i'm thinking about about changing my F/S amp/s looking at running tube amps for something a little different.
- Has anyone used butler or USAmps(TU series) amps or both.
- How much does the sound change when you use a different brand of tube.

Cheers Dave.

I have heard both.

Personally I like US Amps, and are a little biased towards them.

Unfortuantly I haven't heard them back to back and my memory is a little fuzzy.

From what I can remember there was not a lot of difference between them.

meh tube amps

you should have stuck with the ART's

yeah, the arts where nice, so was the zapco comp series.......

I'm leaning towards 'rice' SQ, those USamps internals are damn sexy. :hehe:

personaly i like the butler, but that me.
i listened to the usamps and it' well' sounded like a normal transistor amp, it didn't sound lke there was alot of follow through from the tubes in the preamp stage.

but mabe im just used to class A tube amps, im expecting them to sound like my guitar amp

yes ther can be audible differences in tubes, with the preamp tubes you are limited to only a few types, or the ones they say to use' like 12AX7's/7025'S or ecc81's or 83's etc, but they don't have a huge influece on the sound like output tubes

if true SQ is your goal, throw the tubes out the window

i thought the butler's only had a tube pre-amp?

What a BS statement. Do you know the highest scoring car(SQ Points) in the last CAASQ comp was using a milbert pure tube amp?

SQ is subjective. Some people like the sound of tube colouration. Who are you to tell them that its not SQ? Beauty is in the eye of the beholder.

Both US Amps and butlers are tube hybrids, i.e they have tube buffers and solid state gain stages. It would not sound as tubey as a true tube amp i suppose, but there is a definite difference in the way they sound as compared to solid state amps. Milbert is the only pure tube car audio amp with tube preamp and gain stages. The tradeoff here is relatively low output power(35W x 2, 4 ohm) and its high price, but it sounds bloody fantastic!

I have personally ABed my alpine 1507(solid state, and a legend in its own right) against my US Amps when i first got it. Settings were flat, EQ was off etc etc. My friend was listening with me. Put it this way, the difference we heard was great enough for me to stop looking for an amp upgrade, period. My friend went US Amps hunting the very next day. I think i've had my amp about 8 months now, and i have never been tempted away from my amp(except maybe to a milbert, but i could never afford one LOL). Thats the best endorsement i can possibly give this amp. I never heard the Butler. But from reading online, there are really people who say the US Amps is better, people who say the Butler is better, people who say both are crap, people who say both are excellent. But most of the opinions i have seen say that there is a more distinct tube colouration in the US Amps than the butler...whether or not this is something you want is up to you. Personally, i love the sound of the US Amps.

To the best of my knowledge all amps designed for car audio usage only have a tube pre amp. (Not sure about Milbert though)

i think the tru tech a-class is full tube
tru do make a tube amp with a tube only pre-amp but I'm pretty sure they make a full tube amp be it the a-class or not.

Maybe Rttz can confirm that or shoot me down

Here's some pics of the A-Class rude bits:




Carl- the Copper C7.2AT is all tube, do you see any tubes in the pics?

Dave- what about the Tru Coppers?

The A Class is a Class A amp, the Copper C7 2AT is an All Tube amp. But all the Tru Tech Tube/hybrid Tube amps use both output tubes and preamp tubes with 250 volts on the plates (300v on the all tube).



Bye,
Mo

anyone else notice anything missing in that a-class amp???

that a class is all well and good, but damn for the money you could have prettied it up a little.

Those pics were "work in progress" pics. The production model is much prettier and the jacketed Kimber Kabe in them look real pretty too!

And, please keep in mind, Tru Tech amps are all hand built and because of that you can't really compare they way the internals look to a mass produced amp where every component is installed by a machine...

Whats missing?

Bye,
Mo

pic no: 2, there is a big green resistor, there is a spot next to it for another, but nothing there.

im yet to see a finnished one's internals, but have seen the outside, but pretty plain to me.

