This sort of statement is supposed to mean what?
You are claiming a 15-20W SET amplifier system with high levels of distortion & high output stage impedances,+ runs into clipping & LF magnetic saturation on 350-400V HT is going to be more capable of cleanly reproducing a large dynamic range than a 200W system with lower impedances and 650V HT? 🙄
That's evident nonsense.
Just look at the way most of these systems reproduces LF cleanly where most of the output current needs to be found, and you will usually find your answer.
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are you talking engineering dynamic range or the subjective experience? because in the subjective world there can be micro dynamics at low volume where flea powered SET amps and efficient speakers are for some people, unrivaled. In the SS arena the SEWA amplifier was highly regarded for dynamics and it was a 7W SE amplifier.
Dynamics is the difference between the loud bits, and the soft bits, when listening. A very high percentage of systems, especially those engineered to have lots of wallop - think sound reinforcement, here, 😉 - don't get the soft bits right, they are just sludgy and "thick" in this area. Get the soft bits right, and then the difference between the loud and soft can be dramatic, hence high perceived dynamics ...
No interest in talking about statement classes thanks. If you address yourself to what I write then perhaps I'll respond.
Nope.
Indeed - you wrote it, nuff said 😀
Yes - I'm talking about subjective dynamics, I suspect mullered is talking about measured dynamic range. Subjective dynamics appears to be the OP's original topic, measured dynamic range would appear to be a red herring.
I am thinking of home cinema surround & HD systems in general.
I can't think of a single one that I heard that fitted the description you made, and I reckon I must be one of the few that has gone to the trouble of a valve amplified surround set up.
(I went round a few capital cities in the best "hi-end" shops and couldn't find anyone with a system that was close, in fact 99% of "hi end" stuff was STEREO only! ).
One of the BEST "test" surround recordings I have is the live reggae band "Gladiators" playing (no compression used).
I have yet to hear a "hi end" system (or any commercially sold, mega expense set up), that is capable of reproducing it.
The vast majority of mega expensive amps and speaker systems keel over and die when presented with this. 😀 . I wonder why?
It makes me laugh, when people are talking about subjective dynamics when all they are listening too is compressed music anyhow.
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I doubt it.
If you saw the audio line up and the eye watering price tags, I don't believe it for 1 second.
One of them was the best audio shop in Paris, but the sound reproduction was POS, but he evidently thought it was brilliant, and so did his "hi end" studio audio sound engineer who was present at the time.
🙄
A good recording to have on hand for testing, and as abraxalito suggested, inadequate engineering of the complete circuit used within the power amplifier of the systems you listened to, irrespective of what the spec's might say and how impressive all the bits look ...
In fact, there is a huge range of recordings that present a very impressive dynamic range, in all categories of music. They may have some levels of compression in the extremes, but this doesn't get in the way of creating the impression of "big" sound - they will conjure up tremendous soundscapes, just using 2 channels, provided the overall system is working correctly!
Hi,
Would that be; Gladiators & The Israel Vibration - Live At Reggae Sunsplash
or
Gladiators - Live in Arizona?
or some other?
Thanks.
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Is there not a legitimate Tube amplifier question to be discussed here or have I mistakenly logged into the I know more than you do about irrelevant nonsense forums again?
There are four types of class A amplifiers you are likely to meet. PP valve, SE valve, PP constant current transistor and PP overbiased class AB transistor. Of these the SE valve is the surprising one. With more engineering problems it often ends up best. The reason I suspect is simplicity and a DC biased output transformer. My SE design has 5 to 8 watts, 620 mV in. 15 Hz to 62 kHz and 1% THD dropping to 0.2% 1 watt. The higher level Hiraga style and mostly 2nd at 1 watt. The amplifier shows very nice linearity down to the micro watt levels. The PSU is a MOSFET capacitance multiplier which allows very low hum at 500 VDC 200 mA total ( 140 mA used. Nigel Wright I agree over B+ ). It contributes a small amount of second harmonic distortion. I use various tricks seen in first generation transistor amps to pull rabbits out of hats. The low distortion is by matching a pentode input to a 82% triode UL output. There is no loop feedback. The amplifier rescues bland material. Layers are heard which could be lost, this is so obvioius as to be laughable how different it is. It is also very dynamic. Very cheap speakers retain what it can do. I would suggest a pair of Mission 760 on this amp would be more wonderful than a Krell with KEF LS50. The KEF being one of the few cheaper designs that is worth getting excited about.
