"The Wire" Ultra-High Performance Headphone Amplifier - PCB's

opc

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what size were you using? you might have to look for another reason the fuses are popping ... the current draw on this amp is VERY small; 0.5A @ 120V is 60W, the amp draws less than 5W, and I doubt the inrush current is too huge. I would think 0.2A would be more than enough.

yeah... I'd second that.

After all the confusion with the switch, and the fact that indeed the circuit doesn't draw more than a few dozen mA from the mains means you have a serious problem if you're blowing fuses, even really low current ones. The only exception to this is if you're using a monster size toroid which may have enough magnetization current to blow a low current fuse. If that's the case, you'll have to size the fuse accordingly.

Also, not to be rude, but if you really can't get the stuff on the primary side sorted, you really need to get someone to help you. Messing things up there can get you badly hurt, or burn down your house, or injure someone else. Unless you know exactly what you're doing, you shouldn't be playing with any circuit operating at mains voltages. I'm being very serious about this... if I were you I would stop and get some assistance from someone who knows what they're doing.

Regards,
Owen
 
I cant suggest anything without knowing exactly what transformer and power supply you are running. with a transformer that is just big enough at say 8-10VA and the standard power supply. I already suggested 0.2A as being more than enough. a fuse is not a fuse if it doesnt trip in a fault condition until its too late.
 
@gooniman:

In all likelihood, these will only ever be offered as boards with a complete BOM where you can order your own parts.

Here's the reasoning:

1. The boards are meant to be DIY, and to encourage people to source and build their own stuff. They are not meant to be "lower cost alternatives" to completed products (which I will be offering shortly).

2. It's a serious PITA to stock all the parts for kits, and to pack/prep the kits. It also usually means shipping in parcels instead of lettermail, which gets very expensive for international buyers.

3. If I charged people for the time it took me to order the parts, prep the kits and ship everything out, nobody would buy the parts kits anyhow since they would be way too expensive.

4. I want to leave the option open for people to organize their own group buys and really leverage the DIY spirit to get prices down as low as possible. The parts for these amps can be had much cheaper if your order quantities are in the hundreds or thousands of pieces.

@kuribo see the thread here. I believe completed units was an option Owen was looking into though he hasn't said anything firm about timing of those.
 
yes, I used Owen's earlier version of the board. Se to SE, changed the gain to 3, used 10k stepped controls for volume and balance. Put the power supply in an external case.

I am very happy
 

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didn't measure. I rescued a Pioneer AM FM Tuner from the side of the road and the output from a Nexus tablet is pretty low as well. That is why I set the voltage gain to 3x.

The sound quality of the nexus is not bad but at high volume levels you can hear when I touch and slide fingers on the screen.

The preamp is matched to Owen's LME49830 Lateralfet boards
see post 2024

http://www.diyaudio.com/forums/soli...ifier-based-lme49830-lateral-mosfets-203.html