JP,
Made an UCD180 boxed version but when I switched on the amp. it will give -18V on the output.
On my 400 boxed version I have the ON wire connected to ground. It switches on OK. But when I do this with the 180 it wont switch on. I have to ground it later than on switch on.
Is there any cap. I can take off at the logic gate to have it immediately switched on(when connected to ground) without an additional delay circuit?
thx, Bert
Made an UCD180 boxed version but when I switched on the amp. it will give -18V on the output.
On my 400 boxed version I have the ON wire connected to ground. It switches on OK. But when I do this with the 180 it wont switch on. I have to ground it later than on switch on.
Is there any cap. I can take off at the logic gate to have it immediately switched on(when connected to ground) without an additional delay circuit?
thx, Bert
Bgt said:
Seems to be a problem related to some UcD180 v2. I've the same problem here with my UcD180 v2. The v1 I previously used do not have this problem.
It's an UcD's initialization problem (wrong startup process). This appends only when no speaker is connected to the output. The -18V (to -22V) no longer exist when a speaker is connected.
Add a delay of 3 seconds before connecting the MUTE to ground with a small temporized circuit. With this, you'll be sure to have a good startup in any case.
Problem is I use an output relay, DC offset sensing, so when the output does not connect because of sensing a -18V it will never close. A bit of a nuissance this "ON"circuit.
Bgt said:
I had the same problem on my project. Just add a transistor or an opto-coupler to your DC protection circuit to connect MUTE to ground, and switch ON the MUTE at the end of the start cycle.
The problem is not the MUTE (this is good to have a MUTE) but that the current implementation seems a little buggy.
Please post your DC circuit diagram here. I'll show you where to add the MUTE circuit.
Hi Steff,
It is not a problem to add the mute swich on the prot. pcb but its adds up to extra parts/wire/work for no reason.
It is not a problem to add the mute swich on the prot. pcb but its adds up to extra parts/wire/work for no reason.
Bgt said:
See it. Sorry.
In fact, the difficulty with the DC circuit is that we need to switch the MUTE ON before testing the DC... if not, we are in a bad cycle.
Mute ON with less than 3 seconds -> -18V/-22V
Mute OFF -> -12V
😕
Some pictures of the ready amp. Size 230x230x80mm.
Toroid 225VA 2x30V AC Output at 2Kc is 75Vpeak with both channels driven is about 87Watts@8 Ohm per channel.
Bottom view
Toroid 225VA 2x30V AC Output at 2Kc is 75Vpeak with both channels driven is about 87Watts@8 Ohm per channel.
An externally hosted image should be here but it was not working when we last tested it.
Bottom view
An externally hosted image should be here but it was not working when we last tested it.
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