I made an Aikido tube pre for my F4. It's a simple build and works out great. You can get all the gain you could ever want out of it.
Also, I'm in the Austin area. PM me if you ever want to get together to discuss or listen to DIY.
Phil
Hi Guys,
I am stuck with wiring my dual mono F4 with 240v AC mains. Please see pic attached. I am not very good with reading schematic drawings. Also one more question what fuse should I use the AC?
Transformer specs - 2x24 500 VA - Secondary current - 2 x 10.4 A
Thanks
Dillan
I am stuck with wiring my dual mono F4 with 240v AC mains. Please see pic attached. I am not very good with reading schematic drawings. Also one more question what fuse should I use the AC?
Transformer specs - 2x24 500 VA - Secondary current - 2 x 10.4 A
Thanks
Dillan
An externally hosted image should be here but it was not working when we last tested it.
Dillan,
I assume you have two ~115V primaries. What you basically want is to wire
the primaries in series: The 'live' of one connected to one leg of the thermistor
and the other leg of the thermistor to the neutral of the other primary. (per
F4 manual.)
Your secondary voltage is too high for a standard F4. You probably want
2x18 or thereabout.
Dennis
I assume you have two ~115V primaries. What you basically want is to wire
the primaries in series: The 'live' of one connected to one leg of the thermistor
and the other leg of the thermistor to the neutral of the other primary. (per
F4 manual.)
Your secondary voltage is too high for a standard F4. You probably want
2x18 or thereabout.
Dennis
Thanks Dennis,
With the secondary voltage I am using 35v Capacitor on the PSU board so don't this I'll have a problem there. The primaries is not 115V. It is 230v - I am in the UK so we use 240v power.
This is a pic from the F5 guide PDF, it has info on Wiring your transformer for 240V AC Mains operation - see below.
I just a bit confused with the wiring. Thanks
dev.imageshowcase.co.uk/image/240v.png
On the left side are the primary windings, and on the right side are the secondary windings. Notice that there are two pairs of 115V primary windings? There's also a purple wire that's connected to an interstage shield which you can connect to the chassis ground, but let's just leave it unconnected and concentrate on the two pairs of 115V windings for now. Please dress the purple with heatshrink tubing and tuck it away. I have purposely labeled the wires 1, 2, 3 and 4 for easy reference. What we want to do first is find out which of the four wires are the pairs 1 & 2, and pairs 3 & 4. That's very simple to do.
1. Get your DMM and set it to check for resistance.
2. Now grab one of the red wires and check for resistance between that and the two black wires (Obviously, you will only read a low resistance on one of the black wires).
3. Once you read a low resistance between a red wire and a black wire, label the red wire as 1 and the black wire as 2.
4. Now get the other red and black wire and check for resistance.
5. You should read a low resistance between them confirming that's the other pair.
6. Label the red wire as 3 and the black wire as 4.
7. Prepare a CL-12 thermistor and label it's leads as 5 and 6.
Ok so now we know our pairs 1 & 2 and 3 & 4, and we have our thermistor ready too, we are now ready to wire our transformer for 240VAC operation.
1. Connect the transformer's red wire labeled 1 to the LIVE pin of the Power Entry Module (PEM).
2. Connect the thermistor's lead labeled 5 to the transformer's black wire labeled 2.
3. Insulate that connection with heatshrink tubing.
4. Connect the thermistor's lead labeled 6 to the transformer's red wire labeled 3.
5. Insulate that connection with heatshrink tubing.
6. Connect the transformer's black wire labeled 4 to the PEM's NEUTRAL pin.
And that's it, your power transformer is now ready for 240V AC Mains operation.
With the secondary voltage I am using 35v Capacitor on the PSU board so don't this I'll have a problem there. The primaries is not 115V. It is 230v - I am in the UK so we use 240v power.
This is a pic from the F5 guide PDF, it has info on Wiring your transformer for 240V AC Mains operation - see below.
I just a bit confused with the wiring. Thanks
dev.imageshowcase.co.uk/image/240v.png
On the left side are the primary windings, and on the right side are the secondary windings. Notice that there are two pairs of 115V primary windings? There's also a purple wire that's connected to an interstage shield which you can connect to the chassis ground, but let's just leave it unconnected and concentrate on the two pairs of 115V windings for now. Please dress the purple with heatshrink tubing and tuck it away. I have purposely labeled the wires 1, 2, 3 and 4 for easy reference. What we want to do first is find out which of the four wires are the pairs 1 & 2, and pairs 3 & 4. That's very simple to do.
1. Get your DMM and set it to check for resistance.
2. Now grab one of the red wires and check for resistance between that and the two black wires (Obviously, you will only read a low resistance on one of the black wires).
3. Once you read a low resistance between a red wire and a black wire, label the red wire as 1 and the black wire as 2.
4. Now get the other red and black wire and check for resistance.
5. You should read a low resistance between them confirming that's the other pair.
6. Label the red wire as 3 and the black wire as 4.
7. Prepare a CL-12 thermistor and label it's leads as 5 and 6.
Ok so now we know our pairs 1 & 2 and 3 & 4, and we have our thermistor ready too, we are now ready to wire our transformer for 240VAC operation.
1. Connect the transformer's red wire labeled 1 to the LIVE pin of the Power Entry Module (PEM).
2. Connect the thermistor's lead labeled 5 to the transformer's black wire labeled 2.
3. Insulate that connection with heatshrink tubing.
4. Connect the thermistor's lead labeled 6 to the transformer's red wire labeled 3.
5. Insulate that connection with heatshrink tubing.
6. Connect the transformer's black wire labeled 4 to the PEM's NEUTRAL pin.
And that's it, your power transformer is now ready for 240V AC Mains operation.
It isn't balanced input - I'm just using two transformers and PSU boards.
See pics.
http://dev.imageshowcase.co.uk/image/IMG_2855.jpg
http://dev.imageshowcase.co.uk/image/IMG_2844.jpg
See pics.
http://dev.imageshowcase.co.uk/image/IMG_2855.jpg
http://dev.imageshowcase.co.uk/image/IMG_2844.jpg
There is a single balanced input to a stereo F4 - it turn it into a bridged monoblock that needs to be driven from a balanced source.
First, build two F4, then build Pumpkin, ImPasse, BA-3FE balanced, or something else than can swing +/-20V into an XLR.
XLR + to right +, XLR - to left +, XLR GND to L and R GND, take the output from the speaker positives ... Speaker + to right channel red, Speaker - to left channel red
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