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I'm already finished my board,
- start supply with 12VAC with protect 10Ohm (series with board).
- input short to ground
DC offset measured 3.9V
what first step to do fix this problem?
I find track missing...
Attachments
Hi Apex,
i solved my problem (hum and very hot TR final),
- first steop, i replace MJE350 and BC547 with new one (this solved not stable DC offset)
- second step, i try to bypass signal ground to power ground and this solved my huuumm problem and DC offset get 50-80mV (of course with no hot TR final)
sound very nice (so warm with deep bass
)
NB : my layout for test using 5200/1943 tr final, next step will change using MJ15004/MJ15003.
check this my video test : Ax14 test sound after many troubles - YouTube
i solved my problem (hum and very hot TR final),
- first steop, i replace MJE350 and BC547 with new one (this solved not stable DC offset)
- second step, i try to bypass signal ground to power ground and this solved my huuumm problem and DC offset get 50-80mV (of course with no hot TR final)
sound very nice (so warm with deep bass
)NB : my layout for test using 5200/1943 tr final, next step will change using MJ15004/MJ15003.
check this my video test : Ax14 test sound after many troubles - YouTube
Yes bli John, i will put 1 pair MJ15003/04 too, and will record with my phone again.
this my first time build amp with complex schematic (i'm just enjoy playing with OCL schematic).
thanks for your guides, i hope not make bli john boring with my many questions
NB: i have done try with 1 pair tip2955/tip3055 *sound more mid but bass still deep WoW, this will replace my old ocl board with 3 pair cheap 2955/3055
thanks Bli John, and special for Mile/Apex.
BR// Madde
this my first time build amp with complex schematic (i'm just enjoy playing with OCL schematic
).thanks for your guides, i hope not make bli john boring with my many questions
NB: i have done try with 1 pair tip2955/tip3055 *sound more mid but bass still deep WoW, this will replace my old ocl board with 3 pair cheap 2955/3055
thanks Bli John, and special for Mile/Apex.
BR// Madde
I reread again & found some useful hint...
don't go more than 30VDC like Apex suggest
for bias AX14 :
And also this one :
don't go more than 30VDC like Apex suggest
for bias AX14 :
And also this one :
Yes bli John, i will put 1 pair MJ15003/04 too, and will record with my phone again.
this my first time build amp with complex schematic (i'm just enjoy playing with OCL schematic
thanks for your guides, i hope not make bli john boring with my many questions
NB: i have done try with 1 pair tip2955/tip3055 *sound more mid but bass still deep WoW, this will replace my old ocl board with 3 pair cheap 2955/3055
thanks Bli John, and special for Mile/Apex.
BR// Madde
Tnanks for pdf files
Dear Mr. AndrewT, thanks for your answers,
and one more question, i have 500W full range speaker, how many watt power of PA for best drive this speaker (more than 500 watt or less than 500 watt)?
and if less or more than the 500 watt drive this speaker, what will the impact for sound and the speaker?
BR// Madde
Hi Madde,
the speaker you mention I believe is marked :
"500 watt max power" (tulisan saja)
& I don't think we need 500W amp to drive it, 200 to 300W is more realistic...
If you give it real 500W amp then I believe you will burn it out
(Full range in our town seems not so good, don't turn the bass knob so loud)
The speaker will be just fine with 300W amp if you not drive it until it clip
Usually AndrewT will give you some math, about rails, load & output power...
how many output transistor needed, etc...
So you can estimated how large the power supply, the heatsink, etc
let's waiting for Mr. AndrewT ...
he will explain to you better than me, better than most people I know here
the speaker you mention I believe is marked :
"500 watt max power" (tulisan saja)
& I don't think we need 500W amp to drive it, 200 to 300W is more realistic...
If you give it real 500W amp then I believe you will burn it out
(Full range in our town seems not so good, don't turn the bass knob so loud)
The speaker will be just fine with 300W amp if you not drive it until it clip
Usually AndrewT will give you some math, about rails, load & output power...
how many output transistor needed, etc...
So you can estimated how large the power supply, the heatsink, etc
let's waiting for Mr. AndrewT ...
he will explain to you better than me, better than most people I know here
I have two of these amps (AX14 with 1 pair of output transistors), and they sound very good, but i'm in need of a subwoofer amp and i'm thinking of bridging them and build a 2 way electronic crossover. Power supply is +/- 50 volts and i think the transformer is capable of 200 watts, this will move an 18 inch speaker in a ported box. I'm thinking of projects 09 and 14 of Elliot (ESP), what do you think?
Thanks
Luigi
Thanks
Luigi
It is my point of view that speaker's power should be greater than amp's power.
My reasons are that,
1. It will give your amp a headroom for its power, the speaker will not saturate and not distort the sound.
2. If amp is driven at full power/volume, the speaker can handle it without worry of damage.
If amp's power is greater than the speaker's, the reverse of the above are true. Although you can still use a set up like this, but be mindful to set the volume of the amp to the speaker's ability to handle the power.