OK.....that was not that bad.....found BB 2604AP on ebay for not very much…...from Italy (not China)…….hope they are original...….never know……..
Hello everyone! I have some bad news. Since my last post 3 weeks ago, I've attempted to improve my amp by doing the following:
- Use the standard Hammond aluminum chassis for better grounding and shielding
- Add the C13 and C23 caps
- Add a .47 uF cap between the RCA ground tabs and the chassis ground
- Connect the IEC inlet ground to the chassis ground
The bad news is that I've somehow managed to break the amp!
These are my symptoms:
- There is no music coming through.
- When I plug in my headphones, I hear two or three pops as the jack clicks in. It reminds me of the sound you hear when you touch a 9V battery to a small speaker. I guess that means current is flowing through at a steady voltage?
- When I unplug the amp, the D5 LED slowly dims the way it always did. The D6 LED used to dim at the same rate, but now it dims much more slowly than the D5 LED.
I'm not quite sure what to do next. Does anyone know what the problem might be or how I could diagnose it with a multimeter?
Thank you!
- Use the standard Hammond aluminum chassis for better grounding and shielding
- Add the C13 and C23 caps
- Add a .47 uF cap between the RCA ground tabs and the chassis ground
- Connect the IEC inlet ground to the chassis ground
The bad news is that I've somehow managed to break the amp!
These are my symptoms:
- There is no music coming through.
- When I plug in my headphones, I hear two or three pops as the jack clicks in. It reminds me of the sound you hear when you touch a 9V battery to a small speaker. I guess that means current is flowing through at a steady voltage?
- When I unplug the amp, the D5 LED slowly dims the way it always did. The D6 LED used to dim at the same rate, but now it dims much more slowly than the D5 LED.
I'm not quite sure what to do next. Does anyone know what the problem might be or how I could diagnose it with a multimeter?
Thank you!
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First step is to check the power supply to see if you have the correct +- rail voltages. It is like going through 6L6's steps again. Then you can check opamp and measure voltage over gate stoppers, check bias etc.....
You can also check if you have any input signal at all...…..also check if you have DC at the output. But this will only be an indication of some "other" error and confirm that something is wrong.
You can also check if you have any input signal at all...…..also check if you have DC at the output. But this will only be an indication of some "other" error and confirm that something is wrong.
It sounds like one rail is drawing a lot less Power then the other. So i guess you got a hole lot of DC offset.
Thank you @MEPER and @AudioSan.
As you can see in the photo, I cut out a small corner of the PCB to make everything fit into the case.
In retrospect, this was probably a bad idea. It looks like there might be a trace that runs along the edge in that corner of the PCB.
If that's the problem, is there any way to repair the connection somehow? Or is this mistake so catastrophic that I'll need to order a new PCB and parts kit?
As you can see in the photo, I cut out a small corner of the PCB to make everything fit into the case.
In retrospect, this was probably a bad idea. It looks like there might be a trace that runs along the edge in that corner of the PCB.
If that's the problem, is there any way to repair the connection somehow? Or is this mistake so catastrophic that I'll need to order a new PCB and parts kit?
If it is only one connection you need to find out where it did go and try to repair by solder a wire from component to component so you don't need to scratch off the mask to get clean copper solder points.
Post #5 of this thread has a BOM with Mouser part numbers.
If you want to make a Mouser BOM that's sharable and enables one-click ordering, I'll gladly and enthusiastically include it in this guide. 🙂 🙂
If you want to make a Mouser BOM that's sharable and enables one-click ordering, I'll gladly and enthusiastically include it in this guide. 🙂 🙂
Yeah I can but do you mind waiting 18hrs. Its 1230am here and I need to sleep lol.
Jim, could you please try the link with Mouser card below. It includes different Opamps and MOSFETs:
Mouser Electronics
So what's the go with the opamps. I choose the AD823 but yet to hear it. In the past I have liked a BurrBrown 627bp? But I'm thinking I may go my local with a Burson Audio opamp. Is there any mods I have to consider. I'm using the 6363 power supply.
Cheers lads
Cheers lads
