Not having preouts is a little negative for some users, indeed. This particular style of Pioneer has not gotten the desirability status of the 70's gear, but who knows what the future may bring...thanks for commenting!
Excelente video, yo tengo el A-8 más pequeño, realmente son unos sobresalientes amplificadores con una distorsión casi imperceptible del 0.003% y un sonido espectacular. Fueron los antecesores de la serie Elite. Tengo amigos que tienen Mcintosh de $5000 y el mi A-8 que apenas me costó $200 los supera tranquilamente. Saludos desde Caracas, Venezuela.
Thanks so much for the comment. That style of Pioneer is not as popular for whatever reason, but most folks seem to like them and you are not hearing 0.003% THD, that's for sure!
Thanks for taking a moment to comment! I have always liked the looks of this era of Pioneer gear and expect one day they will become more collectible. They are fine as long as they are working!
I am now 0ver 70 and have loved listening (and playing music today using Roland equipment) since I was 12. So I moved to audiophile-grade recordings and equipment to reproduce music as soon after I gaduated in electonics systems and got a job. I changed my amp in 1973 to the Yamaha CA 1000 - and in 1974 bought the Yamaha NS 1000 speakers, Dual tuntable - and was so proud of them. BUT here is what happened. In 1979 I went for traiing to Germany in digital electronics and stayed with a friend,s family. On one occasion my friend Dirk switched on his stereo in their siting room, we were in the kitchen, and suddenly I heard the kind of absulutely clear and hi fidelity which never heard before. To cut it short it was a Grundig R45A Tuner Amp hooked to Grundig 1000 speakers. I bought a Phase 4 Decca record the ext day. No usually you would need to switch two amps next to each oher while paying the same record to maybe hear a noticable difference. But not this time. It was clearly superior by any measure. Again to cut it short on my return to Malta I told the Grundig agent about my experience and he willingly lended me an R45a. The result was the following. The fidelity and sound difference was huge and easily distinguished by my wife who loves the tunes not the fidelty. Wow she would say when I switch from on to the other. So was it the speakers, the amp, the preamp......... Cut it short. Use the preamp of the Grundig and feed it into the main amp of the Yamaha - and the Yamaha would chane to being as clear and sharp with all instruments ad vocals clearly distinguishable and the response extended at both ends be it at 40Hz base level and 15K top end from one anther same as the Grundig. Unbelievable. One other thing you would notice which is that if you turn the volume up (which I rarely do since the best way to listen is when it is quiet in the eening) the Grundig would continue to drive the yamaha speaker all the way up to 50 watts RMS and amplify 50 wats RMS from 40 HZ to 20k with absolutely no distrotion and or clipping - to the extent that it was the first time I loved hearing music at high volume. Needless to say being an engineer I probed into this more and the agent gave me the specks and graphs. And ther you hae it. When Grundig say distortion is .01. it is measured from the Pre Amp in to speaker out not from Main amp in to speaker out. Secondly the gaphs clearly show a gain of 55RMS from +/- only 2db from 20HZ ro 20K wih distrotio remaining .01. When Phips launched the first CD player - which had a far better signal to noise ration apart from giving recording studios the free hand to record the extreme ends of the audio spectrum - the difference between the Yamaha and the Grundig became huge. I have the R45 till this very day so i is now over 40 years old. Later in life I bought a Yamaha A1 for surroud sound. During that era, as soon as you see the T0-3 power transistors this Yamaha used, you would knew that good money was spent on the components. TO-3 transistors with their large metal enclosure dissipate heat a lot better than the TO220 and other alternatives. But they cost a fortune so they were soon phased out. And still this A1 was no match for the 1979 Grundig. That is my story and what I can say is that although modern amplifier technology has been improved in eery regard, in terms of capacitor, crossover network, transformer, driver material, and digital-to-analog conversion technology over the last five decades; you can still hear the difference if you benchmark with vintage Hi End genuine old amps that only use transistors and that have been sericed and kept running as per blueprint. What I miss is the beautiful looks of Yamaha since the looks of Grundig were so good.
