How else would you explain this?

I´m in the market for a set of KT-88´s, but on seeing this I felt I had benn struck with a jack-hammer over my head.

this is what i can get them at. http://www.partsexpress.com/pe/showdetl.cf...tNumber=072-490

Larry,

Perhaps my phrasing was less than clear. What I was wondering was whether the General Electric Company made KT-88´s were the best ever, for they are, by far the most expensive I have ever seen. Kinda like Western Electric 300B´s.

Sovtek, Svetlana, Shuguang, Harmonix and JJ Tesla, just to name a few, sell modern KT-88´s for a lot less, but are they as good?

crazy eh Jorge?? I dunno but I have smoked glass and clear glass GEC KT66's, as well as Penta Labs KT66's, the Pentas sound fine by me.

How crazy can this hobby become?

That matched quad sold for £ 732, roughly $1,460 or € 956.

this may sound dumb but isnt a tube a tube. if not what are the differences?

here is what i carry. i remembered i could get them thru my dist.
http://www.euroaudioteam.com/kt88diamond.php

Like all electric/electronic devices nothing sounds the same. I mean, all caps sound different, all resistors sound different, all output transformers sound different and all valves too. It all depends mostly of production’s quality, the materials they are made of and who and when manufactory them.
All this factors will determinate the sound characteristic of each valve. Ones are more smooth and airy, other are more details and bright, etc...

And in tube amps there is another factor:
Bias.


Bias refers to the amount of voltage held on the grids of the output power tubes. This controls the amount of current the output tube(s) conduct exclusive of the signal current, or, looking at it another way, the amount of overlap where both tubes are conducting simultaneously.

The idle current in the output tube and the degree to which the output tubes overlap in conduction is what you're trying to adjust, not how many volts go on the grids; you just have to use the grid volts to change the current and conduction angle.

Power tubes individually have slightly different DC gains, so the same bias voltage on two different tubes produces two different current levels. "Matched pairs" are two tubes selected to be close together.

Each power tube needs a certain bias current to keep it operating at the point where the amount and type of distortion under normal conditions is well controlled. Individual tubes vary widely in the grid bias that sets the correct idle bias current.

When i bought my first tube amp somebody says to me:
Welcome to the dark side.... and you know what? He's very right...

I was at another forum that was debating tubes vs solid state. I like them both. I haven't pushed any of my tubes yet. I pushed my Creek amp Fri. I cranked it to full volumne. I had to back off. I was useing my 2 ways. At full it was just to loud and sounded garbled. I took it back to 3/4. Sounded great.
I haven't had my tube amp to 1/2 yet.
They were talking that tubes give you less bass. To me that isn't true. I like my tubes because of the warmth of the sound. I have no problem with bass. My tubes are hooked up to my 3 ways.
I wondered what fun is it if you have to decimate the sound your hearing.I know what I like and I know what I don't. So what fun is the music if you have to analyze your gear every time you listen?

I have an old Mac 275 tube amp. When I got it there was a pair of GEC KT88's in the right channel and a pair of RCA 6550's in the left. Try as I might I couldn't make myself hear a difference. So I have concluded I must have poor hearing. Because everybody else hears the difference.

I recently bought a set of Penta KT88's so all tubes would be new and matched. Even though the Mac is autobiasing. Again I cannot discern any difference between the new tubes and the ones I replaced.

Maybe Greg and I should form a group for those with inferior hearing I'm not making light of those that hear a difference. I'm just glad I'm not one of them. It's saved me countless thousands of dollars since I don't have to ride the upgrade trail constantly.

Mike

What's a tube??

Congrats for your Mac. That's an amp i'd like to own. Do you have the original from the 60's or the Commemorative edition of 94?

That's those funny looking black things that go inside bicycle tires.

With the small difference you don´t have to blow in these ones we´re talking about.