AD536.....
That is an interesting device! And therewith the PCB can still be compact. Or making it even more compact by using a SMD device like the LTC1966. Well, Kaplaars, back to the drawing board
!Interesting but rather expensive ... and you need two of them. But they provide an over 60db (upto 80db) range...That is an interesting device! And therewith the PCB can still be compact. Or making it even more compact by using a SMD device like the LTC1966. Well, Kaplaars, back to the drawing board
One will have first to choose between accuracy and the visual effect ...Human eye or brain one way or another cannot follow the movement of the needle or translate it to an accurate reading of power ...Linear led VU meters is another story ...
So i go for the effect not for accuracy
Kind regards
Sakis
So i go for the effect not for accuracy
Kind regards
Sakis
The VU driver circuit used in the LM1875 is calibrated at 1W RMS @1000 Hz (using a PM2454 AC meter) and goes from zero to full deflection in the range ~0.1 to ~10W. Since I barely exceed those levels, this circuit is more than sufficient when focussing onto effect. But I agree it could be improved.
The design mentioned earlier by Martin et al. has drawn my attention. That design seems to offer the best of both worlds; accuracy, affordability and full (logarithmic) range. What I especially like it that this circuit is underpinned with proper mathematics. It seems to be well thought out. Some simpler circuits are usable, but a considerable amount of designs lack fundamental things such as a proper buffer. Thereby impacting the THD.
Thanks guys for your input, I will conduct some experiments in the near future
The design mentioned earlier by Martin et al. has drawn my attention. That design seems to offer the best of both worlds; accuracy, affordability and full (logarithmic) range. What I especially like it that this circuit is underpinned with proper mathematics. It seems to be well thought out. Some simpler circuits are usable, but a considerable amount of designs lack fundamental things such as a proper buffer. Thereby impacting the THD.
Thanks guys for your input, I will conduct some experiments in the near future
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I use MJ15003 and MJ15004 that have low fT. So, I made slew rate not to high. But 46V/uS still make me worry. Luckyly, it did not blow
Very good bass, "airy" at high frequency but not as good as my previous amplifier.
I surprised with this result.
This is our new fully own developed, fundamentally new approach solid state amplifier - "NEOCLASSIC21". 4 layers board, separate individual class-A powerful SMD drivers for each output power MOS-FET. Thanks to it we have totally no "shelf distotion" without dissipation of kilowatts of heat and no "parasite capacitance accumulation effect". Inner ground and shield layers also acts as a planar radiator for all onboard SMD transistors. Amp is fully symmetrical and true balanced. Optimum intercascade dynamic ranges match without application of zener diodes, dividers and level shift cascades. So amp is very quiet and have precise dynamics. Very linear on all output levels. Near 100 amps of peak output current.
Screenshots from 100MHz professional analog oscilloscope shows:
1. An 140V 1kHz sine clipping. Amplifier loaded with real 8 ohm speaker with capacitive, inductive and reactive load. As seen, clip is fully symmetric. Also we have fully symmetrical cilp enter and out. It shows, that amp is very precise, balanced and self.
2. An wideband unfiltered and unsmoothed 1kHz meander signal transmission. Input (up) and output (bottom) waveforms showed. 30V output voltage. Input meander contains 1, 3, 5, 7, 9, 11, 13 and 15 harmonics. Amplifier loaded with real 8 ohm speaker with capacitive, inductive and reactive load. As seen, no any harmonics lost or added. No any transients or overtones added.
http://rogozhin-labyrinth.blogspot.com/
Screenshots from 100MHz professional analog oscilloscope shows:
1. An 140V 1kHz sine clipping. Amplifier loaded with real 8 ohm speaker with capacitive, inductive and reactive load. As seen, clip is fully symmetric. Also we have fully symmetrical cilp enter and out. It shows, that amp is very precise, balanced and self.
2. An wideband unfiltered and unsmoothed 1kHz meander signal transmission. Input (up) and output (bottom) waveforms showed. 30V output voltage. Input meander contains 1, 3, 5, 7, 9, 11, 13 and 15 harmonics. Amplifier loaded with real 8 ohm speaker with capacitive, inductive and reactive load. As seen, no any harmonics lost or added. No any transients or overtones added.
http://rogozhin-labyrinth.blogspot.com/
Attachments
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Bias current is slightly over compensated. When heatsink cold, bias current is 82mA, but when heatsink hot it become 77mA as predicted. Bias servo (VBE multiplier) use darlington which is new for me.
Looks really nice! just the price of 1500$ USD per module and you need two of them to make a stereo amplifier, won't be easily accessible to DIY, I mean for the majority. Still it looks really good on paper for the specs.
Ciao!
Do
New IPS board. Very simple and baisc CFA, plays really nice (I have some work left to do with it anyway). Just not sure if leave it for audio or SMPS pourposes
Hi Borys,nice work!
We will wait a new thread about this IPS and OUT stage.
Thimios.
work in progress, ready for testing
I'm building this project:
Project 54 | BuildAudioAmps
Boards are ready for testing.
I'm building this project:
Project 54 | BuildAudioAmps
Boards are ready for testing.