The BC 147 with the trapezium shaped body, I have a few of those floating about. Also the yellow base supports on the upright caps was very common too in those days. Great video.
Yes, but only on the long term, let us say 20 (10?) years or so and when they are not used (not under a certain voltage each day). It depends a lot on the quality/manufacturer and it is somewhat unpredictable how good an electrolytic performs after 20 years, being stored or in use. When they dry internally out the isolation layer (aluminumoxide) degrades. In some circuits this does not have to be a problem, especially non power circuits.
I like your taste in music. I enjoy seeing how these older sets were constructed. They were built with pride and designed to last (unlike the cheap electronics today).
That would be the last of the use of germanium transistors in the output stages for home audio amplifiers. Philips produced a lot of these, including data sheets of the transistors. As the production techniques for silicon power transistors became more economical, and the use of the TO-3 case (as well as the TO-66; AD161 & AD162) and more temperature stability, silicon transistors became the preferred design option... Hope you can find the time & components to fix the other channel... The working channel sounds good...
Hi radiofun232, I have recently bought a Philips 22 RH 790 with AD 161 and AC 187. I sounds great! Very refined and clear. There is one problem with it: the volume potentiometer. It is not cracking (I used some electronics contact spray to fix it), but the contacts themselves are moving from the pot's chassis. And the left and right do not measure the same 200 K (strange). The model is 20K + 200K logarithmic double on the same axis. It also has the 11 hour contour (loudness) extra pin. So the total is 4+4=8 pins. I sent you a private message on this subject. Can you please check your parts stock for something compatible (even without the loudness connections). Sorry for posting here, can you please check your private Messages in youtube account?
+Alexandru Necula Hi, I don't have these components, sorry. Perhaps you can bridge the loose contacts with a resistor from 500 K to 1 M to regain an identical (though somewhat different from the original) resistance on both channels. These potentiometers are specially made for this purpose and very rare.
Sorry, I was too quick with my reaction, I searched the www and as far as I know: the printboard came out of the Philips 22 AH 790 (first and best to my knowlegde). Or (second): the Philips 22 RH 580 or the Philips 22 RH 590.
In general their Hfe/Beta (the AD 161/AD 162, both Germanium types of end-transistors) was say between 30 and 60. When they were driven with a substantial current (read: audio signal); that mattered very much. They could be driven by Si or Ge Transistors, with enough Hfe/Beta. Say (as the drivers) between 70 and 100. So they (the Ge end transistors AD 161 and AD 162 in their complementary end stage) could in real/practice generate approx 3-5 Watt audio output. Very much for those days, given their temperature dependancy. That was corrected by temp. sensitive resistors in the end stage, you will know that. 6 august 2022.
@@radiofun232 thanks for explaining. could you please made a vid with the schematic of that amp ? i am thinking of ordering these transistors all the way from germany >.>
@@iceberg789 Sorry, but I don't have that schematic. There are, by the way, many schematics of GE audio amplifiers (1960-1970) on the www. I have made one GE audio amplifier for say 1 or 1.5 Watts audio out and published it on my YT Channel. Perhaps you know the link, if not, tell me, I will give it.
I must have hit a time warp? Am I a young man again? Thanks for the memories. I went from the Apollo Tracking Stations to the railroads before the Space Shuttle started flying. Radio men do it with frequencies and now scientist are now thinking atoms are conscious and the characteristics' of matter is frequency dependant.
I got a junk record player made by Cadensa, it was not working because of some wires being disconected but the electronics inside looked much like yours, it was manufactured in 1972. It has a power amplifier and the pre-amp, I took off the power amplifier, removed some of the capacitors (axial Siemens like the blue ones on your amp) and although they looked very worn out, ALL of then were in specs (the worst one 1000uF/16V measured 1146uF and 0,57 of ESR). The amp has the BC338B as input, AC187/AC188 as the drive and the AD161/AD162 as the power transistors. I powered it with a 12V supply hopping for the best, and, it worked! Both channels working! I noticed that the sound was awful, I hooked my osciloscope in it and messed up with the trimpots 'till I got a nice and round sine wave at the output, I hooked a 4 Ohms power resistor on the amplifier and cranked the volume up untill it started clipping, then I did the math, it is able to output 1W per channel at 4 Ohms and 12V. I looked at the signal at low level on the AD161, and found that this amplifier is class B, the crossover distortion is very audible at low volumes.