Most PP valve amps sound as if singers have colds. As soon as the loop feedback is removed this usually goes away. Some PP valve amplifiers do not suffer this. It seems to say the transfomer needs to be very special along with careful design which GEC were very aware of in the last GEC design book circa 1972. One problem remains with PP valve, a dark sound. I would speculate that an AC bias signal would help make the transformer work better if PP. Class D in valves I suspect is not possible, please show any.
Class A transistor has never been my cup of tea. The best are vaguely better than AB. The Yamaha proves it, A or AB it is "The Kings new suit of clothes"to say which is in use. The overbiased AB being a good idea. One class A amp I built was complimetary feedback pairs with or without loop feedback driven from an OPA604. It had some magic about it. It had almost zero distortion. If I rebuilt it I might try a variety of resistors in the output to see if I could mimic the sound of my SE valve. The theory being the loose coupling is the dynamics. When listening very loud last night the speaker cones never seem to move. It makes me think this matters greatly. This has been said before in other ways . It still is worth going through it. An underdamped system might sound better. It's not really current drive, more like " ideal drive". As I use EQ anyway way not do this? My quest with EQ is always inside the amplifier feedback loop if I can . This means no Bob Stewart losses. To remind you his idea was although hard to prove every amplification stage is a copy and it will loose imformation. It you think carefully what we think we know about hi fi is very 2D. Snapshots made by equally flawed devices. Just like the 2D man, if I step on him he has no idea of the how and the why of how he got killed . Trains were not a great reality when Fourier was in his last days. And yet he was a more a 3D thinker. He even saw how DC values and sub-harmonics could be a problem. From my little understanding of pipe organs the dynamics is only bass and other notes played with correct timing. This requires the musican to prove his or her ability to dance and listen along with knowing music etcetera. Along with dynamics which are not subtle comes beauty and warmth plus depth. The organ has not been moved to do this, nor even the air output. It is just temporal distortion. Whilst I can not easilly say how lessons of the organ can be applied it gives an insight. Dual subwoffers carefully placed might be something to think about. This avoids digital soulutions. These would work from 10 to 100 Hz. Class AB transistor would be ideal. The switching is actually useful if looking at the mains transformer as a storage device which in class A it can not be. In D it becomes more complicated. AB can swing above the rail when asked not unlike bootstrapping. Class D sounds a bit weaker than AB I feel for a given wattage. This might be why. Careful PSU design with class D will bring results.
The PSU will be much the sound of the amp ( 90 %, being just good or excellent if excellent is available ? ). Tune the frequency responce to suit by ear. This is where people come unstuck. It is like people who love dancing who can not dance. Some who love music would never have a quick route to fine tuning by ear. Thus they prefer rules of other as sucess shortcuts. Regardless of tallent, tuning by ear is the only route as long as it is realised it is not a universal truth. Make a change and it should be redone. Input coupling caps and PSU caps would be 90 % of what I am saying. Often smaller caps are better or larger transformers rather than just larger caps. Any feedback cap or supply decoupling also. Sometimes they hit the same note and that might or might not be a good idea.
Most PP valve amps sound as if singers have colds. As soon as the loop feedback is removed this usually goes away. Some PP valve amplifiers do not suffer this. It seems to say the transfomer needs to be very special along with careful design which GEC were very aware of in the last GEC design book circa 1972. One problem remains with PP valve, a dark sound. I would speculate that an AC bias signal would help make the transformer work better if PP. Class D in valves I suspect is not possible, please show any.
