Tubemaister Deluxe 40 TSC question

Hey! Recently I bought the Tubemaister Deluxe 40 and so far it's bean amazing, except the microphonic coming from the power tubes. I just changed the tubes and the sound is a lot better But I just wanted to manually check the tubes via TSC, before and after the change and that's where my question comes
I saw the exact same readings on both groups of tubes and no matter how I swap the tubes the reading is always the same. As I understood from the manual I should get different readings for each tube, depending on the tubes or I'm wrong? Is there some way to "reset" the TSC control(tester)?
Thank you very much!
Cheers!

If your getting equal flashes on all tubes that’s a good thing. It means they are matched and biasing the same. I’ve seen my TSC system read different after a few power on and off cycles but then it always stabilized and read the same. Even a couple flash differences between tubes is fine. I think HK doesn’t want to see more than a 5 flash difference between tubes. Now since you’re new to the forum I’ll let you in on the biggest rule here. You’re not allowed to say tubes sound better or worse, good or bad, harsh or smooth or just about any adjective to describe their sound unless you have at least 3 scientific graphs and 1 pie chart along with the sworn testimony of a audio engineer proving it beyond a shadow of a doubt. Otherwise Uncle Berty is going to come in here and scold you for such reckless statements and blasphemy. Other than all that enjoy your amp

Hey! Thanks for your replay, but that doesn't explain why I get the same readings on the LEDs even when I swap the tubes
And thanks for the constructive criticism, but even that I'm new to the forum I'm not new to the tube amps and I've bean playing with other very expensive amps like Triaxis by Mesa Boogie, Fender Hot Rod Deluxe, Tween Reverb and so on for the last 25 years and I think I have the ears to distinguish a "good" quality tubes sound from "bad" ones But since this is a rule here I'll not talk about tubes anymore sorry!
Cheers!

Hi, let me introduce myself. I'm "Uncle Berty".  I'm afraid Iroc is using this as an opportunity to try to poke his finger in my eye because I take a different view to such things as he and the other mojo gurus do.  I'm afraid Iroc has an agenda as I have severely ticked him off before over similar claims like this which "everyone knows are true because everyone says they are true" but which can be shown to be irrefutably - well - let's just say horse feathers.  There have been correctly conducted tests done on all aspects of this issue of course and they show that there are no major TONAL differences between valve makes.  Even the tests which were used to prove that there ARE differences show there aren't!  Iroc has been pointed to these results but as yet he has made no comment on them.  He just continues to put his head in a barrel and shout loudly "but I can hear the differences" without ever considering "why do I think I can I hear a difference".  Firstly, even with top flight state of the art test equipment valves show the exact same frequency and impulse responses under the same test conditions, and in double blind listening tests people can only detect a difference when they know which they are listening to.  When they do know they can always detect some slight nuance.  When they don't know they consistently show a random guessing result.  It's odd, that is!  That really shows them to have golden ears right?  Iroc is on thin ice with this issue but he prefers to continue to have others see him as "an Acolyte of the Grand Mojo".  In your own case I would suggest you remember - you can't go on fooling someone who doesn't want to be fooled!

What you have experienced with your power tubes is a microphony problem of course.  This is caused by poor construction or with physical breakdown over time with parts developing the ability to vibrate and hence pick up vibrations from around them.  That transfers into changes in the valves' electrical characteristics linked to the speed of the vibration which gives you the feedback.  That's a well documented engineering issue and not at all what "Uncle Berty" argues against.  I ALWAYS argue for engineering process and standards as they can be independently questioned, verified and demonstrated to be true or not.  The opinions of a golden eared section of the Magician's Union are not verifiable in any way and have no factual basis to be considered.  Would you believe someone selling you a carb who told you "You fit my hand worked carb and you'll get at least 450bhp at the wheels.  I've been driving cars for 30years and I can feel it through the seat of my pants.  It always works.  Believe me it'll be 450bhp+" or the results of a rolling road dyno test?