The "empty" hole:

Originally, we had a "Back-up" lithium battery for the E-Prom memory chip. However, with the up-graded chip in combination with 5.5Volt 1Farad Super Cap, it was not needed anymore.

FYI, the E-Prom Chip retains it's "Last Position" of the Volume control. So that the Volume will reposition back to it's last setting when the amp is turned on.

We call it a Volume control instead of Gain because, this amp has "No Pre-amp" meaning, no Gain. It's signal goes straight through. Keeping the signal to the purest form.

On Butler Amp, you can use just about any tubes. Since they are meerly using the tubes like a resistor.

It's somewhat like the light bulb you see in the passive XO.

The last known production of the Tubes (6SL7GT) which Butler uses goes back to 1960. So, you be sure that all the tubes in the Butler amps are at least 44 years old. Unless someone else started to manufature them.

The 6SL7GT are design as a "Power Tubes" and were never intended or used for "Pre-Amp" Tubes. So, I don't see how and why someone would use a power tube in a preamp stage?

Plus the butler has no voltage on the plates? A bit of irony since all tubes do require voltage to get them working properly.

On the other hand, the US Tube amp does have 50Volts ( a bit low) on the plates and will sound more like a tube amp which we are farmiliar with.

Mind you, none of Hybrid tubes will sound as good as my friends old McIntosh 300. However, they do a very good job of getting them there.

Butler IMO, is no tube amp at all and should not even be consider to be part of Tube family.

Anything out there that is valve AND class A?

Retail in $AU on the A Class is...?

Lastly, why the use of the "high quality" cabling (Van Den Hul)?

Retail on the A Class is $5k.
Cabling is Kimber. Why? I dunno, when you're paying $5k you expect these things.

OMFG
:shock:

$5k! I know Tru Tech is about the best you can get, but that is a heck of a lot of money to spend on a 25wrms x2 amp!

anything true class A tube is stupidly expensive, and unfortunatly very limited in its output power but the sound well and truely makes up for it.

i mean my laney 50w class A is $3200, i know its a guitar amp but still!!
when you look inside it its an empty steel box with a few wire conecting all the tube mounts and a big ass transformer.
actually thats what shows its a true class a tube amp is a output transformer.

also one way to make them sound better is to over-voltage the tubes buy ajusting the bias incorectly but it burns out tubes quickly.

tubes due to the way that they work dont clip like solid state gear so u can use all the power availible also due to the way they power for some reason you never want to turn them louder like you always seem to want to on a solid state amp. (ok im not stating this as fact but purely based on my experiances with valve audio gear.)

Thats a very sweet amp you got there mate!
Me I got an old 1958(i think)Sonola 50w tubeamp its a bluesman style amp made in Hindley St Adelaide!
Im looking for a replacement speaker for it(12" dual cone)might have to see total recoil.

yeah those milberts are round the $5000 mark as well, the problem is running a active 3 way front stage like that will get hell expensive.

looks like i'm goin to go for the USAmps tube amps, was basically always goin to go for them, was waiting to get confirmation that i could get them.
Their price is not to bad either at considering you can have 4x75+2x150 round $2000 or even cheaper if you didnt buy direct from usamps, its just a pain that there is no supplier over here.

Good to see that the issue of "Class A" and "tube amps" still get everyone stired up.

a BS statement? if its colouring the sound like they do, thats distortion, and tubes make lots of it hence there unique sound, im not saying its bad, hell the tube amps i run i prefer over most of my solid state amps, but if its distorting the sound, is that technicaly bad sound quality? seen its not a true reproduction of the original?

It can run these figures in A/B also so not exactly small.
4 Ohm RMS: 210W x 2
2 Ohm RMS: 350W x 2
1 Ohm RMS: 500W x 2

But I agree, not exactly chump change either. At least you don't have to pay the US RRP which is the same amount but in USD!

We are retailing this amp in Australia at the cheapest price possible - it retails in the USA for US$5000!!!

