100W Ultimate Fidelity Amplifier

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still4given

still4given

Member
Joined 2004
tnvijay said:
I tried attaching a few pics, but it says it cant be processed because of some security token missing.

Anyway,Mr.Mile,
I have a few doubts in your +/- 12 VOLT ps with 2n5551,2n5401. I built it and got + 0/-16 volt, with the specified components. I replaced the 2n5551 with another one, and it remained the same. I then replaced the same with BC547 and this time i got +16/-15 volt. My doubts are

1.Why i could not get 12 volt ?
2.Anything wrong in my transistor substitution?
3.Is it okay to use this for a tB3 since they are not symmetrical?

Thanks in ADVANCE Mr.Mile. Your help is appreciated.
Click to expand...
Did you make sure the pinout was correct for the 2N551? They have a different pinout than the BC547.
 
T

tnvijay

Member
Joined 2015
Mr.Mile, This schematic I found in your facebook post,not in Diyaudio.
Thanks and regards.
 

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Y

ypaudio

Member
Joined 2013
xrk971 said:
Measure voltage across one of the big power resistors with a DVM. Adjust the bias trimpot (1 of 2 and one near the middle next to BD139) and measure voltage across the 0.47R (2 in parallel so R effective is 0.47R/2). Adjust between 80mA and 200mA. 150mA is a good trafeoff beyween heatboutput and low distortion). Other pot adjust to get 0vdc at output terminal.
Click to expand...

I currently use my old CT transformer with 15VAC output , I get about +22.2 VDC and - 22.2 VDC. Is it okay? I set the current to ~ 100mAh and after 15 minutes, the current is drop to ~ 93mAH. And after 30 minutes it stay about ~ 92mAh. Is it normal? The heatsink still cold after 30 minutes.

I love this amp! The sound is better than myRef, better than LM1875 and absolutely better than TPA3116 . I can hear the high tone is better than myRef amp. Very dynamic sounding. The bass is wooow :p

Thank you very much Mr. Mile for the design, Mr. Xrk971 for the mods, and Mr. Sonal Kunal for the pcb
 
xrk971

xrk971

Founder of XSA-Labs
Joined 2012
etsy.com/shop/XRKAudio
Paid Member
ypaudio said:
I currently use my old CT transformer with 15VAC output , I get about +22.2 VDC and - 22.2 VDC. Is it okay? I set the current to ~ 100mAh and after 15 minutes, the current is drop to ~ 93mAH. And after 30 minutes it stay about ~ 92mAh. Is it normal? The heatsink still cold after 30 minutes.

I love this amp! The sound is better than myRef, better than LM1875 and absolutely better than TPA3116 . I can hear the high tone is better than myRef amp. Very dynamic sounding. The bass is wooow :p

Thank you very much Mr. Mile for the design, Mr. Xrk971 for the mods, and Mr. Sonal Kunal for the pcb
Click to expand...

Glad you like it. (I think we are talking about FH9 right or is it FH12?). That is kind of on low side for voltages and hence why it runs cool. The bias currents in the various stages are probably low due to lower voltage. Mr Mile may be able to suggest alternative resistors for 22v rails. It will sound even better with 35v supply.
 
Y

ypaudio

Member
Joined 2013
ypaudio said:
I currently use my old CT transformer with 15VAC output , I get about +22.2 VDC and - 22.2 VDC. Is it okay? I set the current to ~ 100mAh and after 15 minutes, the current is drop to ~ 93mAH. And after 30 minutes it stay about ~ 92mAh. Is it normal? The heatsink still cold after 30 minutes.

I love this amp! The sound is better than myRef, better than LM1875 and absolutely better than TPA3116 . I can hear the high tone is better than myRef amp. Very dynamic sounding. The bass is wooow :p

Thank you very much Mr. Mile for the design, Mr. Xrk971 for the mods, and Mr. Sonal Kunal for the pcb
Click to expand...

xrk971 said:
Glad you like it. (I think we are talking about FH9 right or is it FH12?). That is kind of on low side for voltages and hence why it runs cool. The bias currents in the various stages are probably low due to lower voltage. Mr Mile may be able to suggest alternative resistors for 22v rails. It will sound even better with 35v supply.
Click to expand...

It is FH9 with BD139 BD140. After 2 hours, temperature of heatsink is just ~42 - 43°C. I tried to set bias current higher ~200mA, but I can't hear the difference. the heatsink is too hot, around ~68°C. I can't touch more than 5s. I set the bias current back to 100 mA
 
Project16

Project16

Member
Joined 2012
Hello everyone

For fun I drew a layout of the AX11 amplifier based on the miniamp with some small modifications to facilitate setting up on the heatsink.
I checked the connections and there is no error but I do not know yet if I will make this amplifier.
If the gerber or .lay6 files are of interest to someone, I will make them available.

:)
 

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apexaudio

apexaudio

Member
Joined 2010
Project16 said:
Hello everyone

For fun I drew a layout of the AX11 amplifier based on the miniamp with some small modifications to facilitate setting up on the heatsink.
I checked the connections and there is no error but I do not know yet if I will make this amplifier.
If the gerber or .lay6 files are of interest to someone, I will make them available.

:)
Click to expand...

Nice work.
Regards
 
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