Hello sakis
Here is the orig lay out , the parts are marked with color code .
Yelow Transistors
Green Resistors
The emmiter resistor goes to the butom of the PC board . Also there is 4 resistor cross each-other , 2 of them goes to the butom
Pink Capacitors both foil and electrolityc
Grey Trimpot
Blue Diodes
Red Jumper
Here is the orig lay out , the parts are marked with color code .
Yelow Transistors
Green Resistors
The emmiter resistor goes to the butom of the PC board . Also there is 4 resistor cross each-other , 2 of them goes to the butom
Pink Capacitors both foil and electrolityc
Grey Trimpot
Blue Diodes
Red Jumper
Attachments
![first%20diy%20amplifier[1].jpg](/community/data/attachments/125/125831-27c9af6ec5fdad8ad43e4d27895dc9f4.jpg)
Re: Re: ok
then this the first time i ve ever seen a thing like that .....
i would be very much intersted to see a schematic .....others too i belive ....
there is similar thread called a darling.....ton story in the forum regrading problems and design considerations around this family of transistor ...in this thread there is a question of designs with multiple darl. outs .... there was no answer
imagine what can happen if you can make an amp same as yours equiped with MJ11015-16 which are almost triple the power and very ruged devices ....
regards sakis
pacificblue said:
then this the first time i ve ever seen a thing like that .....
i would be very much intersted to see a schematic .....others too i belive ....
there is similar thread called a darling.....ton story in the forum regrading problems and design considerations around this family of transistor ...in this thread there is a question of designs with multiple darl. outs .... there was no answer
imagine what can happen if you can make an amp same as yours equiped with MJ11015-16 which are almost triple the power and very ruged devices ....
regards sakis
well
ok then ....but this generally a very bad practice ....its like you desined a car that has brake pedals on the right side and acceleration pedals on the left IE nobody can use ti but you .....
that is bad practice ..... it may sound well ...but i would never work like that ....its just a question of principal
though i would be very much interested to see what it can be done to have the full potential of this amp safely delivered
gaborbela said:
ok then ....but this generally a very bad practice ....its like you desined a car that has brake pedals on the right side and acceleration pedals on the left IE nobody can use ti but you .....
that is bad practice ..... it may sound well ...but i would never work like that ....its just a question of principal
though i would be very much interested to see what it can be done to have the full potential of this amp safely delivered
Re: Re: Re: ok
If I would draw a schematic, I could not publish it anyhow, because it is a commercial design.
As far as my eyes reach into the bowels however there seems to be nothing extraordinary to it. 7 TO-92 and 1 TO-220 for input and VAS (BF422/423 and BD139 or BD140) and 2 TO-202 as drivers for the darlingtons (probably BF869/870). Two LEDs as voltage references for something. Three transistors more than P3A, one less than Blameless.
Including me. Only, each time I open it up with the intention of drawing one, I find it too nested to take far enough apart. E. g. the lower black metal sheet you see in the photo is glued on top of all TO-92 transistors in the first stages. Hard to remove without damaging the transistors.sakis said:
If I would draw a schematic, I could not publish it anyhow, because it is a commercial design.
As far as my eyes reach into the bowels however there seems to be nothing extraordinary to it. 7 TO-92 and 1 TO-220 for input and VAS (BF422/423 and BD139 or BD140) and 2 TO-202 as drivers for the darlingtons (probably BF869/870). Two LEDs as voltage references for something. Three transistors more than P3A, one less than Blameless.
Re: Re: this is just an opinion
it hink that it means that first 5W of the amp are almost working in class A ...then its a typical AB
most AB amplifiers work like that ...thta is nothing really special
let me explain for a sec
the bdw 83-tip142 family is a type of transitor that the base of the transistor is very senistive since the base of the transistor is actually the base of the driver and not the output transistor .... it is expected to be easily driven ....but on the other hand in a row that 6 of them exist if for any reason one of them is more senistive or is picking up anything more on the way ....and just a bit more compaired to the other 5 then kaboom !!!!! the all thing is gone
probably that is the reason why PAPA NESLON used 0.68 balast resitors in the out of every transistor
then again elektor in a similar design and with even 2 only power transistors used 1R 10W resistors ....
makes sense since you want the diference between the transistors to be consumed on the resistors ....
now what will happen if one of them or all of them oscilate just a bit ????
and then again why there is no other designs like that???? only seen the A40 from NP , and then yours , and then gaborbela amplifier ....
that is why i would like to see more in too this ....
