Daniel Pumphrey
100+ Head-Fier
- Joined
- Jun 21, 2001
- Posts
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I recently finished several Hansen amps using the dual 9V Pactec box.
The first amp did not work (I thought), and my two NiMH Rayovac batteries were fully charged. (These two batteries had proven track records but had not been used for a month.) I checked everything including battery voltages at several places on the board. After many hours of attempting to "FIX" the problem, I gave up and trashed the board. I did take out the opamps and Cerafines before hitting the trash can with a forced thud! I had made a mess of resoldering this board over and over attempting to solve the problem and finding none anywhere!
The second board was next installed in the amp to all the same parts and wires, but for some reason I only soldered in one battery jack instead of two just to try it first. I did not do this for the first amp. This identical board worked perfectly the first time. I listened to the amp for a few days before changing it to dual 9v batteries. It then didn't work! The batteries were charged and exhibited the same voltages at the same places. One of these batteries was showing a slightly decreased voltage , 7.5V. though. I figured it should still work at least for a while for testing the amp.
Next, I tried one of these batteries, the amp worked fine, tried the other and it did not work, but again, both batteries passed voltage tests.
I now decided to go to the store and buy some alkalines. When I tried these the amp worked fine with both batteries in place, but showed the same voltage together as the NiMH had.
Now I realized that a NiMh battery which seems perfectly fine can kill the output of all others used with it. These batteries were bought at the same time, from the same batch, etc.
I am posting this to warn other users especially ones who use multiples of these such as many AA's as well as dual 9V.
CHECK THE CURRENT Capabilities of each NiMH battery after charging. They can die all of a sudden and make you think your amp is not working properly. I just wish I had tried the first amp with one battery!! It was probably just fine!!!! as it was built exactly as the other. All parts were correct but the frustration level was breached.
Good Luck! I think I'll try the Energiser NiMh but they cost more and have less voltage. I use a Charger made by Rayovac especially for these new Batteries but suspect too quick charging cycles possibly. These batteries have never been overcharged but do seem to exhibit ever-so-slight swelling on the bottom and top. The Rayovac AA's I bought always work fine, but I use a different charger for them.
Dan
The first amp did not work (I thought), and my two NiMH Rayovac batteries were fully charged. (These two batteries had proven track records but had not been used for a month.) I checked everything including battery voltages at several places on the board. After many hours of attempting to "FIX" the problem, I gave up and trashed the board. I did take out the opamps and Cerafines before hitting the trash can with a forced thud! I had made a mess of resoldering this board over and over attempting to solve the problem and finding none anywhere!
The second board was next installed in the amp to all the same parts and wires, but for some reason I only soldered in one battery jack instead of two just to try it first. I did not do this for the first amp. This identical board worked perfectly the first time. I listened to the amp for a few days before changing it to dual 9v batteries. It then didn't work! The batteries were charged and exhibited the same voltages at the same places. One of these batteries was showing a slightly decreased voltage , 7.5V. though. I figured it should still work at least for a while for testing the amp.
Next, I tried one of these batteries, the amp worked fine, tried the other and it did not work, but again, both batteries passed voltage tests.
I now decided to go to the store and buy some alkalines. When I tried these the amp worked fine with both batteries in place, but showed the same voltage together as the NiMH had.
Now I realized that a NiMh battery which seems perfectly fine can kill the output of all others used with it. These batteries were bought at the same time, from the same batch, etc.
I am posting this to warn other users especially ones who use multiples of these such as many AA's as well as dual 9V.
CHECK THE CURRENT Capabilities of each NiMH battery after charging. They can die all of a sudden and make you think your amp is not working properly. I just wish I had tried the first amp with one battery!! It was probably just fine!!!! as it was built exactly as the other. All parts were correct but the frustration level was breached.
Good Luck! I think I'll try the Energiser NiMh but they cost more and have less voltage. I use a Charger made by Rayovac especially for these new Batteries but suspect too quick charging cycles possibly. These batteries have never been overcharged but do seem to exhibit ever-so-slight swelling on the bottom and top. The Rayovac AA's I bought always work fine, but I use a different charger for them.
Dan
