| ionutgaga |
I want to build an amplifier in this class. I see on Yamaha, Sunfire, Bash, and probably others. But i not found any concrete schematics. Is anyone who have this sch?
L.E. The most big amplifier i have made it, is supply +/-145v class H, 4 tier (+/-50, 85, 110, 145v) |
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| Workhorse |
| quote: | Originally posted by ionutgaga
L.E. The most big amplifier i have made it, is supply +/-145v class H, 4 tier (+/-50, 85, 110, 145v) |
Hi,
Switched rail or Modulated rail, which type did you made in Class-H.....
As you say its 4 Tier, it must be a Switched Rail type, is it full range or Subwoofer amplifier...Would you share the schematic....
regards,
K a n w a r |
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| ionutgaga |
Switched rail, as you see (+/-50, 85...). The switched schematic is from QSC PL6, PL9. The audio is from ElectroVoice P3000 (floating grounded bridge). In time i will post the full schematic and photos.
Is verry efficient, comparative to EV P3000 (class AB), is smaller, transient response is better.
I see EV, Dynacord build class AB, then class H 2 tier, now class H 3 tier. The next step is probably modulated power supply (AB+D).
My wish is to build this class (maybe +/-150v, modulated offcourse). And please email me anything about this class, if you wish.
L.E. My most big amplifier drive cool 4 x PD1850 (mounted in pair in planar wave guide)
L.L.E. Where do i find romanian-english translator? |
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| ionutgaga |
i will atach photos tomorow. Any questions...
These days i will develop other big power amplifier in class BD.
The schematics is in OrCAD, i made a few conventions: IRFP44=IRFP54N, 2SC3281=2SC5200, etc. Feel free to ask details. |
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| SpittinLLama |
I am confused what you are really talking about. Class G is switched rails or tiered rails like you made. Class H is a modulated supply so that it tracks the output, also called a rail tracker. It is an improved on Class G by going to infinite steps in the rails. Class D is a switched output waveform (PWM or some other modulation technique). Both Class G and H typically use a Class AB with a modified power supply. So what is Class AB+D? And what are you calling Class BD? Class AD is a switched output with 2 output states and Class BD is a switched output with 3 output states. I am very interested in a Class GH hybrid for use with integrated chips that need minimum fixed DC rails or the chip shuts off but then modulate the supply above (Class H). The guys at Indigo have a solution found here: http://www.bashaudio.com/technologies.htm. This is Class GH as G for min fixed rails and H for modulated above as needed. This might be along the lines of what you are looking into.
-SL |
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| mikeks |
| quote: | Originally posted by SpittinLLama
........modulate the supply...
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Much more elegant than Class D
Patent here |
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| ionutgaga |
This classes confuse me. BD, GH, H modulated, I, etc.; say big firms uses annotations H (2-3-4 tier), for the switched rail. And so mine. This time i will develop class AB with modulated power supply.
The posted schematics is for 4tier class H (as is presented from QSC, EV, Dynacord, etc).
Sorry for the pictures, i not have momentarly a card reader, still searching. Probably monday i will post the photos. |
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| Workhorse |
| quote: | Originally posted by SpittinLLama
I am confused what you are really talking about. Class G is switched rails or tiered rails like you made. Class H is a modulated supply so that it tracks the output, also called a rail tracker. It is an improved on Class G by going to infinite steps in the rails. Class D is a switched output waveform (PWM or some other modulation technique). Both Class G and H typically use a Class AB with a modified power supply. So what is Class AB+D? And what are you calling Class BD? Class AD is a switched output with 2 output states and Class BD is a switched output with 3 output states. I am very interested in a Class GH hybrid for use with integrated chips that need minimum fixed DC rails or the chip shuts off but then modulate the supply above (Class H). The guys at Indigo have a solution found here: http://www.bashaudio.com/technologies.htm. This is Class GH as G for min fixed rails and H for modulated above as needed. This might be along the lines of what you are looking into.
-SL |
Class-G= Cascode Connected series Devices at outputs, no Square wave type switching involved only Linear Tier switching just like 2 amps with lower and higher voltage rails...
Class-H=No cascode at outputs , but involves Square wave type Step switching using Mosfets for voltage swings and also cost less than class-G...