Thanks for telling your experiences with that old amplifier. These blue electrolytic capacitors are very good, that is also my experience. I still have some of them in stock (made by Philips in the 1970's).
@@radiofun232I found that the preamp is working too, only the potentiometers needs some cleaning. I figured out that the whole thing worked at 22V (with a 18VAC transformer), I did the measurement of the power output again and got 10W per channel at 4Ohms. Pretty decent. :)
@@Ale-Tronic OK, thanks. These 1960-1970 Germanium end-transistor amps are pretty good, though almost always they are protected by PTC or NTC resistors to prevent thermal runaway. But: their sound is very fine, I like it (have a few of these amps in store).
Just did a sound test not bad but not the best either. It uses the same rectangualr entry transistor BC147 i think, a GE driver and those same AD161 AD162 output devices.
Indeed its a memory, how sound sounded in the sixties. I like the sound from amplifiers from the sixties and seventies very much. Thanks.
The BC 147 with the trapezium shaped body, I have a few of those floating about. Also the yellow base supports on the upright caps was very common too in those days. Great video.
Thanks. It is the oldest transistor amp that I have at the moment and when I have time I am going to restore and repair it.
Yes, but only on the long term, let us say 20 (10?) years or so and when they are not used (not under a certain voltage each day). It depends a lot on the quality/manufacturer and it is somewhat unpredictable how good an electrolytic performs after 20 years, being stored or in use. When they dry internally out the isolation layer (aluminumoxide) degrades. In some circuits this does not have to be a problem, especially non power circuits.
I like your taste in music. I enjoy seeing how these older sets were constructed. They were built with pride and designed to last (unlike the cheap electronics today).
That would be the last of the use of germanium transistors in the output stages for home audio amplifiers. Philips produced a lot of these, including data sheets of the transistors. As the production techniques for silicon power transistors became more economical, and the use of the TO-3 case (as well as the TO-66; AD161 & AD162) and more temperature stability, silicon transistors became the preferred design option...
Hope you can find the time & components to fix the other channel... The working channel sounds good...
OK, thanks.
i have opened the Grundig sv80m amp, it is a 1967 amp and the system resemble more to valves. It has the same detail as a valve amp.
i swear my grandfather has one of these amp that has 4 germanium transistor inside mounted on a large heatsink, still working
sounds great KO thanks for sharing
Watch for more info ruclips.net/video/HsTnaCyr2gI/видео.html
Thanks. Philips was a great company those days, it still is, but there is a lot of concurrency.
hmm. I have a Grundig SV 80M amp. I think the transistors are germanium. it has a lot of detail
beautiful sound
Very inspiring video!
+Bayu 63 thanks.
Can l replace the originaly silicon transistors build with germanium one? is it possible?
In general: no, the differences are to big. The schematic has to be changed.
Hi radiofun232, I have recently bought a Philips 22 RH 790 with AD 161 and AC 187. I sounds great! Very refined and clear. There is one problem with it: the volume potentiometer. It is not cracking (I used some electronics contact spray to fix it), but the contacts themselves are moving from the pot's chassis. And the left and right do not measure the same 200 K (strange).
The model is 20K + 200K logarithmic double on the same axis. It also has the 11 hour contour (loudness) extra pin. So the total is 4+4=8 pins. I sent you a private message on this subject. Can you please check your parts stock for something compatible (even without the loudness connections). Sorry for posting here, can you please check your private Messages in youtube account?
+Alexandru Necula Hi, I don't have these components, sorry. Perhaps you can bridge the loose contacts with a resistor from 500 K to 1 M to regain an identical (though somewhat different from the original) resistance on both channels. These potentiometers are specially made for this purpose and very rare.
