not working
Hi could someone direct me to solution, I have checked the pcb for error found none, double checked everything, voltages on bias are good, 1.8v on collector-emitter on bias transistor and so on, but when i switch the device on from the start everything fine, even the waveform comes ut just as nice but then when i make the input signal higher like some 0.7v sine wave about 1khz the output trannies just get opened and fail with sparks and smoke, basically what i am dealing with is that the base voltage of the output trannies just suddenly gets high and opens them and they just blow, takin sometimes some irfs and the driver transistors mje 15033 and 34 with them. Could someone give me some advise?
Thanks in advance.
Hi could someone direct me to solution, I have checked the pcb for error found none, double checked everything, voltages on bias are good, 1.8v on collector-emitter on bias transistor and so on, but when i switch the device on from the start everything fine, even the waveform comes ut just as nice but then when i make the input signal higher like some 0.7v sine wave about 1khz the output trannies just get opened and fail with sparks and smoke, basically what i am dealing with is that the base voltage of the output trannies just suddenly gets high and opens them and they just blow, takin sometimes some irfs and the driver transistors mje 15033 and 34 with them. Could someone give me some advise?
Thanks in advance.
..Good day sir apex, i have transformer 56 35 0 35 55 vac can i use this for test?
hi apex..can i use 2 step driver with ir2117 for h900..and how much tr final i'm needed fir this...sorry for bad english..🙂
Use 150R/10W resistor instead primary fuse for test amp, and post pictures...
Here you are!
I hope that this wouldn´t be your first audio device... Hope it is at least fifteenth!
I hope that this wouldn´t be your first audio device... Hope it is at least fifteenth!
Attachments
no i am newly start h900 ............. so any pre amp. ckt.. for this amp.......... pls ... sudgest..........
That is not so clever,to do an amplifier in H-class 900W as a first project...you might get in a lot of trouble and not so many answers. It would be much better for you to do APEX AX12 or APEX D14 or something ike that. They still have a lot of power and they are not so complicated to do. When you finnish it connect two by two in bridge and there you are-doubled power amplifier!
answer
I have input gnd connected to psu gnd only you can't see it here because the pcb is taken out of the box where the powersupply is mounted.
That isn't the problem.
Maybe you have some other thoughts on what could be wrong.
Thanks in advance Sir Apex.
Girts.
I have input gnd connected to psu gnd only you can't see it here because the pcb is taken out of the box where the powersupply is mounted.
That isn't the problem.
Maybe you have some other thoughts on what could be wrong.
Thanks in advance Sir Apex.
Girts.
input gain selector
hello apexaudio
plz sir upload circuit & pcb of input sensitivity with
1.4v,1.0v,0.77v gain selector for h900
thanks and regard
hello apexaudio
plz sir upload circuit & pcb of input sensitivity with
1.4v,1.0v,0.77v gain selector for h900
thanks and regard
hello sir apex cam i use MPSA42 instead of BF421? and also can i use FMGX12 instead of SFA1603 thanks
Regads
thanks very much...and once question again..can I use 1n4148 in series to replaced BAV21..
hello sir apex i had allready finish my project h900, my rail voltage is 66 47 0 47 66vdc, offset .4v, idling .7v, sounds very nice, but my problem is Mv- 47 cannot inter the diode sfa1603 going to collector of 2sa1943, it takes supply from hv-66, so the other side is -66 collector, and the other side is +47 collector not balance and very hot after 1 song, what would be the problem
Best regards