MJ11015 i think is 160V 20A 200W .... imagine one amp that simple working with 6 of them ....easy power ....
.... dont know ..... will have to construct and see
pacificblue said:
it hink that it means that first 5W of the amp are almost working in class A ...then its a typical AB
most AB amplifiers work like that ...thta is nothing really special
let me explain for a sec
the bdw 83-tip142 family is a type of transitor that the base of the transistor is very senistive since the base of the transistor is actually the base of the driver and not the output transistor .... it is expected to be easily driven ....but on the other hand in a row that 6 of them exist if for any reason one of them is more senistive or is picking up anything more on the way ....and just a bit more compaired to the other 5 then kaboom !!!!! the all thing is gone
probably that is the reason why PAPA NESLON used 0.68 balast resitors in the out of every transistor
then again elektor in a similar design and with even 2 only power transistors used 1R 10W resistors ....
makes sense since you want the diference between the transistors to be consumed on the resistors ....
now what will happen if one of them or all of them oscilate just a bit ????
and then again why there is no other designs like that???? only seen the A40 from NP , and then yours , and then gaborbela amplifier ....
that is why i would like to see more in too this ....
MJ11015 i think is 160V 20A 200W .... imagine one amp that simple working with 6 of them ....easy power ....
.... dont know ..... will have to construct and see
Please use BDW83C type only !
If is no mark behind probably fake transistor .
I never see with out A,B,C,D mar after the BDW83 over the past 20 years.
I'd rather advise buy BDW93C/94C from STM company .
These are the best sounding darlingtons to these application today available in the market with out you have to do any modification in the circuit .
Please do not use TIP147 so on , I tested and poor result .
Also Texas In. darlington is great but hard to find .
D type is the same as C only differences higher voltage .
A and B has different Hfe . Do not use them.
Try to by STM if you find and you will have a great amp !
Even BDW93C/94C will give you 50-60W if you double them in 8 ohms .
That is more than enough to drive a speaker like 87db .
Greats
If is no mark behind probably fake transistor .
I never see with out A,B,C,D mar after the BDW83 over the past 20 years.
I'd rather advise buy BDW93C/94C from STM company .
These are the best sounding darlingtons to these application today available in the market with out you have to do any modification in the circuit .
Please do not use TIP147 so on , I tested and poor result .
Also Texas In. darlington is great but hard to find .
D type is the same as C only differences higher voltage .
A and B has different Hfe . Do not use them.
Try to by STM if you find and you will have a great amp !
Even BDW93C/94C will give you 50-60W if you double them in 8 ohms .
That is more than enough to drive a speaker like 87db .
Greats
Hello sakis
I did tested the Motorola type MJ transistors , with these circuit (because the higher power) it work but there is big sound quality degradation .
It is different inside how they built up the MJ type darlington and the BDW type .
It is possible to use MJ darlington but need to be redesign all the amp . And who knows after how will sound .Yes I sow amp using MJ type for output but I never heard how does it sound .
These amp was design like these .
The guy choose the darlington transistors and built up the amp around the BDW darlington .
I even tried to build up the darlington itself using great quality components but some reason was to slow and the sound was far away from the original design . It need to be very precise calculation on the speed when you build up the darlington .
There is a amp on the net it called SMART KIT , use darlington transistor also, I built that amp about 10 years a go , is a great -great amp but not so good like these .
In these amp the simplicity of the amp provide the great sound . Even if I change the driver from BF to BD there is a big step back in the quality .
The amp use transistors made to the European market , here in N America you do not find them .So I tried a lots of replacement unfortunately nothing work out well, nothing come close to the original design . I only build now again because the BDW93C is the same as BDW83C just lower power .