Class A transistor has never been my cup of tea. The best are vaguely better than AB. The Yamaha proves it, A or AB it is "The Kings new suit of clothes"to say which is in use. The overbiased AB being a good idea. One class A amp I built was complimetary feedback pairs with or without loop feedback driven from an OPA604. It had some magic about it. It had almost zero distortion. If I rebuilt it I might try a variety of resistors in the output to see if I could mimic the sound of my SE valve. The theory being the loose coupling is the dynamics. When listening very loud last night the speaker cones never seem to move. It makes me think this matters greatly. This has been said before in other ways . It still is worth going through it. An underdamped system might sound better. It's not really current drive, more like " ideal drive". As I use EQ anyway way not do this? My quest with EQ is always inside the amplifier feedback loop if I can . This means no Bob Stewart losses. To remind you his idea was although hard to prove every amplification stage is a copy and it will loose imformation. It you think carefully what we think we know about hi fi is very 2D. Snapshots made by equally flawed devices. Just like the 2D man, if I step on him he has no idea of the how and the why of how he got killed . Trains were not a great reality when Fourier was in his last days. And yet he was a more a 3D thinker. He even saw how DC values and sub-harmonics could be a problem. From my little understanding of pipe organs the dynamics is only bass and other notes played with correct timing. This requires the musican to prove his or her ability to dance and listen along with knowing music etcetera. Along with dynamics which are not subtle comes beauty and warmth plus depth. The organ has not been moved to do this, nor even the air output. It is just temporal distortion. Whilst I can not easilly say how lessons of the organ can be applied it gives an insight. Dual subwoffers carefully placed might be something to think about. This avoids digital soulutions. These would work from 10 to 100 Hz. Class AB transistor would be ideal. The switching is actually useful if looking at the mains transformer as a storage device which in class A it can not be. In D it becomes more complicated. AB can swing above the rail when asked not unlike bootstrapping. Class D sounds a bit weaker than AB I feel for a given wattage. This might be why. Careful PSU design with class D will bring results.
The PSU will be much the sound of the amp ( 90 %, being just good or excellent if excellent is available ? ). Tune the frequency responce to suit by ear. This is where people come unstuck. It is like people who love dancing who can not dance. Some who love music would never have a quick route to fine tuning by ear. Thus they prefer rules of other as sucess shortcuts. Regardless of tallent, tuning by ear is the only route as long as it is realised it is not a universal truth. Make a change and it should be redone. Input coupling caps and PSU caps would be 90 % of what I am saying. Often smaller caps are better or larger transformers rather than just larger caps. Any feedback cap or supply decoupling also. Sometimes they hit the same note and that might or might not be a good idea.
NO.
Gladiators LIVE (in Europe) in HD surround.
We did it.
It was a load of surround recordings I did 15 years ago, when most of the sound engineers (and other people) said "WTF are you doing that for"? 😀
I'm just messing with a DVD-A / blue-ray Audio version of it at the moment.
Mine certainly doesn't do that, and we are recording the singers whether they have colds or not.
One music festival we did, everyone had a throat infection for most of the festival.
That's what sorts out the pros from the amateurs.
It just HAS to work on the night, because someone already sold all the tickets 6 months ago. 😉
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I've found most HT receivers lacking in subjective dynamics - they do exactly what somebody said above - lots of wallop in the loud bits though.
I've modified my Pioneer receivers twice, the latest one is improved but it is ultimately limited by the power supply. They use a high rail voltage to claim high power but can't deliver on the current (inadequate VA) and don't put enough rail decoupling near the output of the power amp. As a stop-gap measure I modified the power amp section by adding current mirrors to the input LTP's. I also set the correct bias at the output - they normally set them very low so they can boast about low idle power but are in fact operating them in a nasty fashion. It's not worth doing much more, even an outboard power supply would likely be another band-aid. Best to go with pre-outs and separate power amplifiers.
Of course the main problem with HT is the poor source quality. You need lossless Blu-ray with decent mastering and that is very rare still. The Master and Commander movie shows how it can be done well - great dynamics.
I've modified my Pioneer receivers twice, the latest one is improved but it is ultimately limited by the power supply. They use a high rail voltage to claim high power but can't deliver on the current (inadequate VA) and don't put enough rail decoupling near the output of the power amp. As a stop-gap measure I modified the power amp section by adding current mirrors to the input LTP's. I also set the correct bias at the output - they normally set them very low so they can boast about low idle power but are in fact operating them in a nasty fashion. It's not worth doing much more, even an outboard power supply would likely be another band-aid. Best to go with pre-outs and separate power amplifiers.
Of course the main problem with HT is the poor source quality. You need lossless Blu-ray with decent mastering and that is very rare still. The Master and Commander movie shows how it can be done well - great dynamics.