And yes, Tru Tech amps are the best you can get

Dave,
Looks like you've come to a decission, and between the two choices you original had, i think you made the better choice. All the best with your new amp!

Bye,
Mo

Yes, but they also work differently in terms of harmonics compared to other amps.

Something that I can't remember off the top of my head.
I think it reproduces even numbered harmonics better or something like that.

I see if I can find where I read that and post an exact answer on it.

Sometimes esoteric equipment can't be compared by looking at specs alone. Often intrinsic qualities can't be measured by a "meter" of sorts.

This is why people still buy tube amps that are 30wrms x2 for $5000 even if they have 5% THD at there rated output.

I hope you are joking.

Anyway, it is true that tubes are more non-linear when over driven, but this is not what gives that typical "tube sound".

Once a tube amplifier is distorting audibly, it does not sound good. It sounds distorted. It is true that second order harmonics are more easily masked by the fundamental and thus not as audible - but once it is audible, it sounds bad. Of course we haven't seen any 2nd and 3rd order harmonic distortion graphs from the amplifiers mentioned, so who knows in this case - I think some of the people who believe that all tube amplifiers magically distort differently may be suprised.

The typical "tube sound" is typically the shift in frequency response due to the output impedance of the amplifier being too high. You can get the same effect with any normal amplifier by using ultra thin speaker wire, or some relatively high wattage resistors.
Severely limited frequency response (typically in older tube amplifiers) may also contribute to this sound.

Naturally it is possible to design a tube amplifier with hi-fi specs, so it does not audibly colour the sound. I believe the Tru-Tech is a good example of this. (although I haven't seen the damping factor spec, but I assume it is sufficient)

But tubes have been obsolete for a long time - it is a lot easier and cheaper to produce a high power transistor amplifier that does not colour the sound.

I can see your opinion in regards to Tubes and I can respect that.

However, how many Tube amps have you personally experienced.

It's funny that you seem to ignore Sterophiles. You sound like you've been designing and had multiple experience.

So, what was your personal experience in regards to the staging and the imaging with a McIntosh 300 or Bell Dual mono block?

I sure you are not regurgitating without experience.

One thing for sure, your 1000 words will never equal 1 experience.

So, what is it.

As matter a fact, since you consider "Tubes" as a obsolete product, I'll tell you what,

Let's have a challange:

Use 3rd party Audiphiles (non-car audio)

Test the amps between our Tube and what ever your "State of the Art" Solid State Amp.

If the Audiophiles pick ours, then you buy our amp.

If the Audiophiles pick your "Amp", I'll give you our Tube amp.

Talk is pretty cheap so what it going to be?

Oh, BTW, we have not forgotten about the other thread.

Building products takes presedence over posting.

Personnally I have often admired characteristics like transparency, imaging and the sheer ability to convey the emotion of the music that some valve amps are capable of.

Measure that on your scope

I couldn't care less about the specs if it sounds good. The only test equipment I often use is the one between my ears.
If you don't understand what I mean, you've missed the whole point.

Sorry I dissagree with a few things in this post.
For starters I understand that when you drive a tube amp into clipping it will sound worse than when it is replaying frequencies with a smooth waveform.

HOWEVER- When a tube amp starts to clip the waveform "baloons"
and is still relativly smooth rather than having a "squared off" edge on the waveform like a transistor amp.When a Tube amp clips it has audiable distortion opn even harmonics which is easier on the human ear than odd harmonics which is what is produced when a transistor amp clips.

Tube amps do not color the sound to any discernable extent as compared to transistor amps. If both amps are producing a smooth waveform you couldn't tell the difference this goes for any amp.

The output impedance of a tube amp is virtually infinite.
Getting the "same effect" as a tube amp from a transistor amp using thin speaker wire and resistors is utter sh!t.

Frequency response is directly linked to pre amp devices and speaker choices tube amps have the same frequency response as transistor amps.
(D Class amps are an exception as they are bandwidth limited due to their fast switching speeds)

I expect feedback on this post good or bad, but I was given advice on this topic by a highly qualified electronics tech.