I hope you understand my point .
Greets
I did tested the Motorola type MJ transistors , with these circuit (because the higher power) it work but there is big sound quality degradation .
It is different inside how they built up the MJ type darlington and the BDW type .
It is possible to use MJ darlington but need to be redesign all the amp . And who knows after how will sound .Yes I sow amp using MJ type for output but I never heard how does it sound .
These amp was design like these .
The guy choose the darlington transistors and built up the amp around the BDW darlington .
I even tried to build up the darlington itself using great quality components but some reason was to slow and the sound was far away from the original design . It need to be very precise calculation on the speed when you build up the darlington .
There is a amp on the net it called SMART KIT , use darlington transistor also, I built that amp about 10 years a go , is a great -great amp but not so good like these .
In these amp the simplicity of the amp provide the great sound . Even if I change the driver from BF to BD there is a big step back in the quality .
The amp use transistors made to the European market , here in N America you do not find them .So I tried a lots of replacement unfortunately nothing work out well, nothing come close to the original design . I only build now again because the BDW93C is the same as BDW83C just lower power .
I hope you understand my point .
Greets
Hi Andrew
I have speakers from Visaton 87DB, plus 6db the room ..........
I used -it wit the 8W M Hiraga , I never needed to push the amp all the way .
But to make you wonder , I had a Philips tube amp SE use only a EL95 tube and even that one tube drive mu speaker loud and clear!
Of course it depend how big your room where your system set up .
If a amplifier have a great sound , dynamic etc you do not need 100W to enjoy the music .
Of course I have some big amps like AlephX but I newer push it over 10-15W .
I have the Profet amp which similar to the F5 and only 16W in Class A .The power more than enough!!!!!!!!!! TO ME .
I have speakers from Visaton 87DB, plus 6db the room ..........
I used -it wit the 8W M Hiraga , I never needed to push the amp all the way .
But to make you wonder , I had a Philips tube amp SE use only a EL95 tube and even that one tube drive mu speaker loud and clear!
Of course it depend how big your room where your system set up .
If a amplifier have a great sound , dynamic etc you do not need 100W to enjoy the music .
Of course I have some big amps like AlephX but I newer push it over 10-15W .
I have the Profet amp which similar to the F5 and only 16W in Class A .The power more than enough!!!!!!!!!! TO ME .
Attachments
i know exactly
what you mean
in my years as a technician ( more than 30) i had to repair a gozillion of these amps ....called smart kit ......smart electronics is a greek company
for your your information the smart kit version is equiped with all the goodies available such is ccs in the vas ccs in the ltp full VI limiter, and miller caps in the vas and driver stage .....also smart kit never allowed more than 40+40 rails
the amplifier failed at all times if pushed just a bit
soundwise a simple P3A amplifier is between 100 to 1000 times better
still dont want to disapoint you but this is what data supports so far
what you mean
in my years as a technician ( more than 30) i had to repair a gozillion of these amps ....called smart kit ......smart electronics is a greek company
for your your information the smart kit version is equiped with all the goodies available such is ccs in the vas ccs in the ltp full VI limiter, and miller caps in the vas and driver stage .....also smart kit never allowed more than 40+40 rails
the amplifier failed at all times if pushed just a bit
soundwise a simple P3A amplifier is between 100 to 1000 times better
still dont want to disapoint you but this is what data supports so far
Interesting...i could not make it work fine into the simulator
maybe my error...but i could not..felt unstable and difficult to adjust transistors.
Well..you have it working and fine.... mistery to me...lots of distortions adjusting the standby current low or high.
regards,
Carlos
maybe my error...but i could not..felt unstable and difficult to adjust transistors.
Well..you have it working and fine.... mistery to me...lots of distortions adjusting the standby current low or high.
regards,
Carlos
An externally hosted image should be here but it was not working when we last tested it.
Hello
I wrote about smart kit because I know is a Greek design and uses darlington but day and night between these amp and the smart kit .
