what i need to do to make my amp stronger?
1) to change the medium transistros to more power?
2) to change the output transistros to more power and more transistros?
3) to change the power supply to get more V and A ??
4) change to caps to more volt ?
1) to change the medium transistros to more power?
2) to change the output transistros to more power and more transistros?
3) to change the power supply to get more V and A ??
4) change to caps to more volt ?
Build another amps becaus you will need to change most of the amp anyway.
And the bias circuit of alot of amp will not be able to stay stable with bigger output stage(mostly becaus of thermal stability)
The heatsink will need to be bigger also.
And the bias circuit of alot of amp will not be able to stay stable with bigger output stage(mostly becaus of thermal stability)
The heatsink will need to be bigger also.
how to the "300W Subwoofer Power Amplifier (ESP)" are 300W RMS and the amp work on 56V with 4 output transistors -2sc5200
and my amplifier us in 8 transistors of 2sc5198 and the power supply is 70V and in CARaudio forums thay say to me that my amp only 25W RMS....
how it can be ???
* the medium transistor is matter?
"300W Subwoofer Power Amplifier (ESP)"
and my amplifier us in 8 transistors of 2sc5198 and the power supply is 70V and in CARaudio forums thay say to me that my amp only 25W RMS....
how it can be ???
* the medium transistor is matter?
"300W Subwoofer Power Amplifier (ESP)"
They rate the amp at 150 W, not 300 W.
I am not aware of the amp you are using, so I can't comment on its actual power. If powered off of +/- 70 VDC, I agree, it would seem to be a lot higher than 25 W.
In general, more transistors equal more power, but it is not an absolute. So, if one amp has 4 and other has 8 output transistors, one can't assume one has twice the power of the other. The ratings of the transistors and the heatsinking have a lot to do with how many of them you need for a certain power level. Likewise, rail voltages are a pretty good indication of output power, but one also has to look at how beefy the power transformer is.
I am not aware of the amp you are using, so I can't comment on its actual power. If powered off of +/- 70 VDC, I agree, it would seem to be a lot higher than 25 W.
In general, more transistors equal more power, but it is not an absolute. So, if one amp has 4 and other has 8 output transistors, one can't assume one has twice the power of the other. The ratings of the transistors and the heatsinking have a lot to do with how many of them you need for a certain power level. Likewise, rail voltages are a pretty good indication of output power, but one also has to look at how beefy the power transformer is.
the power supply of my amp is 50~0V AC 750VA it is big power supply... in my amp i have a 8 transistors of 2SC5198-2SA1941
and i connect the amp to home speakers of 300W MAX on 8 OHM and the amp dont out a high power... the i double the medium transistors (2sc2690A - 2sa1220A) from 2 medium tran' to 4 tran' and the power become stronger.... it can be?
and i connect the amp to home speakers of 300W MAX on 8 OHM and the amp dont out a high power... the i double the medium transistors (2sc2690A - 2sa1220A) from 2 medium tran' to 4 tran' and the power become stronger.... it can be?
Maybe it was designed to drive two ohm load so the power at 8 ohm is quite low.
But cahnging the medium power transistor should not change the power output of the amp.
But cahnging the medium power transistor should not change the power output of the amp.
25W from that is kind of low their must be a mistake somewhere.
From eing that low it would be firly easy to make it clip is that the problem you have oy can't you just make the gain high enough. Maybe it's the signal level that is to low.
From eing that low it would be firly easy to make it clip is that the problem you have oy can't you just make the gain high enough. Maybe it's the signal level that is to low.
Hi, DJ.
some A:
maximum output power with +-70V DC is about 300W/8E and 600W/4E in these condition (IMHO):
1.enough voltage amplification (from ca 1V RMS to 50VRMS),
2. enough current amplification-delivery from output BJT-s ( for 8E is ca 6A, for 4E ca 12A), global Beta must be enough (from ca 100mA to 6 or 12 Amps)
3. enough DC power from power supply (if Amp is in class AB for 300W/8E is ca 450W for one ch)
4. enough power capability of output BJT-s (SOA)( current, voltage, power disipation)
5. enough heatsinkig
With new bigger BJT-s you reach points 4 and maybe 2. You must check point 1 (with ca 1V on input, on output must be ca 50V without load), and 3, and after longer work point 5 (temperature on BJT-s)
Can you post shematic of amp? May help in discusion.
regards
zzeenn
some A:
maximum output power with +-70V DC is about 300W/8E and 600W/4E in these condition (IMHO):
1.enough voltage amplification (from ca 1V RMS to 50VRMS),
2. enough current amplification-delivery from output BJT-s ( for 8E is ca 6A, for 4E ca 12A), global Beta must be enough (from ca 100mA to 6 or 12 Amps)
3. enough DC power from power supply (if Amp is in class AB for 300W/8E is ca 450W for one ch)
4. enough power capability of output BJT-s (SOA)( current, voltage, power disipation)
5. enough heatsinkig
With new bigger BJT-s you reach points 4 and maybe 2. You must check point 1 (with ca 1V on input, on output must be ca 50V without load), and 3, and after longer work point 5 (temperature on BJT-s)
Can you post shematic of amp? May help in discusion.
regards
zzeenn
I dont have a shematic of amp...
but way the amp is out a low power in 8 ohm ??? i have a old amplifier onkyo-tx 2000 is 30X2W (STK465) is stronger then my amp in 8 or 16 ohm... !! but my amp stronger on 2 ohm...
wat can is change to make aim batter on 8 ohm ??
wat make aim different ??