What I will go out and say is that the tonal differences in your amp between a GOOD set of power valves by company "A" will sound surprisingly lacking in difference between a GOOD set from company "B".  By good I mean good working, without flaws.  I can point you at the test results which show the lengths that some people will go to to make you believe in "the Priesthood" of the golden eared but which show their argument to be totally fatuous (stoopid!).  There is so little tonal difference between valve makes that it is imperceptible in amongst the other factors which make much larger genuine differences.

You don't have to believe me of course, you can believe in Iroc's snake oil if you prefer but it is important to be open minded, look for and question the ideas of the other side and be critical of anything anyone tells you in this game, (including me who will always show the FACTS which back up my claims when they are requested.  Ask Iroc for his supporting factual info!  If such an obvious difference exists then why can't we measure it?  And if we can then why aren't all the Gurus publishing the data all over the internet to boost their sales of valves?)

There is no rule here about talking about tube tonal differences.  Just don't throw your toys out of your pram when someone like me (I mean me ) comes along and argues with you.  Successfully up to now.  Iroc, as is common nowadays in the internet age, wants the right to spout any old trollop opinion, magic valves, pixie dust tone capacitors and the like, without being called to account for them and it 'aint gonna happen on my watch.  The members of "The Priesthood of the Mojo" are welcome here but it gives them no special privileges.  Their claims will be questioned.  Always.  And if they prove me wrong I will be the first to announce I am a convert.  That way I grow in my understanding of this field which I love and move forwards. I don't stay in a state of "denial ignorance" as they do.

...and to the topic.  As you are a long time valve user I'm sure you are aware that there are silicone rings available which claim to help with this problem. These can help to directly damp vibrations in the outer glass envelope which helps in reducing what is transmitted to the inside. They can't really help much in damping the inside parts directly. The H&K amps have a lot of gain available at their higher end and that makes them particularly susceptible to this sort of issue.

I will admit, I use these as a matter of course. I have no real idea if they help, I won't make any wild claims on that count, but they are so cheap and available it seems unnecessary not to. I don't have a problem with this issue with my H&K amps or any of my Marshalls. And I only use cheap and cheerful JJs!

So to the TSC. It's kind of hard to describe this clearly but do you mean that you get different readings between your new set of valves when you first put them in, but those different readings stay the same when you swap them around and repeat the test again with your plectrum? So that means that, effectively, the readings are not following the valves as you swap them and retest?

The other scenario is that you mean all of the valves have the same reading which is possible with a really well matched set of valves. If that's the case then trust the TSC! If it says they are all the same then they are.

Microphonic valves will not necessarily show any difference in bias current, the two issues are not tightly related. I have spoken to H&K about a possible TSC reset procedure in the long gone past and, sadly, I can't remember the steps they told me to follow. I think it was a "hold buttons and switch on" type of process but it's too hazy in my mind now. If you really really want to reset the TSC to a blank state where it will recalibrate itself you could try searching on the forum as it has been put into a post. I've tried to find it but for some reason the search facility doesn't work too well for me and never has done. However, as I understand it, the system is constantly recalibrating itself anyway to accommodate new valves and changes in conditions such as temperature.

Hi again Andrio.  I've been on to H&K Support about your problem and had a chat with them.  They are interested and have asked for more details.  Here is what they have said:

H&K Support wrote:Hi Albert. Could you please get us the full info from the person concerned (what exactly is going on, is there a problem with the amp/tubes or is this a 'number of flashes' thing, what amp and tubes are involved, etc.), or ask them to contact us directly? We can then involve our techs to help get this sorted.  We've mentioned before that there's a factory reset you can do with most of our newer amps, but not sure that would affect this until we know the full context  Team H&K

That is helpful, (as always).  As it's a Facebook messaging thing I'm not sure if you can access it.  Have a look at the H&K support page on FB here:  H&K Support Page  If it doesn't come up with the correct post at the top then look for October 12th at 14:41 for my original question.  If you can give them whatever details they ask for I'm sure they will help you out with it.  I'll keep an eye out on there too and do anything I can to help.

