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Congratulations!
Such anniversaries are a great opportunity to honor our predecessors, contemplate who we are and how to preserve this world for our descendants!
It is so great to have sincere friends.
Tomorrow, I will say few words about our project.
Enjoy this great spring day.
Congratulations!
Such anniversaries are a great opportunity to honor our predecessors, contemplate who we are and how to preserve this world for our descendants!
It is so great to have sincere friends.
Tomorrow, I will say few words about our project.
Enjoy this great spring day.
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I like to communicate with you friends, I learned a lot of useful things from you. Nobody swears, and we help each other.🙂
I have tried NJW, MJL and 2SA/2SC. All are fine because overall design seems to be fine: perfect square wave response, no low frequency attenuation, frequency response flat like pancake... besides yours look like original stuff. Just do it. 😎
Hello,
I am just on the lookout for an interesting project to build an amplifier to replace my Rotel RA-935BX.
Below is the schematic of my Rotel's power amplifier. Will this A60 clone be a leap in quality compared to the Rotel?
I am just on the lookout for an interesting project to build an amplifier to replace my Rotel RA-935BX.
Below is the schematic of my Rotel's power amplifier. Will this A60 clone be a leap in quality compared to the Rotel?
If you listen to such great musicians, the A60 will not leave your rotel a chance.
@Paroxod4 and @Erlend Sæterdal
You have made my day dear Friends.
I am delighted to see you hanging around.
Right now I have replied one PM with advice how to quickly build and test A60. PMs are useless except for a single person, so let's make it public.:
Q:
My question is:
-How much smoother was darzteel compared to A60?
-Do you think i can make A60 as smooth as dartzeel? Any tips?
A:
I have built both Dartzeel and A60, several pairs. A60 is incomparably better by both sound quality and measurements. It has great frequency response and almost ideal square wave response over the entire audible region.
If I may suggest you, do as follows:
1. Purchase a smaller A60 without the output transistors and electrolyte capacitors. In China this stuff is 100% fake. I have used Vishays with diameter 30mm. I also used different original output transistors, both On Semi and Toshibas.
A pair of A60 boars without transistors and capacitors cost less than 50 Euro, so there is nothing to regret. You still can de-solder valuable components. (WEILIANG AUDIO A60 power amplifier board price of one pair cost €46.76)
2. Now use two power transformers and two small separate 12V transformers (or one with tw0 12V coils) and that's all.
Somewhere back in the thread I have shown how to connect amplifier without ground loops.
For initial tests you may use smaller heat sink at low bias and if you like the amplifier, buy large heat sinks. If you need more power you still can purchase larger A60+ and re-use valuable capacitors and transistors.
You will end-up with a great amplifier.
You have made my day dear Friends.
I am delighted to see you hanging around.
Right now I have replied one PM with advice how to quickly build and test A60. PMs are useless except for a single person, so let's make it public.:
Q:
My question is:
-How much smoother was darzteel compared to A60?
-Do you think i can make A60 as smooth as dartzeel? Any tips?
A:
I have built both Dartzeel and A60, several pairs. A60 is incomparably better by both sound quality and measurements. It has great frequency response and almost ideal square wave response over the entire audible region.
If I may suggest you, do as follows:
1. Purchase a smaller A60 without the output transistors and electrolyte capacitors. In China this stuff is 100% fake. I have used Vishays with diameter 30mm. I also used different original output transistors, both On Semi and Toshibas.
A pair of A60 boars without transistors and capacitors cost less than 50 Euro, so there is nothing to regret. You still can de-solder valuable components. (WEILIANG AUDIO A60 power amplifier board price of one pair cost €46.76)
2. Now use two power transformers and two small separate 12V transformers (or one with tw0 12V coils) and that's all.
Somewhere back in the thread I have shown how to connect amplifier without ground loops.