- the power supply ??
- the output transistrors ??
- the medium transistrors ??
- the signal transistrors ??
part on the amp:
8 2Sc5198
8 2Sa1941
2 2Sc2073
2 2Sa940
8 2Sc1815
6 2Sc1015
3 NE5532P
I think that the gain is to low...
but way the amp is out a low power in 8 ohm ??? i have a old amplifier onkyo-tx 2000 is 30X2W (STK465) is stronger then my amp in 8 or 16 ohm... !! but my amp stronger on 2 ohm...
wat can is change to make aim batter on 8 ohm ??
wat make aim different ??
- the power supply ??
- the output transistrors ??
- the medium transistrors ??
- the signal transistrors ??
part on the amp:
8 2Sc5198
8 2Sa1941
2 2Sc2073
2 2Sa940
8 2Sc1815
6 2Sc1015
3 NE5532P
I think that the gain is to low...
Hi,DJ.
Your supply is single or dual 75V (50V AC)? If is single, then maximum power is 4 times smaller, ca 70-80W on 8E.
regards
zzeenn
Your supply is single or dual 75V (50V AC)? If is single, then maximum power is 4 times smaller, ca 70-80W on 8E.
regards
zzeenn
If the amps has +/-70V rails and it can handle 2 Ohm speakers
well, then it may be that the voltage is too low. Then, either
you need more amplification, or the problem is your source.
What source do you use? Maybe its output voltage is too low,
or the input impedance of the amplifier is too low for the source?
You cannot change the amplification by replacing any transistors
or ICs. The amplification will most certainly be set by resistor
values, so a schematic would be necessary. Anyway, modifying
the amplification is a difficult thing to do, since it will most
likely change the sound and require other changes to make
amplifier stable etc.
The easiest test would be to try with a source that can give
higher output voltages, or using an extra preamplifier that
can do so.
well, then it may be that the voltage is too low. Then, either
you need more amplification, or the problem is your source.
What source do you use? Maybe its output voltage is too low,
or the input impedance of the amplifier is too low for the source?
You cannot change the amplification by replacing any transistors
or ICs. The amplification will most certainly be set by resistor
values, so a schematic would be necessary. Anyway, modifying
the amplification is a difficult thing to do, since it will most
likely change the sound and require other changes to make
amplifier stable etc.
The easiest test would be to try with a source that can give
higher output voltages, or using an extra preamplifier that
can do so.
Study Electronics
Hey DJ it seems to me you need more basic electronics knowledge. I hate to be a *****, but read something or take an evening course. Transistors aren't just plug in parts. The entire circuit topology is the amp not just the transistors. I picked up a few books from the library, learned some basic things (ohms law, etc.), got a prototyping plug board, laid out some basic transistor biasing circuits, learned about voltage division in the process, learned about AC behaviour of Capacitors and inductors and Kirchoffs Laws(Network analysis), and lots more....and I still couldn't design an amp from scratch I would be happy with. I think the essence of DIY and this discussion group is the learning more than the product (I could be wrong). I would come at this problem you have with some appreciation of the process...not just wanting a product from it. The products will tumble out once you have the basics. 🙂
Hey DJ it seems to me you need more basic electronics knowledge. I hate to be a *****, but read something or take an evening course. Transistors aren't just plug in parts. The entire circuit topology is the amp not just the transistors. I picked up a few books from the library, learned some basic things (ohms law, etc.), got a prototyping plug board, laid out some basic transistor biasing circuits, learned about voltage division in the process, learned about AC behaviour of Capacitors and inductors and Kirchoffs Laws(Network analysis), and lots more....and I still couldn't design an amp from scratch I would be happy with. I think the essence of DIY and this discussion group is the learning more than the product (I could be wrong). I would come at this problem you have with some appreciation of the process...not just wanting a product from it. The products will tumble out once you have the basics. 🙂
the amp power supply is single 0~48V 750VA
my be the medium transistor is 2 low..?!
in start was 8 medium transistors to 8 output transistors...
now a connect all the 8 output transistors to 2 medium transistors... my be before i change the amp out on 8 ohm more power??
my be the medium transistor is 2 low..?!
in start was 8 medium transistors to 8 output transistors...
now a connect all the 8 output transistors to 2 medium transistors... my be before i change the amp out on 8 ohm more power??
Hi,DJ.
48V is AC on transformer or DC after rectification and filtering? How big are filter caps?
zzeenn
48V is AC on transformer or DC after rectification and filtering? How big are filter caps?
zzeenn
the filter caps is 4700uF 50V x4...
but i need answer for this :
in start was 8 medium transistors to 8 output transistors...
now a connect all the 8 output transistors to 2 medium transistors... my be before i change the amp out on 8 ohm more power??
but i need answer for this :
in start was 8 medium transistors to 8 output transistors...
now a connect all the 8 output transistors to 2 medium transistors... my be before i change the amp out on 8 ohm more power??
Hi, DJ.
maybe is now overall hfe smaller (2 small drive 8 big), but if yor amp is good on 2E load then is hfe high enough. I think that you have problem with to small power supply voltage. And on your image i dont see output elco (if power supply is single and amp is not in bridge, you need output elco !?? )
zzeenn
maybe is now overall hfe smaller (2 small drive 8 big), but if yor amp is good on 2E load then is hfe high enough. I think that you have problem with to small power supply voltage. And on your image i dont see output elco (if power supply is single and amp is not in bridge, you need output elco !?? )
zzeenn
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