Class-BD= When 2 PWM amps are bridged in a fashion which involves same in Phase carrier frequency , but out of Phase Audio Frequency, used to cancel the switching residual at outputs...Its output is 3 Level +1,0,-1
Class-AD= When 2 PWM amps are Bridged in such a way that both Carrier Frequency and Audio signal are out of Phase to each other respectively......Its output is 2Level=1,0
Class-TD=Lab Gruppen uses this,..Its a combination of Class-D power supply with integeration of Class-AB amp, which involves Tracking of output voltage by supply voltage rails for example in Carver Lightstar amp the Tracking rails are always just above the output voltage by the margin of 6 volts,[I hope DJK & Anatech will better explain this] which again increases efficiency....
| quote: | Originally posted by ionutgaga
This classes confuse me. BD, GH, H modulated, I, etc.; say big firms uses annotations H (2-3-4 tier), for the switched rail. And so mine. This time i will develop class AB with modulated power supply.
The posted schematics is for 4tier class H (as is presented from QSC, EV, Dynacord, etc).
Sorry for the pictures, i not have momentarly a card reader, still searching. Probably monday i will post the photos. |
Hi
ionutgaga,
The Modulated supply amp is very complex than plain Class-D and also poses pitfalls in some areas as compared to other Classes...EVA[Another female forum member clearly illustrates it]
If you want to try your hands on bigger amps than move on to Class-D PWM amplification...these are lot more things to explore ....
Meanwhile Have you ever built All N-Channel Vertical Mosfet Class-H 2 or 3 Tier, I have Built it and it simply exceeds any Bipolar Class-H when power level exceeds 2KW++
I am currently working on Both Class-H Bipolar [Smaller power level upto 1600W/Ch] and Class-D PWM ++5KW levels....
regards,
K a n w a r |
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| mikeks |
| quote: | Originally posted by SpittinLLama
...... modulate the supply.....
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I suspect the tracking power-supply must necessarily do so at a higher slew rate than the amp. it powers... :scratch2: |
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| SpittinLLama |
Mikeks, your first link is the same link I had in my post for what Class GH hybrid is, fixed DC rail with rail tracking when the AB amp needs to go higher than the DC rail. I believe the slew rate of the supply will need to have a higher slew rate. This is similar to Douglas Self's conclusion that a regulated supply is better as long as the supply is faster than the amplifier. As an experiment, power a small AB amp, like 20W from a higher powered AB amp as the rails that is faster than the small AB amp. Then measure THD and compare it to a unregulated supply or slower bench fixed supplies.
I am using Douglas Self's definition of Class G and H.
When ever you see a new class like Class I or Class T be skeptical. Class T is not a real class, just marketing (T after Tripath, Tripath is from the founder's last name). Class I is Class BD, same type of modulation that TI uses in their Class D chips just Crown uses a new name of their own choosing. BTW, Class AD does not need to be bridged but Class BD does need to be bridged to get 3 states. Rockford Fosgate has a patent on a Class BD design, I didn't see it on Toino's list. It is patent number 6097249. It is a very interesting read. Thanks for the links. I will have to take some time to look at them.
Class TD sounds just like what I have learned is Class H which says nothing about how the supply rail tracking is created but one would almost assume Class D for efficiency reasons. I don't understand what Workhorse is calling Class H. If you have some links it would be helpful or more explanations. See the BASH amplifier link in my earlier post or in Mikeks post (elegant link).
Sorry to side track the thread so much. I have heard of ideas where you use a Class D to create the output and drive the current but then in parallel with a small AB amp to correct the waveform some and improve THD but over efficiency gain is good or change from class AB into D at some level. Hence, Class AB+D. I have seen a chip do AB into D (can't say where ;)) but getting THD good is the challege. The D in parallel with an AB sounds interesting but that is all I know about it so want to understand more.
-SL |
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| TOINO |
The patent number 6097249 is not in the list because is not a tracking supply, is just 3 level class-D.
About class-I patent the only thing I could see is two Buck converters, one positive the other negative. For me is a kind of switched class AB amplifier.
The irony of the list is that the patents are almost the some.
I steel not understand how it is possible to patent the some thing so many times…:confused: |
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| forr |
---Class-G= Cascode Connected series Devices at outputs---
Cascade, yes; cascode, I don't think so. |
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| Workhorse |
Hi Forr,
This is Class-G.... |
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| mikeks |
| quote: | Originally posted by SpittinLLama
........This is similar to Douglas Self's conclusion that a regulated supply is better as long as the supply is faster than the amplifier. ....... |
I don't think Self arrived at any such conclusion...:bigeyes: |
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| SpittinLLama |
Are you guys saying the only difference between Class G and Class H is how the output stage is connected? What Toino linked calling Class H looks to me like Class G, rails jump as necessary. So what is the class where the supply follows the output at a few volts higher than the output to keep the xsistors out of saturation or think of infinite rail jumps with infinite levels to jump?
