Burnedfingers,
I'm impressed! Impressed that you needed fans as well. Is that how you got your screen name?
Biggest amp I needed to "let burn" was 600W. I needed a bunch (4) of those Dale 8R 250W resistors on big heatsinks. Anything else needed a 2R load and would pop the panel breaker long before warming anything up.
-Chris
I'm impressed! Impressed that you needed fans as well. Is that how you got your screen name?
Biggest amp I needed to "let burn" was 600W. I needed a bunch (4) of those Dale 8R 250W resistors on big heatsinks. Anything else needed a 2R load and would pop the panel breaker long before warming anything up.
-Chris
Hey Mark,
You lucky guy! I paid full pop for my resistors. How much did you get them for?
Corrosion occurs when oxygen gets at the metal with water present. "Simple Green" is an aqueous cleaner that strips oil - no trouble. I would tend to leave everything sealed if I made that type of load anyway.
-Chris
You lucky guy! I paid full pop for my resistors. How much did you get them for?
Corrosion occurs when oxygen gets at the metal with water present. "Simple Green" is an aqueous cleaner that strips oil - no trouble. I would tend to leave everything sealed if I made that type of load anyway.
-Chris
Water Resistors
Typically used for higher resistances than 4-8ohm, but quite cheap and sturdy. Not suitable for DC use.
Typically used for higher resistances than 4-8ohm, but quite cheap and sturdy. Not suitable for DC use.
Burnedfingers,
I'm impressed! Impressed that you needed fans as well. Is that how you got your screen name?
Biggest amp I needed to "let burn" was 600W. I needed a bunch (4) of those Dale 8R 250W resistors on big heatsinks. Anything else needed a 2R load and would pop the panel breaker long before warming anything up.
Well Chris you got me! Many times I have pushed the single 100Watt load resistor to the point of being able to boil water with it and yes many a time I have burned my fingers. This led to making overkill load resistor setups. Yes, fan cooled to save the fingers. I have had them come in handy with I bench test some of the newer commercial power amplifiers or one running mono bridged at over 1.5 KW.
I'm impressed! Impressed that you needed fans as well. Is that how you got your screen name?
Biggest amp I needed to "let burn" was 600W. I needed a bunch (4) of those Dale 8R 250W resistors on big heatsinks. Anything else needed a 2R load and would pop the panel breaker long before warming anything up.
Well Chris you got me! Many times I have pushed the single 100Watt load resistor to the point of being able to boil water with it and yes many a time I have burned my fingers. This led to making overkill load resistor setups. Yes, fan cooled to save the fingers. I have had them come in handy with I bench test some of the newer commercial power amplifiers or one running mono bridged at over 1.5 KW.
Hi burnedfingers,
Mysteries explained.
I had a seasoned service tech testing a Yamaha P2200 bridged into a single Dale 8R 250W non-inductive load on a big heatsink. His name is Dave. I came in and said "Hey, Dave, what's that smell. Somethings smells really hot!" He said " I don't smell anything". About that time I heard "ting .... ting ... ting...", "Do you hear anything Dave?" About that time we heard a dull pop as the end of the resistor slid out of the casing. Boy was he embarrassed. I had to ask him why he thought a 250W resistor would take that much power. (Yah, I touched it and burned my fingers). He didn't think the amp would really put out that much power.
I think the replacement resistor was around $54.00 + shipping + taxes.
-Chris
Mysteries explained.
I had a seasoned service tech testing a Yamaha P2200 bridged into a single Dale 8R 250W non-inductive load on a big heatsink. His name is Dave. I came in and said "Hey, Dave, what's that smell. Somethings smells really hot!" He said " I don't smell anything". About that time I heard "ting .... ting ... ting...", "Do you hear anything Dave?" About that time we heard a dull pop as the end of the resistor slid out of the casing. Boy was he embarrassed. I had to ask him why he thought a 250W resistor would take that much power. (Yah, I touched it and burned my fingers). He didn't think the amp would really put out that much power.
I think the replacement resistor was around $54.00 + shipping + taxes.
-Chris
hi anatech
u r a professional and in this bussiness.i m an elect. engg. student and whenever i test amp,i head to my college lab for that.
please tell me that when u cant see the output amplified waveform and input waveforms then how u determine the performance of amp.i see the respective waveforms.see the deviations visually and measure with meters and visuals etc to get the performance figures.
how u do it??
u r a professional and in this bussiness.i m an elect. engg. student and whenever i test amp,i head to my college lab for that.
please tell me that when u cant see the output amplified waveform and input waveforms then how u determine the performance of amp.i see the respective waveforms.see the deviations visually and measure with meters and visuals etc to get the performance figures.
how u do it??
Hi sagarverma,
I'm not sure I completely understand you. You type in "web shorthand" instead of complete words and thoughts. My daughters do that too. Makes it hard to understand.
When testing an amp - or whatever, I do look at waveforms, measurements and spectrum analysis. So I can't quite understand what you mean.
Once the design is to a certian stage I listen to it, possibly even on my main system. At that point, if it sounds "okay" I build another and change that, using the original as a reference. In this way the design always moves forward, not sideways or backwards. I also test components in this same way. Can we hear a difference in two identical otherwise amps?
A design will never be completely done "by the numbers" or by listening tests alone. I believe that a good design is arrived at by looking at it in every way possible. I also think that other opinions are more valuable in judgement. I am too critical of my own work, or I could be too forgiving. Children and women keep me honest. They seem to have the best sense of sound.
-Chris
I'm not sure I completely understand you. You type in "web shorthand" instead of complete words and thoughts. My daughters do that too. Makes it hard to understand.
When testing an amp - or whatever, I do look at waveforms, measurements and spectrum analysis. So I can't quite understand what you mean.
Once the design is to a certian stage I listen to it, possibly even on my main system. At that point, if it sounds "okay" I build another and change that, using the original as a reference. In this way the design always moves forward, not sideways or backwards. I also test components in this same way. Can we hear a difference in two identical otherwise amps?
A design will never be completely done "by the numbers" or by listening tests alone. I believe that a good design is arrived at by looking at it in every way possible. I also think that other opinions are more valuable in judgement. I am too critical of my own work, or I could be too forgiving. Children and women keep me honest. They seem to have the best sense of sound.
-Chris
dummy load sch...
Found this simple schematic for building a switchable 2-4-8-16 ohm dummy load box from the ever helpful Aiken amplification site. The link takes you to the home page where you need to click - Tech info – Advanced – dummy loads.
http://www.aikenamps.com/
here is the schematic -
Found this simple schematic for building a switchable 2-4-8-16 ohm dummy load box from the ever helpful Aiken amplification site. The link takes you to the home page where you need to click - Tech info – Advanced – dummy loads.
http://www.aikenamps.com/
here is the schematic -
Hi sklimek,
Good ideas. I use only 4 and 8 ohm commonly. I have 0.511 precision power resistors to use for power supply testing.
The only problem I see is the switch contacts. Nice high current switches are expensive. To that end, I just wire them as I need them. 8 and 4 ohm are permanently set up in a box on a heatsink. You might be further ahead to do something similar.
-Chris
Good ideas. I use only 4 and 8 ohm commonly. I have 0.511 precision power resistors to use for power supply testing.
The only problem I see is the switch contacts. Nice high current switches are expensive. To that end, I just wire them as I need them. 8 and 4 ohm are permanently set up in a box on a heatsink. You might be further ahead to do something similar.
-Chris
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