Wow! Thanks so much for sharing! I am not likely to get any Grundig gear in to test, but one never knows...Aside from the amount of low level hum, and maybe a very small turn on "thump" most vintage amps I have looked at sound good.
You are welcomed. Hi, I wish I could give you this Grundig R45 for you to benchmark. It is a bit unique and was produced first in 1979 but they stopped 2 years later in 1981 since it was not economically feasable to produce it in large numbers AND SELL THEM too. Just for guidance £100 in 1979 is equivalent in purchasing power to about £623.93 today And this R45 retailed for over 400STG in 79. So it was expensive. When connected to a Revox CD player (since the source is important) - No hum or hiss at all even if you push the volume to full with the player paused. Needless to say I was curious at the time and opened it up. You would find the pre amp completely covered and enclosed in a metal box which has 6 prongs going straight into the circuit board neutral and soldered. Fortunately the components are all top class mostly made by General Insruments Europe, Texas Instruments, Rubycom caps and to very low tollerances. It proved to be absolutely reliable and connot cmpehend how it is still going strong after 40 years. @@vintageaudioreview
@@politicalfoolsandhorses THe R45 is probably holding up so well because they used quality components with good workmanship. Maybe my buddy Ian has a grundig of sorts floating around..
@@upupandaway5646 Well thanks for taking the time to comment! The owner sold it (he buys, sells and keeps) and I guess the person he sold it to is very happy with it. That style of Pioneer gear has not really caught on (yet), but I think it has a nice look to it and is typically affordable. Making these videos is a labor of love I suppose, and the channel growing so I guess many appreciate the videos.
There are a few Pioneer from around that time that seem similar- and are a pain to work on- have not seen the SX-V90 but it would not surprise me. Thanks for the comment
I love my Pioneer A-9 so much that it is not going anywhere. It is very detailed, and has a nice sibilance to the high registers while being slightly warm. I find that the amplifier plays well with my Q Acoustics 3020i bookshelf speakers but powering Q Acoustics Concept 500 floor-standing speakers with that same amp would blow me away with the synergy and sonic qualities.
I love seeing lots of discrete transistors, as opposed to a sea of cheap IC's. This vid reminded me of how good Japanese quality was. Well, it probably still would be, but even the Japanese are having things made in China nowadays...
Thanks for the nice comment! I like seeing lots of discrete transistors except on the A9 and some of its brethren, where you have to unsolder maybe 8 of them in order to remove the heatsink they are all mounted to in order to replace components under the heatsink fins. A bit different than on the receiver video I am working now....
I have an A 10 which is identical in appearance and functions etc to the A 9 .I have been unable to find any reference to this model in my searches any info on how to find reviews manuals for this model would be much appreciated . Thanks ,Andy.
Thanks for the comment! I had not thought of any MCS gear until your comment. But I remembered it was sold by JC Penny back in the day w/out any hesitation. It does resemble the Pioneer. Back in the 90's I had a list that showed, by UL code #, what company made a certain product, but that list has long disappeared. Most likely JCP had several companies make product for them- apparently Technics was one.
@@vintageaudioreview Thanks for the info - didn't know JCPenney outsourced MSC to so many OEMs. I love the design. Way ahead of its time even by today's standards and it still looks modern (especially on vintage channel :)))) ). They do look alike (Pioneer and MCS) - seems like done by the same designer. Great videos, enjoy watching it, very informative and professional. Glad I've discovered it, thanks !
Very important question -Do you measure the bias voltage on pins 18 ,19, 20, 21 on the amplifier board GWH-146 (GWH-148 listed in the service manual) , before to measure the distortion , to be sure that the bias is properly adjusted and you not have a crossover distortion? How many miliwolts are the bias 5 minutes after the cold start up and after 20 minutes after cold start up?
