Holton's N-Channel amp Exhibits Severe Cross-Conduction at high Input signal. - diyAudio
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Old 9th August 2004, 12:52 PM   #1
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Arrow Holton's N-Channel amp Exhibits Severe Cross-Conduction at high Input signal.

To all Diyers who have built Anthony's N-channel amp.
PLZ
perform this test on ur Holton's N-channel Mosfet amp.

1 Fed a high frequency say 12khz or music signal with HF content to input of ur amp.
2 Donot connect any load or speaker to output , i.e. open circuit operation.
3 Now raise the volume upto threshold of clipping.
4 Check the output mosfets temperature , they start self heating due severe cross- conduction between upper and lower mosfets.
AS far as my experience is concerened the mosfets will get destroyed due to cross-conduction between them.

PLZ correct me If I WERE WRONG.

Regards,
AmPmAn
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Old 9th August 2004, 01:00 PM   #2
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I did almost the same test with my RT75 (scroll down, pictures at the bottom). 200 kHz without not load--> boom--> smoke.

First of all: Don't torture the amp.

Second: Connect speakers!

Third: Play music!

If Mr. Holton wanted to make an amp for these conditions, I'm sure he would have fixed this.
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Old 9th August 2004, 01:14 PM   #3
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Arrow Commentable Thoughts

Quote:
Originally posted by peranders
I did almost the same test with my RT75 (scroll down, pictures at the bottom). 200 kHz without not load--> boom--> smoke.

First of all: Don't torture the amp.

Second: Connect speakers!

Third: Play music!

If Mr. Holton wanted to make an amp for these conditions, I'm sure he would have fixed this.
Hi P-e-r-a-n-d-e-r-s,

In my opinion 200kHz signal is not a worth in an audio amp, instead use 12khz or 18khz signal i.e under audio spectrum, then perform the test and see the death of Mosfets.

Secondly, about torturing the amp.
Suppose in a professional DJ setup if this amp is used and for some reason the speaker is damaged and it get open circuited and finally the amp which is running at full volume will see no load and will brust into smoke in no time , So this test ensures the safety level of the amp.

Whereas In our N-Channel Amp [our own creation] there is nothing like Cross-Conduction ever happened.

Professionalism must be maintained at any cost!
regards,
Ampman
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Old 9th August 2004, 01:34 PM   #4
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Please note that 12kHz full power is not a musical signal, it is a test signal. You can of course design an amp that can survive this, but it will cost extra without giving you better music. Marketing people will often want this.

Why are you sure it is cross-conduction, and not, say, oscillation? Did the amp have an RC-network from speaker/output to ground (10 Ohms + .1 uF)? No? There you go...

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Old 9th August 2004, 01:45 PM   #5
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ampman you are right but you can hardly call Holton's amps for professional PA amps. I think he have designed them for home use or light duty PA. Those who really want a rugged PA amp buys a rather cheap one... or Labgruppen! 6400 watts! Swedish of course, he, he!

www.labgruppen.com
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Old 9th August 2004, 01:47 PM   #6
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Default Professional amps.

Why are you picking on one amp and trashing it against what you make? You don't seem to be sure what is really happening except that it heats up. And was it built by you or friends ?

It might be possible that there are numerous 'professional amps' that can withstand all kinds of torture tests in the field.
If your amp is better designed and built than all those , you are sitting on a gold mine. Get moving and start selling it across the globe.

Meantime we would really like to see pictures of the insides of your amplifiers . Must be great. Something we can all learn from.
After all , the thing that DIY'ers love to do all the time is open up a new product to see what's inside.
We are waiting.
Thanks.
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Old 9th August 2004, 01:49 PM   #7
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Not connecting a speakerload (nor 10Ohm/100nF) feeding a high full-scall high frequency sine is asking for trouble ... with any amp..

But I asume you are correct. Such topologies might exhibit cross-conduction...
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Old 9th August 2004, 01:59 PM   #8
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Arrow Commentable Thoughts

Hi Janneman,
The RC network is present at output and secondly no oscillations are present only severe cross-conduction.

hi P-e-r-a-n-d-e-r-s,
U r rite to some extent but it is dangerous to use this amp in PA or DJ Rigs.

Hi Ashoka the Great,
I am not talking about the competition of mine amp with Anthony's amp, The matter is simple Holton's amp Exhibit Cross Conduction Thats It.Secondly my Friend has built this amp not me.[i dont Copy someone's design , instead of it use my own creative instinct to design a Pro-amp]

hi TSCHrama,

The RC network is present and this topology [which is used by anthony]is not worth in Pro amps.

Regards,
Ampman
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Old 9th August 2004, 02:21 PM   #9
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Man, I wish I could build amps on instinct alone and get rid of that need for knowledge and stuff.
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Old 9th August 2004, 02:22 PM   #10
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Default Re: Professional amps.

Quote:
Originally posted by ashok
Meantime we would really like to see pictures of the insides of your amplifiers . Must be great. Something we can all learn from.
After all , the thing that DIY'ers love to do all the time is open up a new product to see what's inside.
We are waiting.
Thanks.
I have many times thought the same thing. How does your stuff looks like really. Do you have a website, any promotion material, pdf's etc? Much smoke, no fire.

I think you (ampman) should be nice to Mr. Holton and also discuss real topics. Saying that Holton's amps are no good in torture test without knowing what's happening is not very constructive.
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