OK, now what do you think about the possibility of separating pairs of these amplifiers by cutting the PCB. It seems that more power can be available by running two of them in the bridge arrangement, with only a simple phase inverter required. That seems like a simple way to get twice the power, or maybe four times the power, although the amplifiers are limited in the current that they can supply. But at least twice the power.
We can not tell because we can not see the foil side of the boards. If each amp is more separate, then it could be done.

i cant see a problem if the inverter is placed on an small extra assy....connectors for every channel in and output are given and the space should be enough to ad jumpers or whatever ....

 

Hello everyone. I have D2390 and B1560 transistors from the old pioneer AVR. I want to make an amp using this. I googled to find a PCB diagram but couldn't find it. Same as these forums. Can anyone give me a circuit diagram?

The big question is WHY You want to use these particular Transistors ????

What do You expect the end-product to be ?

There are far simpler solutions to building an Amplifier.

Are You doing it just to see if You can build your own ?
.
.
.

 

The big question is WHY You want to use these particular Transistors ????

What do You expect the end-product to be ?

There are far simpler solutions to building an Amplifier.

Are You doing it just to see if You can build your own ?
.
.
.

i have a workshop that focuses on upcycling and vintage technology. Many of the transistors have simply accumulated. I am self-taught and can combine both. i learn something and in the best case i end up with a few amps or active modules which are then passed on to friends

 

Now that I have seen the arrangement of the foil side of the circuit board it is clear that separating the amplifier sections by cutting the board will not be an option. The circuits are far to closely packed and there is no spacing between sections.
But still this could be arranged to have a good stereo amplifier with two bridged output channels. The package will be a bit bigger, but is that a problem?
It would also be possible to use the same circuit with the same parts to build up individual amplifiers.

In addition, those transistors may not be quite as good as what is presently available.
I know that in some parts of the world electronic components are both hard to obtain and also very expensive, that may be the reason for selecting those devices.

 

Now that I have seen the arrangement of the foil side of the circuit board it is clear that separating the amplifier sections by cutting the board will not be an option. The circuits are far to closely packed and there is no spacing between sections.
But still this could be arranged to have a good stereo amplifier with two bridged output channels. The package will be a bit bigger, but is that a problem?
It would also be possible to use the same circuit with the same parts to build up individual amplifiers.

In addition, those transistors may not be quite as good as what is presently available.
I know that in some parts of the world electronic components are both hard to obtain and also very expensive, that may be the reason for selecting those devices.

the powerampstage is not everything ...more important is a good preamp and in best case a high end aktiv crossovercircuit ...if the poweramp stages has a linear frequencie response and a good design with well calculated partvalues and heatsinks the 1560/2390 can still do a great job! and they are easy to drive with a few parts .... i'm going to try an ic as driver for them .... with a lf356, taa765 or tda2030 it could work well ... i will let u know what the result was
(its only an example circuit ... i dont know if i ll need extra transistors as driver )

 

I cropped and enlarged your schematic so we can see its text.
The opamp and transistors cannot produce enough output current.
If you add extra transistors then the output voltage swing will limit the output power to about the same 0.5W output power.
The BD240 is almost obsolete. The TDA2030 and TDA2030A are obsolete and are not available.

 

I cropped and enlarged your schematic so we can see its text.
The opamp and transistors cannot produce enough output current.
If you add extra transistors then the output voltage swing will limit the output power to about the same 0.5W output power.
The BD240 is almost obsolete. The TDA2030 and TDA2030A are obsolete and are not available.

many thanks for your effort. that means a lot to me because there is a lot of teaching material that I'm dealing with anyway.
if the circuit diagram is wrong I would be very surprised. the source is
https://www.elektronik-kompendium.de/public/schaerer/endstu_p.htm.

I rule out errors there! otherwise it was just an example of the rough layout.

Possibilities that I am considering would be the following:

1)control the 1560/2390 with a taa765 since the control of darlington trs is specified in the data sheet under typical application. the ic would of course receive a separate voltage supply and the powertransis would receive additional drivers or a current amplifier if necessary.

2)I still have tda2030. I only deal with vintage technology and have the standard components from 1960-1990 in stock. with a pair of bd907 / 908 together, for example, the whole thing is sure to work well
amplifier.

3)Regarding the circuit diagram, my rough thoughts were as follows:
they used a ne5534 instead of the lf356, it should also be possible to control the bd 239/240 with the lf356.
the bd 239/240 are very similar to the transistors 2sc2168 / a958 with which one could in turn control a par 2sc5200 / a1943. of course with a separate psu if necessary.

but these are all just thoughts at first!

what you wrote next to the circuit diagram i will read through in peace! thank you again and greetings

p.s.if u ever need obsolete parts just ask me! i'll send what u need if i have and you have to pay only shipping .... litl reward for your work!!
sorry for bad english - i have no time to correct that at the moment

 

The TS asked, back in post #1, for an amplifier circuit using the specific transistors. So that Is whyy I keep suggesting using the hardware that is on hand and uses those transistors. If that design is not optimum, perhaps it is good enough. And in some parts of the world even cheap modern parts are horribly expensive. Also, just adding some good preamplifier sections would be simpler than building a complete new system.

 

Many 'teachers" do not know or do not calculate the details.

The LF356 is also old with many versions obsolete and not available.
Its datasheet says 2k ohms minimum load, 10V/2k= 5mA which is much less than the output current of the NE5534.

Why are you low current output transistors? If you want 25 Watts into 8 ohms then the peak speaker current is 5A so transistors that work well at 10A should be used and the power supply needs to be a total of 45V or more.

Why are you re-inventing an audio power amplifier circuit when many high performance ICs are available today?

 

Hello,

Or you could use one of the projects of Elliot:
https://sound-au.com/projects.htm
An other option is reading a good book on amplifier design, like Audio Electronics & Transistor Amplifiers Design Handbook D. Self :
https://archive.org/details/fe_Audio_Electronics_Transistor_Amplifiers_Design_Handbook_D._Self

Bertus

 

Hello,

Or you could use one of the projects of Elliot:
https://sound-au.com/projects.htm
An other option is reading a good book on amplifier design, like Audio Electronics & Transistor Amplifiers Design Handbook D. Self :
https://archive.org/details/fe_Audio_Electronics_Transistor_Amplifiers_Design_Handbook_D._Self

Bertus

I'd thoroughly recommend Doug Self's book.

 

Many 'teachers" do not know or do not calculate the details.

The LF356 is also old with many versions obsolete and not available.
Its datasheet says 2k ohms minimum load, 10V/2k= 5mA which is much less than the output current of the NE5534.

Why are you low current output transistors? If you want 25 Watts into 8 ohms then the peak speaker current is 5A so transistors that work well at 10A should be used and the power supply needs to be a total of 45V or more.

Why are you re-inventing an audio power amplifier circuit when many high performance ICs are available today?

because i have to buy parts than. but there is no need because i only touch vintage devices, i have tons of vintage parts and i want to learn more about the old circuits and parts - thats all

 

Indeed!! Not every part of the world has new electronic parts stores on every corner selling the very latest electronic components at clearance prices. Shipping prices alone to some localities are very high, and deliveries may take quite a while.