I'll give it a try and post results ASAP, i'll use complementary pairs of MJL4281A & MJL4302A from ON semiconductors along with MJE15034 & MJE15035, i'll keep you updated about progress of this new task, See ya....
Sat Shree Akal again Paaji,
I have no more connection with Andrew Lebon. Wo aapki meharbanion es bahut unchi chees ban gaya hai success has got his mind.This is what I have done recently.Meter is showing Peak output voltage with 2 ohm load .Rail voltage 85-0-85.Continuos output voltage into 1 ohm load with .8 voltage music signal reached upto 43 volt. My aim is to achieve 60 voltage undistorted into .5 ohm load
I have no more connection with Andrew Lebon. Wo aapki meharbanion es bahut unchi chees ban gaya hai success has got his mind.This is what I have done recently.Meter is showing Peak output voltage with 2 ohm load .Rail voltage 85-0-85.Continuos output voltage into 1 ohm load with .8 voltage music signal reached upto 43 volt. My aim is to achieve 60 voltage undistorted into .5 ohm load
Attachments
Other than the lack of feedback from the driver stage, and the lack of diodes in the bias circuit, it sure looks like a Leach.
multiplying the number of outputs will not make a high power amplifier
amplifier of this range of power will need proper protection
---one may calculate how much current will be drawn from this circuit per rail and then realize that a ""wire "" of 1.5mm cannot and will not deliver this amount of current
--Then again there is so many transistors placed in such a proximity in a relatively thin pcb that will actually warm each other up .... the result will be that even if a vent is used it will be not possible to cool down the amp ....fins are too small ...
---It should be plenty more ....
amplifier of this range of power will need proper protection
---one may calculate how much current will be drawn from this circuit per rail and then realize that a ""wire "" of 1.5mm cannot and will not deliver this amount of current
--Then again there is so many transistors placed in such a proximity in a relatively thin pcb that will actually warm each other up .... the result will be that even if a vent is used it will be not possible to cool down the amp ....fins are too small ...
---It should be plenty more ....
Yes, It is sure a leach amp alright..look at the background schematic. originally its a 700w 16TR design but he doubles it.
But D.Self shows us that doubling the output stage lowers the distortion, even into the same loading.
Look at his Blameless and compare to the Load Invariant.
But, using 1943/5200 at high voltage is a complete waste of semiconductor devices.
No matter how many one uses, there are far better devices available that can work well at the higher voltages. These higher SOAR devices can reduce the required numbers of output BJTs by a factor of at least 2 and often better than a factor of 3.
Look at his Blameless and compare to the Load Invariant.
But, using 1943/5200 at high voltage is a complete waste of semiconductor devices.
No matter how many one uses, there are far better devices available that can work well at the higher voltages. These higher SOAR devices can reduce the required numbers of output BJTs by a factor of at least 2 and often better than a factor of 3.
Last edited:
Yes Sir this is a leach amplifier modified.no P.c.b. is used in output section. Rail wires are 2.5 m.m. thick.Today I run this amp for 6 hours non stop with 8nos. 15' speakers+8 nos.12" speakers +8 nos. Tweaters Total d.c resistance .5 ohm upto 52 volt and 33 amps on output. Crispy crystal clear highs lively mid and deep low was what I got . I am happy with result.Sugestion to make this was by Capsighter Chinoko .sending some more photos.Paa ji Aap ko main aap ki id par message bhejunga.
Attachments
can you snap a photo of the heatsink profile you used? is that a local job and how much does it cost? thanks
.... did you try to overdrive the amp by ""accident "" ?..... if you construct such an amplifier a situation like that will happen in the feature ....this is a simple fact
Hello Mr. Sakis,
no I did not overdrive amp by accident.I did it purposely.Because i had a challenge from some local guy who made an amplifier and drive 40 12" speakers parallel on one channel.I have a challenge to drive 8 18" speakers parallel on one channel for 12 hours.Still I have not reached my goal because for that kind of amp i need minimum 70 volts and 35 amps at output on given load condition that is 8/8=1 ohm and around 2400 watts .and I am up to that .maybe with 16 pairs of 15024-25 I will achieve that. Need a good Driver circuit for this purpose.Supply is no problem for me as I wind my own transformers.E I and Torrid both.At present I am using 2750 watts transformer on my bench.About the cost of heat sinks I don't remember because I was planning all this since a long time. As you can see i have ample collection of components cores heatsinks in my work shop. I have already made dx turbo with 18 transistors in one channel.E T i 320 watts with 12 mj3773 in one channel .Dirty harry by Fotios 20 24-25 one channel.Quasar legend stage master with triple drive and many more My first 4 channel amp I made in 1982.E.T.I master mixer with equaliser modified to 10 channels in 1983 and so on.Audio is my hobby and profession both.Now at the age of 56 I want to shift from field work to table work.Since 5 years I was learning quietely from All Learned people from difrrent forums.Now only I am showing What a little I have learned. My motto.The day you stop learning you are no more.Thanks to all learned ones. attached some more photos.