Thank you very much! I'll check out the FB page today and I'll explain what exactly I experience with my Tubemaister

Actually I didn't tried the factory reset option! I'll see the manual on how to do it and I'll try it tonight

bordonbert wrote:...and to the topic.  As you are a long time valve user I'm sure you are aware that there are silicone rings available which claim to help with this problem.  These can help to directly damp vibrations in the outer glass envelope which helps in reducing what is transmitted to the inside.  They can't really help much in damping the inside parts directly.  The H&K amps have a lot of gain available at their higher end and that makes them particularly susceptible to this sort of issue.

I will admit, I use these as a matter of course.  I have no real idea if they help, I won't make any wild claims on that count, but they are so cheap and available it seems unnecessary not to.  I don't have a problem with this issue with my H&K amps or any of my Marshalls.  And I only use cheap and cheerful JJs!

So to the TSC.  It's kind of hard to describe this clearly but do you mean that you get different readings between your new set of valves when you first put them in, but those different readings stay the same when you swap them around and repeat the test again with your plectrum?  So that means that, effectively, the readings are not following the valves as you swap them and retest?

The other scenario is that you mean all of the valves have the same reading which is possible with a really well matched set of valves.  If that's the case then trust the TSC!  If it says they are all the same then they are.

Microphonic valves will not necessarily show any difference in bias current, the two issues are not tightly related.  I have spoken to H&K about a possible TSC reset procedure in the long gone past and, sadly, I can't remember the steps they told me to follow.  I think it was a "hold buttons and switch on" type of process but it's too hazy in my mind now.  If you really really want to reset the TSC to a blank state where it will recalibrate itself you could try searching on the forum as it has been put into a post.  I've tried to find it but for some reason the search facility doesn't work too well for me and never has done.  However, as I understand it, the system is constantly recalibrating itself anyway to accommodate new valves and changes in conditions such as temperature.

I get the same readings when I swap the new tubes (Not sure for the original tubes I didn't check with them) and they are not perfect matched because there is 4 flashes difference between some of the tubes and this readings don't change even if I swap the tubes and put them randomly, which I guess is not correct. For example if let say the first tube blinks 9 times, if I swap this tube to let say the 3 position it should show 9 flashes again, because it's the same tuber I'm wrong?

I have another question If all tube should sound the same, why are there web sites like this one?
https://www.amplifiedparts.com/tech-articles/12ax7-comparison-current-made-tubes

Here is another forum topic on the same theme:
https://www.tdpri.com/threads/tech-says-tubes-cant-change-amp-sound.431595/

Excellent question Andrio, and as luck would have it you chose the exact same site I was talking about.  You will find a thread in the Lounge I started where I described this site in particular as it is setting out to PROVE that there are differences but in fact their own results show that there are none of any note.  If you can wade through the snake oil of course.

Firstly ask yourself "why have they posted that site at all"?  If you look closely you will find this at the bottom of the page:

Amplified Parts wrote:By Kurt Prange (BSEE), Sales Engineer for Antique Electronic Supply - based in Tempe, AZ. Kurt began playing guitar at the age of nine in Kalamazoo, Michigan. He is a guitar DIY'er and tube amplifier designer who enjoys helping other musicians along in the endless pursuit of tone.  [My Bold, BB]

Notice Kurt Prange is the "Sales Engineer".  That highlights the fact that they are selling valves (and other things) so this is actually a piece of marketing copy.  It's to their advantage to spread this sort of belief as it increases sales.

