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I remember the time when mine rack contains 2 Crown 5000VZ, and was more than 80 Kilos... I have made some Leco Amplifiers with SMPS, not so powerfull but much lighter, but I sold all because people love them and want them. One of it I was trade with one Yamaha P7000S+cash difference from his...

Even if I'm more to big power amps, I decided to make also something smaller around 200Watts/8 ohms amplifier for "home use" Hi Fi. It was developed from Leco V2 amplifier, with less output trannies and more developed on input and VAS stages and extended freq range, from 5Hz until 300kHz (max...

I worked alot to build this one (just 10 modules made), is all in one amplifier ClassAB+B, (initially it was one ClassH prototype but I quit on that and keep AB+B class). Each module contains balanced to unbalanced stage, IOC limiter (input output comparator limiter), thermal protection...

Down is another Leco V2 complete amplifier. Featured protections: Thermal (SMPS and audio stages , shortcircuit on outputs, delayed speakers connection, DC out, IOC anticlipping limiter, overvoltage >265Vac, undervoltage <160Vac Minimum guaranteed output power (225Vac) 2x1000W/4R continuous...

I have repaired today one Labgruppen LAB4000 amplifier, TD class amplifier. Is supplied at +/- 155Vdc, and the trouble was in low frequency classB part amplifier. I have replaced all 10 pairs of MJL21193+MJL21194 trannies, with brand new ones, I replaced some 18kOhms/2W resistors with 4 W...

Upgrading this amp http://www.forum.poweraudio.ro/viewtopic.php?f=64&t=19182 with newer versions of Leco Amp modules, with the recovered modules from it, I decided to make another Leco Amp with transformer and those 2 modules. Output devices used are a little special with SOA of...

Some improvements compared to the previous version: 6 output devices per rail. Triple deep darlington configuration, full simmetrical from in to out. Offset adjustment. Faster transistors on differential and VAS stages, with lower Cob capacitance. Double feedback pre-post L-R out filter...

I kept 6 amplifiers modules Leco, with a destination a little special, becoming 2 Leco amplifiers with SMPS, one with 2 modules and second with 4 modules 2 bridged on each cnannel. Finished first one with 2 modules, modules wich uses some output devices with SOA of 2,50A/80V/1Sec, supplied at...

Some pictures during output devices replacement: http://postimg.org/gallery/4u0du5k/ Explanation of repairing and recalibration (in Romanian language) and tests on dummy load: http://www.youtube.com/watch?v=_5S_k8y_X7c&feature=youtu.be...

Longtime ago, I wanted to be able to "negociate" with frequencyes UNDER 25Hz, "mine best friends on audio", but for that, must have sometring REAL strong. 200 liter internal volume usable (after all reinforcements),18" Maelstrom X Gen 2 speaker, and space to place the infrabass speaker...

Finally finising mine SMPS project for Audio Power Amplifiers, and not only audio, ready for selling. Is an resonant LLC ZVS SMPS mode, soft switching. This SMPS will be mage custom every client (output tensions and power for amplifier power supply) and will have power from 2500W to 5000W...

I have conected 2 modules in bridge, one master, second slave ,oficial amp will have 180 degrees phase inverter for minimum distortion possible. Intro: http://www.youtube.com/watch?v=AnGkY01DQR8&feature=youtu.be Bridge 8 ohm dummy load...

Leco SMPS on 12 ohms loading , 140,5 volts DC output on idle, 139,5volts DC on 12 ohms load. 50 Ampres/100milivolts shunt seried , shows 22,6 mV on it ,so curent on load is 11,25 Amperes. Power is 11,25A x 139,5V = 1509.5 watts http://www.youtube.com/watch?v=EJ5yIu2unQg&feature=youtu.be...

After studying and studying, Yamaha and Labgruppen TD amplifiers schematics, I decided to give a try to implementate something on mine AB class amplifier. So I go to the Yamaha's Eee schematics (autooscilant) and extracted what I need for implementation to see if it works. Yamaha uses on...

On air, spider montage testing: Rezonant mode, half bridged IRG4PC50W IGBT's ETD59 core, 3C90 material, 600x0,071 litz for primary winding , 2x200x0,08 for secondary winding,maximum randament achieved ay 55 Khz (don't know why)... Tried more or less spires for primary, in any case, maximum...

The professional PCB's has arrived, and I have finally made it. This is my prototipe done for selling, please don't ask for schematics sharing, because I will not make public, thanks for understanding. Power supply +/- 95 Vcc, input level 1,00V RMS, for max output below clipping. Some...