He has experience repairing both tube and transistor amps and sells both.
I thought i would research this b4 opening my big fat mouth, rather than give a response that is false or misleading.

If anyone has any issues with this post please don't hesitate to contact me via PM to converse about this further.

Do you know for a fact that the (6SL7GT) tubes used in the Butler amps are at least 44 years old? Do you have any evidence to back up your words? Can you show us?



Do you know for a fact that the tubes (6SL7GT)Butler amps use are for the pre-amp stage? Are you 100% sure what you "said" is correct? According to what I know, the tubes are not even used for the pre-amp stage.



Working properly in what way? Please be more specfic, I am interested to learn.




So have you actually auditioned the US Tube amp? Or are you making an assumption that the US tube amp will sound more familiar to a tube amp based on reading the spec that "it has 50Volts (a bit low) on the plates" ?

Have you auditioned the Tube Driver Blue? What differences in tonal characteristics do you experience between the US amp, Butler and the Tru Tech?

Anthony

wow!! what a discussion
in the end though if a amp sounds nicer to your ears it is considered better and the 'tube sound' is a perfect example. so what if its adding to the signal!
with some music it could be a blessing! but with tube amps you definatly listen to the amp but its not a bad thing, its bad when the amp adds something that is unpleasant to listen to.

transistor amps by nature are very transparent and sterile in there sound and its what makes judging the sound difference between trans amps difficult, the alteration in sound is always so suttle.
you definatly carn't compare true tube amps to transistor amps in there output sound there's to much tonal difference in the two.
its like comparing a electric guitar to a full bodied acoustic, ones not nessacarily better than the other just different' the acousic's sound is full of harmonic's, a G chord is the same on both electric and acoustic but the acoustic sound is richer in harmonics.

ST170ish wrote


the amp is a VC50, the best i've heard and the clean channel is a strong rival to fender it is unfortunatley a quite noisy amp by nature and can have a tend to sound very trebly :?
you should try local guitar shops etc, if your after the same sound another dual cone would be the go, celestion,eminence of fender may make replacements' probably try fender as a few of there older amps had them. failing that a repair job may be in order, there is usually few places that repair PA type stuff and have experience in guitar amp stuff' cos you dont whan a shop recoiling it or putting a new surround on it and changing its sonic character or coil parameters :| unless its crap to begin with

Well I always say:
"If you can hear it, then you can measure it, but just because you can measure it, doesn't mean you can hear it".

This means that speakers/amplifiers can be engineered to sound good.
Obviously, if you can really hear it, but can't measure it, then you are using the wrong tool to measure it. Of course to most people understanding how it really works is irrelevant, as long as it sounds good. But to those who care to know, or need to know, then it is important. Naturally, since the end result is you will be listening to the amplifier, it is important that the design is not only theoretically correct, but is actually correlated with how it sounds. But remember, that sound is not only heard by your ears - the thing between your hears has a role too and can be easily influenced...



If there are increased second order harmonics, then the wave will become more sawtoothed, rather than squared off. A rounded off edge will occur if there is limited bandwidth - if you lowpass a square wave, then it will look more rounded.



Yes, correctly (well) designed amplifiers do not audibly colour the sound...



Ideally the output impedance of the amplifier should be close to zero. In the real world, as long as the damping factor is high enough, it will be fine. Most tube amplifiers have damping factors that are low. As you know, the impedance of a speaker is not completely flat - if the damping factor is too low, then those frequencies where the impedance rises will be accentuated.



Ok, it is obvious that your point is that certain "Stereophiles" (ie the ones you'd pick for the test) prefer the sound of these tube amplifiers. My point is, that if you gave the transistor amplifier an equally low damping factor, then the stereophiles may find it hard to tell the difference. Otherwise, I could just as easily find a bunch of people that dislike the sound of a low damping factor - but this wouldn't prove anything.

