Yes i tried that it didnt make any difference.
capacitor of around 27pF(i think) i didnt tried any other values when i found out that the amp is stable without the feedback cap.
I am going to try to do some SOA test's on the transistors i got.
does anyone got a nice circuit for that?
capacitor of around 27pF(i think) i didnt tried any other values when i found out that the amp is stable without the feedback cap.
I am going to try to do some SOA test's on the transistors i got.
does anyone got a nice circuit for that?
Nordic said:There are photos of real sc5200s in the "is my transistor real" thread...
I think those are fake like mine, but mine works fine... gain in the 40s.
at what Ic?the gain I quoted was what the tip41s measured... the big ones were 98 and 100...
I suspect the best you can achieve is a pass/fail at a fixed power dissipation. But, how do you intend monitoring Tj & Tc to ensure you stay within manufacturer's limits? Both these temperatures are inaccessible when the device is mounted on the heatsink.inex said:I am going to try to do some SOA test's on the transistors i got.
does anyone got a nice circuit for that?
Well.... i am printing stuff while you go ahead with that gain conversation.
Negative...i will not burn my transistor to have sure if he will be able to hold 15 amperes.
Yeah!...i gave up related that..... i have changed my mind...for good!
I will not answer questions to my transistor anymore...i will just put it to play music.
regards,
Carlos
Negative...i will not burn my transistor to have sure if he will be able to hold 15 amperes.
Yeah!...i gave up related that..... i have changed my mind...for good!
I will not answer questions to my transistor anymore...i will just put it to play music.
regards,
Carlos
Attachments
Printing the Italian Philips audio book.
I will have a lot of fun this weekend....for sure i will have.
regards,
Carlos
...............................................................................................................
Inex
Good that we are in direct conversations and images going and images returning about Dx amplifier.... soon we will find something strange.
regards,
Carlos
I will have a lot of fun this weekend....for sure i will have.
regards,
Carlos
...............................................................................................................
Inex
Good that we are in direct conversations and images going and images returning about Dx amplifier.... soon we will find something strange.
regards,
Carlos
Attachments
Yes don't ask questions, just build it!!!!!!!!!!!
An externally hosted image should be here but it was not working when we last tested it.
I did some power disapation test's with my real/fake toschiba 2sa1943
and acording to my DMM its still alive.
I dont know if i did everything right but the dissipation was about 130W with 26V on E-C and a IC of 5A.
If the measurements and the calculations are corect the transistor got a gain of 188.
The text on 2 of my toschiba(2sa) is a litle smaller and on all my toschiba the text "japan" is more to the left instead of the centre.
and acording to my DMM its still alive.
I dont know if i did everything right but the dissipation was about 130W with 26V on E-C and a IC of 5A.
If the measurements and the calculations are corect the transistor got a gain of 188.
The text on 2 of my toschiba(2sa) is a litle smaller and on all my toschiba the text "japan" is more to the left instead of the centre.
Not so hard this way dear Nordic, but not so different too...ahahahahah!
builders can do whatever they want..... i nice compensation.
People that is just thinking in build are also very kindly received too.
And as you know, i do whatever i can to help.
You are funny dear Nordic, and much better without the wisdom teeth.... clever too.
regards,
Carlos
builders can do whatever they want..... i nice compensation.
People that is just thinking in build are also very kindly received too.
And as you know, i do whatever i can to help.
You are funny dear Nordic, and much better without the wisdom teeth.... clever too.
regards,
Carlos
It seems Inex, that your transistors are original, exception is the gain that seems
to be a little bit bigger than the others pair i have (8 pairs) and the other 7 pairs i have used to construct Dx amplifier to others.
They were all around 100.... a little bit bigger or a little big smaller gain measured with small current.... from 88 to 127 of DC gain i have found measuring under low current and voltage conditions, multimeter gain measurements.... Ic divided by Ib, beeing Ic very small.
Your high gain under heavy work, the test you made, is a little bit suspectius to me....well, i am not expert in this transistor, to tell you the true i am using it since i have constructed mine Aksas two an half years ago..... maybe some samples can reach bigger gain.
This is more for theorical people, .... i hope they land here when needed.
Toshiba use "S" dear Inex.....ahahahha...if your has a "C".... toschiba...for sure it is fake.
regards,
Carlos
...............................................................................................................
