Getting Ready to Turn this on
Months in the making, about ready to turn this on.
I think a 2.5 slow blow fuse is the correct one to use with a Antek AS--0520-50VA-20V transformer?
I've mapped all the wiring and have implemented accordingly. If anyone sees anything amiss, I'd appreciate it.
I have stumbled into a ground loop/hum issue on a different project, so I guess I'm trying to be extra careful here.
Months in the making, about ready to turn this on.
I think a 2.5 slow blow fuse is the correct one to use with a Antek AS--0520-50VA-20V transformer?
I've mapped all the wiring and have implemented accordingly. If anyone sees anything amiss, I'd appreciate it.
I have stumbled into a ground loop/hum issue on a different project, so I guess I'm trying to be extra careful here.
Attachments
Chip,
That wiring guide is your old one with the fuse not wired correctly. I see that in your build your fuse is wired correctly.
If this is the first power-on test, you should first power up with a dim bulb tester. Also test in stages. Do not do your first power-on test with power supply and preamp boards all connected. Test your power supply first. If it works correctly then add one preamp channel. If that works then add the other channel.
That wiring guide is your old one with the fuse not wired correctly. I see that in your build your fuse is wired correctly.
If this is the first power-on test, you should first power up with a dim bulb tester. Also test in stages. Do not do your first power-on test with power supply and preamp boards all connected. Test your power supply first. If it works correctly then add one preamp channel. If that works then add the other channel.
Always start with dim bulb or be one. Check.
No connections to preamp board. Check
I grabbed the wrong drawing.
Thanks
1. yes
i) why not ; as long you put OS and accompanying biasing circuit together, you don't need anything else to have functional power follower
ii) why not ; as long you put OS and accompanying biasing circuit together, you don't need anything else to have functional power follower
2. regular F4, sans input JFet buffer; you don't need it if you feed rest of amp (Crippled F4) with gain stage having sufficiently low Rout
i) why not ; as long you put OS and accompanying biasing circuit together, you don't need anything else to have functional power follower
ii) why not ; as long you put OS and accompanying biasing circuit together, you don't need anything else to have functional power follower
2. regular F4, sans input JFet buffer; you don't need it if you feed rest of amp (Crippled F4) with gain stage having sufficiently low Rout
Ok. I've youtubed bleeding capacitors and get the concept. But how to do it to capacitors installed on the PSU is a mystery to me?
Regulated PSU output drops ~4v when connecting the BA3 stage
Hello, I have just completed the building a BA3 gain stage and this is what I see.
Transformer is AS-1224 and using a simple LM317/337 regulated PSU. Before connecting the BA3 gain stage, I have adjusted the PSU output to +/- 24v. As soon as I connect the BA3 the output of the regulator drops to +/- 20v also if I measure the AC output of the transformer, there is a significant drop. I tried with different regulated PSUs and the result is the same.
I have connected the power supply via a 25watt lamp and the lamp turns on and goes off in a sec or so.
What could be the issue here? I don't see any component overheating. Any pointers on debugging would be of great help.
BA3 has been built using J313/K2013 and 500R pots. J74/K170 are matched around 8.5mA.
Thanks!
Hello, I have just completed the building a BA3 gain stage and this is what I see.
Transformer is AS-1224 and using a simple LM317/337 regulated PSU. Before connecting the BA3 gain stage, I have adjusted the PSU output to +/- 24v. As soon as I connect the BA3 the output of the regulator drops to +/- 20v also if I measure the AC output of the transformer, there is a significant drop. I tried with different regulated PSUs and the result is the same.
I have connected the power supply via a 25watt lamp and the lamp turns on and goes off in a sec or so.
What could be the issue here? I don't see any component overheating. Any pointers on debugging would be of great help.
BA3 has been built using J313/K2013 and 500R pots. J74/K170 are matched around 8.5mA.
Thanks!
Thanks Zen Mod.
Under load, Vac of the transformer drops is 21vac and the Vdc in front of regs is 24vdc. The output after the regs is about 22v.
Without load, Vac is 24.9vac and Vdc in front of regs is 31vdc. The output after regs was set at 24v.
I tried setting up the bias / offset of the line stage and played some music through it. It seems to work well. Need to find out what causes the drop?
I have a 28vac transformer which I will try later tonight and see what the behavior is.
Under load, Vac of the transformer drops is 21vac and the Vdc in front of regs is 24vdc. The output after the regs is about 22v.
Without load, Vac is 24.9vac and Vdc in front of regs is 31vdc. The output after regs was set at 24v.
I tried setting up the bias / offset of the line stage and played some music through it. It seems to work well. Need to find out what causes the drop?
I have a 28vac transformer which I will try later tonight and see what the behavior is.