At that time I probably did not adjust the bias or DC offset, unless I mentioned it in the video, which I am not sure if I did. On one of the Pioneer amps I did. Typically, if the amp's THD looks close or better than the old spec I would not do it. Doing a before and after bias/offset adjust would make a nice "segment" to a video, and I will keep that in mind- in fact, I have an integrated tube amp in that might work with. I would follow the procedures in the service manual for any adjustments. Thanks for taking the time to ask this!
@@vintageaudioreview Thank you for the reply sir. This amplifier is NSA with a high frequency DC servo bias. Which is a rather strange thing. I have several such amplifiers, I tried to set the bias on all of them exactly as it is in the service description - But on all amplifiers, the bias after a few minutes drops between .063V to 0.068V. In one place it is called variable bias, others say that if it does not sit at 75 millivolts, it is a failure. There is no evidence for either one. The most important thing is that these amplifiers, even with a bias of 0.0 Volts, do not give on the oscilloscope crossover distortion. And so if you still have this amp I would like to ask if you could measure its bias after it warms up and also measure its distortion at 0.0 Volt bias. The result will stir up a lot of discussion for sure
@@johnadams9041 The amp was returned to my friend, who sold it. Unfortunately, it is difficult to say what the bias should be set to on an older amp like this. Sometimes I will wait for however long it takes for the reading to stabilize with the inputs shorted and the amp hooked up to 8ohm loads. Might take 5-15min. Then I would let it cool down and see what happens when I power it on. I doubt there is going to be much difference between 63mv and 75mv- would have to watch the THD reading on my analyzer for the lowest value and see what the bias is set for at that point.
@@vintageaudioreview I've tried a million different ways to adjust this bias on not one but several of these amps. Also, in the service description, they say to have no load on the output but I also try bout ways. The result is always the same. The bias drops from 75 mV to 63 mV which is equal to 50+(75-50)/2=62.5 mV =63 mV approx which looks to me likes a middle point for self variation between 50mV and 75 mV . Since this always happens to all amplifiers, original and repaired, it cannot be accidental and cannot be a defect. If the bias is persistently adjusted and increased with VR2 and VR4, it simply stays at 75 mV for a longer time, but then it drops again, with the only result being the increasingly strong heating of the OPS, and finally it comes to turning VR to max to a very high temperature of the OPS and reducing the power of the amp and the quality of the music. And we have to get him out of this condition. The question is whether this bias is a variable that is set to a minimum value 50mV and then varies itself depending on the input signal???
@@johnadams9041 You certain have spent a lot of time with this issue. Unfortunately, the nuances of the biasing are beyond what understand or choose to research beyond a certain point. I am able to look at the performance of the amp in real time and if it is meeting or close to its spec, and is not running hot with say it putting out 5w/8ohms for 45min or so, I would call it a day. I would expect it to run on the hot side if I pushed it to its max rated output power using a test signal, but the amp should run cooler with actual music.
It has two 470uf 100v caps in the +/-80Vdc rails as well as two 470uf 63v caps in the +/-40vdc supplies. There are two 15000uf 71v caps on the +/- 62vdc rails. Plus there are some smaller caps in the power supply as well.
Nice kit. Lovely classic Pioneer. Too bad no pre-outs. Good to see people hold on to pieces like this one.
Not having preouts is a little negative for some users, indeed. This particular style of Pioneer has not gotten the desirability status of the 70's gear, but who knows what the future may bring...thanks for commenting!
Excelente video, yo tengo el A-8 más pequeño, realmente son unos sobresalientes amplificadores con una distorsión casi imperceptible del 0.003% y un sonido espectacular. Fueron los antecesores de la serie Elite. Tengo amigos que tienen Mcintosh de $5000 y el mi A-8 que apenas me costó $200 los supera tranquilamente. Saludos desde Caracas, Venezuela.
Thanks so much for the comment. That style of Pioneer is not as popular for whatever reason, but most folks seem to like them and you are not hearing 0.003% THD, that's for sure!
