As good an explanation as I have heard, ever! Thanks Paul for de-mystifying some issues many of us, don't or half understand.
@palipixel
2 жыл бұрын
Thanks Paul. Not to be overly pedantic, but it is very common for brand new tubes to lose 10 -20% of their gm in the first few hundred hours of operation - then settle down at their new gm for the long run, provided the tube is not being electrically abused too much. To really match them tightly, they should be pulled off the burn-in rack and inspected (matched) on a curve tracer. Followed by noise floor measurements and any other desired parameter that may be pertinent for the intended audio application. I believe the last manufacturer to do this for some of their tubes was Tektronix. Not even an audio application, and back when they were making their iconic line of tube-based oscilloscopes.
@eugenepohjola258
Жыл бұрын
Howdy. Yes. The gain matching is the most important aspect. There is a point in bias matching too. When the bias is balanced the residual hum will be cancelled out in the output transformer. Regards.
@andydelle4509
2 жыл бұрын
You may also want to mention that transistors in audio products need matching too. When you have multiple pairs of output transistors in a large power amp (> 100W), they need to be matched. There is some slop allowed due to the emitter resistors but overall they should be reasonably matched. Another area are the transistors on the input diff amp stage. These too need to be closely matched and are often coupled together mechanically so they both are always at the same temperature.
@johnmarchington3146
2 жыл бұрын
When I built my class A monoblocks, with multiple Motorola MJ15003s in the output stage, I built a test unit that allowed me to match the hFEs of the transistors at a specific current rating for lower distortion levels, so I consider matching to be important in solid state amplifiers too.
@gitmobob6266
2 жыл бұрын
I just want to inform people but matching components is a thing whether they are tubes or bipolar transistors. Resistors capacitors and inductors and diodes virtually every component are all checked to be within specified tolerances. You either like the sound of tubes or you don't it's a personal choice.
@AllboroLCD
2 жыл бұрын
I live an hour away from Rogue Audio! Definitely on my list of "brands I'd buy from immediately when I can afford it" . They dont venture into the digital realm and stuff isnt as fancy looking as PS Audio gear, but the craftsmanship/build quality is neck & neck!
@bobross6802
2 жыл бұрын
Good push-pull amps match transistors as well as tubes.
@NoVoiOvi
2 жыл бұрын
I had to do matching by hearing, as i had no proper tools. When imbalances are found, the sound comes more from the other channel, and the sound direction is sifted. I had 6 tubes and just switched one side of my FX-Audio tube 03 till sound was coming from the centre.( keep left the same and switch right side, i had to switch the left once too, as the starting tube had no good match)
@666kty3
2 жыл бұрын
I match gain in tubes by using my Amplitrex AT1000....but I also balance the bias as well...both are critical to overall quality.
@ocfranco4
2 жыл бұрын
Os amplificadores híbridos com o estágio de entrada a válvulas, são excelentes, e está bem-aceite hoje no mercado mundial. Parabéns, Paul por seus vídeos esclarecedores.
@steveford7804
2 жыл бұрын
Are tubes matched when buying mono-blocks such as Steller M1200s?
@milkman100001
2 жыл бұрын
im just ready for a bit of tube rolling. just purchased a new set of mullard's and a set of jj electronic. just to see how much difference there is between them both
@hugobloemers4425
2 жыл бұрын
That was short and sweet.
@Dutchamp
2 жыл бұрын
Paul your right but how does it work for example power tubes like my kt88/6550? With bias I set the current the same. Even when one tube has less gain it sets it in balance.
@GK-rw2op
2 жыл бұрын
They are both the same
@Dutchamp
2 жыл бұрын
@@GK-rw2op what are the same? Power tubes and pre amp tubes? Noway they aren't. In pre amp tubes it is a must to have a balanced matched pair, depends a lot on how it is in use ofcourse. By setting bias to power tubes the minus amping and plus amping tube can be set equal. In pre amps almost impossible.
@dhpbear2
2 жыл бұрын
Bias CAN affect gain!
@rainman3269
2 жыл бұрын
What brand and model of input tubes do you use in your amps please ... Thanks in advance
@googoo-gjoob
2 жыл бұрын
check their site. under accessories, they replacement tubes identical to OE.
@ptg01
2 жыл бұрын
The question was about buying matching output tubes.... Hmmm....
@zulumax1
2 жыл бұрын
1:32 He did say output tubes, then went down another path explaining gain, but did not explain why gain was important in push pull output sets. Symmetry of the positive and negative halves Paul!
@ptg01
2 жыл бұрын
@@zulumax1 I wonder if amps with auto-bias makes a difference. I never buy matching output tubes though...
@janinapalmer8368
2 жыл бұрын
gm is the gain of a tube ..
@graxjpg
2 жыл бұрын
In guitar amps, I like to have them mismatched a bit. This tends to afford a good amp more harmonic complexity.
@johnsweda2999
2 жыл бұрын
Yes you don't want them matched in a push-pull configuration can lead to tube oscillation but what Paul is talking about showing is singing ended configuration
@graxjpg
2 жыл бұрын
@@johnsweda2999 single ended guitar amps like what was normal in the 50s and before are really great sounding too.
@mvb819
2 жыл бұрын
@@graxjpg yes, but highly inefficient and low in power output.
@graxjpg
2 жыл бұрын
@@mvb819 well, yeah, but that is entirely irrelevant to a musician or studio owner who’s using it properly haha!
@bartvanransbeeck1341
2 жыл бұрын
I had 3 audio research classic 60 and 2 sansui tube integrated, none sounded the same
@ontogeny6474
2 жыл бұрын
Musically speaking, I love how forgiving tubes can be when pushed to their upper limit and how they shimmer harmonically. Their transistor, sink-enmeshed brethren do not always fare so well.
@wilcalint
2 жыл бұрын
LOL that's called 2nd Order Distortion. And I agree lots of people love it.
@johnsweda2999
2 жыл бұрын
What tubes do you use in your front end stage? have you thought about trying 45's I think you should give them a go
@artyfhartie2269
2 жыл бұрын
The story goes that the inventor of the vaccum tube had many attempts at perfecting the vaccuum tube and finally came up with nothing.
@johnsenchak1428
2 жыл бұрын
Gain in tubes is listed as Mu
@neira.francisco
2 жыл бұрын
I guess that the same is valid for the final stage of the vintage ham radio rigs, isn't it?
@garysmith8455
2 жыл бұрын
Paul, too funny............."Just not my particular cup of tea, but, I LOVE the way they sound." A little internal ying and yang going on there ? lol I say, just sit back and enjoy the music, the sound, and not so much on how it's being produced. Again, you love they way they sound (tube amplifiers).
@silviopimentel7247
2 жыл бұрын
Guess it's all in the personal taste. I tried ps and tube amplifier. & wow realized it's a preference. Decware zen destroyed ps. In my ears! Same gear to compare. Opinions are personal
@PooNinja
2 жыл бұрын
Gainful information here.
@googoo-gjoob
2 жыл бұрын
(booooo)
@bearchow1929
2 жыл бұрын
All that's matched in modern tubes is how bad they are.
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