Discussion of Solid State vs. Tubes

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Hi all,

I'm just starting to get into the audio world. My experience is basic stuff, HS electronics course, hands on with computer hardware, circuit repair, with lots of reading :D

The books I own at the moment are:
Dickerson's Loudspeaker cookbook
Rosenblit's Tube Audio Design
Some of my dad's old electronic books like:
Navair Volume 1 Electronic Circuit analysis (Airforce tech manual) :D
Navair Volume 2 ELectronic Circuit analysis (Airforce tech manual) :D
Basic Electronics by Paul Zbar (McGraw-Hill)
Industrial Electronics by Paul Zbar (McGraw-Hill)
Basic Electricity by Paul Zbar (McGraw-Hill)
Eletronic Instruments and Measurements by Paul Zbar (McGraw-Hill)
Ordered books that are on the way:
Morgans Valve Amp. Ed. 2
Active filter crossover cookbook
Tube preamp cookbook

Yes, that's it. I typed all that out to give you some backround and show you I'm serious about this.

So, I've been reading this board for months now and I feel I'm ready to start designing a schematic for a preamp.

If I may outline my thoughts of tubes vs solid state:

Tubes
+untouchable detail
+low DF(debatable)
-High voltage
+soft clipping & "pseudo-Loudness" (due to 2nd/3rd Harmonic distortion)
+lower Current
-extra heat
-initial finacial outlay
-replacement of parts more frequent

Solid State
+Lower Voltage
+Less expensive in initial outlay and maintanence
+High DF (debatable)
-higher current capacity of transistors
-Hard clipping
-Live stage effect not there (detail)

What I want to do is have a preamp with 8 output channels
(2front, center, 2 rear, two side, and a sub)
Sorry Audiophiles, I like my AC3 and DTS

So this thing would be a monster.

I want to go the tube route, just because of detail and pure sexiness. But, it would be more expensive.

1. I guess my question is, what are the pros and cons of tubes vs. Solid.

Is my reasoning sound or not?

When reading Bruce Rozenblit's book I found it funny that one could make a UL or Cascode amp and have it so pure that one did away with the tubes main salvation; that of detail or presence.

2. Ignoring heater elements, do tube give the same amount of power per watt that solid state does?

3. And giving the Voltage to Amp ratios between tube and solid state, does one eat more energy?

I apologize for the long post and the extraneous material. I want you to know where I'm coming from. I have been thinking about this for a few weeks and can't seem to put straight in my head to, what I've been reading.

Quite truefully, the initial expense of tubes and their subsequent maintanance, along with those impressive voltages, scare me just a tad.

So what say ye?

Sincerely,

Eternalightwithin

P.S. I hope I haven't stirred up hornets nest too much?
 
Listen! Listen! Listen!

Despite all the technical and theoretical pros and cons of solid state and tubes, people just tend to prefer one or the other. I don't exactly agree with all of your assumptions (you say solid state has no detail) you have sort of the right ideas. Tubes in general, as well as class A amps are horribly innefficient. But, lots of people like the sound and build them anyway. Solid State, if not executed correctly, can sound very bad. Their clipping is pretty nasty, but that's why you design it to have enough headroom not to clip.

Point is, you can reason it out all you want, but when it comes to listening, you are going to prefer one or the other. Go listen to a crapload of amps before you decide. And make sure you listen to a lot because there are plenty of crappy sounding SS and plenty of crappy Tube amps around.

No matter which you pick, half of the world will disagree with you.
 
sam9

First, there is simply the matter of personnal taste. If you simply like the sound of tube amps vs. SS (or the other way around) all the logical arguments are a waste.

That said, your reading list looks somewhat heavily weighted pro-tube. That's fine, of course, but if want to read up on the other side of the debate here's some sources.

www.sound.au.com. Rod Elliots website
www.dself.demon.co.uk. Doug Self's wensite
" Audio Power Amplifier Design Handbook" by Doug Self
"High-Power Audio Amplifier Construction Manual" by G.Randy Slone

For my part I have say a couple of things from my own limited experience:
A-Solid state amps can and have been designed with soft-clipping. The earliest I'm aware of is NAD amps in the late 70's and early 80's. The early ones may have added some noise. These days soft-clipping is fairly common on more powerful higher end designs. (If only because customers were partial to the health of their speakers!)
B-"Live stage effect" has much more to do with acoustic environment and speaker design and placement than the amplifier. I've heard some pretty remarkable results with mid-fi receivers used in good rooms with well placed speakers.
C-It seems to me there may be two strategies to have one's cake and eat it too. Simplest is to combine a tube preamp and a SS power amp. More complex is to bi-amp, using a tube amp to drive the mid and upper range and a SS to handle the bass (especially the deeeep heavy duty stuff).
 
Build whichever you like, but as the marketing dweebs at Nike like to say, "Just do it".

Rest assured that no matter what you build, you'll be messing around with it for many months, then you'll get started on the next generation, better design.

Voltages in tube equipment can be hazardous, and if you have no experience putting together electronic stuff, you might consider going solid state for your first go at it. You can learn to solder and all the mechanical stuff required to build electronics using much cheaper parts so you don't have to worry so much about burning something up.