Great work! Thx for uploading!!
Thanks for the encouragement!
in my opinion , looks so classy design , minimalist but the lights looks like high tech classic .
Thanks for taking a moment to comment! I have always liked the looks of this era of Pioneer gear and expect one day they will become more collectible. They are fine as long as they are working!
Nice amp & review!
I appreciate your comment!
I am now 0ver 70 and have loved listening (and playing music today using Roland equipment) since I was 12. So I moved to audiophile-grade recordings and equipment to reproduce music as soon after I gaduated in electonics systems and got a job. I changed my amp in 1973 to the Yamaha CA 1000 - and in 1974 bought the Yamaha NS 1000 speakers, Dual tuntable - and was so proud of them. BUT here is what happened. In 1979 I went for traiing to Germany in digital electronics and stayed with a friend,s family. On one occasion my friend Dirk switched on his stereo in their siting room, we were in the kitchen, and suddenly I heard the kind of absulutely clear and hi fidelity which never heard before. To cut it short it was a Grundig R45A Tuner Amp hooked to Grundig 1000 speakers. I bought a Phase 4 Decca record the ext day. No usually you would need to switch two amps next to each oher while paying the same record to maybe hear a noticable difference. But not this time. It was clearly superior by any measure. Again to cut it short on my return to Malta I told the Grundig agent about my experience and he willingly lended me an R45a. The result was the following. The fidelity and sound difference was huge and easily distinguished by my wife who loves the tunes not the fidelty. Wow she would say when I switch from on to the other. So was it the speakers, the amp, the preamp......... Cut it short. Use the preamp of the Grundig and feed it into the main amp of the Yamaha - and the Yamaha would chane to being as clear and sharp with all instruments ad vocals clearly distinguishable and the response extended at both ends be it at 40Hz base level and 15K top end from one anther same as the Grundig. Unbelievable. One other thing you would notice which is that if you turn the volume up (which I rarely do since the best way to listen is when it is quiet in the eening) the Grundig would continue to drive the yamaha speaker all the way up to 50 watts RMS and amplify 50 wats RMS from 40 HZ to 20k with absolutely no distrotion and or clipping - to the extent that it was the first time I loved hearing music at high volume. Needless to say being an engineer I probed into this more and the agent gave me the specks and graphs. And ther you hae it. When Grundig say distortion is .01. it is measured from the Pre Amp in to speaker out not from Main amp in to speaker out. Secondly the gaphs clearly show a gain of 55RMS from +/- only 2db from 20HZ ro 20K wih distrotio remaining .01. When Phips launched the first CD player - which had a far better signal to noise ration apart from giving recording studios the free hand to record the extreme ends of the audio spectrum - the difference between the Yamaha and the Grundig became huge. I have the R45 till this very day so i is now over 40 years old. Later in life I bought a Yamaha A1 for surroud sound. During that era, as soon as you see the T0-3 power transistors this Yamaha used, you would knew that good money was spent on the components. TO-3 transistors with their large metal enclosure dissipate heat a lot better than the TO220 and other alternatives. But they cost a fortune so they were soon phased out. And still this A1 was no match for the 1979 Grundig. That is my story and what I can say is that although modern amplifier technology has been improved in eery regard, in terms of capacitor, crossover network, transformer, driver material, and digital-to-analog conversion technology over the last five decades; you can still hear the difference if you benchmark with vintage Hi End genuine old amps that only use transistors and that have been sericed and kept running as per blueprint. What I miss is the beautiful looks of Yamaha since the looks of Grundig were so good.
Wow! Thanks so much for sharing! I am not likely to get any Grundig gear in to test, but one never knows...Aside from the amount of low level hum, and maybe a very small turn on "thump" most vintage amps I have looked at sound good.
