)
I will be using a DL304 with 40 Ohms output impedance and 0,18 mV output.
So R1 should be 40 Ohms or as close as possible ( 39 Ohms) and R2 should be 7,2 K I guess ( 6,8 KOhm).
This will give a total gain of 60 DB for the PC3 , maybe an additional 1,5 KOhm would be ideal so I can play with the gain a little.
So R1 should be 40 Ohms or as close as possible ( 39 Ohms) and R2 should be 7,2 K I guess ( 6,8 KOhm).
This will give a total gain of 60 DB for the PC3 , maybe an additional 1,5 KOhm would be ideal so I can play with the gain a little.
Almost Complete
2 days ago my PCBs arrived from Richard. Today my Phonoclone 3 is up and running. My only problem is my outboard power supply is imparting some buzz into the signal. I've temporarily swapped in a 800ma Radio Shack 12v wall wart (I know, no intention of keeping it like this) but I'm more than pleased with the results. There's no buzz or hum at all if I use the wall wart, so I'm down to troubleshooting my power supply.
I've got a 48VA Hammond PCB mount split core transformer and an oversized 25A rectifier in an outboard aluminum box with a pigtail to the Phonoclone. Grounding the power chassis does nothing. Moving the rectifier away from the transformer doesn't change the buzz at all. I'm wondering if it's just my components were a bad decision. It imparts a buzz even with the Phonoclone off, so somethings not right.
I'm a complete amateur at soldering and assembly but everything went smoothly. I ordered everything through Mouser off the BOM other than Velleman cases and some hardware I picked up at a nearby electronics shop I recently discovered. I purchased a moderately priced soldering station online and practiced on a small Velleman kit before the boards arrived. Just need to resolve the power supply issue and apply some decals and I'll post some pictures and specifics on my parts used.
Thanks Richard!
2 days ago my PCBs arrived from Richard. Today my Phonoclone 3 is up and running. My only problem is my outboard power supply is imparting some buzz into the signal. I've temporarily swapped in a 800ma Radio Shack 12v wall wart (I know, no intention of keeping it like this) but I'm more than pleased with the results. There's no buzz or hum at all if I use the wall wart, so I'm down to troubleshooting my power supply.
I've got a 48VA Hammond PCB mount split core transformer and an oversized 25A rectifier in an outboard aluminum box with a pigtail to the Phonoclone. Grounding the power chassis does nothing. Moving the rectifier away from the transformer doesn't change the buzz at all. I'm wondering if it's just my components were a bad decision. It imparts a buzz even with the Phonoclone off, so somethings not right.
I'm a complete amateur at soldering and assembly but everything went smoothly. I ordered everything through Mouser off the BOM other than Velleman cases and some hardware I picked up at a nearby electronics shop I recently discovered. I purchased a moderately priced soldering station online and practiced on a small Velleman kit before the boards arrived. Just need to resolve the power supply issue and apply some decals and I'll post some pictures and specifics on my parts used.
Thanks Richard!
Hi,
While I get the gist of what's going on, posting a photo would be really helpful.
The recommended transformer is a Talema toroid. R-core or other toroidals are fine, but split core (EI) types may be problematic.
Double check all the connections and voltages around the power supply, and show us a photo ... but I suspect you have everything right, its the transformer that's letting you down.
Never skimp on the iron, you'll always regret it later.
Richard
While I get the gist of what's going on, posting a photo would be really helpful.
The recommended transformer is a Talema toroid. R-core or other toroidals are fine, but split core (EI) types may be problematic.
Double check all the connections and voltages around the power supply, and show us a photo ... but I suspect you have everything right, its the transformer that's letting you down.
Never skimp on the iron, you'll always regret it later.
Richard
You overestimated me, I didn't have it connected correctly.
I reviewed your construction guide and realised I had commited several mistakes.
First I had the earth ground passing through the power case directly to the phonoclone COM. The case wasn't even grounded..not good. So this gets me thinking about why COM, seperate from GND, is going from the transformer to the phonoclone. I had hooked up my transformer in parallel so had no COM. I only had +V -V and earth going to the phonoclone.
My transformer is the 48VA Hammond 229D24, I figured out to hook it up in series, and now have a center tap.
My own fault for just taking the power supply part of the project for granted as the simple part, and overlooking a very important detail. It's actually the only part of the project I was sure I had a complete understanding of. Oh well..
So it's up and running great. The difference with it operating via the Wall wart and the proper power supply is very obvious, as it should rightly be. Most obviously in depth of bass, and in busy sections of music where everything seems to break apart with the wall wart.