You'll also learn where to find parts and how much they cost, and what tools you need, and long it takes to build your own equipment. Then you'll learn about how to fix it because it probably won't work the first time you power it up.

You're in for lots of fun and learning. Don't take it too seriously and you'll enjoy every step along the way.

MR
 
Ex-Moderator
Joined 2002
I had tube amps that sounded great (old "Mac 30's") and tube amps that sounded horrible (LUX SUX). But I can say the same for SS amps. In the end, it's has to be what suits you best.

I loved my Mac's but every time I heard a pop, crackle, or sizzle, I thought my tubes were going bad. It was very distracting. I started to become a "Bad-Tube-Neurotic", so I sold them and got an NAD for my horns (Tri-Amp, above 1200Hz). I had a AR D-50 for a while (until it died) that sounded as good as the Mac's. I will stick with SS. I hope to have a DIY Aleph running before the years up, got most of the parts, but we'll see.

You gotta do what makes you happy.
Rodd Yamashita
 
MRehorst said:
Voltages in tube equipment can be hazardous, and if you have no experience putting together electronic stuff, you might consider going solid state for your first go at it. You can learn to solder and all the mechanical stuff required to build electronics using much cheaper parts so you don't have to worry so much about burning something up.

Exactly, good point!
When I go TUBE I have the basics
Will be a pre amp EF86
 
Good post MR
MRehorst said:
Build whichever you like, but as the marketing dweebs at Nike like to say, "Just do it".

Rest assured that no matter what you build, you'll be messing around with it for many months, then you'll get started on the next generation, better design.
Really? That's never happened to me :D

Voltages in tube equipment can be hazardous, and if you have no experience putting together electronic stuff, you might consider going solid state for your first go at it. You can learn to solder and all the mechanical stuff required to build electronics using much cheaper parts so you don't have to worry so much about burning something up.
Absolutely. High voltage has the potential to do you some harm unless you follow all the safety proceedures. It's not hard to learn and mainly common sense, but not worth the risk. See if you can find an older radio or ham operator and ask them to show you. You'll probably pick up lots of useful related info too.

I read on another forum where a total electronics newbie decided to build an 845SE amp with 1kV B+. I hope he and his family have good accident and life insurance. Foolish stuff.

However, tubes are usually much more forgiving of errors than SS stuff. Get an SS amp wrong and it'll belch a bit of smoke and/or sit there cold. Tubes can usually take abuse where you exceed their operating conditions by a lot for a short time and still work. Some amp manufacturers (ARC cj VTL) produce amps where the tubes operate outside their published ratings as standard practice.

You'll also learn where to find parts and how much they cost, and what tools you need, and long it takes to build your own equipment. Then you'll learn about how to fix it because it probably won't work the first time you power it up.

You're in for lots of fun and learning. Don't take it too seriously and you'll enjoy every step along the way.

MR
It takes at least twice as long and twice as much as you expect to build your first amp. But it's much more fun than reading $phile and TAS and auditioning at a dealers. After a while you accumulate lots of spares and tools and it's quite easy to knock up an amp. Buy quality parts and you'll often recycle them into the next one.

Relax, have fun, and enjoy yourself.

Cheers
Brett
 
frugal-phile™
Joined 2001
Paid Member
Brett said:
tubes are usually much more forgiving of errors

tube circuits are also generally simpler with fewer parts than a SS amp. It is generally easier to get them close to good (ie it is harder to make a really good SS circuit than a tube one, just as it is easier to make a good sounding SE circuit than a PP one.

It takes at least twice as long and twice as much as you expect to build your first amp.

This is just a corollary to the 90% rule -- it takes 90% of the time to do the 1st 90% and the other 90% of the time to do the rest.

dave
 
Ex-Moderator
Joined 2002
You forgot, tubes look cool. I'm not plugging tubes, I'd never spend all the cash to make a current gain stage with tubes (they cost alot more then a FET). But they look so weird in a really cool way.

My Mac 30's were monos and I had them sitting next to the speakers, left and right. When I really wanted to listen to music, it would be at night with the lights out. You're right, they looked pretty cool with the tubes glowing in the dark, reflecting against the chrome bases. Sort of "retro-tech". Sometimes I miss them.

Rodd Yamashita
 
Ex-Moderator
Joined 2002
Gro,

Read back to to my first post. I started to develop a "Bad-Tube-Neurosis", so I sold they about 15 years ago.

You're right though, nothing like falling asleep in the swivel-rocker front of the stereo. I one time fell backwards with the chair to the last line of "Stairway to Heaven", HaHaHa.

Rodd Yamashita
 
Oops. What I really meant to post is that Grey has mentioned the aphrodisiac effect of little filaments glowing in the dark. Maybe that will help make up your mind.
I'm thinking my next amp may have a few tubes, but they won't actually do anything other than glow.
 
Ex-Moderator
Joined 2002
What I really meant to post is that Grey has mentioned the aphrodisiac effect of little filaments glowing in the dark.

Soooo... That's what this is all about. Typical engineer, "if a little is good... ".

Rodd Yamashita
 

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