Studio Reference Amplifier

[mprivitera1]

There is thread for more informations about HV23
http://www.diyaudio.com/forums/solid-state/162043-mosfet-amplifier-irfp240-irfp9240-71.html

thanks...

 

[samratsarkar]

Dear Sir,
I have completed the SR200 amp and it is working. But when I am connecting drivers with RCA cables hum noise is noticed if i put my ears close to speakers.

Please advise what I need to DO to stop the hum noise.

Regards,
Samrat

 

[apexaudio]

Dear Sir,
I have completed the SR200 amp and it is working. But when I am connecting drivers with RCA cables hum noise is noticed if i put my ears close to speakers.

Please advise what I need to DO to stop the hum noise.

Regards,
Samrat

Can you post your ground wireing circuit? Is there hum and noise with shorted input to gnd.

 

[shravanth]

hello apex sir i have made this coil for SR-200, on 10mm daimeter and 12turns with 1.2mm wire.

 

[shravanth]

hello sir i made apex sr-200

powered with 67-0-67 VDC and bias - 80ma

R7,8,9,10 and R24 are getting hot? what should i do

 

[AndrewT]

Have you measured the voltage and from there calculated the current through these 5 resistors?

Post1 shows 2k2 and 6k8
The 2k2 will have ~26Vdc across each.
The 6k8 will have ~120Vdc across it.
The powers dissipated will be ~300mW and 2100mW
No wonder they are running hot !

 

[apexaudio]

Have you measured the voltage and from there calculated the current through these 5 resistors?

Post1 shows 2k2 and 6k8
The 2k2 will have ~26Vdc across each.
The 6k8 will have ~120Vdc across it.
The powers dissipated will be ~300mW and 2100mW
No wonder they are running hot !

Current thru 6k8 is 10mA power dissipate will be 680mW

 

[shravanth]

Thanks for your help andrew

I am using R24- 10k 2 watts not 6k8 is there any problem?

 

[AndrewT]

Have you measured the voltage and from there calculated the current through these 5 resistors?

Post1 shows 2k2 and 6k8
The 2k2 will have ~26Vdc across each.
The 6k8 will have ~120Vdc across it.
The powers dissipated will be ~300mW and 2100mW
No wonder they are running hot !

Current thru 6k8 is 10mA power dissipate will be 680mW

Thanks for your help andrew

I am using R24- 10k 2 watts not 6k8 is there any problem?

Apex is confirming that the cascode transistor is absorbing approximately half of the voltage drop.

Measure your circuit and post the results.

Have you measured the voltage

 

[shravanth]

Apex is confirming that the cascode transistor is absorbing approximately half of the voltage drop.

Measure your circuit and post the results.

Across R24- 10k 2watts its 73volts

 

[apexaudio]

Across R24- 10k 2watts its 73volts

The powers dissipate is about 500mW, 2watts resistor is ok and must be hot

 

[shravanth]

The powers dissipate is about 500mW, 2watts resistor is ok and must be hot

Apex sir any voltages to be measured to conform amp is ok

 

[den054]

Hello all!

Is it possible to use 10000uF/80V caps in PSU-10 when using 600VA/2x50VAC?
I plan to get 65VDC regulated output, is it ok with these trafo and caps?

Sorry if it's already answered.

 

[shravanth]

Hello apex sir please help me

 

[shravanth]

What are voltages to be there across R7,8,9,10 and R24

 

[apexaudio]

Hello apex sir please help me

Voltage on zeners must be 15V, on resistors R16, R17 about 1,5V and on R27, R28 about 1V.

 

[apexaudio]

What are voltages to be there across R7,8,9,10 and R24

This voltages isn't important.

 

[Junie]

SR200 paired in DIY Lovecraft's Big Ben speakers, the result is really impressive the clarity is noticeable on that big speakers.

 

[apexaudio]

SR200 paired in DIY Lovecraft's Big Ben speakers, the result is really impressive the clarity is noticeable on that big speakers.

And look impressive

 

[shravanth]

Voltage on zeners must be 15V, on resistors R16, R17 about 1,5V and on R27, R28 about 1V.

Voltages on zeners 15.87V , on resistors R16,R17 - 1.6V and on R27,R28 - .98V

powered with 65-0-65VDC, what do you say Mr.apex