Maybe I am paraphrasing Self or I have him confused with another author. I'll see if I can clarify by getting the reference.
-SL |
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| SpittinLLama |
You are correct Mikeks, I did not find this conclusion in the book I have by Self. He pretty much recommends the unregulated supply route with the amplifier correctly designed for such. I can't remember where I read it but it is not something I learned on my own. Couldn't find it quickly in my other books and time is tight right now.
-SL |
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| forr |
Hi Workhouse,
I apolologize, you're right. In a class G amp, the outer devices and the inner devices work as followers in a cascode mode. The first time I've seen this kind of followers was in a paper written by Nelson Pass. However, I do not remember Self using the term "cascode" for his class G amp, whihc should explain my mistake.
Hi SpittinLLama,
---This is similar to Douglas Self's conclusion that a regulated supply is better as long as the supply is faster than the amplifier. ......
[...]
I can't remember where I read it but it is not something I learned on my own.---
May be it was in a Crimson amplifiers note which, like Self, does not recommend regulated supplies "which should have to be better than the amp itself", it said, I think. |
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| SpittinLLama |
I don't know guys, I think the tracking rail design is Class H and all others that only have fixed rails but jumps between them is Class G. Just doesn't make much sense, the difference between Class G and H you guys are showing me is really minimal. The ideas for almost all classes have been around for decades including Class D, way before they could actually be implemented. Anyway, thanks for the information and links. Based on the Power dissipation plots on that Yamaha page it looks more like couple different rails than a modulated supply. Still gotta download all those patents for fun.
-SL |
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| Workhorse |
| quote: | Originally posted by SpittinLLama
I don't know guys, I think the tracking rail design is Class H and all others that only have fixed rails but jumps between them is Class G. Just doesn't make much sense, the difference between Class G and H you guys are showing me is really minimal. The ideas for almost all classes have been around for decades including Class D, way before they could actually be implemented. Anyway, thanks for the information and links. Based on the Power dissipation plots on that Yamaha page it looks more like couple different rails than a modulated supply. Still gotta download all those patents for fun.
-SL |
The Real Difference between Class-H & Class-G
In Class-G the switching from Lower Tier to Upper Tier is linear and its amplitude is proportional to the output voltage....
In Class-H the switching from Lower Tier to Upper Tier is Steep Stepped Square wave whose amplitude remains constant[equals to upper Tier voltage] but the width of envelope changes according to the output voltage amplitude...
Donot relate Tracking Rail [Class-TD]designs to confuse with Class-H, the literature from which your are taking reference is not correct at all...
regards,
K a n w a r |
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| ionutgaga |
Hi to all!
I'm back with photos: |
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| Workhorse |
Hi ,
Whats the power output... |
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| ionutgaga |
It drive this:
I estimate 2kw x 2 in 4 ohm at +/-145v. |
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| ionutgaga |
| This amplifier drive 4 x PD1850: |
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| ionutgaga |
| Other amplifier (class AB, floating source, +/-140v), drive 4 x PD918 (mid-bass) |
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| ionutgaga |
| For mid-high, amplifier +/-110v, class AB, floating source, drive 4 x ElectroVoice DL15X + 2 x Eminence Delta Pro 15 + 6 x Eminence PSD2002: |
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| ionutgaga |
| Speakers from back: |
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| Workhorse |
Hi ION,
Have you completed your tracking supply amp.
Meanwhile while I am also developing a tracking supply amp with tracking only on one rail as the amp is self centring grounded bridge type using all N-channel Mosfets....
regards,
K a n w a r |
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| jayrjoe |
hello guys,
please I would like to know some comments here or some unbias ideas from the experts of amplifiers here. im no expert on amplifiers but a general idea from you guys would help a lot.
which would be much better between these two designs....it will be mainly used for driving bass speakers
first...a 4 steps class H, almost the same as Ion use... the voltages from the transformer are as follows.. 35V -73V-111V -141V
it puts out 1800 watts @ 8ohms
second ...same as lab gruppen design, TD |
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