diyAB Amp The "Honey Badger" build thread

[Deleted member 550749]

Can I use bc549c+2sc1815+A933 for differential amp section, power supply will be 24-0-24 for modified circuit ?

 

[UncleMud]

Hello forum members,
I am fairly new to the hobby of amplifier construction and could use some guidance. I am gathering parts for my honey badger build but am having trouble sourcing the noble resistors. I found some online but the website was unsecure, and am unwilling to enter all my information on it.
These resistors from mouser appear similar, would they work? I am appealing to builders with more knowledge to help me here. I have already gathered most of the parts needed for the amplifier pcb's. Thank you in advance. Dave M.

 

[UncleMud]

Probably would help if I attached the file.

 

[Deleted member 550749]

I have polystyrene capacitor 470pf and 100pf is it better than ceramic for this amp??

 

[anatech]

Hi MrAK87,
NP0 / C0G ceramic capacitors are perfectly fine. Polystyrene are heat sensitive, so be careful soldering them.

 

[Deleted member 550749]

Thanks bro for replying 👍♥️🙏

 

[anatech]

Never a problem.

 

[anatech]

Hi UncleMud,
Those will work perfectly. They are non-inductive "plate" resistors. You can also find a vertical "bathtub" style resistor that is non-inductive.

 

[UncleMud]

Thanks for your response anatech. It is greatly appreciated! 🙂

 

[Chiptech]

Ok, I'm back. I took a detour into the DC blocker world. Now I've built one and installed it. I was hoping that using the 12V leads would eliminate my hum.

No luck.

First question I'd appreciate input on is: what do I do with the 18V leads off my AN-8445 - 800VA 45V Transformer? See photo. If there some way that it is causing my hum? Oh, that it would be that easy.

I've built 4 F series amps without any hum issues. I guess it's my turn at bat.

Otherwise, I'm really open to suggestions.

Thanks,

 

[jwilhelm]

Just tie the 18V wires off and insulate the ends. They won't be causing hum.

What sort of hum are you hearing? low hum or load buzz? Does it go away if you short the inputs? One or both channels?

 

[jwilhelm]

I assume your transformer is mounted under the supplies. Do you have a bolt through the metal plate through the center of the transformer? If so that will act like a shorted winding in your transformer and will buzz pretty badly.

 

[danieljw]

Ok, I'm back. I took a detour into the DC blocker world. Now I've built one and installed it. I was hoping that using the 12V leads would eliminate my hum.

No luck.

First question I'd appreciate input on is: what do I do with the 18V leads off my AN-8445 - 800VA 45V Transformer? See photo. If there some way that it is causing my hum? Oh, that it would be that easy.

I've built 4 F series amps without any hum issues. I guess it's my turn at bat.

Otherwise, I'm really open to suggestions.

Thanks,

There are a few layout tips in the "wiring your amplifier" video in the playlist linked in my signature if that helps a little.

 

[Chiptech]

I assume your transformer is mounted under the supplies. Do you have a bolt through the metal plate through the center of the transformer? If so that will act like a shorted winding in your transformer and will buzz pretty badly.

Yes, that is my set up. I've used this in four F series amps with no issues. What am I missing or what is different in this amp? Note, I only have the PSU up and running, no amp boards installed.

 

[UncleMud]

Hey folks,
I am following this topic closely, as I am just beginning my Honey Badger build. I had intended on securing my toroid the same way. Although I have only one amp project under my belt, (FH9HVX) I used this method without problems.
My question is; what is the alternative method? Am I missing something about safely securing toroids? Why is a metal bolt and washer included if it's a non-starter?
I'm not trying to be oppositional in the least. Simply trying to figure out what I'm not understanding about this phenomenon.
Thanks, Dave M.

 

[UncleMud]

(Or maybe more importantly, what is a better method?)

 

[jwilhelm]

The bolt through the middle of the transformer isn't a problem. The problem arises if the metal plate you have mounted above it contacts the bolt going through the transformer or the large washer on top. This would create a high current low resistance shorted winding for the transformer.

My question was if the bolt went through the metal plate your supplies are mounted on.

 

[UncleMud]

Understood. Thank you.

 

[UncleMud]

I realize with some chagrin that in my excitement I have interrupted the current conversation. My sincere apologies. I will follow the conversation quietly and learn.

 

[Chiptech]

UncleMud, we welcome all input here. Thanks for helping me get to the issue. I have checked and don't think the bolt is touching my plate. Just to be sure, I put a rubber mat in between. And still have a low hum coming from somewhere in the transformer/PSU board. That is all I have wired up at this point. No amp boards. Haven't even built them. I wanted to resolve this hum before going ahead.