copy that Sir Mile, thanks!
@Still4,
consider my question a newbie curiosity..
Merry X'mas to all of you!
I said I don't understand your questioncopy that Sir Mile, thanks!
@Still4,
consider my question a newbie curiosity..
Merry X'mas to all of you!
I will play some more, but with BJT output, which looks better to me
MC2 E15/25 output stage schematic attached. This is absolutely the same concept in case of the driver stage.
Sajti
Yes Sajti, is the same concept ...
Never seen that sch before!
Look at these concept with LM3886 like driver,
plenty of drive current, we can drive 5-10 output pairs.
LM3886 GND is now referencing to OUT and we need some fine offset ADJ
Mute pin for "no bump"
Mounting LM3886 on main heat-sink we achieve thermal tracking with system shutdown
THD is on range 22E-05% @1Waverage
BW 405KHz
SR is a bit higher
etc...
Attachments
MC2 audio is famous about the very good sound quality of their amplifiers. So this means that the concept is good.
Nice data! I will give a chance for this topology once I will finish my current project (600W PA amp).
Sajti
When we add C+R in that mode we create the pole (or zero) at specific freq,
so now we can compensate better to that spec freq and it is no more only cut off-roll off with C alone.
I played around with it some more. I tried using a trimmer in place of the 10k. No matter what setting it was worse than with the 10k. Actually the best seems to be a 47pF alone. There is still a slight notch but it lower than the top of the wave. I listened to the two channels on my A/B setup and the modified channel is better.
-use non-inductive/plastic screwdriver to setting properly,
also there is some added capacitance with fingers proximity and screwdriver around.
You must playing with trimming in "on-line" fashion, carefully trimming while looking at scope, must be visible same or at least minor changes,
notch point is changing his freq middle point
-we can`t proper trimm comp with only one change, for proper trimming use multiple trimming points, notch here notch there (poles-zeros)...
-this is a prototype and you do it working!!! this is important!!!Bravo!!!
- minor changes here and there, ...and that`s all for this amp!
-BW is our limit here, higher harmonics are too much attenuated to do proper/good square response
a) leave some "I" pronouncement, and we`ll be mach faster, but with some overshoot, maybe a little longer settling time with some +period to vanish in flat horizontal response
b) do at limit comp, we achieve stable amp, but once again...that fu**ing BW stop as!!!
If you are interested in building a prototype from post #5816
or even from post #5823 with LM3886 driver
I `ll help you,
attempt to design an PCB, with two out pairs?
Much better BW, lower THD...
LP
Dragan
LP= lepe pozdrave=best regards
-use non-inductive/plastic screwdriver to setting properly,
also there is some added capacitance with fingers proximity and screwdriver around.
You must playing with trimming in "on-line" fashion, carefully trimming while looking at scope, must be visible same or at least minor changes,
notch point is changing his freq middle point
-we can`t proper trimm comp with only one change, for proper trimming use multiple trimming points, notch here notch there (poles-zeros)...
-this is a prototype and you do it working!!! this is important!!!Bravo!!!
- minor changes here and there, ...and that`s all for this amp!
-BW is our limit here, higher harmonics are too much attenuated to do proper/good square response
a) leave some "I" pronouncement, and we`ll be mach faster, but with some overshoot, maybe a little longer settling time with some +period to vanish in flat horizontal response
b) do at limit comp, we achieve stable amp, but once again...that fu**ing BW stop as!!!
If you are interested in building a prototype from post #5816
or even from post #5823 with LM3886 driver
I `ll help you,
attempt to design an PCB, with two out pairs?
Much better BW, lower THD...
LP
Dragan
LP= lepe pozdrave=best regards
Hi Dragan,
I did the adjustments while watching the scope. Adjusting C11 Does tend to lower the leading corner of the wave but does not eliminate the notch until the edge is quite rounded. At this point I suspect it is being generated somewhere else. I'm beginning to wonder if it might be in the OPS. I may try adding some caps across the outputs just to see what happens.
Merry Christmas everyone!
That link took me to post5821, instead of 5778
Does 5778 mean post5778?
I can see 5 off 2u2F
How many did I miss?
Ground is not strange but floating rail for OP amp to drive outputs direct without VAS.
This is new topology in DIY, Terry made very first prototype.
This caps is for bootstrap (higher cliping level) not for compensation. Amp work fine with litle rounded 10kHz square way no need to changes.
What about sound compare to laterals?
Regards
I can't say about sound difference. I will try to get around to that on Saturday or Sunday. I prefer to build the lateral. Less parts and no thermal concerns.
A couple other things of note. I tried TL072, NE5532 and LM4562. They all exhibit the same "notch" in the square wave.
Also, this amp is highly sensitive to an open input. Without something plugged in or the input shorted the amp oscillates instantly.
A couple other things of note. I tried TL072, NE5532 and LM4562. They all exhibit the same "notch" in the square wave.
Also, this amp is highly sensitive to an open input. Without something plugged in or the input shorted the amp oscillates instantly.