Hii all .... my problam :
I build the amp ... i connect all the parts right ! like the pic !!!
now.... that i turn the power on.... the "R7" and "Q8" start to hot.... (the LED "D1" dont work.....) and the fuse blow...
i put a new fuse....
and... i deconnect the base of "Q5" and "Q6"....
turn on the power.....( the LED "D1" still dont work.....) and the fuse dont blow but now the "Q2" start to hot.... but slowle.....
i reconnect the the base of "Q5" to secend ! and the fuse blow again......
what my problam....... ?
***** and i connect to 35V +/- no to 56V +/- it is matter?
http://sound.westhost.com/p68-f1.gif
I build the amp ... i connect all the parts right ! like the pic !!!
now.... that i turn the power on.... the "R7" and "Q8" start to hot.... (the LED "D1" dont work.....) and the fuse blow...
i put a new fuse....
and... i deconnect the base of "Q5" and "Q6"....
turn on the power.....( the LED "D1" still dont work.....) and the fuse dont blow but now the "Q2" start to hot.... but slowle.....
i reconnect the the base of "Q5" to secend ! and the fuse blow again......
what my problam....... ?
***** and i connect to 35V +/- no to 56V +/- it is matter?
http://sound.westhost.com/p68-f1.gif
Last edited by a moderator:
Hi DJ,
first, keep the base of Q5, and Q6 disconnected. Check the polarity of the LED, and check the connection or Q1, and R8. You can remove Q1, too, and if the LED works, there was problem with Q1.
So the first step to get some light from the D1, and don't care with other parts of the amplifier. Until the D1 doesn't work, Your amplifier will out of order!
Sajti
first, keep the base of Q5, and Q6 disconnected. Check the polarity of the LED, and check the connection or Q1, and R8. You can remove Q1, too, and if the LED works, there was problem with Q1.
So the first step to get some light from the D1, and don't care with other parts of the amplifier. Until the D1 doesn't work, Your amplifier will out of order!
Sajti
try to leave D2 out off the corcuit, dont leave it open but take a wire and shorten him.
This aint good but would solve the problem with shorten the voltage rails, iff the problem still remeans ... dunno, probebly wrong connections, and maybe intresting to post all the voltages when the power transistors ( q5 and Q6 ) or disconnected.
Greetz
This aint good but would solve the problem with shorten the voltage rails, iff the problem still remeans ... dunno, probebly wrong connections, and maybe intresting to post all the voltages when the power transistors ( q5 and Q6 ) or disconnected.
Greetz
Use Google:
http://ourworld.compuserve.com/homepages/g_knott/elect56.htm
http://www.elexp.com/t_test.htm
http://www.eatel.net/~amptech/elecdisc/ampfail.htm
Tamir, I really don't want to **** you off but I think you should do a basic course Electronics so that you'll know what you're doing. Faults ( even dangerous ones ) are easily made when basic skills are not adequate. But as an assuring remark I can tell I began the same way, it only takes more time and a lot more errors
As a second advise I can recommend buying Rod Elliotts PCB. They are very cheap and good quality. The risk of connecting LED and transistors wrong will be lower AND it looks better. If you buy boards from Rod you'll get access to his secured webpages where you'll find more information on the project including helpful tips.
http://ourworld.compuserve.com/homepages/g_knott/elect56.htm
http://www.elexp.com/t_test.htm
http://www.eatel.net/~amptech/elecdisc/ampfail.htm
Tamir, I really don't want to **** you off but I think you should do a basic course Electronics so that you'll know what you're doing. Faults ( even dangerous ones ) are easily made when basic skills are not adequate. But as an assuring remark I can tell I began the same way, it only takes more time and a lot more errors
As a second advise I can recommend buying Rod Elliotts PCB. They are very cheap and good quality. The risk of connecting LED and transistors wrong will be lower AND it looks better. If you buy boards from Rod you'll get access to his secured webpages where you'll find more information on the project including helpful tips.
jean-paul said:
Jean-paul, I think it's difficult for DJ to obtain the PCB from Rod via Internet.
He mentioned that somewhere in an earlier post.
DJ, the link for measuring transistors has been given to you in the past. You should bookmark that site as well as the sites jean-paul gives you. This is very important and good info.
/Hugo - thanks I live in Belgium, everything is possible here. (Well almost)
I read that before and I seriously doubt that you can't buy from abroad. What's so special in Israel that you can't buy a PCB, I think it is a free country ? Israel exports and imports goods so there must be a way. Please explain where the difficulty is: the payment or the packet or...
The problem of VAT is not a problem if you have the packet send labelled as a gift ! If you have a credit card it is very simple to buy PCB's from Rod.
