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Post by opus131 on Oct 8, 2013 13:34:06 GMT
Hi. I just tried replacing the stock tube amp on my Bravo Ocean with a Gold Lion ECC82 B749 12AU7 (saw it recommended else where. Not sure if it was the best choice, but i have the tube now, so i guess it doesn't matter anymore), and now it seems the left channel no longer works. Prior to replacing the tube, i noticed that the left channel would sometimes not work after turning the amp on, but unplugging and plugging the RCA cable back in always fixed it so i figured it was the fault of the cable itself and i'd just have to replace it at some point. I suppose it wasn't the cable after all and by opening the amp i finished braking whatever was already faulty (the left channel is still out even after putting the old tube back in, so that isn't the issue). I tried using the 3.5 mm TRS input, and it does the same thing, so i guess i can rule out the RCA inputs altogether. I'm now looking at the inside of the amp but all i can tell is that no capacitor seems blown, nothing seems shorted (that i can tell with the naked eye) and there are no fuses to begin with. I'm planning to take it to a local repair shop anyway, but it would help if i could identify the problem beforehand, since i have no idea whether they have any experience with those type of amps. Furthermore, since i'm availing myself of competent help, is there any mod anybody would recommend, assuming the left channel problem can be fixed? I skimmed through the Bravo 12AU7 thread in this very forum but that seems to be about the other Bravo models and i'm not sure the mods apply for the Ocean.
Thanks for all the help.
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Post by opus131 on Oct 8, 2013 14:28:02 GMT
I'm looking around a bit, and it seems many have recommended using the following components rather than stock: IRL510 LM317A Panasonic Capacitor 25volts 2200uF Panasonic Capacitor 3300uF 35V Judging from the mod mentioned in this thread, i would assume the 25v capacitors are the two black ones on the side while the blue one in the back is the 35volts: www.head-fi.org/t/444400/bravo-audio-funny-looking-little-tube-amps/1950Would this be a decent complement to the new tube?
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Post by PinkFloyd on Oct 8, 2013 20:58:47 GMT
Your EXPERT on these amps is a guy from The Netherlands... he has cloned them and taken them to new levels..... he will be able to answer your questions...... you can contact him by doing a google search for Fans de Gruiter.
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Post by opus131 on Oct 9, 2013 10:40:01 GMT
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Deleted
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Post by Deleted on Oct 9, 2013 11:53:23 GMT
He is no longer a member here. I deleted his membership recently at his request, when he was unable to do this himself. Alex
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Post by opus131 on Oct 9, 2013 12:02:33 GMT
Just my luck i guess. Plus, the people at the repair shop i went to said they couldn't help me, since they don't actually fix electronics, they just change parts.
I'll try to replace the stock IRF630 with the IRL510 (those are pretty cheap at least) myself and see how that goes. If it works, i'll post an update here for future reference, in case anyone else is interested in modding this amp.
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Post by mingo on Oct 10, 2013 5:36:52 GMT
Maybe I can help a little. Solderdude has his own column at hoved-fi.dk. First you have to be a member: Go to "Tilmeld" and fill in the required spaces. I suppose you can translate the page, so it will be easier for you. When you have done so, go to "Gør det selv" (DIY) and at the top of the page there is a column called "Ask Solderdude", which is in English. Hope that helps.
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Post by Deleted on Oct 10, 2013 5:57:30 GMT
I have already sent a PM to Opus131 giving him the appropriate contact information.
Alex
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Post by juhzuri on Nov 16, 2013 0:05:00 GMT
I have done four upgrades on my Bravo Ocean. It has left me pleasantly surprised. Using it with line in from iPod classic running RockBox and Grado SR80 headphones.
Genalex Gold Lion Tube x 1 LM317AT x 2 IRL530N x 2 5K trimpot x 2 (Replacing 3K resistors)
I'm going to be doing capacitors next. I'll leave results of that when I do. The above mods work just fine on this iteration of the amp though.
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