no I did not overdrive amp by accident.I did it purposely.Because i had a challenge from some local guy who made an amplifier and drive 40 12" speakers parallel on one channel.I have a challenge to drive 8 18" speakers parallel on one channel for 12 hours.Still I have not reached my goal because for that kind of amp i need minimum 70 volts and 35 amps at output on given load condition that is 8/8=1 ohm and around 2400 watts .and I am up to that .maybe with 16 pairs of 15024-25 I will achieve that. Need a good Driver circuit for this purpose.Supply is no problem for me as I wind my own transformers.E I and Torrid both.At present I am using 2750 watts transformer on my bench.About the cost of heat sinks I don't remember because I was planning all this since a long time. As you can see i have ample collection of components cores heatsinks in my work shop. I have already made dx turbo with 18 transistors in one channel.E T i 320 watts with 12 mj3773 in one channel .Dirty harry by Fotios 20 24-25 one channel.Quasar legend stage master with triple drive and many more My first 4 channel amp I made in 1982.E.T.I master mixer with equaliser modified to 10 channels in 1983 and so on.Audio is my hobby and profession both.Now at the age of 56 I want to shift from field work to table work.Since 5 years I was learning quietely from All Learned people from difrrent forums.Now only I am showing What a little I have learned. My motto.The day you stop learning you are no more.Thanks to all learned ones. attached some more photos.
Attachments
vedmitraa, good job...keep stabbing at your goal, you'll get there....the 1943/5200 seem plentiful and cheap even in Manila.......just be aware that there are fakes....some sellers here would even ask if you want originals or fakes as price spread is greater than 3 to 1....
i am interested in your heatsink profile, is that a local extrusion or did you import? do you have profile drawings with dimensions that you can send me?
i also make my own transformers for amps that i build.....good luck and safety first, amps to follow....😎
i am interested in your heatsink profile, is that a local extrusion or did you import? do you have profile drawings with dimensions that you can send me?
i also make my own transformers for amps that i build.....good luck and safety first, amps to follow....😎
Thanks Tony for compliments,
Heat sinks, cores,power resistances, capacitors and many other components I buy from Agra disposal market where they sell most of military disposal goods. My oscilloscopes , Signal generator,Philips analogue multi meter and many more I buy from this market on down to earth prices.Heat sink I buy lot in Kg. rates of scrap and these parts are better than market new parts.In cabinet i will be using 2 heatsinks to create tunnel and fan from both side suction and throw.
Heat sinks, cores,power resistances, capacitors and many other components I buy from Agra disposal market where they sell most of military disposal goods. My oscilloscopes , Signal generator,Philips analogue multi meter and many more I buy from this market on down to earth prices.Heat sink I buy lot in Kg. rates of scrap and these parts are better than market new parts.In cabinet i will be using 2 heatsinks to create tunnel and fan from both side suction and throw.
i see we share common interests, i too am a frequent visitor to these metal recyclers, junk shops if you will, where imported discarded electronics are dismantled for precious metals like gold, silver, copper and aluminium...
i buy discarded boards for their parts, boards are sold by the kilo also....the quality of components in those boards are first rate....
i am about your age and also done with my kids' education, so now i have more time for my first love which is electronics diy...
keep up the good work....
i buy discarded boards for their parts, boards are sold by the kilo also....the quality of components in those boards are first rate....
i am about your age and also done with my kids' education, so now i have more time for my first love which is electronics diy...
keep up the good work....
Schematic
http://www.diyaudio.com/wiki/Workhorse_1500W_Bipolar_Class_H
Cheers.
By saying "Complementary Pairs" it's about using NPN/PNP transistors, where PNP has same or almost the same characteristics of it's NPN counterpart, as for the schematic you're requesting it's a Kanwar's design, called WORKHORSE 1500 WATTS BIPOLAR CLASS H and you can see it here:
http://www.diyaudio.com/wiki/Workhorse_1500W_Bipolar_Class_H
Cheers.
Last edited:
Truly a good place to find interesting things...
Best Regards.
You are right about that, i am a regular visitor at the metal recycler as you can find a variety of first grade components, as well as very good fans, heatsinks, capacitors, xformers and lots of hi-Q electronics that sometimes are hard-to-find even new from electronics supplier.
Best Regards.
- Status
- Not open for further replies.