AL, wouldn't it be preferable to swap al PS section to another board where it's possible to mount 35mm diam cap, or grown up symasym board to mount 35mm diam cap?
May be i could help to route under eagle this section?
May be you can juste keep DTV for this version name. That discribe this version and sound good to hears : AAK symasym 1.3 DTV or simply AAK symasym 1.3 D
regards Marc
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Thanks Hugh, I really appreciate it.
This project has been on my mind for over two years so I'm really happy that I was able to get this far with it and very pleased with the result. I agree, MikeB did as outstanding job, but don't forget Roender, he also deserves a lot credit for the work he did on Mike's conceptual design.
BTW, I was wondering with your expertise if you have any ideas as to why the 2nd harmonic output in my design is less the input? You can find the THD plots in post #31. A friend of mine said he read somewhere that it may be caused by grounding issues causing partial cancellation between input/output. I'm thinking that maybe the power supply and amplifier being on the same board creating short ground paths may have something to do with it.
Regards,
Al
This project has been on my mind for over two years so I'm really happy that I was able to get this far with it and very pleased with the result. I agree, MikeB did as outstanding job, but don't forget Roender, he also deserves a lot credit for the work he did on Mike's conceptual design.
BTW, I was wondering with your expertise if you have any ideas as to why the 2nd harmonic output in my design is less the input? You can find the THD plots in post #31. A friend of mine said he read somewhere that it may be caused by grounding issues causing partial cancellation between input/output. I'm thinking that maybe the power supply and amplifier being on the same board creating short ground paths may have something to do with it.
Regards,
Al
Hi Marc,
The board was designed with the on-board capacitors and rectifiers to make it easier to wire without the wiring clutter of an external PS. Take a look at post #32 to see what I mean. You can see how clean it all wires up, hook up the transformer and your ready to go.
If you would like to use external PS (illustrated in post#34) the on-board capacitors will provide 9400uf of extra AC filtering per rail. You can even use a 0.1ohm or 0.2ohm resistor in place of one of the rectifiers on each rail to provide some additional filtering. Keep in mind that for most applications 9400uF per rail is enough. Now If your using the DTV version driving speakers with 4ohms consistently at high volumes or running the amp with a an Iq of 75mv or above across each transistor pair then an external PS makes sense.
I’ve attached a schematic to illustrate how to configure the on-board PS when using an external PS.
Regards,
Al
The board was designed with the on-board capacitors and rectifiers to make it easier to wire without the wiring clutter of an external PS. Take a look at post #32 to see what I mean. You can see how clean it all wires up, hook up the transformer and your ready to go.
If you would like to use external PS (illustrated in post#34) the on-board capacitors will provide 9400uf of extra AC filtering per rail. You can even use a 0.1ohm or 0.2ohm resistor in place of one of the rectifiers on each rail to provide some additional filtering. Keep in mind that for most applications 9400uF per rail is enough. Now If your using the DTV version driving speakers with 4ohms consistently at high volumes or running the amp with a an Iq of 75mv or above across each transistor pair then an external PS makes sense.
I’ve attached a schematic to illustrate how to configure the on-board PS when using an external PS.
Regards,
Al
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Hi andrew,
Of course, i will. 2010 will be by me a amp test year since i want to try between severel amp model such as symsym, nmos, brother of quasi, lynx and pearhaps one with LME49810 as front end. For my own use 40-50Vdc rail wil be enough so i just have to switch beetwen amp board. I have enough rubish heatsink to play with to.
Marc
Hi Andrew,
I don't disagree with you; you’re basically doubling the rule. What really matters is what sounds best to you.
But there are some commercial designers like Randy Sloan, and Hugh Dhein that pretty closely follow the rule of thumb. In the case of Randy Sloan he states in his book that the rule is overindulgent and goes on and says that 6800uF per rail will provide excellent results from a 100watt RMS amplifiers.
It's a matter of preference.
Regards,
Al
I don't disagree with you; you’re basically doubling the rule. What really matters is what sounds best to you.
But there are some commercial designers like Randy Sloan, and Hugh Dhein that pretty closely follow the rule of thumb. In the case of Randy Sloan he states in his book that the rule is overindulgent and goes on and says that 6800uF per rail will provide excellent results from a 100watt RMS amplifiers.
It's a matter of preference.
Regards,
Al
AL works is good enough to provide customisation. Once can start with standart configuration and test some modification at this level. PS modifications won't touch "circuit spirit", so testing could be easely done and evaluated...I will proceed this way since i have materiel for on hand.
Marc
Marc
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