Yes you right , the Smart kit only use one pair darlington with 40V and normal size heat sink . Not biased in class A not even for a couple Watt , if I remember 50 or 100mA bias .
I go with two pair . Probably 42V rail or 56V I will see if how much the sound difference between the two power supp rail .
If I go with 42V I bias the amp at least 400mA Iq .
When I said is not bad amp the smart kit that mean com pair what you can get from the store frome that price .
Actually I didn't buy the kit I made the PC board myself and mostly I used exotic parts .I used 4 PC 50 000uF capacitor in the power supply .
I didn't kept the amplifier , the sound it does not reach that nin. limit to keep it . For me it was not a keeper .
Carlos U use BJT output instead darlington , and please use BF drivers .Of course you get lot of distortion !
Also the main capacitor on the board 1000uF .
One more time when the amp was design it was built around the BDW83C/84C darlington transistors .
Another think I'm not a child to push the amp up to 50W or so .
I want to listen great music , good sound , not loud bum- bum -bum.
Greets
I wrote about smart kit because I know is a Greek design and uses darlington but day and night between these amp and the smart kit .
Yes you right , the Smart kit only use one pair darlington with 40V and normal size heat sink . Not biased in class A not even for a couple Watt , if I remember 50 or 100mA bias .
I go with two pair . Probably 42V rail or 56V I will see if how much the sound difference between the two power supp rail .
If I go with 42V I bias the amp at least 400mA Iq .
When I said is not bad amp the smart kit that mean com pair what you can get from the store frome that price .
Actually I didn't buy the kit I made the PC board myself and mostly I used exotic parts .I used 4 PC 50 000uF capacitor in the power supply .
I didn't kept the amplifier , the sound it does not reach that nin. limit to keep it . For me it was not a keeper .
Carlos U use BJT output instead darlington , and please use BF drivers .Of course you get lot of distortion !
Also the main capacitor on the board 1000uF .
One more time when the amp was design it was built around the BDW83C/84C darlington transistors .
Another think I'm not a child to push the amp up to 50W or so .
I want to listen great music , good sound , not loud bum- bum -bum.
Greets
Re: Interesting...i could not make it work fine into the simulator
It only works with the BDW darlingtons.
I used these models with the ndarlington symbol in LTSPice and they (and the amp) worked fine.
* BDW93C NPN EPITAXIAL SILICON TRANSISTOR ELECTRICAL PARAMETER
* Power Darlington Transistor
* =======================================================================
* Hammer Drivers, Audio Amplifiers Applications
* Complement to BDW94, BDW94A, BDW94B and BDW94C Respectively
* =======================================================================
* Vcbo & Vceo: BDW93 45V / BDW93A 60V / BDW93B 80V / BDW93C 100V