Nor does the Marantz Model 9.
90% of what I know is transistors. I try my best to be on subject. My studies were valve. We were the last students with that bias of learning in this region. Our teachers were happier as they didn't understand transistors and said so. 90 % of what I learned was electrical engineering which is the better qualification I gained in electronics. For example my tutor didn't know how a power supply really works. My electrical engineering tutor was brought in to answer a question I asked as my electronics tutor couldn't. From reading much of what is said most electronics engineers struggle with PSU design ( me also ).
I have done a down grade of my OB speakers using a very high grade air cored inductors. 90 uH 0.06R measured. Horrible. I had no idea. The maths looked good for what I did. The speaker is fed by thin wire so I doubt the DCR. It was head and heart. Head liked the change and heart hated it. The drive units needs something. It is not this. Dynamics were ruined. The hook was gone. Now resoldered and happy again. The drive unit is unfiltered with simple meachanical upgrades to damping. That was briefly removed to be sure. It was even worse.
90% of what I know is transistors. I try my best to be on subject. My studies were valve. We were the last students with that bias of learning in this region. Our teachers were happier as they didn't understand transistors and said so. 90 % of what I learned was electrical engineering which is the better qualification I gained in electronics. For example my tutor didn't know how a power supply really works. My electrical engineering tutor was brought in to answer a question I asked as my electronics tutor couldn't. From reading much of what is said most electronics engineers struggle with PSU design ( me also ).
I have done a down grade of my OB speakers using a very high grade air cored inductors. 90 uH 0.06R measured. Horrible. I had no idea. The maths looked good for what I did. The speaker is fed by thin wire so I doubt the DCR. It was head and heart. Head liked the change and heart hated it. The drive units needs something. It is not this. Dynamics were ruined. The hook was gone. Now resoldered and happy again. The drive unit is unfiltered with simple meachanical upgrades to damping. That was briefly removed to be sure. It was even worse.
LTP. Did you keep the Cdom the same ? Very interesting if you did . You might have marginal instability which is argued to sound better. I have always thought slew rates are bogus. What is most likely is it simply is impedance matching. That is transistor amps into the VAS are not quite pure I to V converters. The voltage ghost into the VAS base is not quite a ghost. The single VAS makes it worse as it is like a single legged cyclist. Source and sink is unbalanced. The old Hitachi MOS FET amp had no great slewing. It had more than enough. What it did have was great symetry of current drives. In theory 6 V/uS is OK for any music when 100 watts. The Hitachi was about 35 V/uS I think ? The Hitachi had high ouput device slewing instead. Some say the special MOS FET's work in the nano seconds. I suspect they must.
I ask as the only logical upgrade of the Hitachi is to do what you did. BCV61 ( or 62 if the other way ) is ideal and very cheap. The Hitachi would clamp them at 2 V so the 20 V rating is fine. They should work without degeneration even. Mostly this would be to massage the technical spec. It would perhaps be +/- 70 V/uS source and sink. If it requires the VAS Cdom to rise from 27 pF to 47 pF then it is dubious that any good was done. Some good no doubt.
I stand corrected.
I would stand by my list of three in recording as well;
1) Lower PSU output impedance
2) Better open loop linearity (use tubes with good curves loaded with flat loadlines in a forced balanced topology)
3) Transient response, tube grid driven by source followers
These are the principles I plan to use on my mic preamp build.
People sell all kinds of things and other people are ready to pay stupid money on them. Question is, what can you build, and how do you design it?
Not at all. I have no idea what connectors have to do with dynamics or amp design at all (construction, yes).
There's no need to use ancient anything, that I agree with. Many ancient triodes have some of the best curves, so they have very good potential for first class linearity, but they are expensive. There are alternatives with just as good curves, even better.
With proper, MODERN tube design, it's not difficult to get a clean 100 kHz with lowly and cheap Hammond transformers.
Could you share some more concrete ideas and things you've done regarding actual circuit design? What kinds of things have you built?
Indeed. Please discuss technical ideas and not make comments on other people posting here.
You are correct. Put a source follower (preferably loaded with a CCS, at least 5mA) in front of the 300B grid, and it's no longer slow. Regulate B+, and it'll get even faster.
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