Hello, i would like to make a quality tube amplifier for household use and research for a schematic.
I have not any experience on this sector and any help is welcome. Know anybody to suggest me a schematic? I need and preamplifier or not? As source will be a CD player or anything else.
Thanks in advance.

 

Hello,

Perhaps you can get some ideas from the following book:
https://archive.org/details/ValveAmplifiers

Bertus

 

What is your budget for this? Some of the major components (e.g. a high quality output transformer) may be hard to come by and expensive.

 

Bertus thank you for the link. I will learn many from it.
About the budget i have not any idea. I think 200-300 Euros, but it is not absolute.
I have see many schematics, but i don't know on which of them I can rely on, if preamplifier is neccesery and enything else that i must know.

 

A preamplifier is required if you want tone controls.
Otherwise you can likely drive the amp directly with a pot at the input for volume control.

 

Why tubes?
Do you want stereo (two channels)?
How much power per channel?
Look for an ultra-linear design.
Note that good audio power transformers run upwards of $100US each.

 

Why tubes?
Do you want stereo (two channels)?
How much power per channel?
Look for an ultra-linear design.
Note that good audio power transformers run upwards of $100US each.

I would like tubes because (i thing) of the high sound quality and for the beautiful (for me) look.
Yes i want two channels. The price of transformers yes, i see now, they are expensive.
The true is that i have not hear real tube sound. Only in youtube videos compared with solid state.
Do you think that it is not worth it? The balance of money and final sound quality?

 

Do you think that it is not worth it? The balance of money and final sound quality?

Some audio-fanatics with a "golden ear" claim tube-amps sound better.
To me that just means they like the sound of the typical 2nd harmonic distortion, or the high frequency roll-off that tube amps often have.
A good solid-state amp requires no transformers in series with the audio signal, (I remember some people actually constructing amps with multiple output tubes in parallel so a transformer, with its deficiencies in producing HiFi audio, wasn't required) and good solid-state amps have nearly unmeasurable distortion. Plus they are more efficient and you don't have to periodically replace the tubes.

For example Siegfried Linkwitz, one of the premier audio speaker designers, (he also co-invented the widely-used Linkwitz-Riley crossover filters) uses only solid-state amplifiers in his designs, so that's good enough for me.

So, unless you are really into tubes for their look, I see no reason to use them.

 

You could always cheat and use a solid state amp with a couple of tubes doing nothing but glow .

 

Some very expensive audio amplifiers have a solid state circuit but have tubes glowing on top. They are made for Audiophools.
Audiophiles use modern extremely low distortion solid state amplifiers that are not very expensive anymore.

My first hifi amplifier 57 years ago used vacuum tubes. The output tubes needed to be replaced every 3 months to keep the distortion less than 10%. I replaced it with a hifi solid state receiver 54 years ago and used it without replacing anything until last year when its selector switch wore out.

Electric guitars use antique vacuum tube amplifiers because they like the mellow distortion and reduced high audio frequencies.
Some bands replace the tubes for every show.

 

The issue was settled for me way back when transistor amps were fairly new. Popular Electronics decided to test a high quality tube amp against the latest and greatest transistor amp with blinded listening tests performed by an audiophile group. They all picked the tube amp. The writers than analyzed the outputs of the two amps. The added distortion, reduced the frequency response and even added 60 Hz hum to the transistor amp then retried the test. The audiophiles could no longer tell the difference between the two.

Bob

 

You could always cheat and use a solid state amp with a couple of tubes doing nothing but glow .

A pair of KT88's would look impressive.

 

I always suspected that a portion of the "tube character" was the power supply.

 

I always suspected that a portion of the "tube character" was the power supply.

It what way?
The output sound of a tube audio amp can be generally explained by the tube and audio transformer characteristics.
No need to involve the power supply in that.

 

Hello,

Here are some pages with some tube amplifier and other schematics:
https://www.ampage.org/schems/
http://www.schematics.ca/

Bertus

 

If you wanted to start simple this Bogen class A PA amp is fairly simple if you can find the parts.
SG

 

The schematics posted of old vacuum tube amplifiers are not hifi, instead they are for severely distorted electric geetars.
They make fuzz and overdrive noises.

The Bogen low power PA amplifier is also not hifi.

I remember 57 years ago a MacIntosh vacuum tubes amplifier was hifi, when its tubes were new.

 

The Bogen low power PA amplifier is also not hifi.

Nobody said it was. It was just an example as a starting point.
SG

 

Building tube equipment would be difficult for the un-experienced. Buying an rebuilding old tube equipment can be interesting.

 

Thanks you all for your infornation. I will study it a little and I will even decide. Maybe I turn to solid state.