Now, ignore the first 95% of the page with its pretty pictures of 12AX7s and the Red/Grey/Yellow bargraphs representing the responses of each model and go to the ONLY piece of relevant information on there.  That's the single graph right at the base of the page which shows the frequency response of all of the graphs laid over each other.  Did you spot that one?  If you did, were your eyes quickly drawn away to the pretty descriptions of the valves above it with their captivating but meaningless diagrams because it was a "bit techy"?  I have attached a slightly more informative version of it.  It is a common thing to only show part of a graph as it expands and shows up the fine detail better but it also distorts the relevance of that fine detail to the overall picture.  When the full graph is shown the differences are a bit less significant.  I won't criticise them for that point but it is relevant to our discussion.  Click on that graph at the bottom of their page and it will expand to a better size.  Is minimising the only bit of real info, perhaps to make it less clear and a little more insignificant, a marketing strategy or not?  I'm not sure on that one either.

Look at the individual plots on that graph.  You should notice a couple of things.  Firstly each one is sitting at a different level.  That level shows the gain of the circuit they have been tested in.  Putting the valves into a Fender style preamp and measuring each of them within that circuit is a reasonable way to approach things but it would have been better to show some measurements of the valves' real characteristics in a bland test bed too.  Anyway, you should understand that the plots are related to a valve's characteristics but are not a direct measurement of them.

Look at the vertical axis and see that it is graduated in Decibels representing the voltage gain of the preamp with each valve in place.  Do you really know what the difference in decibels means to the human ear?  The maximum difference between all of those models is about 2.8dB and that includes a rogue valve (the lowest yellow plot) which is an odd amount below all of the rest.  In truth, statistically speaking, that one should be given less significance as should the top one.  Every other plot lies within about 1.6dB of each other.  That is a ridiculously small spread and your ear would be hard pressed to even detect it in the real world.  For a bit of background try going to this site, Harbeth Sound Level Test, and IMMEDIATELY go to post #11 and take the test.  Listen to the 4 samples and see what order of volume you put them into.

Now to the REAL stuff!  The levels of those plots are really irrelevant.  Ok, so each valve has a very slightly different gain within the circuit.  (Valves do not have a stated "voltage gain" of their own.)  Don't we have Volume controls to trim that if it becomes noticeable?  The REAL point becomes obvious when you slide each plot over each other.  The SHAPE of each plot is the only measurement of their "tonal signature".  They are all the same!  Exactly the same!!!  The slightest less than 0.1dB differences at any particular frequency are totally irrelevant in audible terms and are within the spread we could expect from even different valves from a single manufacturer's output, and the test equipment even though it was good quality, and variations in the test conditions like the warm up time of each valve or mains variations.  The manufacturers spread of characteristics is around +-40% for valve transconductance, anode current is allowed to vary around +-20%, what is the relevance of those comparisons when even valves in each manufacturer's acceptable range can vary by far more than those results show?  ("Getting The Most Out Of Vaccuum Tubes" - Page 64"  The whole thing is a complete fudge of the reality of the results.

So why the pretty Red/Grey/Yellow bargraphs?  Surely they show there are differences?  Let me show you what that is about with an example.  Have a look at the Dummy Valve Comparison I set up.  I made up some data similar to the frequency plots and chose a value for Bass, Mid and Treble just as they did.  I then took the values at those points and plotted them on a barchart just as they did.  That is what it looked like, just like theirs.  Now from that you could say that "the blue valve has a well balanced frequency response with good tight dry bass, bell like natural mids and a smooth transparent treble, while the orange valve has strong bass and mids with a slightly recessed delicate treble."  The graphs show that don't they?  However if you look at the horizontal axis you will see that, even though the length of the bars looks impressively different it actually represents only a range of 0-0.05 MAX.  A tiny difference of less than 0.05% in the real original measurement values, way within measurement error or natural characteristics spread, has been stretched out to look highly significant.  Now take a look at the individual barcharts on that site and you will see that they are designed to take advantage of the same effect.  They even recalibrate the tiny decibel differences to a fake scale of 1-10 to disguise the truth.  If we accept that the maximum difference between all of the valves is less than 3dB at any frequency, each step in value from 0-10 represents a difference of less than 0.3dB which is inaudible.  Those charts are nothing more than a marketing ploy.  In common with the latest rash of TV adverts you could say that they utilise "Visuo Lookyseewhatwewantyoutosee Technology".