Nevertheless, if colouration of the sound is desired, then these days you can do whatever your heart desires with dsp. With a very flexible EQ, with the ability to simulate the response of various classic lo-fi amplifiers, as well as ability to add as much 2nd order distortion as you desire etc. (for car audio, TA as well, and for the nostalgic, a white noise generator. :wink: )
However, for some reason such a product does not exist yet. Whereas, in the musical instrument world, manufacturers already make products that are able to accurately simulate the nonlinearites of classic speaker cabs/amps.

quote="Bassaholic"]
Well I always say:
"If you can hear it, then you can measure it, but just because you can measure it, doesn't mean you can hear it".[/quote]

So, I say it again, what is your personal experience? Anyone of us can write about it. Bottom line, music's are to be heard not measured.

We measure things to see what the amp is doing. However, many engineers will tell you other wise.

I will agree with you in regards to "Digital Domain" products. However, in "Analog Domain" the answer would be categorically "NO".

It seems that you have very little experience in designing electronics. Or else you would not have posted such statements. I just went and asked my engineer the same question and he stated" WHAT? LOL"

So, then, find an analog Power supply engineer and see if they will agree with you.

BTW, our engineer John Fairchild has been involved with electronics since 1953. So, you can say, he's been around. Also, worked under Jim Fosgate (Fosgate Electronics before Rockford) in 1979.



I merely pointed out Stereophiles not because of them might liking "Tube" amps. I pointed towards Stereophiles because of their "Mature, experience elevated reference points in regards to sound".

Let's face it, for the most part; we car audio users have extremely poor reference points. Meaning, our typical reference points are either;

#1) our own car audio system - poor reference

#2) our friends car audio system - poor reference

#3) our pathetic computer speakers using MP3 format - even worse reference

Just like you have wine critics that can differentiate various wines because of their experience.

So, which group of people would be most likely candidate to audition, Car Audio or Stereophiles with many years of experience?

I think the answer would be obvious.



So, what you are stating is a hypothetical scenario? So, you've never had the opportunity to audition any?

I ask you again, what is your experience?

Our Engineer John Fairchild remembers the tubes when it was in use back in the late '40s and '50s. Military used them quite extensively for their communication systems.

Right around the time of late '50s, military went with solid state for power and the "6SL7GT Tubes" were known to be last manufactures in 1960. Like I said before, if you can find a current 6SL7GT being produced, please let me know.



I stand corrected, the Butler Tube is not being used for Pre-amp. As matter a fact they are really not being used for anything.



For a proper Tube to function, the Plates (the metal plates inside the tubes) needs to see fairly hi voltage to work. With high voltage on the plates, it excites (charge) the cathodes start to move around. The higher the voltage, the more and faster the cathodes move. Thus, creating Tubes signature sound of "Warm extension, wider stage, solid focused imaging".

The Tubes require Voltage on the plates, just like a car needs fuel to make it run.

The "orange light" that is inside the tube is just a filament (heater) for the tubes.




Yes, we have auditioned, benched and dissected both the US and Butler and these were our findings.

how do tubes do this?

This will be a statement for "Open to interpertation".

Many times we've sat and listen and listened and there are differences in the way the stage can sound wider and deeper.

I would expect many to debate over this particular part.

The 6SL7GT is still made, sovtek (new sensor) are at least one manufacturer and they are more of a preamp tube than a power tube, according to sovtek themselves.

the older ones are still beter anyway, there usually made more solid and heavyer built than a lot of the newer versions, making them last longer.
the NOS tubes are quite sort after especially if they have stoped making them.

Bassaholic wrote:
My point is that if you gave the transistor amplifier an equally low damping factor, then the Stereophiles may find it hard to tell the difference


Very true, my nice little 15w mosfet class-A with a dampening factor of around 8, sounds very much like a few of the tube amps in my collection.

and as for the do tubes add more distortion or not, all of the tube amps i have owned and seen make more distortion the EQUALY PRICED solid state units, but no one has mentioned, maybe that distortion of the sound is good?

