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jbl_man View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jbl_man Quote  Post ReplyReply Direct Link To This Post Posted: 15 January 2024 at 2:51pm
Was it just this one channel board Kevin, the other 3 are ok? 
Be seeing you.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote kedwardsleisure Quote  Post ReplyReply Direct Link To This Post Posted: 15 January 2024 at 5:52pm
It's one of a rack of these so it's nice to keep everything the same I suppose.
Only 1 channel down, the amp was happily still operating on the other 3 channels.




Kevin

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EmPro View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EmPro Quote  Post ReplyReply Direct Link To This Post Posted: 15 January 2024 at 6:29pm
Nice work and proper done Clap
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Earplug Quote  Post ReplyReply Direct Link To This Post Posted: 15 January 2024 at 6:35pm
Originally posted by EmPro EmPro wrote:

Nice work and proper done Clap


Ditto.  Smile




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Post Options Post Options   Thanks (0) Thanks(0)   Quote Lucasdude Quote  Post ReplyReply Direct Link To This Post Posted: 15 January 2024 at 9:48pm
I'm kinda guessing that last pic is the working one...
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Wikl109 Quote  Post ReplyReply Direct Link To This Post Posted: 15 January 2024 at 10:23pm
Originally posted by Lucasdude Lucasdude wrote:

I'm kinda guessing that last pic is the working one...

I'm pretty certain that looks like the broken one after it's been repaired.
Look at the scorch marks on the board around a couple of those resistors.
It has cleaned up pretty well.
Cheers, Chris.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EmPro Quote  Post ReplyReply Direct Link To This Post Posted: 20 January 2024 at 3:50pm
Originally posted by jbl_man jbl_man wrote:

"Lyonforge A400 2x200w (on paper)"

When you have spare time, just run it up, and see what it is actually making at Clipping?


I just finished the bench test for it and the results are as follow:
-27.40v rms 4R measured in 50hz 100hz and 1000hz sinewave (no clipping)
-31.80v rms hard clipping
Both measurement shows the same values on HPS 5 osciloscope and Fluke multimeter.

Both ch shows same behavior,i test them one by one,not at the same time...so both ch driveing at the same time will push no less than 180w rms clean :) i was surprised to see how good response i got in 50hz from such a small toy LOL


Edited by EmPro - 20 January 2024 at 3:52pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KDW32 Quote  Post ReplyReply Direct Link To This Post Posted: 20 January 2024 at 4:18pm
Is a HH VX900 worth resurrecting? It's got one channel down. Not opened it yet. I found it on a wall with a some plates being given for free a long time ago and gave it a mate. It's made it's way back to me. I never used them back in the early 90s when I stared. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EmPro Quote  Post ReplyReply Direct Link To This Post Posted: 20 January 2024 at 4:34pm
I had a poor VX900 long time ago...my one was in badly body condition,the front plastic grils we're missing etc etc...also one ch down but nothing too serious,the eight hitachi's were totally fine,the working ch sounded good,i donate it to a guy who has the same one but good body and one ch down as well so he just moved parts from my own and made a proper good one,if yours is in good shape is worthing to be saved,they punch some serious continuous power all the way down almost to dc where the triac starts to cut the output Smile when they go usualy the problem
is in the driver board...easy to acces and more easy to repair,my own had two axial capacitors done and 2-3 resistors,nothing serious Smile


Edited by EmPro - 20 January 2024 at 4:35pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EmPro Quote  Post ReplyReply Direct Link To This Post Posted: 20 January 2024 at 4:38pm
Also be carefull to discharge the reservoir tanks because they store a lot of current in 60.000uf/100v LCR's LOL
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KDW32 Quote  Post ReplyReply Direct Link To This Post Posted: 20 January 2024 at 4:43pm
Thank you Thumbs Up the case just has a bit of paint peeling rest of it is ok. I'll it on the bench next week and have a proper look. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote EmPro Quote  Post ReplyReply Direct Link To This Post Posted: 20 January 2024 at 5:01pm
Then save it mate,you won't regret,it performs well on any application and plenty of real power available with no limiting,but first make sure you have all the Hitachi's good in it :) if not...but i don't think will be the case,will be a problem to find proper K135 and J50 devices....these days.
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