General guide as per late Andrew_T
VA =your power output per ch x 2 channels x 1.5-2 times
not. I am not a supporter (fan) of such primitivism. A14 is the minimum that I did, as well as A20 and A40.
Sorry to keep bugging you, and how many watts is the Apex FH-9 XRK Mod amp board capable of producing at +-35v?
I am thinking of using the Connexelectronic SMPS300RE +-36V (dual voltage) 110V SMPS Power Supply rather than an unregulated toroidal/rectifier/cap bank power supply.
Thank you for all your assistance in all the threads you have replied in! 🙂
David.
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Might be pushing the limits but XRK used a +/-53Vdc SMPS and didn’t have any trouble. I think he got right at 100watts at 8- ohms.
To have a little safety I would go for a +/-42-45Vdc SMPS and you would get about 80watts at 8-ohms
The SMPS you are looking at would work great and much easier to assemble.
+/-35Vdc will get you about 60 watts at 8-ohms
To have a little safety I would go for a +/-42-45Vdc SMPS and you would get about 80watts at 8-ohms
The SMPS you are looking at would work great and much easier to assemble.
+/-35Vdc will get you about 60 watts at 8-ohms
I have used the SMPS300RE for my AEM6000 build see here.
It works beautifully, no humm no hiss and can be boosted to +-39V with a trimpot.
Hi sir Apex.
How can I decrease gain and sensitivity of AX 14 amplifier .I have made it but gain is very high and at very low audio a very high frequency hiss hiss sound is comming .Normal bias current is 15mA.but at heat it's become 50mA per transistor.it's sound very loud at very low volume of my mixer . please help.
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hiss / noise should not be with the standard gain. maybe the volume control is too high impedance and catches all the interference? what is the resistance of the volume control?
it's 10k volume inside mixers in amplifier there is no volume .I have just test it without volume knob.Hiss sound is coming when audio input gain volume is very low around 5% and master volume is full .but when change feedback resistance 22k to 15 K and input resistance 22k to 15k hiss sound is gone .22pf capacitor is not suitable for my twitters .and change it to 100pf.feedback capacitor is 56pf.
Hi mr apex
I made apex ax 17 with mj2955/2n3055 tow pair
Replace c6 with 1000u/63
R20 is 1.8k
Set bias to 50 ma
Sound be good and clear in 35-0-35 volt dc
Can i use 50-0-50 dc? I think that i most incrace r20 to 2.2k...
Can u help me
I made apex ax 17 with mj2955/2n3055 tow pair
Replace c6 with 1000u/63
R20 is 1.8k
Set bias to 50 ma
Sound be good and clear in 35-0-35 volt dc
Can i use 50-0-50 dc? I think that i most incrace r20 to 2.2k...
Can u help me
Hi all. I need the wiring connection diagram for the APEX A38(40) amplifier please. The two ground connections at the rear I dont know what they are for
hello ballisticz4,
referring to this pcb design 100W Ultimate Fidelity Amplifier
the 2 ground connections at the back are to be connected to psu ground and also PGND to PSU ground.
referring to this pcb design 100W Ultimate Fidelity Amplifier
the 2 ground connections at the back are to be connected to psu ground and also PGND to PSU ground.
here is biasing procedure that can be generalized for any class-AB amp either BJT (with emitter resistors ) or a mosfet amplifier without source resistors).