* Ic(DC) 12A / Ic(Pulse) 15A / Ib 0.2A
* =======================================================================
* Connections: Collector 1 Base 2 Emitter 3
* =======================================================================
.SUBCKT BDW93C 1 2 3
Q1 1 2 4 Q1model
Q2 1 4 3 Q2model 5.2266
D1 3 1 Dmodel
R1 2 4 10.000E3
R2 4 3 600
.MODEL Dmodel D
+ IS=1.67E-12 N=1.01 RS=1.854
+ CJO=2.8833E-10 M=0.3227 VJ=0.4449
+ BV=110.0 IBV=0.1
.MODEL Q1model NPN
+ IS=1.4507E-14 BF=7.88E3 NF=0.85
+ VAF=138.92 IKF=0.8207 ISE=6.298E-13
+ NE=1.2 BR=21.99 NR=0.8
+ VAR=200 IKR=0.5 ISC=1.367E-13
+ NC=2.8 RB=6.193 NK=0.6
+ RE=0.001 RC=0.185 EG=1.110
+ CJE=1.055E-10 VJE=0.7775 MJE=0.4512
+ CJC=1.601E-10 VJC=0.8966 MJC=0.3035
+ XCJC=0.4455 FC=0.5
.MODEL Q2model NPN
+ IS=1.4507E-14 BF=7.88E3 NF=0.85
+ VAF=138.92 IKF=0.8207 ISE=6.298E-13
+ NE=1.2 BR=21.99 NR=0.8
+ VAR=200 IKR=0.5 ISC=1.367E-13
+ NC=2.8 RB=6.193 NK=0.6
+ RE=0.001 RC=0.185 EG=1.110
+ CJE=1.055E-10 VJE=0.7775 MJE=0.4512
+ CJC=1.601E-10 VJC=0.8966 MJC=0.3035
+ XCJC=0.4455 FC=0.5
.ENDS BDW93C
* ======================================================================
* FAIRCHILD CASE: TO-220 PID: BDW93C
* FEB-02-2001 CREATION
* BDW94C PNP EPITAXIAL SILICON TRANSISTOR ELECTRICAL PARAMETER
* Power Darlington Transistor
* =======================================================================
* Power Linear and Switching Applications
* Complement to BDW93, BDW93A, BDW93B and BDW93C Respectively
* =======================================================================
* Vcbo & Vceo: BDW94 -45V / BDW94A -60V / BDW94B -80V / BDW94C -100V
* Ic(DC) -12A / Ic(Pulse) -15A / Ib -0.2A
* =======================================================================
* Connections: Collector 1 Base 2 Emitter 3
* =======================================================================
.SUBCKT BDW94C 1 2 3
Q1 1 2 4 Q1model
Q2 1 4 3 Q2model 5.2266
D1 1 3 Dmodel
R1 2 4 10.000E3
R2 4 3 600
.MODEL Dmodel D
+ IS=5.29E-12 N=1.087 RS=1.533
+ CJO=3.888136E-10 M=0.3464517 VJ=0.6514732
+ BV=110.0 IBV=0.1
.MODEL Q1model PNP
+ IS=1.02E-14 BF=4.297E3 NF=1
+ VAF=55.63 IKF=0.15858 ISE=2.255E-12
+ NE=1.533 BR=4.995 NR=1.1
+ VAR=100 IKR=19.98 ISC=2.38E-9
+ NC=2.997 RB=1.63932 NK=0.5957
+ RE=0.002 RC=0.3025 EG=1.0569
+ CJE=2.248747E-10 VJE=0.8353946 MJE=0.3402586
+ CJC=2.256645E-10 VJC=0.6074885 MJC=0.2521917
+ XCJC=0.4445 FC=0.5
.MODEL Q2model PNP
+ IS=1.02E-14 BF=4.297E3 NF=1
+ VAF=55.63 IKF=0.15858 ISE=2.255E-12
+ NE=1.533 BR=4.995 NR=1.1
+ VAR=100 IKR=19.98 ISC=2.38E-9
+ NC=2.997 RB=1.63932 NK=0.5957
+ RE=0.002 RC=0.3025 EG=1.0569
+ CJE=2.248747E-10 VJE=0.8353946 MJE=0.3402586
+ CJC=2.256645E-10 VJC=0.6074885 MJC=0.2521917
+ XCJC=0.4445 FC=0.5
.ENDS BDW94C
* ======================================================================
* FAIRCHILD CASE: TO-220 PID: BDW94C
* FEB-02-2001 CREATION
Regards
David
Olá, Carlos,destroyer X said:
It only works with the BDW darlingtons.
I used these models with the ndarlington symbol in LTSPice and they (and the amp) worked fine.
