Hi,
@matsurus
Thanks for the schematics.
@m0rten
Many Thanks for these information, I understand better. It is an another schematics MA-9S2. My version is very different from the MA-9S2. It is a simplistic version of this amplifier : other transistors, other polarization. In definitive I didn't like the sound, false in the treble. Honestly I transformed my amplifier like a A60, it works better to my ears.
@Berlusconi
I didn't measure yet the response of my "A60" with my oscilloscope. I have to finish to change the drivers with MJE15030/15031. It is A940/C2073 which I have some doubts.
I think no comparison is possible A60 with L20SE, you compare a Ferrari to a Fiat 500 🙂
The A60 is a high performance complete solution, works well ! The input stage has more performance with current feedback, lower distortion and higher bandwidth.
My next plan is to transform a A60+ with MOSFET like an original Accuphase A60.
@matsurus
Thanks for the schematics.
@m0rten
Many Thanks for these information, I understand better. It is an another schematics MA-9S2. My version is very different from the MA-9S2. It is a simplistic version of this amplifier : other transistors, other polarization. In definitive I didn't like the sound, false in the treble. Honestly I transformed my amplifier like a A60, it works better to my ears.
@Berlusconi
I didn't measure yet the response of my "A60" with my oscilloscope. I have to finish to change the drivers with MJE15030/15031. It is A940/C2073 which I have some doubts.
I think no comparison is possible A60 with L20SE, you compare a Ferrari to a Fiat 500 🙂
The A60 is a high performance complete solution, works well ! The input stage has more performance with current feedback, lower distortion and higher bandwidth.
My next plan is to transform a A60+ with MOSFET like an original Accuphase A60.
I finished to test my "A60", works very very well to my ears ! A true high end amplifier. Very surprised with the quality of the treble. Never thought, it is possible with a power stage BJT polarized class B. Some progress were done with the new BJT, I have old reference like BDV6XX, TIPxx. But the beasts get very hot, I need to put them on a bigger radiators, the provided radiators are too small.
More info, found with Google.
1. About the M9S2 clone : Marantz M9 clone in bridge : "Someone on diyaudio has written that the measured slew rate is very low 4V/uS for a current feedback amplifier".
2. Service manual of the Accuphase A60 : Accuphase A60 Electrical Diagram
More info, found with Google.
1. About the M9S2 clone : Marantz M9 clone in bridge : "Someone on diyaudio has written that the measured slew rate is very low 4V/uS for a current feedback amplifier".
2. Service manual of the Accuphase A60 : Accuphase A60 Electrical Diagram
Interesting, so Marantz MA-9S2 is current feedback design.
This actually makes me more interested in hearing A60, since it also has CF.
I wonder do they share similar topology, as a beginner amplifierbuilder i cannot verify is this true or not but it is interesting.
My friend had MA-9S2 amplifier, he sold them years ago but after that he has always regretted it. No matter what he has tried, very expensive tubes, class A, Class D, all very high-end stuff, he never has had same quality as he had from MA-9S2..
Some might have little better treble, or bit more open but as a completely package with control and speed & open sound & civility, never same level..
I admit i was bit sceptical because of feedback since i personally like nonfeedback amplifiers, but i also have heard very good amplifiers that had feedback included tastefully and carefully into design, and those were very good.
I will build A60 test amplifier and report back, does it have similar "open organic" sound that i like in nonfeedback design..
This actually makes me more interested in hearing A60, since it also has CF.
I wonder do they share similar topology, as a beginner amplifierbuilder i cannot verify is this true or not but it is interesting.
My friend had MA-9S2 amplifier, he sold them years ago but after that he has always regretted it. No matter what he has tried, very expensive tubes, class A, Class D, all very high-end stuff, he never has had same quality as he had from MA-9S2..
Some might have little better treble, or bit more open but as a completely package with control and speed & open sound & civility, never same level..
I admit i was bit sceptical because of feedback since i personally like nonfeedback amplifiers, but i also have heard very good amplifiers that had feedback included tastefully and carefully into design, and those were very good.
I will build A60 test amplifier and report back, does it have similar "open organic" sound that i like in nonfeedback design..
Such modules are not in short supply, what is so interesting about them, tell me? They were used (and are still being used) in ancient times by FM ACOUSTICS amplifiers. The Chinese have learned how to make them. 
https://aliexpress.ru/item/32947883...7673b74a3aab1ac395471acba6&sku_id=66200106323 https://aliexpress.ru/item/10050023...&terminal_id=9332537673b74a3aab1ac395471acba6
https://aliexpress.ru/item/32947883...7673b74a3aab1ac395471acba6&sku_id=66200106323 https://aliexpress.ru/item/10050023...&terminal_id=9332537673b74a3aab1ac395471acba6Ah little misunderstanding..
The modules itself are not that interesting, but possibly link to MA9-S2 is.
(though it seems that it might not be real link after all..)
The modules itself are not that interesting, but possibly link to MA9-S2 is.
(though it seems that it might not be real link after all..)
I think meaning sometimes get lost in the translation..
I put information about MA9-S2 because i wanted to see if there would be link between A60 and MA9, shared schematic and other parts (someone with more knowledge would verify is there connection) basically outsourcing knowledge..
We are getting off-topic, i will come back once i have built a60 test amplifier..
I put information about MA9-S2 because i wanted to see if there would be link between A60 and MA9, shared schematic and other parts (someone with more knowledge would verify is there connection) basically outsourcing knowledge..
We are getting off-topic, i will come back once i have built a60 test amplifier..
Hello everyone. I want to remove the relay volume control and other gadgets on the A60, there is a preliminary one with the same control and two outputs for 2 amplifiers, the same for Dartzil. I want to leave it only as a power amplifier. But along with it, the temperature protection is also removed. Please advise a simple protection circuit for exceeding the temperature of the outputs, preferably on KSD-0.1 H thermostats (I have them). Maybe like turning on a relay and turning off the power?🙄
Do you have a regulator from Antecom? Is the power supply also from this? So maybe you can leave it in place and buy another one if necessary?
Hello friends, i bought the a60 normal version but i only have at home 2 transformers 2x39 vac witch gives -+55vdc.
is it ok to use or is too much??
Thks for the help.
is it ok to use or is too much??
Thks for the help.
The description for the A60 says up to 2x42V AC. Provide it with good large radiators. If you don’t need more power, buy a 2x33V transformer.
Thanks @Topa41 for this useful link. Also it will be virtually impossible to find an adequate electrolytic capacitor with just 25mm diameter.
@pistollero : Carefully gringo with high voltages, otherwise there will be: Bang! Bang!
https://aliexpress.ru/item/10050020...l.0.0.267a4aa6Djm4oJ&sku_id=12000018558174274 These 22000uFX63v will fit. Size 35x70.
Attachments
Thanks,
That was my unreliable memory: I was sure that capacitors were just 25 mm. I have measured them right now, in my workshop: 35mm is correct and there must be enough available high voltage alternatives.
This was helpful to me
Always happy to help.