For initial tests you may use smaller heat sink at low bias and if you like the amplifier, buy large heat sinks. If you need more power you still can purchase larger A60+ and re-use valuable capacitors and transistors.
You will end-up with a great amplifier.
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I discover this thread a little late. I bought this amp to test it because it has a current feedback, DC coupling.
2SC5200 / 2SA1943 Module Amplificateur Mono Class AB 250W 4 Ohm
The schematic of the amplifier, miss some functions:
Different to A60 but look to be a clone ?
The problem with the sound, something subjectively wrong with the treble, no clear treble, very curious for this schematic with current feedback and dc coupling.
The transistors in my module are the 2SC945/SA933 2SB646/2SD667, very different from the schematic, not 2SA970/2SC2240... Only the Toshiba C5200/A1943 was keep. I remembered the 2SC945 doesn't sound good in HIFI.
I rebuild the amp with a schematic a little different of my composition and with 2SA921/ SC1880 2SA949/2SC2229 and all are OK now.
It sounds good to my ears now, continue to listen 😉
The A60+ seems to be a monster amp 🙂
2SC5200 / 2SA1943 Module Amplificateur Mono Class AB 250W 4 Ohm
The schematic of the amplifier, miss some functions:
Different to A60 but look to be a clone ?
The problem with the sound, something subjectively wrong with the treble, no clear treble, very curious for this schematic with current feedback and dc coupling.
The transistors in my module are the 2SC945/SA933 2SB646/2SD667, very different from the schematic, not 2SA970/2SC2240... Only the Toshiba C5200/A1943 was keep. I remembered the 2SC945 doesn't sound good in HIFI.
I rebuild the amp with a schematic a little different of my composition and with 2SA921/ SC1880 2SA949/2SC2229 and all are OK now.
It sounds good to my ears now, continue to listen 😉
The A60+ seems to be a monster amp 🙂
Kit 2SA970/2SC2240, MJE15034/MJE15035, Toshiba C5200/A1943 plays amazing. The A60 board on those transistors that you indicated at the beginning in China costs an order of magnitude cheaper. The sellers do not hide that they are worse. 😉
Hi!
Here you can buy A60 PCBs only
Version with 3 output pairs as PCB only
I am a little ashamed to admit I have had both the A60 and MA-9S2 for a while, but not started building them yet. This thread is inspiring, though. I hope to pull myself together and build them soon!
🙂 morten
Here you can buy A60 PCBs only
jerome69:
This schematic is also found in PCBs as clones of Marantz MA-9S2 (finished with 2 output pairs, schematic shown)Version with 3 output pairs as PCB only
I am a little ashamed to admit I have had both the A60 and MA-9S2 for a while, but not started building them yet. This thread is inspiring, though. I hope to pull myself together and build them soon!
🙂 morten
@m0rten & @jerome69
Welcome on board guys and thanks for sharing valuable information.
I am looking forward to hearing from you more. For example: Jerome and I were already discussing issues of another amplifier board - L20SE. Now, Jerome, you have both boards (mee too) and you can directly compare them with oscilloscope. What are your findings? How they do compare?
Besides I have performed comprehensive measurements of several of these LJM "blameless" amplifiers and I know very well that A60 is convincingly better and has everything you need to make complete amplifier - speaker protection, servo, power supply and in addition to that: safe DC coupling. That's huge for so little investment.
I'll get back with more information on this subject.
Welcome on board guys and thanks for sharing valuable information.
I am looking forward to hearing from you more. For example: Jerome and I were already discussing issues of another amplifier board - L20SE. Now, Jerome, you have both boards (mee too) and you can directly compare them with oscilloscope. What are your findings? How they do compare?
Besides I have performed comprehensive measurements of several of these LJM "blameless" amplifiers and I know very well that A60 is convincingly better and has everything you need to make complete amplifier - speaker protection, servo, power supply and in addition to that: safe DC coupling. That's huge for so little investment.
I'll get back with more information on this subject.