[glynnw]

Like may Circle members I have been on a lifelong search for the perfect amp (at least to my tastes) and have owned at least 6 or 7 amps in the last 5 years - including Shindo, First Watt, Music Reference, Carver, a custom 2A3, a custom F2, and more...you get the picture.  A while back I purchased a pristine Conrad Johnson MV75a - bought it from the original owner who had had it maintained by a tube place in Seattle.  Having purchased a new CJMV45a-1 back in the day, I bought it more as a collector piece than with an intention to use it heavily.  I love this amp, played through both a Spatial Audio M3TM and Daedalus Custom Studio spkrs.  It brings an ease to the music, a flow if you will, that I seldom find in amps.  No claim that this is the last amp for me (although at age 72 it might well be) but I have to ask what the heck have amp designers learned in the 40 years since this MV75 was designed? 

[FullRangeMan]

Imo the transformers are great in this amp, a long with the huge power 75W, by the little I know other parts are usual.
Congratulations

[FullRangeMan]

About the title of this topic I wish clarify that a current new tube amp have real chance to sound worse than a vintage tube amp from the same price, due some factors as current tubes have short life and worse SQ than the NOS tubes, mainly NOS military tubes.

A simple SE tube amp from 1930 years as AD1 or 300B already have great SQ for current standards and in the next centuries also will have great SQ compare to the amps of the future, the tube amp sound becomes a classic, a reference.

[OzarkTom]

Marantz 8B is another to look at. Made in 1962 and now selling for 3K and more on Ebay. That one is better sounding than the CJ, but at the current price probably out of reach for many.

At one time I could buy them for $600-800. Now where is that Delorean.

[Early B.]

My guess -- at the end of the day, it all comes down to build quality. This applies to most industries, not just audio. Decades ago, goods were generally made with higher quality parts and designed to last. My first car was made of US steel. Today, it's fiberglass which will dent if you press your finger on it too hard. Technology notwithstanding, which car would you choose today?

The design of amps hasn't fundamentally changed in 50 years, so what's left? Parts quality. Today, a high quality amp will cost several thousand dollars and is out of reach for most people.   

[FullRangeMan]

My guess -- at the end of the day, it all comes down to build quality. This applies to most industries, not just audio. Decades ago, goods were generally made with higher quality parts and designed to last. My first car was made of US steel. Today, it's fiberglass which will dent if you press your finger on it too hard. Technology notwithstanding, which car would you choose today?

The design of amps hasn't fundamentally changed in 50 years, so what's left? Parts quality. Today, a high quality amp will cost several thousand dollars and is out of reach for most people.   

Correct. Recently I said in other topic to chosse a amp by built quality not by sound quality and was criticized.

[glynnw]

FYI, I am using new KT120 tubes - I think the others are NOS, but the markings are almost gone.

[FullRangeMan]

FYI, I am using new KT120 tubes - I think the others are NOS, but the markings are almost gone.

Nice, when you had a consistent info on the time life of these 120 let me know please.

[galyons]

Correct. Recently I said in other topic to chosse a amp by built quality not by sound quality and was criticized.

Because the statement lacks merit.  Sound quality is paramount.  Build quality is a waste of effort and resources if it does not sound good. (There are way too many examples of that foolishness.)  It follows that a good design, well implemented is most likely to produce quality sound. But to say "chosse (sic) a amp by built quality not by sound quality" is the opposite of good sense if one want to reproduce music with fidelity and quality.

Why is that concept so difficult to comprehend?

Cheers,
Geary

[Early B.]

Because the statement lacks merit.  Sound quality is paramount.  Build quality is a waste of effort and resources if it does not sound good. (There are way too many examples of that foolishness.)  It follows that a good design, well implemented is most likely to produce quality sound. But to say "chosse (sic) a amp by built quality not by sound quality" is the opposite of good sense if one want to reproduce music with fidelity and quality.

I believe what FRM is saying is that great amp designers are more likely to use high quality parts because they know that quality improves the sound. Very few of us have the luxury of testing an amp in our systems before we buy it, so one approach is to buy based on build quality. That's how I bought my amps.

