I have developed a new prototype audio amplifier where I try to mix simplicity with performance as well. So, I wanted to build an audio amplifier to provide the best performance in a price as low as possible and be an alternative observable to other audio amplifiers as well.
I would say, the GX400 is the most solid DIY audio amplifier (with fewer electronic parts) if will be used quality electronic components and the key electronic components of the diagram are sorted.
Some of these performances are shown in table amplifier characteristics of the project.
Relating to construction and operation of the GX400 audio amplifier I would like to say:
- GX400 amplifier has the advantage of automatically enter a state of MUTE if one fuse blows for some reason;
- To contact TEMP can attach a temperature sensor, such as a thermostat (the protection is indicated by led PROTECT);
- if the MUTE header is shorted, then the audio amplifier state will be MUTE;
- GX400 amplifier has DC protection to protect the acoustic enclosure for DC voltage that could arise for various reasons at the output amplifier (the protection is indicated by led PROTECT);
- I did not include a reverse polarity protection voltages (very carefully when connecting the plus and minus voltage power supply);
- the SIG and PEAK leds I made in the simplest way possible. If you are carefully calibrated (especially the PEAK LED), then this led may very well signal when the amplifier is overloaded;
- I recommend sorting 2SA970 transistors on the input and the output power transitors.
Discussions in the romanian language arise here:
KIT102.4 = GX400 - Amplificator Audio Hi-Fi 400W - Comunitatea Tehnium Azi
and discussions in the english language can be run here, in this thread.
Since the project size exceeds the possibilities of attachment of this forum, I invite those interested to download the project from the web link above (you must be a registered user you can download it).
So, I wait for yours reviews.
Best Regards
I would say, the GX400 is the most solid DIY audio amplifier (with fewer electronic parts) if will be used quality electronic components and the key electronic components of the diagram are sorted.
Some of these performances are shown in table amplifier characteristics of the project.
Relating to construction and operation of the GX400 audio amplifier I would like to say:
- GX400 amplifier has the advantage of automatically enter a state of MUTE if one fuse blows for some reason;
- To contact TEMP can attach a temperature sensor, such as a thermostat (the protection is indicated by led PROTECT);
- if the MUTE header is shorted, then the audio amplifier state will be MUTE;
- GX400 amplifier has DC protection to protect the acoustic enclosure for DC voltage that could arise for various reasons at the output amplifier (the protection is indicated by led PROTECT);
- I did not include a reverse polarity protection voltages (very carefully when connecting the plus and minus voltage power supply);
- the SIG and PEAK leds I made in the simplest way possible. If you are carefully calibrated (especially the PEAK LED), then this led may very well signal when the amplifier is overloaded;
- I recommend sorting 2SA970 transistors on the input and the output power transitors.
Discussions in the romanian language arise here:
KIT102.4 = GX400 - Amplificator Audio Hi-Fi 400W - Comunitatea Tehnium Azi
and discussions in the english language can be run here, in this thread.
Since the project size exceeds the possibilities of attachment of this forum, I invite those interested to download the project from the web link above (you must be a registered user you can download it).
So, I wait for yours reviews.
Best Regards
Donpetru,
Thank you for your post and your willingness to share your project.
For non-Romanian speakers, registration is a bit awkward, would you be prepared to simply present the schematic, either in simple format or complete, as an attached image here for people to easily view?
Appreciated,
Hugh
Thank you for your post and your willingness to share your project.
For non-Romanian speakers, registration is a bit awkward, would you be prepared to simply present the schematic, either in simple format or complete, as an attached image here for people to easily view?
Appreciated,
Hugh
The maximum pdf file size that can be loaded on this forum is 195.3 KB but my project is over 1Mb. If anyone is helpful to increase the load limit per file special for me, with the greatest pleasure I upload project file here.
Otherwise, please visit the above web link by selecting the bottom forum option of language viewing: "English".
Regards
Otherwise, please visit the above web link by selecting the bottom forum option of language viewing: "English".
Regards
OK.
???? running 4 pair IRF's directly from a a non-buffered (driverless) 10ma VAS ?
Both CCS's are thermally compensated , but a standard 2Q CCS offers much better PSRR and comparable tempco. To decouple the CCS's ground reference will improve things further.
No degeneration on input pair ... tough to match, Offset quite possible.
Work on that Vbe , IRF OPS's have a very small bias "window" to obtain proper idle current. Nice set of MJE15034/35 drivers would go a long way. Unless you would prefer the run that VAS at 30-40mA.
OS
Interesting that the 4 ohm output power rating is is MORE then TWICE the 8 ohm rating. Not sure if it is possible to get even 2x into into 4 ohms with an unregulated supply and resistive losses ?
@ostripper, initially I was thinking to realize 2Q CCS and not transistor + 2 diode, but instead of two diodes I used transistor + diode, performance of the two types of CCS are very close to maintain constant current when the voltage stages amplifier is changes. If you are sorted well transistors on the amplifier input and output stage, it will be very small offset (utmost 20mV). I not preferred to increase the polarization of the current VAS stage amplifier, because I don't observed a significant performance improvement (heats more VAS amplifier stage).
@jam, the gate rail capacitors (39pf) are necessary to fill, well, the role of the output amplifier coil (coil, which in this case, I have not used it).
@Art M, my project is a theoretical one to be put into practice (already started to be made by a user from my forum). Certainly will need one or two complete revisions to complete this project. So, their powers are results of spice simulations we have done.
Regards
@jam, the gate rail capacitors (39pf) are necessary to fill, well, the role of the output amplifier coil (coil, which in this case, I have not used it).
@Art M, my project is a theoretical one to be put into practice (already started to be made by a user from my forum). Certainly will need one or two complete revisions to complete this project. So, their powers are results of spice simulations we have done.
Regards
GX-400
Are there some variations in design mentioned,,,,i need to know is this a 100% working prototype without hassels
Are there some variations in design mentioned,,,,i need to know is this a 100% working prototype without hassels
As this has now become a commercial enterprise it has been moved to the Vendors forum.
http://www.diyaudio.com/forums/vend...audio-amplifier-made-romania.html#post3969712
Thanks @hpavictor and I think you wanted to say "BLAMELESS Amplifier".
Last revision of this amplifier can be found here (with PCB for sale):
http://www.diyaudio.com/forums/vendors-bazaar/258481-gx400-400w-audio-amplifier-made-romania.html
Last revision of this amplifier can be found here (with PCB for sale):
http://www.diyaudio.com/forums/vendors-bazaar/258481-gx400-400w-audio-amplifier-made-romania.html
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