Great video, would you have the model number of the amplifier by any chance?
No, sorry. I salvaged it (say) 25 years ago and only have the printboard.
It was (for sure) made by Philips in the 1970's.
Sorry, I was too quick with my reaction, I searched the www and as far as I know: the printboard came out of the Philips 22 AH 790 (first and best to my knowlegde). Or (second): the Philips 22 RH 580 or the Philips 22 RH 590.
@@radiofun232 thank you very much :)
transistors those ad161/162 driven by ?
and what kind of hfe these have ?
In general their Hfe/Beta (the AD 161/AD 162, both Germanium types of end-transistors) was say between 30 and 60. When they were driven with a substantial current (read: audio signal); that mattered very much. They could be driven by Si or Ge Transistors, with enough Hfe/Beta. Say (as the drivers) between 70 and 100. So they (the Ge end transistors AD 161 and AD 162 in their complementary end stage) could in real/practice generate approx 3-5 Watt audio output. Very much for those days, given their temperature dependancy. That was corrected by temp. sensitive resistors in the end stage, you will know that. 6 august 2022.
@@radiofun232 thanks for explaining. could you please made a vid with the schematic of that amp ? i am thinking of ordering these transistors all the way from germany >.>
@@iceberg789 Sorry, but I don't have that schematic. There are, by the way, many schematics of GE audio amplifiers (1960-1970) on the www. I have made one GE audio amplifier for say 1 or 1.5 Watts audio out and published it on my YT Channel. Perhaps you know the link, if not, tell me, I will give it.
@@radiofun232 i think i have seen it. will recheck it, thanks for reminding.
I must have hit a time warp? Am I a young man again? Thanks for the memories. I went from the Apollo Tracking Stations to the railroads before the Space Shuttle started flying. Radio men do it with frequencies and now scientist are now thinking atoms are conscious and the characteristics' of matter is frequency dependant.
I got a junk record player made by Cadensa, it was not working because of some wires being disconected but the electronics inside looked much like yours, it was manufactured in 1972. It has a power amplifier and the pre-amp, I took off the power amplifier, removed some of the capacitors (axial Siemens like the blue ones on your amp) and although they looked very worn out, ALL of then were in specs (the worst one 1000uF/16V measured 1146uF and 0,57 of ESR).
The amp has the BC338B as input, AC187/AC188 as the drive and the AD161/AD162 as the power transistors. I powered it with a 12V supply hopping for the best, and, it worked! Both channels working! I noticed that the sound was awful, I hooked my osciloscope in it and messed up with the trimpots 'till I got a nice and round sine wave at the output, I hooked a 4 Ohms power resistor on the amplifier and cranked the volume up untill it started clipping, then I did the math, it is able to output 1W per channel at 4 Ohms and 12V.
I looked at the signal at low level on the AD161, and found that this amplifier is class B, the crossover distortion is very audible at low volumes.
Thanks for telling your experiences with that old amplifier. These blue electrolytic capacitors are very good, that is also my experience. I still have some of them in stock (made by Philips in the 1970's).
@@radiofun232I found that the preamp is working too, only the potentiometers needs some cleaning. I figured out that the whole thing worked at 22V (with a 18VAC transformer), I did the measurement of the power output again and got 10W per channel at 4Ohms. Pretty decent. :)
@@Ale-Tronic OK, thanks. These 1960-1970 Germanium end-transistor amps are pretty good, though almost always they are protected by PTC or NTC resistors to prevent thermal runaway. But: their sound is very fine, I like it (have a few of these amps in store).
zeer goed geluid
where is the power transformer 120volts in about 20_30 volts put
It is gone, the amp. is supplied by a lab power supply.
hello searche equivalent ad 161 and ad 162
They don't exist.
@ the moment reviving such amp als but unfortunately the old C core transformer is dead
In this case it worked properly and it can be replaced easily.
Just did a sound test not bad but not the best either. It uses the same rectangualr entry transistor BC147 i think, a GE driver and those same AD161 AD162 output devices.