You are welcomed. Hi, I wish I could give you this Grundig R45 for you to benchmark. It is a bit unique and was produced first in 1979 but they stopped 2 years later in 1981 since it was not economically feasable to produce it in large numbers AND SELL THEM too. Just for guidance £100 in 1979 is equivalent in purchasing power to about £623.93 today And this R45 retailed for over 400STG in 79. So it was expensive. When connected to a Revox CD player (since the source is important) - No hum or hiss at all even if you push the volume to full with the player paused. Needless to say I was curious at the time and opened it up. You would find the pre amp completely covered and enclosed in a metal box which has 6 prongs going straight into the circuit board neutral and soldered. Fortunately the components are all top class mostly made by General Insruments Europe, Texas Instruments, Rubycom caps and to very low tollerances. It proved to be absolutely reliable and connot cmpehend how it is still going strong after 40 years. @@vintageaudioreview
@@politicalfoolsandhorses THe R45 is probably holding up so well because they used quality components with good workmanship. Maybe my buddy Ian has a grundig of sorts floating around..
I picked this up at auction for 35.00 canadian. It's a lovely amp
That is a heck of a buy- I'm assuming it worked w/out any repairs!
@@vintageaudioreview I just cleaned it out cleaned pods and works wonderfully. Thank you for great videos
@@upupandaway5646 Well thanks for taking the time to comment! The owner sold it (he buys, sells and keeps) and I guess the person he sold it to is very happy with it. That style of Pioneer gear has not really caught on (yet), but I think it has a nice look to it and is typically affordable. Making these videos is a labor of love I suppose, and the channel growing so I guess many appreciate the videos.
👍🏻😎 Looks pretty much like a Pioneer SX-V90 under the hood.
There are a few Pioneer from around that time that seem similar- and are a pain to work on- have not seen the SX-V90 but it would not surprise me. Thanks for the comment
solid amp
Thanks for the comment and I agree!
I love my Pioneer A-9 so much that it is not going anywhere. It is very detailed, and has a nice sibilance to the high registers while being slightly warm. I find that the amplifier plays well with my Q Acoustics 3020i bookshelf speakers but powering Q Acoustics Concept 500 floor-standing speakers with that same amp would blow me away with the synergy and sonic qualities.
Thanks for taking the time to share your enthusiasm for the A-9. As long as it is working there is no reason for it to go!
I love my A9 vintage in gold colour, need to sort out left channel blown i think, will get it fixed soon 😢.
Good luck with the repair- they are not easy to work on in I remember correctly. I appreciate the comment!
I love seeing lots of discrete transistors, as opposed to a sea of cheap IC's. This vid reminded me of how good Japanese quality was. Well, it probably still would be, but even the Japanese are having things made in China nowadays...
Thanks for the nice comment! I like seeing lots of discrete transistors except on the A9 and some of its brethren, where you have to unsolder maybe 8 of them in order to remove the heatsink they are all mounted to in order to replace components under the heatsink fins. A bit different than on the receiver video I am working now....
Even a US built Japanese amplifier would be a breathe of fresh air.
I have an A 10 which is identical in appearance and functions etc to the A 9 .I have been unable to find any reference to this model in my searches any info on how to find reviews manuals for this model would be much appreciated . Thanks ,Andy.
This is the only info I could find about the A10:
www.hifiengine.com/manual_library/pioneer/a-10-k.shtml
Its futuristic look reminds me so much my MCS 3237 - I was under impression MCS made by NEC around that time beginning of 80th, but maybe by Pioneer?
Thanks for the comment! I had not thought of any MCS gear until your comment. But I remembered it was sold by JC Penny back in the day w/out any hesitation. It does resemble the Pioneer. Back in the 90's I had a list that showed, by UL code #, what company made a certain product, but that list has long disappeared. Most likely JCP had several companies make product for them- apparently Technics was one.
@@vintageaudioreview Thanks for the info - didn't know JCPenney outsourced MSC to so many OEMs. I love the design. Way ahead of its time even by today's standards and it still looks modern (especially on vintage channel :)))) ). They do look alike (Pioneer and MCS) - seems like done by the same designer. Great videos, enjoy watching it, very informative and professional. Glad I've discovered it, thanks !