And if it is really that impossible there is the possibility that a forum member buys the board and sends it to you. Or is it forbidden to receive packets at all ? You only have to pay the amount including shipping costs to the forum member. I can be such a member. Was going to order a board anyway.
You soldered the LED in reverse so sorry I assumed you are a beginner.
The problem of VAT is not a problem if you have the packet send labelled as a gift ! If you have a credit card it is very simple to buy PCB's from Rod.
And if it is really that impossible there is the possibility that a forum member buys the board and sends it to you. Or is it forbidden to receive packets at all ? You only have to pay the amount including shipping costs to the forum member. I can be such a member. Was going to order a board anyway.
You soldered the LED in reverse so sorry I assumed you are a beginner.
Mr DJ
Building an amp is not that difficult, but it is very easy to make a mistake. If left unchecked, this mistake can destroy a lot of expensive parts. I think what people here are trying to say is that experience is not a scale to which one's ability to build an amp must be measured. Better sure than sorry.
What I would do if in your shoes:
1. If you made your own PCB then check it entirely for short, cracks, and most important is if it's correct. Buying the PCB can ensure your chances for success.
2. Check each transistor carefully.
3. Make sure that you identify the transistors leads before connecting to your amp. Better get datasheets for these. Never connect them backwards!
4. Use a way to monitor your current and voltages. Did you hear someone ask for the voltage? Voltage and current are the only language your amp can speak to you so get them fast.
5. Be confident, you can do it.
JojoD
Building an amp is not that difficult, but it is very easy to make a mistake. If left unchecked, this mistake can destroy a lot of expensive parts. I think what people here are trying to say is that experience is not a scale to which one's ability to build an amp must be measured. Better sure than sorry.
What I would do if in your shoes:
1. If you made your own PCB then check it entirely for short, cracks, and most important is if it's correct. Buying the PCB can ensure your chances for success.
2. Check each transistor carefully.
3. Make sure that you identify the transistors leads before connecting to your amp. Better get datasheets for these. Never connect them backwards!
4. Use a way to monitor your current and voltages. Did you hear someone ask for the voltage? Voltage and current are the only language your amp can speak to you so get them fast.
5. Be confident, you can do it.
JojoD
Dj,
I hope you have a digital meter handy. If so, put it on diode check. Most meters will also "beep" in this mode. For the T0-3's all you have to remember is the way to hold them and the English alphabet. Hold the transistor so that the 2 leads are away from you and the mounting holes are in a vertical position. The distance between the hole closest to you and the leads should be greater than the distance between the leads and the other hole. At this point remember the first few letters of the English alphabet...... a, B, C, d E...... The pins are now in order.... The base is on the left, the collector is the case and the emitter is the right pin. This is the standard for ALL T0-3, 3 pin devices and is for both PNP and NPN. A PNP device, you put the negative lead on the base and the positive lead on the collector and it should beep and say something from .300 to .700. do the same between the 2 leads and you should get the same reading. NOW, put the two probes from the right pin, (emitter) and the case..... You shouldn't read anything. Use the same way but opposite polarity on the other type transistor. If you start and you get nothing, change polarity and you'll see, at once, which transistor you have!
Make sure that you DO NOT have a short between the collectors of the 2 types of outputs as the rails should be on them and you will blow more than just fuses if you do.
The other guys have said a lot of very valuable information especially about checking your wiring many times, I suggest checking continuity with your meter.
The worst thing I saw for you to do is to short the diode. Look at the current path. You have a 22K + 10 ohm to ground plus you are putting DC voltage on your input diff. pair and you'll get DC on the output. If you have a speaker on the output, kiss it goodbye! As you power up the amp, look for DC on the output. If there is about 1 volt or a little more, it is just the bias being too high but there could be other problems. Set the bias and if you can't, there is another problem. Check all wiring and for shorted transistors or damaged resistors.
I am building an amp and I have printed the complete .PDF files for all of the semiconductors, diodes included. I know how big they are and the exact pin configuration and voltages for each of them. You should do the same.
The best advice came in the form of "Know more about what you are doing before you start such a large project" If you don't even know how to check the transistors, how do we know if you put the right ones in the right spot and in the way the should go? I'm not trying to be a jerk but this is a rather large project. You need more experience with discreet amplifiers and how top build them AND how to troubleshoot it in a simple way, THE BASICS, just as others have said. What will it take before you finally listen?
