hi, isolater said in another thread that his 3d80 had fake tweeters, anyway im sure i hear sound where the fakes are supposed to be so i thought id take a look, it does have tweeters!,

also i dont have the red button in the picture whats going on

earlier models =black button/tweeters

[let`s save money]

later models =red button/no tweeters




??????????????????

do you hear an output signal?

only just noticed the bit at the bottom of your post "do you hear an output signal" , what do you mean ?

I mean :are the tweeters in function ?

yes they do, they only become active at very high frequency, its a lot easier to hear them work with a cd, but the sounds usually heard are symbols and high pitch jingles its difficult to hear exactly what comes through because it blends in with the full range, they also really come alive with the surround mode.

of topic but a i just noticed that if i play a tape with the bass high the vocals distort badly but if i play a cd it cranks all the way up and the only distortion is when the woofers start to get overworked wierd ?

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of topic but a i just noticed that if i play a tape with the bass high the vocals distort badly but if i play a cd it cranks all the way up and the only distortion is when the woofers start to get overworked wierd__?_______________________


I guess isolator or autoreverser could help you in this case...

x0moto, can you take a picture or just write down what amp chips are inside your 3D80? Thanks a lot in advance.

hi, yeah i got it open now its.....

2x NEC JAPAN
upc 1278H
8802D

there are two mounted parallel to each other on a large aluminium heat sink in a "U" shape i will keep it open for 20 mins if you want to know any other bits let me know i will take a pic of the amp i will edit it in once i have uploaded it

Thank you x9moto!

That's the very same transformer/amp board in my 3D88 but yours got bigger output coupling caps for the woofers (2200 vs. 1000 µF). That results in a better bass response on your Hitachi. If the big capacitor behind the rectifier is also better, this will explain the "more power" phenomenon a bit more. I could change the caps on mine, but once it's open i think i'll mod the whole amp section and mount better speakers as well...

interesting..... glad i could help. actually while i had mine open i noticed someone had spilt something sticky in the back and it was all around the amp chip pins so i cleaned it all with ipa and it sounds a lot clearer now on the mids and trebble