Dear Graham
You are not the theorical, you are an explendid mix of theories and practice blended with the most precious scientific mind, eagle vision and clever aproach.
Do you think Inex transistor is fine?
You are the one i can trust to answer me this..... of course Hugh too, Michael Bittner too and others, but they do not track this thread constantly...both are extremelly busy folks...... maybe another friend has that experience with 2SC5200 and 2SA1943 to help us "cleaning" this doubt from our minds.
Nice winds of happyness are flowing into your direction dear Graham, a refreshing breeze to move your hairs and make you happy..... two wonderfull folks, have the intention to construct GEM
regards,
Carlos
to be a little bit bigger than the others pair i have (8 pairs) and the other 7 pairs i have used to construct Dx amplifier to others.
They were all around 100.... a little bit bigger or a little big smaller gain measured with small current.... from 88 to 127 of DC gain i have found measuring under low current and voltage conditions, multimeter gain measurements.... Ic divided by Ib, beeing Ic very small.
Your high gain under heavy work, the test you made, is a little bit suspectius to me....well, i am not expert in this transistor, to tell you the true i am using it since i have constructed mine Aksas two an half years ago..... maybe some samples can reach bigger gain.
This is more for theorical people, .... i hope they land here when needed.
Toshiba use "S" dear Inex.....ahahahha...if your has a "C".... toschiba...for sure it is fake.
regards,
Carlos
...............................................................................................................
Dear Graham
You are not the theorical, you are an explendid mix of theories and practice blended with the most precious scientific mind, eagle vision and clever aproach.
Do you think Inex transistor is fine?
You are the one i can trust to answer me this..... of course Hugh too, Michael Bittner too and others, but they do not track this thread constantly...both are extremelly busy folks...... maybe another friend has that experience with 2SC5200 and 2SA1943 to help us "cleaning" this doubt from our minds.
Nice winds of happyness are flowing into your direction dear Graham, a refreshing breeze to move your hairs and make you happy..... two wonderfull folks, have the intention to construct GEM
regards,
Carlos
Hi Carlos / Inex,
I have come across only one 2SC5200 which hit 180 gain but that was at low current only.
These are genuine Toshiba devices.
Note the 'O' just left above 'JAPAN' this indicates standard gain.
Such a device is unlikely to hit more than 100 at low current.
If devices do not look exactly like these they are not Toshiba, and might well have higher junction capacitances.
Cheers ......... Graham.
I have come across only one 2SC5200 which hit 180 gain but that was at low current only.
These are genuine Toshiba devices.
Note the 'O' just left above 'JAPAN' this indicates standard gain.
Such a device is unlikely to hit more than 100 at low current.
If devices do not look exactly like these they are not Toshiba, and might well have higher junction capacitances.
Cheers ......... Graham.
Attachments
Long plan
Wooowwwwwwwww ... nice planning
1. future Kit to Brazilian Market
2. Competitive with cheaper amp
3. Advertising ... Propaganda
4. Offer the boards
5. Distributed wide world
6. Real Corporation will born.
7. Find cheap boards manufacturers
8. I have to create a company
9. To enter Pay Pal system
10. Brazilian mail system
For number
3. Pay advertising in world hifi magazine
4. Just post in DIY Audio forum
- Vendor bazaar - Find moderator
- Your DX thread
- Trading Post
- Can add in other forum
5. Go to post office, try ems just US$ 7.5
until US $ 12 / 250gr worldwide
6. Congratulation but becarefull with
- Taxman
- Thief & Criminal
- Unhealthy condition ( Achieve target ... )
