I did make some amplifiers with TMC (Transitory Miller Compensaton) and never have any stability problem or ringing with square wave test. That was in practice.
I know from long discussion on this forum and other one that TPC (Twin Pole Compensation) and TMC are theoretically the same thing. I followed Edmond Stuard argument too.
Now I did some simulation to compare TMC to TPC and here is result.
First TMC as I made this amp and listening to it every day.
Here is a schematic, square wave test, first with no parallel capacitor to 8ohm load, and second one with 1uF parallel to load.
dado
I know from long discussion on this forum and other one that TPC (Twin Pole Compensation) and TMC are theoretically the same thing. I followed Edmond Stuard argument too.
Now I did some simulation to compare TMC to TPC and here is result.
First TMC as I made this amp and listening to it every day.
Here is a schematic, square wave test, first with no parallel capacitor to 8ohm load, and second one with 1uF parallel to load.
dado
Attachments
I tried to simulate TPC amp with similar distorton and OLG.
You can see that square wave has overshoot and ringing. I could not get ride of it with simple additional compensation, and my decision is that TMC is "better" and simpler in practical use. I was thinking about TPC in a way to decrease EMF influence from a loudspeaker on input stage.
I know that for many people this discussion is closed, But I would like to hear other opinion.
Here are TPC diagrams
You can see that square wave has overshoot and ringing. I could not get ride of it with simple additional compensation, and my decision is that TMC is "better" and simpler in practical use. I was thinking about TPC in a way to decrease EMF influence from a loudspeaker on input stage.
I know that for many people this discussion is closed, But I would like to hear other opinion.
Here are TPC diagrams
Attachments
I dont know how to select values in TMC.
Like to hear more how to design TMC.
ostripper uses and recommends it.
And is TMC possible in a Current Feedback Amplifier.
Like to hear more how to design TMC.
ostripper uses and recommends it.
And is TMC possible in a Current Feedback Amplifier.
lineup,
You can find a lot of TMC explanation in this forum, search for TMC and Edmond Stuart.
Main principle is that serial connection of TMC capacitors is similar to value of Miller cap.
Using Spice you can experiment and see OLG and phase relation.
I never used CF amp, but I think it is possibe.
dado
You can find a lot of TMC explanation in this forum, search for TMC and Edmond Stuart.
Main principle is that serial connection of TMC capacitors is similar to value of Miller cap.
Using Spice you can experiment and see OLG and phase relation.
I never used CF amp, but I think it is possibe.
dado
My explaination is because TMC sets a local feedback around the output stage, it is better in pole splitting effect. TPC also splits poles, but only by virtue of low impedance driving output stage, but feedback mechanism is more agressive everything else being similar.
TMC also lowers VAS impedance , making for a lower distortion EF2 OPS regardless of load. I'm pushing my new AX/Nikko right to the rails a I type and WOW! Amp has such a clean "top end" at nuclear volume levels. I must again thank E. stuart for the idea. 🙂
OS
OS
OS, you were the one who inspired me to start to experiment and thanks for that.
You are quite sure, it looks for me, that you have found your AMP.
Maybe there is a better and still simple SS amp, don't stop to explore different circuit ideas.
dado
No , you also inspire me.
Strange , Dadod ... that you started your new "triple OP" thread. Unlike DX , I feel that even with the reduced impedance , any more than 2 pair OP's deserves and NEEDS a better circuit. In fact , your triple is EXACTLY what I was thinking for the PB150 power board. The TMC blameless is the best it can be but why not play with other topologies. That is why I am staying modular (below).
Also , the AX is universal TMC , TPC , CMC .... lots of room for play. I will not go "stagnant" ... 😀
PS , I'll be over in your triple thread soon 🙂 .
OS
Strange , Dadod ... that you started your new "triple OP" thread. Unlike DX , I feel that even with the reduced impedance , any more than 2 pair OP's deserves and NEEDS a better circuit. In fact , your triple is EXACTLY what I was thinking for the PB150 power board. The TMC blameless is the best it can be but why not play with other topologies. That is why I am staying modular (below).
Also , the AX is universal TMC , TPC , CMC .... lots of room for play. I will not go "stagnant" ... 😀
PS , I'll be over in your triple thread soon 🙂 .
OS
Attachments
Hi Everybody! Let me introduce myself...
I am new to this forum, but I am reading it from a while.
I find it by far the best of all on the technical side.
BTW I have followed a lot of the development of the Mongrel by OStripper, and I think is a great project!
Also I have seen that in the BX version the TMC somehow did not give good results. Do you have any idea why?
I am playing with a simple bootstrapped CFP *with* TMC and I would like to learn more...
Thanks to all
@Audio
I am new to this forum, but I am reading it from a while.
I find it by far the best of all on the technical side.
BTW I have followed a lot of the development of the Mongrel by OStripper, and I think is a great project!
Also I have seen that in the BX version the TMC somehow did not give good results. Do you have any idea why?
I am playing with a simple bootstrapped CFP *with* TMC and I would like to learn more...
Thanks to all
@Audio
You mean, probable, DX from Carlos. I don't know why is not good, but it could be very good, look at this tread.
http://www.datasheetcatalog.org/datasheet/supertex/DN3135NW.pdf
dado
Sorry, your link shows only a datasheet fom a vertical MOS. Although interesting, I do not understand what it has to do with the topic.
vulgarizing TMC
Cheers,
E.
PS: It was patented again in 2010: US Patent 7652531. I wouldn't be surprised if some those 'US patent attorneys' would also attempt to file a patent on a wheel.
And it would be doomed to fall into oblivion, if not somebody reinvented this technique and brought it to the attention of a broader public. 😀
Cheers,
E.
PS: It was patented again in 2010: US Patent 7652531. I wouldn't be surprised if some those 'US patent attorneys' would also attempt to file a patent on a wheel.
Hi, Edmond
Glad to see you by there again.
Indeed, Hitachi s patent is very clear, although i didn t see
it implemented in their amps, unless i did miss something..
Multistage Amplifier Circuit
cheers,
Wb
Re :vulgarizing TMC ???
Not me ???? 😕 Mine is "textbook". Results of real amp w/load were exceptional , sound is utterly transparent (even driven to 250w peaks). Dadod did tell me about the driver (mje15032/33) basestopper issue, changed to 22R ... tiny bit of transient ringing - GONE. 🙂 TMC is as "rock solid" as CMC in the real world. (saturday night party with many VERY impressed listeners). 😀
OSD
Not me ???? 😕 Mine is "textbook". Results of real amp w/load were exceptional , sound is utterly transparent (even driven to 250w peaks). Dadod did tell me about the driver (mje15032/33) basestopper issue, changed to 22R ... tiny bit of transient ringing - GONE. 🙂 TMC is as "rock solid" as CMC in the real world. (saturday night party with many VERY impressed listeners). 😀
OSD
It looks as everything was invented a long time ago. Hitachi patent from wahab link was meant for IC,but thanks to Edmond it started to be used in DIY community here.
I think that Edmond, by vulgarizing, means about talk who was the first?
dado
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