The interesting thing is they have done a pretty good job of the measurements but then if they fudged those "real" results it would really be too obvious and perhaps open them up to accusations of malpractice.  Keep on questioning, it's the only way to the truth.  No salesman is ever going to tell you that.  Nor is any self styled guru who doesn't understand too much of this anyway.  They just "know what they know what everyone knows and says".

...oh, and to the other point.  Here is a reply in that forum discussion you posted:

Online forum wrote:He just doesn't know.  I'd find another tech if he doesn't know more about amps than that.

 That says it all!!!   He just doesn't know, get someone else who believes without question.  And the guy is reputed to be someone with decades of experience in the field.  The idea that you can change a set of valves and compare them by ear from memory with a couple of minutes between is total nonsense and would not stand up in any respected engineering arena.  Your audio memory lasts only a few seconds then your brain resets and any differences you hear cannot be given any reliability.  After that you hear what you expect or want to hear.

Technically, even just refitting the same valve could give you a measurable difference as the contacts are wiped clean on pulling and replacing.  The measurements in state of the art test equipment are the only thing you can go by.  How many guitar gurus does it take to change a light bulb?  274!  1 to change the bulb and all of the others to start the rumour that there is a huge difference in the way the light from them illuminates your room.  And if your electrician doesn't fit the correct "best light" bulb of the moment then just  - get another electrician who knows his stuff properly.

EDIT:  Incidentally if you read through the first couple of pages of that thread you will find the more knowledgeable (read technical) posters are defending him.  There are many many people out there like me.  It's just that we all speak with forked tongue and offend many people with our "fake news".  You can mock, belittle and badmouth the reputation of an engineering type to win your point, you can't do that to a piece of high tech test equipment.  Best not put it out to rely on test results, eh?  

Incidentally.  H&K Support repleid to Andrio's request for help with his TSC.  Here is their reply:

H&K Support wrote:OK, so we asked our techs about this, and they said there is something you can try. TSC has a memory system - it could be that the memory is full and can't change what it's displaying. So to reset this memory, simply turn the amp off completely. Then turn the amp on - but instead of flipping the Standby switch first, flip the power switch first, and the Standby (don't worry, this won't damage the amp).

They also said: you said you repositioned the tubes totally randomly... is it possible all of them actually ended up in exactly the same place as before? If you're not certain about that, you could also try this again, making sure you know which tube was which.

If these two options don't help, then we'd recommend dropping in to see your local tech with the amp, and have them take a look - just in case

Hope this helps, and let us know how you get on!

All the best,

Team H&K

As I've always said, they are very responsive to positive requests for info.

Thanks for all the info you provide!
I have few more questions
As I know tubes even they are the same type,can have different construction and could be made from different materials. For example two different 12ax7 tubes has at least visually different internal construction. Isn't this a prerequisite to make them sound different?

Another think is... I had a stereo power amp which had one side EL34 tubes and on the other 6L6 tubes (I know that Mesa Boogie has similar amp with both EL34 and 6L6). The amp was designed like (if I was using it mono) ,that I could change the output tubes with a flip of a switch even when I was playing...Actually I had presets with the different output tubes for different sound.
Now my question is... Since all other components (transformers, caps the schematics and so on) are the same (because as I know you could swap EL34 for 6L6, but just have to adjust the voltage to much the tubes requirements ) why they sound different? My opinion is, because they are with different construction and even they share the same schematics, they sound different So it should be the same for other tubes I guess...
Thank you!
Cheers!

Again great questions.  This is still only about tone in circuits.