Very good point, this sense of "distortion" is very endearing and is often what tube amplifier fans rave about when they say how "warm" the sound is.

Distortion isn't bad if you like how it sounds

Which question was this?




I agree that many people have poor reference points when it comes to audio reproduction. However, not all stereophiles happen to prefer tube amps so if these people were selected, then the test would be skewed in my favor - but this wouldn't prove anything. There is of course the psychological pressure that influences people into believing things that aren't neccesarily the case. When people are getting into audio, they notice that tube amplifiers happen to be rather expensive and there are people who act like they have "Mature, experience elevated reference points in regards to sound", thus to fit in, these people then tell themselves that these amplifiers are the bees knees and it becomes a self fulfilling prophecy. So it is obvious that bias can easily be introduced in the selection of listeners in this proposed test.





No, these tests have been done before. But your question works both ways - have you personally compared the difference between these tube amplifiers and transistor amplifiers with equally low damping factors? (with the gains very tightly matched, ABX listening test)



Honestly, I never pay much attention to peoples qualifications or experience, because unfortunately, I have noticed it doesn't neccesarily correlate with the accuracy of the statements they make.

I could easily pull the experience/qualifications card on you - your role at Tru-Tech is "Sales / Marketing", not "Engineering / Technical Support". But honestly, I don't really care.

Anyway, I prefer to base my conclusions on the reality of the situation - whether the statement is correct or not. Remember that even the brightest and most experienced can easily make mistakes. If people assume that they are correct, then these mistakes can easily spiral out of control.

i got 2 points to add

1) why would you want a amp to "colour" the sound like a tube amp can? fair enough if you are buying say a Guitar amp casue thats the sound you want, but a car/home amp is there to reproduce the recorded music as it was recorded. therefor any colourisation(sp) should not exist in any form (eg: distortion)

1) why spend craploads of $$ on an amp when soon as you turn a key out go's any benifits out the window, it's bad enough with all the reflections etc in a cars envoiroment, i honstly cant justify spending that much on a car amp, i rather put my hard earned cash on a quality built amp thats not going to fail from the stress of a car, and some good xovers built in (or none preferably)

I see your point of view.

However, I do remember we required an ABX test to conduct what sounds good.

As for your comments regarding about Stereophiles being skewed? I ask for varifacation.

Since you quoted Tubes being "Obsolete", I challange you to a test. A simple Test.

So, which amps have you tested in ABX? in regards to Tubes?

I find your statements with no substance but rather stating a comments.

Even a Wine critics will at least taste the wine before making such judgement calls.

At least a movie critic will at least whatch the movie and state his or her findings.

So, again, what amps have you tested ?

simple enough?

It should be if you actually did the test.

Have you listen to a tube amp?



I can see your valid point. However, it's no different than drinking wine for the first time. You won't be able to tell the difference. However, in time with maturity and experience, one will noticed the difference between a $5 bottle vs. $50 Bottle.

As yourself the question why? Simple, no one wishes to keep driving their Daewoo when they want more refined performance.

your 1000 words and point of view will never equal 1 experience. I don't mean it in a bad way.

i have listen to a few Home Valve amp's, and only one car Valve amp. im more than willing to put one of your tru techs Valves against my trusty PPI art 2 chan.

as i said, there are no audible differences while driving down the road. mabey if your in a Lexus but cause we are all into car audio, the speakers amps etc seem to prevent that haha

I will agree with you in regards to the car noise issues.

However, have you consider the fact that particular amps have different characteristics?

Also, most ppl who purchase tube amps tend to drive cars that are particularly quite. Meaning, either a luxury car or they understand the acoustic loss and threat their cars with dampening.

Currently, we are the only car audio amplifier company in which Ray Kimber from Kimber Kable gave us his blessings.

Tube amps are not for everyone. If you can't tell the difference than who can say that you are wrong. Doesn't mean that you are right either.

It boils down to experience. We find that most ppl who appreciates tubes been involved deeply in audio for 5+ years.