Begin at home is the best thing, make your daughter
Sales director, i will buy one
7. Just googling finish in 1 hour
Maybe you can look too in china
very cheap for product & shipment
8. Good idea to start with a company
but very effective to begin from home
industries ... low cost, no need pay salary
except you want to sell complete amp
9. For this begin today just 5 minutes bussiness
my idea listed by your identic email than you
can upgrade to bussiness
10. Go to post office ask about regular air mail system
It is very cheap
byee carlos, great success
Wooowwwwwwwww ... nice planning
1. future Kit to Brazilian Market
2. Competitive with cheaper amp
3. Advertising ... Propaganda
4. Offer the boards
5. Distributed wide world
6. Real Corporation will born.
7. Find cheap boards manufacturers
8. I have to create a company
9. To enter Pay Pal system
10. Brazilian mail system
For number
3. Pay advertising in world hifi magazine
4. Just post in DIY Audio forum
- Vendor bazaar - Find moderator
- Your DX thread
- Trading Post
- Can add in other forum
5. Go to post office, try ems just US$ 7.5
until US $ 12 / 250gr worldwide
6. Congratulation but becarefull with
- Taxman
- Thief & Criminal
- Unhealthy condition ( Achieve target ... )
Begin at home is the best thing, make your daughter
Sales director, i will buy one
7. Just googling finish in 1 hour
Maybe you can look too in china
very cheap for product & shipment
8. Good idea to start with a company
but very effective to begin from home
industries ... low cost, no need pay salary
except you want to sell complete amp
9. For this begin today just 5 minutes bussiness
my idea listed by your identic email than you
can upgrade to bussiness
10. Go to post office ask about regular air mail system
It is very cheap
byee carlos, great success
We are not paying taxes to dream in my country...at least they did not discover how
to detect nice dreams to order some taxes on them.....hehe
thank you by the support,
By the way...hummmm, nice 6800uf condensers.... the 63 Volts units.
You are nice for our forum Jeffry, very communicative and funny.
Has good mood... a very positive behavior.
You will be the forum king in a couple of years.
Very nice your posts.... and pictures made by Ixus are excelent.
regards,
Carlos
to detect nice dreams to order some taxes on them.....hehe
thank you by the support,
By the way...hummmm, nice 6800uf condensers.... the 63 Volts units.
You are nice for our forum Jeffry, very communicative and funny.
Has good mood... a very positive behavior.
You will be the forum king in a couple of years.
Very nice your posts.... and pictures made by Ixus are excelent.
regards,
Carlos
I have made tests, today, using 2 ohms real speaker loads
Power measured, undistorted power, was 212 Watts RMS... and this is the circuit limit.
The supply was 37 plus 37 volts.... 4.8 Amperes each rail...i had to install two supplies in parallel to hold the power needed.
One emitter resistance was adjusted to do it.
Sounded good too.
Two pairs were used into the output, and 0.33 ohms emitter resistances were used.... also 2,2 ohms in series with each output base transistor.
regards,
Carlos
Power measured, undistorted power, was 212 Watts RMS... and this is the circuit limit.
The supply was 37 plus 37 volts.... 4.8 Amperes each rail...i had to install two supplies in parallel to hold the power needed.
One emitter resistance was adjusted to do it.
Sounded good too.
Two pairs were used into the output, and 0.33 ohms emitter resistances were used.... also 2,2 ohms in series with each output base transistor.
regards,
Carlos
2sa1943
Here is a pic of my 2sa1943, the text is a bit different than the text on the pic Graham posted.
So i guess mine transistors are fake . Is the music quality reduced with the use of fake transistors? I can always use them for a lab powersuply.
If anyone knows a good source for real output transistors,that acept advance to bank payment and have low shipping cost, please post it .
Those Toshiba at Ampslab are they real?, how much are the shipping cost? and can i use Paypal without a creditcard?
About the DX amp
the oscillation's i got, can they be caused by fake output? Tomorrow I will try some transistors from an old broken poweramp.
Here is a pic of my 2sa1943, the text is a bit different than the text on the pic Graham posted.
So i guess mine transistors are fake . Is the music quality reduced with the use of fake transistors? I can always use them for a lab powersuply.
If anyone knows a good source for real output transistors,that acept advance to bank payment and have low shipping cost, please post it .
Those Toshiba at Ampslab are they real?, how much are the shipping cost? and can i use Paypal without a creditcard?
About the DX amp
the oscillation's i got, can they be caused by fake output? Tomorrow I will try some transistors from an old broken poweramp.
Attachments
Hi Inex,
Can we see the whole body and pin-out legs please.
Is the back mirror shiny (apart from possible scrathes ?
The barch number on your device is much more recent than mine.
Mine are not new supply - held in my components box so that I will not be stuck !
Cheers ....... Graham.
Can we see the whole body and pin-out legs please.
Is the back mirror shiny (apart from possible scrathes ?
The barch number on your device is much more recent than mine.
Mine are not new supply - held in my components box so that I will not be stuck !
Cheers ....... Graham.
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