Have you got the speaker protection board yet, and has pacificblue found me a circuit that does not use relays
Don't mean to bring back the whole speaker protection board thing...but I am. 😀
Does the uPC1237 platform allow you to use only ONE mono signal instead of stereo. I'd like to add a subwoofer eventually, and I hope to use the same board because it is cheap. Can I simply hook up only 1 channel and get it to work effectively? Anyone an expert on these things?
Thanks.
Does the uPC1237 platform allow you to use only ONE mono signal instead of stereo. I'd like to add a subwoofer eventually, and I hope to use the same board because it is cheap. Can I simply hook up only 1 channel and get it to work effectively? Anyone an expert on these things?
Thanks.
Yes. Here is one example.
2x Speaker Protection C1237 (UPC1237) Mono DIY Kit_Delay Protection_Accessories Kit_Analog Metric Limited - DIY Audio Kit
Regards
2x Speaker Protection C1237 (UPC1237) Mono DIY Kit_Delay Protection_Accessories Kit_Analog Metric Limited - DIY Audio Kit
Regards
Hey barry
i dont see how you could do a non relay speaker protect.It has to be last in line to the speakers and carry that higher voltage signal.I think any Ic based protection would be built into the chip such as the lm3886's mute function.
i dont see how you could do a non relay speaker protect.It has to be last in line to the speakers and carry that higher voltage signal.I think any Ic based protection would be built into the chip such as the lm3886's mute function.
I think you are right. That means Naim don't have any protection and they are very good and very expensive amps.
Naim amps may be expensive and good sounding, but they are a bit special in that regard.
For some of their amplifier models Naim still oblige their customers to use a specific cable with high inductance. That is due to a missing or incomplete Thiele circuit at the amplifier output. Using another cable could lead to oscillation and even the destruction of the amp. Nowadays they hide that fact behind having to comply with European safety regulations.
Surprisingly they also have amps that comply with European safety regulations without the need of using special cables. Allowing the use of any cable you like is still worth noting in the user's manual in their opinion. I.e. if their amps are designed to withstand such 'abuse'.
Naim has also been trying to convince customers during many years that loud popping noises at start-up and shut-off are normal behaviour of amplifiers and not harmful to speakers at all. Nevertheless they advise after a thermal shutdown to
At least they have a thermal protection circuit.
So I got one of the protection boards today. I'll take pictures/post later. But for now....
It has a 26VAC input (1 hole), + 32VDC + DC Ground. Capacitors come from Elna and Teapo. Relays remain the same. Looks like good quality to me.
It has a 26VAC input (1 hole), + 32VDC + DC Ground. Capacitors come from Elna and Teapo. Relays remain the same. Looks like good quality to me.
No Andrew, It is for measurement of AC from the transformer. The other side of the board has the DC-0 for operating the relays.
No.
All circuits require a circular route (= circuit).
If there is one connection from AC there must be a second connection to the AC to complete the circuit.
There MUST be a second connection from the PCB back to the transformer secondary. Is it hidden in the grounding?
All circuits require a circular route (= circuit).
If there is one connection from AC there must be a second connection to the AC to complete the circuit.
There MUST be a second connection from the PCB back to the transformer secondary. Is it hidden in the grounding?
This must not be, Andrew.
I did a similar design.
I have a transformer with 2 secondary windings and defined (connected) one end of each secondary winding as (to) GND.
The idea behind this is: as soon as the mains is powered off, the Speaker Protection PCB looses its input voltage (I assume, that the AC voltage is rectified by a (one) diode) and will no longer be able to keep the relay's coil closed.
Best regards - Rudi_Ratlos
I did a similar design.
I have a transformer with 2 secondary windings and defined (connected) one end of each secondary winding as (to) GND.
The idea behind this is: as soon as the mains is powered off, the Speaker Protection PCB looses its input voltage (I assume, that the AC voltage is rectified by a (one) diode) and will no longer be able to keep the relay's coil closed.
Best regards - Rudi_Ratlos
A circuit must be a circular route.
There are no exceptions.
The secondary must have two connections to the PCB. There are no exceptions.
Connecting one secondary AC to the PCB does not complete the circuit.
There are no exceptions.
The secondary must have two connections to the PCB. There are no exceptions.
Connecting one secondary AC to the PCB does not complete the circuit.
Yes, of course that is true. I think one of the secondary wires is connected to ground and that completes the circuit. Sometimes this connection is taken for granted or it goes through other wires making it less obvious, but it must be there for the circuit to work.
All I am saying is there is only one AC connection to the transformer and a supply of DC-0
for the board. It has all been covered in previous posts.
for the board. It has all been covered in previous posts.
Sorry for reviving this topic again, but damn, I still don't get why there's only one hole for AC. Is current not even flowing through it at all? Is that how "AC sense" works?
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On another note, I finally go to ordering all of the parts for this board as well as an LM4780 board I hope to use as a subwoofer amp. I decided to be a little cheap. The only thing I really went big on was those damn Wima caps that were like $4.50 each. I was going to use polyester (Mylar), but an overwhelming amount of people were bashing polyster for coupling caps...so I decided to just suck it up. Audiophile resistors= bulls---. I just got some cheap-o Xicon metal films. I can't believe people will pay $2+ for a 1/4W RESISTOR...Sheesh. $0.13 each, thank you very much. Of course 10,000uF didn't come cheap either...
I should have the stuff in by Friday, and I'll try to have both boards all soldered up by Saturday/Sunday latest! Woohoo!
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On another note, I finally go to ordering all of the parts for this board as well as an LM4780 board I hope to use as a subwoofer amp. I decided to be a little cheap. The only thing I really went big on was those damn Wima caps that were like $4.50 each. I was going to use polyester (Mylar), but an overwhelming amount of people were bashing polyster for coupling caps...so I decided to just suck it up. Audiophile resistors= bulls---. I just got some cheap-o Xicon metal films. I can't believe people will pay $2+ for a 1/4W RESISTOR...Sheesh. $0.13 each, thank you very much. Of course 10,000uF didn't come cheap either...
I should have the stuff in by Friday, and I'll try to have both boards all soldered up by Saturday/Sunday latest! Woohoo!
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Yes you can use one chip for a stereo set.... with a dual pole relay... its basicaly only the relay that changes, between mono and stereo.
The AC connection is just to check the power status of the mains, as on the DC side of things, there are capacitors keeping the rails active even after power down.
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