Apex HV23

[Shelah]

Dear all,

i just had a look at Apex audio circuits and i zoomed on one of them. what i need about this design is fine and if i can have the go ahead to make it.

 

[44250]

You should use APEX PSU7 with HV23,and than you have clip indication on amp. board,overload/dc protect,mute/time delay,soft-start for transformer and main PSU; all six of those at one pcb APEX PSU7. The thing about HV23 that you should know is that ALL FOUR input transistors should be matched as close as possible,otherwise the dc at the output will be large. With them matched with cheap DMM i have got 12mV at the output. Bias should be about 30-50mA per pair and it is to be set when amp gets warm,do it several times as it is getting its working temperature. Set bias at sors-resistor with largest voltage across. Bias will be larger when amp is cold but it will soon decrease as it gets its working temperature. It may happen that you will not be able to reach the 30mA bias but it is easy to reach that with changing the value of the resistor that is in series with bias trim.pot. When i get home i will post some pictures of my APEX HV23 + PSU7,and files with them. ONE MORE THING,pay attention at transistor pin-out,because the pcb is for 2sa/2sc transistors,and the BC XXX also do not share all the same pinout. I used 2n5441/5551 but i have payed attention on this. Amp is very nice sounding,with a lot of power as you expect,maybe even more!

 

[44250]

the FILES

Here it is:


(and some more pictures,how did i do it at this link: APEXaudio HV23 pictures by 44250 - Photobucket )

 

[44250]

Talking is in serbian,sorry...

APEX HV23 uradio/done by 44250 I. - YouTube

APEX HV23 uradio/done by 44250 II. - YouTube

APEX HV23 uradio/done by 44250 III. - YouTube

but the sound is there! 🙂

 

[Shelah]

Thanks for your reply pliz check also the thread called crown and give me some advice there as well.

 

[44250]

I am not qualified to judge about that question,i am jut a diy-enhusiastic that has built a few amplifiers,that´s all...