Studio Reference Amplifier

[suryadi5417]

Use +/-75V for 4R load.
Regards

How about the current ? 10A or 15A enough for dual kit ?

 

[apexaudio]

How about the current ? 10A or 15A enough for dual kit ?

10A is enough

 

[suryadi5417]

10A is enough

Thank you for the replay's , sir

Regadrs

 

[Kay Pirinha]

Hi Apex !

Refer to POWER OUTPUT. What will be the difference betwen B500 with 4 pairs transistor and this SR250 with 4 pairs fo transistor too ?

Oops! Would you please have a close look at the SR 250 schematics: Only three pairs of 2SA1943/SC2500 output devices here! Best regards!

 

[herimanana]

Oops! Would you please have a close look at the SR 250 schematics: Only three pairs of 2SA1943/SC2500 output devices here! Best regards!

Yeah !! Y're right ! only three pairs of 1943/5200.

 

[AndrewT]

Yeah !! Y're right ! only three pairs of 1943/5200.

3pr of 1943/5200 gives a total Pmax of 900W
Since 1943/5200 have such poor high voltage SOA you need to divide by ~6 rather than by ~5 for more robust transistors to arrive at the maximum output power. i.e. ~150W for 3pr.
3pair of 2n3773, which are also 150W devices, can easily manage 180W and probably 200W reliably.

 

[Bhushan]

which is best in quality and performance

Hello Sir Apex, i am curious about which is the best amp to give Quality and Power, Is it SR150 or A40.? Thanku

 

[apexaudio]

Hello Sir Apex, i am curious about which is the best amp to give Quality and Power, Is it SR150 or A40.? Thanku

A40

 

[herimanana]

A40

hi every body !!

Can i just replace C5200 / A1943 with MJL21194/MJL21193 without changing anything on APEX B500 ?

I want to build a stereo B500. but there in my country C5200 / A1943 are almost fake. We can only find MJL21194 original.

Even 2N5401 are fake

 

[apexaudio]

hi every body !!

Can i just replace C5200 / A1943 with MJL21194/MJL21193 without changing anything on APEX B500 ?

I want to build a stereo B500. but there in my country C5200 / A1943 are almost fake. We can only find MJL21194 original.

Even 2N5401 are fake

Yes you can, also you can use: MJL4281 and MJL4302, MJW21195 and MJW21196, NJW0302 and NJW0281...
Regards

 

[herimanana]

Yes you can, also you can use: MJL4281 and MJL4302, MJW21195 and MJW21196, NJW0302 and NJW0281...
Regards

Thank you very much Apex audio !

 

[Bangla H]

I like 2SA1294 2SC3263 too.

 

[apexaudio]

I like 2SA1294 2SC3263 too.

2SA1492 2SC3856

 

[Bangla H]

Yes,
and other options:
I have bought both here: 2SA2223AY - Power Transistor -260V -15A
And my trusted German dealer: Sanken 2SA1492 Japan Transistor PNP 180V 15A 130W Audio Power Amp 854308 | eBay

Digikey: http://www.digikey.com/product-detail/en/sanken/2SA1492/2SA1492-
ND/3661804
And eBay too: 5pairs(10pcs) of 2SA1492 & 2SC3856 SANKEN Transistor A1492 & C3856 | eBay
Not sure genuine?

I will try Sanken in your SR60 with Olaf's boards- in progress.

 

[apexaudio]

SR300

Dual FET input

 

[behrad]

mr mile
finally i built sr100 today
my amplis is stereo but i built one ampli now
i will build second ampli tomorrow
i dont know how adjust bias voltaje by p1
please guide me

respectfully

 

[apexaudio]

mr mile
finally i built sr100 today
my amplis is stereo but i built one ampli now
i will build second ampli tomorrow
i dont know how adjust bias voltaje by p1
please guide me

respectfully

View attachment 589730

View attachment 589731

Set 20mV on 0R33/5W resistor.
Regards

 

[behrad]

Set 20mV on 0R33/5W resistor.
Regards

which one resistor mr??
resistor in right or left?
i dont have any voltage on resistor left???
please explain clearer to me

 

[behrad]

thanks mr
i found her way

 

[alex mm]

Dual FET input

This, nice schematic, deserve a decent layout ,don't you think ?