[galyons]

IMO, the problem with "modern" tube amps is that designers have, for years now, made them sound more like solid state amps than traditional tube amps. Audio Research led the decline into overly sophisticated circuits, other manufacturers followed.  Sand regulated  filament supplies, sand rectified and regulated B+,  transistor based constant current sources, etc. have robbed modern tube amps of the very characteristics that make a tube amp a tube amp. As speakers become more " sophisticated", (read as less efficient), designers pushed the power tube dissipation to near the limit in search of ammo in the wattage wars.  Now, not only do the modern tube amps not sound as good, they are often less reliable, as well.

I am still a SE DHT, paper-in-oil capacitor, horn speaker luddite!  So take my opinions with that in mind.

Cheers,
Geary

[galyons]

so one approach is to buy based on build quality. That's how I bought my amps.

How does one go about doing so?  Purchase based on schematic? Purchased based  on BOM? ... Audio mag reveiws? ....Pictures? 

Asking for a friend! 

Cheers,
Geary

[witchdoctor]

My guess -- at the end of the day, it all comes down to build quality. This applies to most industries, not just audio. Decades ago, goods were generally made with higher quality parts and designed to last. My first car was made of US steel. Today, it's fiberglass which will dent if you press your finger on it too hard. Technology notwithstanding, which car would you choose today?

The design of amps hasn't fundamentally changed in 50 years, so what's left? Parts quality. Today, a high quality amp will cost several thousand dollars and is out of reach for most people.   

I happen to agree with build quality but amp design HAS fundamentally changed but not because of the amps per se, but because of room correction systems. The OP stated he was never 100% satisfied with his previous amps. I get it but was the amp the problem or how the amp sounded in his room?

paradigm has ARC room correction in their Anthem and Paradigm line of amps. It is a HUGE difference. Check out my review here:

https://www.audiocircle.com/index.php?topic=162334.new#new

[Tyson]

IMO, the problem with "modern" tube amps is that designers have, for years now, made them sound more like solid state amps than traditional tube amps. Audio Research led the decline into overly sophisticated circuits, other manufacturers followed.  Sand regulated  filament supplies, sand rectified and regulated B+,  transistor based constant current sources, etc. have robbed modern tube amps of the very characteristics that make a tube amp a tube amp. As speakers become more " sophisticated", (read as less efficient), designers pushed the power tube dissipation to near the limit in search of ammo in the wattage wars.  Now, not only do the modern tube amps not sound as good, they are often less reliable, as well.

I am still a SE DHT, paper-in-oil capacitor, horn speaker luddite!  So take my opinions with that in mind.

Cheers,
Geary

Agreed.  I've churned through a fair number of tube amps and have a few "rules of thumb" when it comes to buying anything nowadays:

1. Must use octals in the driver stage.  Sorry but octals just sound better than peanut sized 9 pin tubes.
2. Must use a tube rectifier.
3. Single Ended generally sounds better than push-pull.  Single ended parallel is the way to go if you need more power.
4. Small amounts of feedback can be OK, but moderate or large amounts of feedback always sounds bad (tube or SS)
5. Parts quality is important, especially transformers. 

[witchdoctor]

Agreed.  I've churned through a fair number of tube amps and have a few "rules of thumb" when it comes to buying anything nowadays:

1. Must use octals in the driver stage.  Sorry but octals just sound better than peanut sized 9 pin tubes.
2. Must use a tube rectifier.
3. Single Ended generally sounds better than push-pull.  Single ended parallel is the way to go if you need more power.
4. Small amounts of feedback can be OK, but moderate or large amounts of feedback always sounds bad (tube or SS)
5. Parts quality is important, especially transformers.

How much of that tube magic can be obtained with the iTube in your opinion used as a buffer between a source and a preamp?

[Tyson]

How much of that tube magic can be obtained with the iTube in your opinion used as a buffer between a source and a preamp?

