Another Yamaha P7000S modified by me

DjLeco

Moderator
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 owner.

The P7000S is not bad amplifier but SMPS part is weak, reason why is clipping fast on 4 ohms, lack of bass and cannot offer enough power continuous.

I decided to modify the SMPS part of Yamaha, including IGBT's and storage capacitors and make it powerfull with greater current output and bigger voltage rails, and of course ZCS resonant mode to increase efficiency, of SMPS part because I have almost doubled the power.

Also I have replaced all output devices, predrivers, mosfets on switching part, soa curve, and output current limit.

Officially measured, the amp is delivering around 1100 watts/4 ohms load, now, is more than 2000Watts/4 ohms, if mains suppply not saggs under 221Vac

Some pictures during modifications:


SMPS board






 
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DjLeco

Moderator
Increased secondary storage capacitors



Point where measured mains supply in idle mode


Idle mains supply voltage at home
 
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DjLeco

Moderator
Points of measure DC rails


New DC rals of +/-155Vdc (+/- 165Vdc at 232Vac)





Yamaha initial, output power 1000-1100W/4R

[video=youtube;zn_iDqCSYes]https://www.youtube.com/watch?v=zn_iDqCSYes&feature=youtu.be[/video]

Yamaha modified, output power around 2000-2100W/4R

[video=youtube;gzW_QgIKRS0]https://www.youtube.com/watch?v=gzW_QgIKRS0&feature=youtu.be[/video]

Mains saggs during high load:

[video=youtube;8YmERYyBWyI]https://www.youtube.com/watch?v=8YmERYyBWyI&feature=youtu.be[/video]
 
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