Hey guys. I've built some CMOY amps before and they all worked great. They all used a single 9v battery, tho, and now i am building a more powerful one. I've already constructed a PSU, using a 220v to 2 x 12v transformer, according to this scheme:
I tested the CMOY i built for this set up with a little battery bench psu i made for testing my older cmoys (2x cap 2x resistor and a battery) and it works as expected. However, when i connect it to the 2 x 12v PSU, it doesn't. I am not exactly sure how things go when i don't have virtual ground, so i suppose that's where the problem lies. I think this should be a "real" instead of a "virtual" ground, but i might be wrong.
I connect the V+ and the V- to the corresponding pins and the common ground on the cmoy to the PSU's ground pin and all i hear is hiss. Is this how i am supposed to connect it, ground to ground with nothing in between?
I've measured the 2 x 12v PSU output with my Fluke DMM and it is exactly +12V and -12V, so at least this works.
I'd really appreciate any insight into this. Thanks in advance
I tested the CMOY i built for this set up with a little battery bench psu i made for testing my older cmoys (2x cap 2x resistor and a battery) and it works as expected. However, when i connect it to the 2 x 12v PSU, it doesn't. I am not exactly sure how things go when i don't have virtual ground, so i suppose that's where the problem lies. I think this should be a "real" instead of a "virtual" ground, but i might be wrong.
I connect the V+ and the V- to the corresponding pins and the common ground on the cmoy to the PSU's ground pin and all i hear is hiss. Is this how i am supposed to connect it, ground to ground with nothing in between?
I've measured the 2 x 12v PSU output with my Fluke DMM and it is exactly +12V and -12V, so at least this works.
I'd really appreciate any insight into this. Thanks in advance
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Draw the schematic include your "CMOY" - which shouldn't be called one since it doesn't need that virtual ground
That's the psu, the cmoy is just an usual cmoy, only the amplification part, the same as in Tangent's schematic. I guess my question is, how do i wire the ground when there's no virtual ground, but a real one instead?
I'll bet you forgot to move the ground on your volume pot and/or your input jack over to the real ground. 🙂 The hiss probably means you have no input signal, which is what happens when the source ground is not connected to the real ground along with the rest of the circuit. In Tangent's schematic that is the ground on the 10K input pot.
The changeover from "battery with virtual ground" to your "power supply with real ground" is correct as you have it described.
Some photos would help.
The changeover from "battery with virtual ground" to your "power supply with real ground" is correct as you have it described.
Some photos would help.
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All the grounds are connected together, including the volume pot ground, both input and output jacks, and it all goes to the real ground. It is just like the way i do it when i use a battery, but instead of virtual ground there's a real one. Is this the correct way to do it?
You are doing it correctly. 🙂 What op-amp are you using?
Photos would really help, maybe we can spot your wiring error.
Photos would really help, maybe we can spot your wiring error.
There isn't much to go wrong schematic-wise... so I'm going to blame assembly or parts.
What's the voltage on the output? (Relative to ground.)
What's the voltage on the output? (Relative to ground.)
Might have something to do with the psu assembly, it's the first one i've done. I will check it more closely.
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