Very important question -Do you measure the bias voltage on pins 18 ,19, 20, 21 on the amplifier board GWH-146 (GWH-148 listed in the service manual) , before to measure the distortion , to be sure that the bias is properly adjusted and you not have a crossover distortion? How many miliwolts are the bias 5 minutes after the cold start up and after 20 minutes after cold start up?
At that time I probably did not adjust the bias or DC offset, unless I mentioned it in the video, which I am not sure if I did. On one of the Pioneer amps I did. Typically, if the amp's THD looks close or better than the old spec I would not do it. Doing a before and after bias/offset adjust would make a nice "segment" to a video, and I will keep that in mind- in fact, I have an integrated tube amp in that might work with. I would follow the procedures in the service manual for any adjustments. Thanks for taking the time to ask this!
@@vintageaudioreview Thank you for the reply sir. This amplifier is NSA with a high frequency DC servo bias. Which is a rather strange thing. I have several such amplifiers, I tried to set the bias on all of them exactly as it is in the service description - But on all amplifiers, the bias after a few minutes drops between .063V to 0.068V. In one place it is called variable bias, others say that if it does not sit at 75 millivolts, it is a failure. There is no evidence for either one. The most important thing is that these amplifiers, even with a bias of 0.0 Volts, do not give on the oscilloscope crossover distortion. And so if you still have this amp I would like to ask if you could measure its bias after it warms up and also measure its distortion at 0.0 Volt bias. The result will stir up a lot of discussion for sure
@@johnadams9041 The amp was returned to my friend, who sold it. Unfortunately, it is difficult to say what the bias should be set to on an older amp like this. Sometimes I will wait for however long it takes for the reading to stabilize with the inputs shorted and the amp hooked up to 8ohm loads. Might take 5-15min. Then I would let it cool down and see what happens when I power it on. I doubt there is going to be much difference between 63mv and 75mv- would have to watch the THD reading on my analyzer for the lowest value and see what the bias is set for at that point.
@@vintageaudioreview I've tried a million different ways to adjust this bias on not one but several of these amps. Also, in the service description, they say to have no load on the output but I also try bout ways.
The result is always the same. The bias drops from 75 mV to 63 mV which is equal to 50+(75-50)/2=62.5 mV =63 mV approx which looks to me likes a middle point for self variation between 50mV and 75 mV . Since this always happens to all amplifiers, original and repaired, it cannot be accidental and cannot be a defect. If the bias is persistently adjusted and increased with VR2 and VR4, it simply stays at 75 mV for a longer time, but then it drops again, with the only result being the increasingly strong heating of the OPS, and finally it comes to turning VR to max to a very high temperature of the OPS and reducing the power of the amp and the quality of the music. And we have to get him out of this condition. The question is whether this bias is a variable that is set to a minimum value 50mV and then varies itself depending on the input signal???
@@johnadams9041 You certain have spent a lot of time with this issue. Unfortunately, the nuances of the biasing are beyond what understand or choose to research beyond a certain point. I am able to look at the performance of the amp in real time and if it is meeting or close to its spec, and is not running hot with say it putting out 5w/8ohms for 45min or so, I would call it a day. I would expect it to run on the hot side if I pushed it to its max rated output power using a test signal, but the amp should run cooler with actual music.
This amp did not have capacitors in the main supply.
It has two 470uf 100v caps in the +/-80Vdc rails as well as two 470uf 63v caps in the +/-40vdc supplies. There are two 15000uf 71v caps on the +/- 62vdc rails. Plus there are some smaller caps in the power supply as well.
@@vintageaudioreview He meant "No couplig capacitors"... I think
Классный усилитель!👍 У меня в коллекции его младший брат А6, отлично работает!)
Let's hope it continues to work well! thanks for the comment