Valves may have different constructions but that is not what defines them as a particular designation of valve.  They are categorised in circuits only by their electrical characteristics.  A 12AX7 is only that because it has a set group of electrical characteristics, nothing about its physical build is relevant to that.  If one has a long plate anode and another a short plate anode that is irrelevant in normal use if they both have exactly the same values of electrical variables.  I have attached the datasheet for a 12AX7.  Just take a very quick overview of the first page or two and notice there is absolutely no mention of any physical properties being relevant to the circuit action at all.  Any valve which fits that spec is a 12AX7 no matter what its inside is like.  The circuit your valve is put in does not care if the valve's heater coatings are different or if it has an extra mica mounting as long as the defined parameters which the spec sheet lays out are met correctly.

This is the mistake many non-technical people have made with this issue in the past.  The only thing which makes any difference to tone in circuit is the electrical characteristics as this is all, that is literally the only thing in any way, that the circuit is affected by in its ability to amplify differing frequencies.  Yes, noise contribution or microphony can be different and are separate factors but that does not affect tone in a circuit, they are separate small independent signals laid over (added to) the wanted one.  If I design a valve made out of an old jar with internal parts I manufacture on my kitchen table out of old tin cans, and I can evacuate it of air to the correct level, as long as it has pretty much close to those values laid out in the "Characteristics And Typical Operation" section of the datasheet it is a 12AX7.  Any circuit I put it in would not know the difference between it and a NOS Mullard.  (That datasheet is from "General Electric" but you could compare it with say a Mullard or a Brimar datasheet to see they are just the same).  It might not last too long    but it will function exactly as any other 12AX7 for as long as it remains undamaged.

Ask yourself how the circuit could respond to a difference in something physical inside the valve if that change did not cause any difference in the electrical characteristics?  How can your mains electricity know that the insulation of a mains cable is PVC or rubber as long as they are both in good condition?  If there GENUINELY IS a difference in circuit action due to a physical difference in construction then it must have made a change in the electrical properties of the valve and we must be able to measure that - if it REALLY exists.  The two go hand in hand.  When you can't measure any difference there is no difference to hear.

There is even another factor in this question.  Valves, let's say our 12AX7 triode, are basically devices which use a signal voltage across their Grid and Cathode to change the current passing through from their Anode to their Cathode so the current is a perfect match (as near as possible) to the grid signal voltage.  A normal triode gain stage usually shows a fairly common design.  There is a grid resistor to keep the grid at ground level for DC which we use as a common reference for the input and output voltages.  There is an anode load resistor to convert the anode current to a voltage, (note I said earlier that a valve has no voltage gain, it produces a signal current which can be converted to a voltage by that resistor).  It also normally has a resistor in the cathode.  Ask yourself why that is there.  It generates voltage feedback to the grid of the valve based on the changing anode signal current, which does a number of things.  It sets the bias current of the valve by adjusting the grid/cathode voltage to reduce the current when that voltage is trying to increase it and vice versa.  This means the valve settles to a current level which is within a very close range even with wide changes between valves.  It drops the gain of the stage, through a similar action on the signal input voltage.  It widens the stage's frequency response to way beyond anything we would ever use, (the class of valves we use for guitar amps are actually radio receiving valves from the old days so their frequency response is already up in the RF band).  It even reduces the noise level that the stage generates.  And it does all of that and more to whatever valve you put in there bringing them all very close to the same setup of the stage.  That is why you don't ever have to bias a preamp stage, the cathode resistors take care of it and set the stage up the same for any valve you put in there.  Even if there is a spread of parameters in any manufacturer's production runs the negative feedback in the circuits pretty much takes care of it.  That's good design!

The voltage gain of a stage can be increased by putting a capacitor across the cathode resistor and this increase is across the frequency spectrum above a certain frequency defined by the resistor and capacitor values.  By using the same method to the anode resistor the frequency response can be altered to reduce the upper cutoff frequency.  By careful design you can choose the value of these components and others to alter the frequency response of the stage to almost anything you want.  All that is common to see in amp circuits but that is not the valve altering the stage's response in any way.