America...
 
There are different classes of audio amplification. Most known as class A, class AB and class D. There is amajor difference in all of them/

Goals are:
1. No DC on the speaker terminals (Capacitor and transformer coupling ae two ways to eliminate)
2. Efficiency (class D is the highest) There's class A, AB and D ( and sometimes H) that are used for audio. You might start there.
3. No crossover distortion. The area where the signal crosses the voltage axis.
4. Distortion (TIM, IM)
5. Sound (Valve vs solid state)

Dual rails allow one supply to be used for negative going voltages and one for positive going voltages.
 
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