Well my first build, and very happy 
Thanks to all on the Forum (and Jim via email when I didn't put a cl60 on the primaries and blew several fuses!). I have some hum coming from the speakers I still have to work on - so any tips greatly received, but here are a few pics of my build (BA-3 preamp now on the 'to build' list!)
Thanks to all on the Forum (and Jim via email when I didn't put a cl60 on the primaries and blew several fuses!). I have some hum coming from the speakers I still have to work on - so any tips greatly received, but here are a few pics of my build (BA-3 preamp now on the 'to build' list!)
I have some hum coming from the speakers I still have to work on - so any tips greatly received, but here are a few pics of my build
@ Bristto
Congratulations excellent first amp build
Tips ? Ok
If you can reverse transformer and PSU positions
to keep more distance from speakers outputs.
Twist togheter pairs wires of transformer.
All is show in 6L6 builds guides
Keep all wires far from transformer and his magnetic radiation.
Hope this give you more clean background sound.
Greetings
Christophe
Thanks Christophe...!
Oddly enough (sadly playing with it at 0600hrs this morning lol) - the hum only occurs when its plugged into my preamp (preamp on or off!)
I have just completed some cable management - so audio cables are further away from the transformer... Still humming....
This may rectifiy itself when I finish my preamp build for it?!
Thanks
Oddly enough (sadly playing with it at 0600hrs this morning lol) - the hum only occurs when its plugged into my preamp (preamp on or off!)
I have just completed some cable management - so audio cables are further away from the transformer... Still humming....
This may rectifiy itself when I finish my preamp build for it?!
Thanks
use a soft start one CL60 does not have sufficient resistance for 240Vac mains supply. Try using a bank of 20r 5W resistors. Close rate your mains fuse (<=transformer VA / 240Vac) Increase the number of 20r until your T rated fuse stops blowing, or calculate.
You have a few twisted pair wires in there. But very many single wires separated from their complement. Close couple all pairs. Twist if possible. Once that is done, compare your hum measurement with what you have at present.
F5 Grounding issue
I have the same problem others have mentioned, a slight buzz. I've lived with it for a couple years, I just don't put my ear up to the speaker, but I would like to fix this. When I short the inputs it's dead silent, so it has to be a grounding issue, right? My amp is pretty much identical to the build guide.
I have some ideas to try, but am wondering what others have used as their grounding schemes to solve this issue.
I have the same problem others have mentioned, a slight buzz. I've lived with it for a couple years, I just don't put my ear up to the speaker, but I would like to fix this. When I short the inputs it's dead silent, so it has to be a grounding issue, right? My amp is pretty much identical to the build guide.
I have some ideas to try, but am wondering what others have used as their grounding schemes to solve this issue.
On all my Firstwatt diy amps, I used the basic grounding scheme and every one is dead silent. Every Time I have experienced any hum, it was caused by something up stream. I posted some while back about a hum problem with F5 when using a roku box as a test source. Turned out it was the monitor I was using along with roku box. Unplugging it returned all to dead silence! (it was only a temp test source.)
If when you short the input it is quiet, I thought that meant all was good with the amp, and something upstream was indicated?
What the heck do I know!?!Russellc
The amp has a slight hum with nothing connected. If I short the inputs it is silent.
Yes, the RCA's are isolated from the case with the plastic washers, but I will double check with meter.