apex,
by the way tlo step is working,
temporary I use step down transformer,(to step down 96-48-0-48-96 ac primary)
and the result is better,better bass more power (and still clean sound)and most important it is not dissipating heat as before(class ab b500) w/o step driver,i'm amased with this class(h),
by the way tlo step is working,
temporary I use step down transformer,(to step down 96-48-0-48-96 ac primary)
and the result is better,better bass more power (and still clean sound)and most important it is not dissipating heat as before(class ab b500) w/o step driver,i'm amased with this class(h),
Attachments
Mje
Ty B500 is working now,ill post some picture when already in place,but i notice lower volume seems to be distorted or something..
My trafo 55 0 55 25amp ,32 0 32 25amp
Ty B500 is working now,ill post some picture when already in place,but i notice lower volume seems to be distorted or something..
My trafo 55 0 55 25amp ,32 0 32 25amp
step drive component replacements
engel sir...
can you please tell me which components of step drive available here in our country???...
which components are hard to find???...
and what are the components that needs replacements???...
for i am thinking of building sir apex' h class using tl072 step drive...
thanks
regards
ees...
engel sir...
can you please tell me which components of step drive available here in our country???...
which components are hard to find???...
and what are the components that needs replacements???...
for i am thinking of building sir apex' h class using tl072 step drive...
thanks
regards
ees...
b500 working
ok one question the protect cicuit have terminal -/+15v do i have to connect this to main amp -/+15v without ground??
And here are my DIY B500 thanks to you APEXAUDIO
By the way Heat Sink are little bit small i have to find big one.this is for test only
ok one question the protect cicuit have terminal -/+15v do i have to connect this to main amp -/+15v without ground??
And here are my DIY B500 thanks to you APEXAUDIO
By the way Heat Sink are little bit small i have to find big one.this is for test only
Attachments
eesbiboi,
MUR1620,(hard ti find)but.......
any 100v 8a will do,(back to back diode),
I use D5LC0U,from scrap
and.....,
BF422/423,... ecb ....(hard to find)....but
MPSA92/93,.... ebc .... will do (different pin out)
Thanks apexaudio ,
Can I used only two pairs of 2SC5200 & 2SA1943 for 250 Watt @ 8 Ohm ?
I think the current will be 5 Amp for each Transistor @ +/- 75V DC @ 8 Ohm if I am not wrong if I used two pairs only .
Please is there any formula shown the relation between the PSU voltage and amplifier wattage ?
For example , if I take your advice and run the B500 @ 75V DC @ 8 Ohm to give 250 Watt @ 8 Ohm , what is your calculations ?
I am realy confused about this matter .
Regards,
Sinan Edmond
Nice work, thank's for pictures,
You can connect +/-15v from protect to main amp and protect GND must be connect to PSU GND. GND from PSU is better to connect to input terminal (cinch) GND. Use 2k2/2W instead 4k7/2W.
Regards
Ok ty for your advice ill do it now,but i dont get this part ,, Use 2k2/2W instead 4k7/2W?? do you mean on amp side R25 and R24??
and the pro terminal of protect board should it be also connected to pro terminal of the amp?
my voltage on trafo is 55 0 55 ac 25amps,,output Dc with 15000 UF/85vx2 is +/-75V do need to change R24/25??
i also have trafo with 23 0 23 10amps/ 32 0 32 25amps/ 55 0 55 ac 25amps
Can i use this trafo on H900??
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last first.
Output voltage = sqrt(output power * Rload * 2)
Vpk = sqrt(250W * 8ohms * 2) = 63.2Vpk.
A supply between +-70Vdc and +-75Vdc will be about right for 250W into 8r0.
A 50Vac transformer will give about +-74Vdc.
Peak output current on a long term sinewave signal will be ~ Vpk/Rload = 7.9Apk.
On a fast transient it can be higher, ~70/8 ~8.8Apk
Into a moderately reactive speaker load, allow about half this current simultaneously with 74Vce and look up the SOA (25degC) in the data sheet.
Can a pair of 1943/5200 manage 4.4A @ 74Vce when cold? 2.2A @ 74Vce is ~163W
How hot do you allow the transistor to get and still be able to pass that 2.2Apk/device?
2pair won't survive a 8r0 load.
3pair won't survive an 8ohm speaker load.
I think 4pair might survive domestic use into a moderately reactive 8ohm speaker load, if kept cold.
I would aim for 5pair or 6pair. The 2sa1943/c5200 are terrible at higher voltages. Use more robust higher SOAR transistors.
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