* BDW93C NPN EPITAXIAL SILICON TRANSISTOR ELECTRICAL PARAMETER
* Power Darlington Transistor
* =======================================================================
* Hammer Drivers, Audio Amplifiers Applications
* Complement to BDW94, BDW94A, BDW94B and BDW94C Respectively
* =======================================================================
* Vcbo & Vceo: BDW93 45V / BDW93A 60V / BDW93B 80V / BDW93C 100V
* Ic(DC) 12A / Ic(Pulse) 15A / Ib 0.2A
* =======================================================================
* Connections: Collector 1 Base 2 Emitter 3
* =======================================================================
.SUBCKT BDW93C 1 2 3
Q1 1 2 4 Q1model
Q2 1 4 3 Q2model 5.2266
D1 3 1 Dmodel
R1 2 4 10.000E3
R2 4 3 600
.MODEL Dmodel D
+ IS=1.67E-12 N=1.01 RS=1.854
+ CJO=2.8833E-10 M=0.3227 VJ=0.4449
+ BV=110.0 IBV=0.1
.MODEL Q1model NPN
+ IS=1.4507E-14 BF=7.88E3 NF=0.85
+ VAF=138.92 IKF=0.8207 ISE=6.298E-13
+ NE=1.2 BR=21.99 NR=0.8
+ VAR=200 IKR=0.5 ISC=1.367E-13
+ NC=2.8 RB=6.193 NK=0.6
+ RE=0.001 RC=0.185 EG=1.110
+ CJE=1.055E-10 VJE=0.7775 MJE=0.4512
+ CJC=1.601E-10 VJC=0.8966 MJC=0.3035
+ XCJC=0.4455 FC=0.5
.MODEL Q2model NPN
+ IS=1.4507E-14 BF=7.88E3 NF=0.85
+ VAF=138.92 IKF=0.8207 ISE=6.298E-13
+ NE=1.2 BR=21.99 NR=0.8
+ VAR=200 IKR=0.5 ISC=1.367E-13
+ NC=2.8 RB=6.193 NK=0.6
+ RE=0.001 RC=0.185 EG=1.110
+ CJE=1.055E-10 VJE=0.7775 MJE=0.4512
+ CJC=1.601E-10 VJC=0.8966 MJC=0.3035
+ XCJC=0.4455 FC=0.5
.ENDS BDW93C
* ======================================================================
* FAIRCHILD CASE: TO-220 PID: BDW93C
* FEB-02-2001 CREATION
* BDW94C PNP EPITAXIAL SILICON TRANSISTOR ELECTRICAL PARAMETER
* Power Darlington Transistor
* =======================================================================
* Power Linear and Switching Applications
* Complement to BDW93, BDW93A, BDW93B and BDW93C Respectively
* =======================================================================
* Vcbo & Vceo: BDW94 -45V / BDW94A -60V / BDW94B -80V / BDW94C -100V
* Ic(DC) -12A / Ic(Pulse) -15A / Ib -0.2A
* =======================================================================
* Connections: Collector 1 Base 2 Emitter 3
* =======================================================================
.SUBCKT BDW94C 1 2 3
Q1 1 2 4 Q1model
Q2 1 4 3 Q2model 5.2266
D1 1 3 Dmodel
R1 2 4 10.000E3
R2 4 3 600
.MODEL Dmodel D
+ IS=5.29E-12 N=1.087 RS=1.533
+ CJO=3.888136E-10 M=0.3464517 VJ=0.6514732
+ BV=110.0 IBV=0.1
.MODEL Q1model PNP
+ IS=1.02E-14 BF=4.297E3 NF=1
+ VAF=55.63 IKF=0.15858 ISE=2.255E-12
+ NE=1.533 BR=4.995 NR=1.1
+ VAR=100 IKR=19.98 ISC=2.38E-9
+ NC=2.997 RB=1.63932 NK=0.5957
+ RE=0.002 RC=0.3025 EG=1.0569
+ CJE=2.248747E-10 VJE=0.8353946 MJE=0.3402586
+ CJC=2.256645E-10 VJC=0.6074885 MJC=0.2521917
+ XCJC=0.4445 FC=0.5
.MODEL Q2model PNP
+ IS=1.02E-14 BF=4.297E3 NF=1
+ VAF=55.63 IKF=0.15858 ISE=2.255E-12
+ NE=1.533 BR=4.995 NR=1.1
+ VAR=100 IKR=19.98 ISC=2.38E-9
+ NC=2.997 RB=1.63932 NK=0.5957
+ RE=0.002 RC=0.3025 EG=1.0569
+ CJE=2.248747E-10 VJE=0.8353946 MJE=0.3402586
+ CJC=2.256645E-10 VJC=0.6074885 MJC=0.2521917
+ XCJC=0.4445 FC=0.5
.ENDS BDW94C
* ======================================================================
* FAIRCHILD CASE: TO-220 PID: BDW94C
* FEB-02-2001 CREATION
Regards
David
Re: Re: Re: this is just an opinion
I know that it is nothing special. It was an answer to your assumption that those transistors might be stable with a lot of bias. 5 W class A is a lot of bias (for my taste), so maybe you are on the right track there.sakis said:
Mine has 0,47 Ohm.sakis said:
Hello
I wrote these is a great amp , but I do not want to force nobody to build it .
