Is this a valid calculation for this project, 410 va what size fuse do I need 4 amp slo blow?
Not a 300W bulb at all. This tester is designed to reduce the amount of juice reaching your amp, using the reistance of the bulb. Lower wattage = higher resistance = less juice getting through.
The Dim-bulb Radio Tester
The Dim-bulb Radio Tester
no.
Fit one correctly rated fuse to each transformer input.
If one transformer, of a pair, goes faulty with a double size fuse in place then that faulty side could dissipate double the heat (fire) until the fuse blows.
Besides having not more than a few mv of dc offset, is there anything else to check for? The heatsink on the 3886 is supposed to be warm when not playing any signal, is this normal?
That's quite normal, and it will get slightly warmer under load. Do you have a picture of the heatsink?
This heat is normal.
Check for the voltage supply on the opamp and the LM3886, check for AC signal on the output (should be noise and near zero)....and nothing else relevant.
Remember to do all tests with the input shorted to ground.
More lightspeed PSU
My lightspeed will be in it's own case and I won't have power to tap off of like I would if I made an integrated amp. I am looking for power supply options. I have seen regiregi's schematic in post #540 of this thread. Could I just use that and a 9v wall wart to supply the DC to the circuit? Can 9v from a wall wart be regulated to 5V with this circuit?
How about this wall wart?
5V 1000 mAh DC Power Supply (Wall Wart) ? ESawdust
Would this be a plug and play Power supply? I am under the impression that the 5V needed by the lightspeed isn't very demanding. I would break open the case of the wall wart to extract the circuit board and mount it in a case with a beefy 120 Vac cord into to preamp to hide the fact of the very simple psu. 😛
Thoughts or links that might be relevant and TIA,
rick
My lightspeed will be in it's own case and I won't have power to tap off of like I would if I made an integrated amp. I am looking for power supply options. I have seen regiregi's schematic in post #540 of this thread. Could I just use that and a 9v wall wart to supply the DC to the circuit? Can 9v from a wall wart be regulated to 5V with this circuit?
How about this wall wart?
5V 1000 mAh DC Power Supply (Wall Wart) ? ESawdust
Would this be a plug and play Power supply? I am under the impression that the 5V needed by the lightspeed isn't very demanding. I would break open the case of the wall wart to extract the circuit board and mount it in a case with a beefy 120 Vac cord into to preamp to hide the fact of the very simple psu. 😛
Thoughts or links that might be relevant and TIA,
rick
Wallwarts are okay. Not great. Switching wallwarts or switching supplies in general is not going to sound as good as just a small transformer into a few diodes and then Regi's circuit.
Uriah
Uriah
no.
The wall wart is almost certainly certified as double insulated. It may be CE marked.
If you break open the case or make any modifications to the internals you must then build to ClassI regulations.
Keep the Wall wort intact.
Before I discovered John Ango at Antek - Your reliable source of transformers, power supplies, and more. who built a PSU for me, I bought a Velleman kit and a AN-0012 transformer to power it.
Then he build a PSU board and sized the transformer for my Pass B1 .
He also has a 5 vdc for the LDR project.
Then when you are ready for a case he has Par-Metal
I believe he will give a discount to forum members, just ask.
Attachments
A an external wallwart is very convenient. Take a 9v or 12v wallwart and regulate it down to 5v with my regulator. It is easy and cheaper. It will make a bit of noise, but it won't be relevant or measurable.Remember that after the switching PSU there is a regulator, and after that there is an LDR lighted by a diode. So, the switching noise is not on the signal path.
Great deal that regulator, Dario 😉 Very very cheap and nice components.
Regards,
Regi
I wont harp on this point but I will say I told you so later on. If you use a small transformer and a few diodes before Regi's circuit it will sound much better than a wall wart of the switching kind. The switching noise does in fact get through. You will never notice it however until you compare with just transformer and diodes. So, yeah its nearly insignificant but I think its worth a fully linear supply.
Uriah
Uriah
In fact, I am talking for nothing, because I haven't compared a linear and a switched PSU. I haven't even tried an LDR attenuator. So if Uriah sais that there is a difference, there may be 😉
Advice heartily accepted as I don't want to compromise anywhere (beyond those already designed in) on this build. What VA rating would be required for the transformer? Is there a preferred voltage out on the transformer? Would smoothing caps be advantageous before the regulator to ease its function? If so, what value caps are recommended?
TIA,
rick
1VA is fine.
Any reasonable voltage. 12 would be fine.
Any small caps you have. Maybe 1000uf would be fine. Its a tiny amount of power.
Uriah
Any reasonable voltage. 12 would be fine.
Any small caps you have. Maybe 1000uf would be fine. Its a tiny amount of power.
Uriah
Does this kit require any breakin, since it is known that BGs do require some breaking in? It seems to be a little bass shy at the moment, and I was wondering if it needed some breaking in to show it's true potential.
That sounds reasonable to me. But there might be a million reasons why the bass seems less prominent compared with your previous amp...
Just picked up my box from 91106, Uriah. Excellently packed, and I was delighted to see all those quality parts bagged up!! 😀
Thaks ever so much to you and your good lady for all the hard work that went into this GB!!
Cheers
Jon
Yeah, all electrolytic capacitors (no only BG) need to reform their electrolytic, so after a bunch of hours they should perform as they should. There's no place for discussion here, this is a fact.
Then we can discuss burn in of semiconductors, film capacitors, resistors or even wires. Here is where you will hear the funniest arguments.
- Status
- Not open for further replies.