1DIFFQC amplifier - Page 3

evette · 16th September 2012, 12:06 AM

IThis amp t,s 33K per rail. This amp can really swing the current. Evette

evette · 16th September 2012, 12:07 AM

I,m sorry but this silly computer is acting up again. Evette

Kindhornman · 16th September 2012, 12:20 AM

So am I reading this correctly that we are talking about 66,000ufd per amplifier? Plus a 500Vas transformer per channel at what voltage rating?

evette · 16th September 2012, 02:22 AM

Yes you are reading correctly. This is my personal choice because I like big amps. Evette

Nico Ras · 16th September 2012, 09:42 AM

Quote:

Originally Posted by evette

Yes you are reading correctly. This is my personal choice because I like big amps. Evette

Is there any valid reason for the choice of transformer and reservoir cap size?

Would 10 000uF be worse and 100 000uF be better or maybe not. Is 500VA enough for powering 150 watt per channel amp with 33 000 uF per rail.

Did you make any useful measurements to confirm if your choice is good, bad or just a personal preference?

evette · 16th September 2012, 02:02 PM

Hello Mr. Nico Ras,,,This 1 channel that I,ve built so far is my test amp for this board each amp per channel will have a total of 66k mfd and a 500va power tranformer in addiction I,ve Moded the output slighty, The tip,s 142 is a good transistor, but there are better devices for this device. check the spec,s for a mjh6284 then you,ll see what I mean,, Regards Evette

Kindhornman · 16th September 2012, 04:23 PM

Evette,
The On-Semicondutor MJH6284 do not look like they are readily available. Did you have these sitting around for some time or are they still available for purchase? Anybody know the answer to this? I see both Digikay and Mouser do not list a price for this item. Anyone with a source or is there an even better current part that we should be looking at. Lastly do we need to make any changes to any values on the board to take maximum advantage of a change such as this? I see that the dc power should be increased with this transistor but what else should change?

Steven

evette · 16th September 2012, 05:09 PM

Hello Mr. Kindhornman, ONSEMI still list them in their inventory You can check their website. I,m still using my devices that I bought in 2005 and 2006. Regards evette

Nico Ras · 16th September 2012, 05:30 PM

Quote:

Originally Posted by evette

Hello Mr. Nico Ras,,,This 1 channel that I,ve built so far is my test amp for this board each amp per channel will have a total of 66k mfd and a 500va power tranformer in addiction I,ve Moded the output slighty, The tip,s 142 is a good transistor, but there are better devices for this device. check the spec,s for a mjh6284 then you,ll see what I mean,, Regards Evette

Dear Evette,

what I meant was and I am very interested in knowing how the amplifier performs with the choice of your power supply, and what inspired your choices, was there any calculations that you followed or experience that caused you to choose the specific value.

Were you influenced by other constructors or Harrison or read somewhere that gave rise to your reasoning. No disrespect meant at all Evette I am curious because of all that is said in the Power Supply tread.

evette · 16th September 2012, 07:12 PM

Hello Mr.Nico Ras, first of all I should explain that this 1 channel was built using all junk parts that were collected over many years you know old tv sets radios anything I couls salvage. I haven,t collected information from others or mr. harrison. Nor have I read any power supply thread. The changes I made werte because I wanted to really open this amp up,,The pcb,s that Mr. Harrison was so kind to give to me I felt that he had given me the tools to begin with so I simply took it to the next level. Evette

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16th September 2012, 12:06 AM	#21
evette diyAudio Member Join Date: Jun 2006	IThis amp t,s 33K per rail. This amp can really swing the current. Evette

16th September 2012, 12:07 AM	#22
evette diyAudio Member Join Date: Jun 2006	I,m sorry but this silly computer is acting up again. Evette

16th September 2012, 12:20 AM	#23
Kindhornman diyAudio Member Join Date: Aug 2012 Location: Los Angeles, California	So am I reading this correctly that we are talking about 66,000ufd per amplifier? Plus a 500Vas transformer per channel at what voltage rating?

16th September 2012, 02:22 AM	#24
evette diyAudio Member Join Date: Jun 2006	Yes you are reading correctly. This is my personal choice because I like big amps. Evette

16th September 2012, 02:02 PM	#26
evette diyAudio Member Join Date: Jun 2006	Hello Mr. Nico Ras,,,This 1 channel that I,ve built so far is my test amp for this board each amp per channel will have a total of 66k mfd and a 500va power tranformer in addiction I,ve Moded the output slighty, The tip,s 142 is a good transistor, but there are better devices for this device. check the spec,s for a mjh6284 then you,ll see what I mean,, Regards Evette

16th September 2012, 04:23 PM	#27
Kindhornman diyAudio Member Join Date: Aug 2012 Location: Los Angeles, California	Evette, The On-Semicondutor MJH6284 do not look like they are readily available. Did you have these sitting around for some time or are they still available for purchase? Anybody know the answer to this? I see both Digikay and Mouser do not list a price for this item. Anyone with a source or is there an even better current part that we should be looking at. Lastly do we need to make any changes to any values on the board to take maximum advantage of a change such as this? I see that the dc power should be increased with this transistor but what else should change? Steven

16th September 2012, 05:09 PM	#28
evette diyAudio Member Join Date: Jun 2006	Hello Mr. Kindhornman, ONSEMI still list them in their inventory You can check their website. I,m still using my devices that I bought in 2005 and 2006. Regards evette

16th September 2012, 07:12 PM	#30
evette diyAudio Member Join Date: Jun 2006	Hello Mr.Nico Ras, first of all I should explain that this 1 channel was built using all junk parts that were collected over many years you know old tv sets radios anything I couls salvage. I haven,t collected information from others or mr. harrison. Nor have I read any power supply thread. The changes I made werte because I wanted to really open this amp up,,The pcb,s that Mr. Harrison was so kind to give to me I felt that he had given me the tools to begin with so I simply took it to the next level. Evette