I now have to rethink my power switch and (super cool) blue LED I have. With the power supply set up as I had it before, I just used the switch to break +V and after that had the LED and resistor to -V. Now it seems that voltage leaks back through the phonoclone boards +v to the LED, when the switch is off.
I guess just a diode? Or is it necessary to use a 2 pole switch for both +V and -V due to the potential +-6v at COM?
I reviewed your construction guide and realised I had commited several mistakes.
First I had the earth ground passing through the power case directly to the phonoclone COM. The case wasn't even grounded..not good. So this gets me thinking about why COM, seperate from GND, is going from the transformer to the phonoclone. I had hooked up my transformer in parallel so had no COM. I only had +V -V and earth going to the phonoclone.
My transformer is the 48VA Hammond 229D24, I figured out to hook it up in series, and now have a center tap.
My own fault for just taking the power supply part of the project for granted as the simple part, and overlooking a very important detail. It's actually the only part of the project I was sure I had a complete understanding of. Oh well..
So it's up and running great. The difference with it operating via the Wall wart and the proper power supply is very obvious, as it should rightly be. Most obviously in depth of bass, and in busy sections of music where everything seems to break apart with the wall wart.
I now have to rethink my power switch and (super cool) blue LED I have. With the power supply set up as I had it before, I just used the switch to break +V and after that had the LED and resistor to -V. Now it seems that voltage leaks back through the phonoclone boards +v to the LED, when the switch is off.
I guess just a diode? Or is it necessary to use a 2 pole switch for both +V and -V due to the potential +-6v at COM?
Switch the AC line, never the output voltage. Use a 250V rated toggle switch, or, more conveniently, an IEC socket with a built in switch and fuse for convenience.
The LED can go on the secondaries, from V+ to V-, with a resistor in series to limit the current (and LED brightness). 3k3 should be about right.
If you have two transformers, or two independent secondaries, you can connect two bridge rectifiers and bring the four +,-,+,- wires individually back to the phonoclone PCB. Connect as +=V+,(-,+=COM),- =V-) to each board.
The LED can go on the secondaries, from V+ to V-, with a resistor in series to limit the current (and LED brightness). 3k3 should be about right.
If you have two transformers, or two independent secondaries, you can connect two bridge rectifiers and bring the four +,-,+,- wires individually back to the phonoclone PCB. Connect as +=V+,(-,+=COM),- =V-) to each board.
Suggestions??
Unfortunately, I built my outboard power supply without a switch and switched the secondaries, treating the power supply like an outboard transformer. I can see how it's not as safe as it would be switched at the mains but isn't every wall adapter also always hot on it's pigtail? I do have a 1/2amp fast acting fuse in the brick.
Plugged in it the transformer has a very quiet hum. Curious as to how much power it's consuming just plugged in a DMM shows it drains .97mA AC. however, with the phonoclone powered up it's 1.6 mA which can't be right, less than a watt???. Maybe I'm not measuring it correctly. Again, I'm a total newbie at this. W=V*A??
On to the Phonoclone itself.
Here's the Phonoclone enclosure
View inside
The power brick needing a switch
Not as much space in there as it looks in this picture
Any ideas for a proper mains switch?
Putting a switch in the power enclosure is going to be a tight fit. Maybe I could put a power switch in the lid and turn it on and off like a stomp box?
I could leave the switch on the phonoclone just to turn on the LED if the cosmetics concern me.
Unfortunately, I built my outboard power supply without a switch and switched the secondaries, treating the power supply like an outboard transformer. I can see how it's not as safe as it would be switched at the mains but isn't every wall adapter also always hot on it's pigtail? I do have a 1/2amp fast acting fuse in the brick.
Plugged in it the transformer has a very quiet hum. Curious as to how much power it's consuming just plugged in a DMM shows it drains .97mA AC. however, with the phonoclone powered up it's 1.6 mA which can't be right, less than a watt???. Maybe I'm not measuring it correctly. Again, I'm a total newbie at this. W=V*A??
On to the Phonoclone itself.
Here's the Phonoclone enclosure
View inside
The power brick needing a switch
Not as much space in there as it looks in this picture
Any ideas for a proper mains switch?
Putting a switch in the power enclosure is going to be a tight fit. Maybe I could put a power switch in the lid and turn it on and off like a stomp box?
I could leave the switch on the phonoclone just to turn on the LED if the cosmetics concern me.
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