Good luck,
Chris
I hope you have a digital meter handy. If so, put it on diode check. Most meters will also "beep" in this mode. For the T0-3's all you have to remember is the way to hold them and the English alphabet. Hold the transistor so that the 2 leads are away from you and the mounting holes are in a vertical position. The distance between the hole closest to you and the leads should be greater than the distance between the leads and the other hole. At this point remember the first few letters of the English alphabet...... a, B, C, d E...... The pins are now in order.... The base is on the left, the collector is the case and the emitter is the right pin. This is the standard for ALL T0-3, 3 pin devices and is for both PNP and NPN. A PNP device, you put the negative lead on the base and the positive lead on the collector and it should beep and say something from .300 to .700. do the same between the 2 leads and you should get the same reading. NOW, put the two probes from the right pin, (emitter) and the case..... You shouldn't read anything. Use the same way but opposite polarity on the other type transistor. If you start and you get nothing, change polarity and you'll see, at once, which transistor you have!
Make sure that you DO NOT have a short between the collectors of the 2 types of outputs as the rails should be on them and you will blow more than just fuses if you do.
The other guys have said a lot of very valuable information especially about checking your wiring many times, I suggest checking continuity with your meter.
The worst thing I saw for you to do is to short the diode. Look at the current path. You have a 22K + 10 ohm to ground plus you are putting DC voltage on your input diff. pair and you'll get DC on the output. If you have a speaker on the output, kiss it goodbye! As you power up the amp, look for DC on the output. If there is about 1 volt or a little more, it is just the bias being too high but there could be other problems. Set the bias and if you can't, there is another problem. Check all wiring and for shorted transistors or damaged resistors.
I am building an amp and I have printed the complete .PDF files for all of the semiconductors, diodes included. I know how big they are and the exact pin configuration and voltages for each of them. You should do the same.
The best advice came in the form of "Know more about what you are doing before you start such a large project" If you don't even know how to check the transistors, how do we know if you put the right ones in the right spot and in the way the should go? I'm not trying to be a jerk but this is a rather large project. You need more experience with discreet amplifiers and how top build them AND how to troubleshoot it in a simple way, THE BASICS, just as others have said. What will it take before you finally listen?
Good luck,
Chris
i go to my friend.... he is a technician of Electronics he have a electronic store....
so...... he check my circuit..... because the led....that i connect inverted.... it is destruction all the 2sc/a and the MJE part of them.....
and the circuit is connect right..... so now i need to get a need transistors....
thanks for u all !.... i will continue from here....
and i have the new 36~0~36VAC 1500VA transformer...
for 2 ohm subwoofers....
so...... he check my circuit..... because the led....that i connect inverted.... it is destruction all the 2sc/a and the MJE part of them.....
and the circuit is connect right..... so now i need to get a need transistors....
thanks for u all !.... i will continue from here....
and i have the new 36~0~36VAC 1500VA transformer...
for 2 ohm subwoofers....
Hi DJ,
if You try to switch on Your amplifier first time, just do some safety actions:
1, Get some 10ohms/5W resistor and put them series with +/- supply rails. If You have any problem, the resisitors will smoke little bit, but they will protect Your output devices! (I think two resistors are cheaper than some transistors
2, For the first switch on, don't put Your speaker to the output terminal. Just put 100ohms/1-2W resistor, and nothing else. If this resistor will be hot, there is some problem with the amplifier.
3, If all of the resistors remains cold, and there is no other problem, just try to connect Your CD player to the input. Connect Your speaker BUT series with the 100ohms resistors!!!! Keep the 10ohms in the power supply rails! Just play some music, not very loud. If the sound is not distorted, no strange noises, and everything looks nice, remove the test resistors, and enjoy the music
During the test check the bias current regularly on the output devices! Just check the voltage across the R18,R19, R20, R21, in every 5 minutes. They have to be same (almost same, within 10-20%), and if this voltages increase as the heatsinks warm up, there is some problems with the bias regulation.
Sajti
if You try to switch on Your amplifier first time, just do some safety actions:
1, Get some 10ohms/5W resistor and put them series with +/- supply rails. If You have any problem, the resisitors will smoke little bit
, but they will protect Your output devices! (I think two resistors are cheaper than some transistors 2, For the first switch on, don't put Your speaker to the output terminal. Just put 100ohms/1-2W resistor, and nothing else. If this resistor will be hot, there is some problem with the amplifier.
3, If all of the resistors remains cold, and there is no other problem, just try to connect Your CD player to the input. Connect Your speaker BUT series with the 100ohms resistors!!!! Keep the 10ohms in the power supply rails! Just play some music, not very loud. If the sound is not distorted, no strange noises, and everything looks nice, remove the test resistors, and enjoy the music
During the test check the bias current regularly on the output devices! Just check the voltage across the R18,R19, R20, R21, in every 5 minutes. They have to be same (almost same, within 10-20%), and if this voltages increase as the heatsinks warm up, there is some problems with the bias regulation.
Sajti
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