Yes if you burn the power transistor it will take you speaker out .
When you set up the bias please use a cheap speakers and turn the trim pot very slowly .It can go very high the bias 3A or so and you burn the amp .My advice to use multi turn trim pot if you can find .
There is two possibility to resolve the safety problem .
Use over sized heat sink and check the temperature for test push it a bit hard .
Another what I don't like speaker protection or DC detector .
Many time the more compact amp like the smart kit amp it does not have the sound what we DIYers looking for .
Otherwise I buy some commercial amp .
But where is the DIY spirit , the fun .
I also use 047R 5W resistor , at first was 033R but the designer told me if I double the output transistors to increase the 5W resistor value a bit .
I would like to build these amp with 2SJ162/2SK1058 original Hitachi lateral mosfets .
That would be a great choice .
I'd like to use lateral mosfets in a simple circuit like these .
I found on the net one amp using not much parts .I will test that to sometimes .
I already made the PC boards .I want a amp with lateral output but not with Jet input .Some BJT sound nice in the input .
Greets .
I wrote these is a great amp , but I do not want to force nobody to build it .
Yes if you burn the power transistor it will take you speaker out .
When you set up the bias please use a cheap speakers and turn the trim pot very slowly .It can go very high the bias 3A or so and you burn the amp .My advice to use multi turn trim pot if you can find .
There is two possibility to resolve the safety problem .
Use over sized heat sink and check the temperature for test push it a bit hard .
Another what I don't like speaker protection or DC detector .
Many time the more compact amp like the smart kit amp it does not have the sound what we DIYers looking for .
Otherwise I buy some commercial amp .
But where is the DIY spirit , the fun .
I also use 047R 5W resistor , at first was 033R but the designer told me if I double the output transistors to increase the 5W resistor value a bit .
I would like to build these amp with 2SJ162/2SK1058 original Hitachi lateral mosfets .
That would be a great choice .
I'd like to use lateral mosfets in a simple circuit like these .
I found on the net one amp using not much parts .I will test that to sometimes .
I already made the PC boards .I want a amp with lateral output but not with Jet input .Some BJT sound nice in the input .
Greets .
Attachments
I will try once more Pacificblue...i like the schematic
The idea is very nice.... this type of circuit seems lovely to my ears and heart.
I do love it first sigth..and i will insist..thank you very much Pacific.
And sorry Gaborbela....i have no bad feelings to bother forum friends..i just had some problems..this does not erase your value, your effort, your words and decense.
Thank you as you have shared dear Gaborbela.
accept me as a friend..because this is what i am
regards,
Carlos
The idea is very nice.... this type of circuit seems lovely to my ears and heart.
I do love it first sigth..and i will insist..thank you very much Pacific.
And sorry Gaborbela....i have no bad feelings to bother forum friends..i just had some problems..this does not erase your value, your effort, your words and decense.
Thank you as you have shared dear Gaborbela.
accept me as a friend..because this is what i am
regards,
Carlos
Carlos you are always welcome .
I really enjoy to read your comments , I know you are a great guy .
I have no bad feeling at all .
I respect you as a great friend .
You bring to the forum life always .There is nothing to not to love about you , or your comments .
I really appreciate your DYI effort .
Greetings from Toronto
I really enjoy to read your comments , I know you are a great guy .
I have no bad feeling at all .
I respect you as a great friend .
You bring to the forum life always .There is nothing to not to love about you , or your comments .
I really appreciate your DYI effort .
Greetings from Toronto