If you're running an SS system and just want some better tonality, a buffer like the iTube2 is a good option.  On the other hand, if you're running a fully tubed system already (I am nowadays), then an iTube2 is redundant. 

The tube the iTube2 uses, the 2C51, is one of the very few 9 pin tubes that sounds (and measures) like a 6SN7.  Which is probably why I like that buffer so much (and it's also used in the iDSD Pro, which I really love). 

For pure tube magic, nothing really beats my Type 45 SET amp with 6SN7 drivers.  It's just really low powered at only 2 watts.  Luckily I have 97db efficient speakers so it's possible to use an amp like that.  Beauty uber-alles is really the style of that amp.

However, the 45 mostly sits in the closet because the Dennis Had Inspire amps have a similar level of beauty and clarity but with quite a bit more grunt.  Love those things. 

EDIT:  But, to go back to the original post, re: how can something so old sound so good.  I have another crazy theory.  That electronics (like good quality tube gear) actually sounds better with age.  And the more age, the better.  Obviously some parts wear out and need to be replaced (electrolytic caps, especially), but I think other parts like transformers, wires, film caps, etc... all mellow and bloom over the years. 

Which is part of why I never buy tube gear new.  I'm perfectly happy to let someone else put a few thousand hours on a piece of gear.  The more, the better. 

[Early B.]

How does one go about doing so?  Purchase based on schematic? Purchased based  on BOM? ... Audio mag reveiws? ....Pictures? 

After buying lots of amps (tube and SS) over 25 years, you learn what to look for.   

[FullRangeMan]

Because the statement lacks merit.  Sound quality is paramount.  Build quality is a waste of effort and resources if it does not sound good. (There are way too many examples of that foolishness.)  It follows that a good design, well implemented is most likely to produce quality sound. But to say "chosse (sic) a amp by built quality not by sound quality" is the opposite of good sense if one want to reproduce music with fidelity and quality.

Why is that concept so difficult to comprehend?

Cheers,
Geary

Hey Geary Iam in audio since 1974 and already see this salesman talk many times, I call it golden the pill, always to sell again to naive audio buyers, since listen in a shop is difficult to perceive any sound improvement and as they are young people they lack audio listening experience, which are different from live music.

Your statement is the summary of the modern audio dealer trickery and planed obsolescence to sell poor made amps with cheap parts that lasts 5 years for a high price due to their supposed sound quality, while with high quality parts and a simple SE design the equipment would last 20 years or more or as in this topic case 40 years.

Sound quality with good parts will be even better than the cheap parts usual 10% precision resistences and raw EI 0.5mm silicon steel. Saying that a good design with cheap parts can sound good is to induce the music lover to spend your hard earned money in a poor made amp to buy again after a couple of years preferable in your shop.

Good design is a variable opinion concept according everyone, by example the ''good'' design of Macintosh is a disaster of excess redundant parts that even increases internal heat and modify the sound of the tube to create the ''Mac sound'', the owner tube rolling and the sound is always the same!

The good sound and reliable design of tube amps were made in the 1930s and 40s and were most simple SE amps with small count parts. When I see a tube amp underside photo I can say if it will sound good and have a short life.
Have a nice day.

[galyons]

After buying lots of amps (tube and SS) over 25 years, you learn what to look for.

Ok, I guess it must be WAG!!!  To me, it's all about the music, (sound) reproduction.  I have never figured out how to "look for" that.  I have been buying amps for over 50 years and building tube equipment for half that(other than Dynakit ST40 and PAS 3X in the '60's).  Sadly I only know what to look for after I know what I hear.  Otherwise....

Cheers,
Geary

[FullRangeMan]

3. Single Ended generally sounds better than push-pull.  Single ended parallel is the way to go if you need more power.
4. Small amounts of feedback can be OK, but moderate or large amounts of feedback always sounds bad (tube or SS)

I highlight the SE topology, with PP or NFB the soundstage are not deep and palpable as SE and zero feedback, mainly if one use monopole speaker that emit sound only to front, usually this mean small power, unless it use a hot big triode.