Spontaneous electrical failures
- By Sadface
- Construction Tips
- 9 Replies
G'day Guys,
What causes a perfectly functioning device to spontaneously fail?
Exhibit A:
This is the controller pcb from a commercial blender.
The blender functioned perfectly until it suddenly decided to put out some magic smoke.
To me it appears as though an arc has occurred across the lead of a diode to the lead of a mosfet.
Exhibit B:
This is an Ebay speaker protection board. It worked perfectly the first 5 or so times it was powered up however during a recent test of an amp I was building I saw a little puff of smoke come out and found the melted pcb trace.
What causes a perfectly functioning device to spontaneously fail?
Exhibit A:
This is the controller pcb from a commercial blender.
The blender functioned perfectly until it suddenly decided to put out some magic smoke.
To me it appears as though an arc has occurred across the lead of a diode to the lead of a mosfet.
Exhibit B:
This is an Ebay speaker protection board. It worked perfectly the first 5 or so times it was powered up however during a recent test of an amp I was building I saw a little puff of smoke come out and found the melted pcb trace.
Graaf input selector identification help
- By Mr.Ian
- Analog Line Level
- 2 Replies
Trying to find a replacement input selector for a Graaf 13.5Bii looking at the Elma data chart for type 4 selectors I think it may be an Elma 04-1453. Shorting, single wafer, 4 pole, 5 input
The switch fitted looks to have input terminals in banks of 5 which appears to match the data sheet but images I found on line look to show 22/24 terminals. That is to say lugs between the banks of 5 which the fitted switch does not appear to have.
As the switch is soldered directly to the board I need an exact fit drop in replacement.
anyone had experience of this amp/switch that can shed some light on the matter
The switch fitted looks to have input terminals in banks of 5 which appears to match the data sheet but images I found on line look to show 22/24 terminals. That is to say lugs between the banks of 5 which the fitted switch does not appear to have.
As the switch is soldered directly to the board I need an exact fit drop in replacement.
anyone had experience of this amp/switch that can shed some light on the matter
LKS Audio USB 100 Interface problem
- By noyan
- Digital Source
- 6 Replies
Hello,
I bought a LKS Audio USB 100 Interface from ebay. Unfortunately when i checked inside i noticed that instead of Crystek clocks they installed Femto Clocks. I wrote to seller to compansate me 100 USD for the clock replacement cost and waiting the answer. The second problem is, when i turn on the device first it shows me 44.1khz on its screen. When i open hi resolution music on youtube, nothing changing on the screen and all the time shows 48. I wrote to LKS Audio and waiting their response.
Any idea for this ???
pictures up loader website
I bought a LKS Audio USB 100 Interface from ebay. Unfortunately when i checked inside i noticed that instead of Crystek clocks they installed Femto Clocks. I wrote to seller to compansate me 100 USD for the clock replacement cost and waiting the answer. The second problem is, when i turn on the device first it shows me 44.1khz on its screen. When i open hi resolution music on youtube, nothing changing on the screen and all the time shows 48. I wrote to LKS Audio and waiting their response.
Any idea for this ???
pictures up loader website
Car Audio DIY Crossover Design Help
So I'm going to change my car audio system to the following:
Woofer/Midbass: Dayton Audio RS180-4
Tweeter: Dayton Audio ND25FN-4
Firstly, does this combination seem good? Looking at the frequencies and from what I've read about the RS180-4 drivers, they need crossing over about 3khz for best performance and the tweeters should be okay crossing over above 2.5khz.
I've had a go at designing a crossover on xSim and wondered if the more knowledgable on the forum could point out my errors.
Any help would be greatly appreciated!
Woofer/Midbass: Dayton Audio RS180-4
Tweeter: Dayton Audio ND25FN-4
Firstly, does this combination seem good? Looking at the frequencies and from what I've read about the RS180-4 drivers, they need crossing over about 3khz for best performance and the tweeters should be okay crossing over above 2.5khz.
I've had a go at designing a crossover on xSim and wondered if the more knowledgable on the forum could point out my errors.
Any help would be greatly appreciated!
DIY amp completed - part II : FB Custom
- By tubelectron
- Instruments and Amps
- 4 Replies
I built this one for an amateur luthier friend who helped me restore guitars and built some custom-made models for me... 🙂
The FB CUSTOM offers a 10WRMS clean power output, plus FSWable booster and master volume, allowing to juggle on with an array of clean-unboost / overdrive-boost settings if desired, even at home loudness.
And this time, the weight is correct with (only 🙄) 10.5kg FSW incuded... 😎😉
A+!
The FB CUSTOM offers a 10WRMS clean power output, plus FSWable booster and master volume, allowing to juggle on with an array of clean-unboost / overdrive-boost settings if desired, even at home loudness.
And this time, the weight is correct with (only 🙄) 10.5kg FSW incuded... 😎😉
A+!
Simple DIY volume control for a subwoofer
- By Jacktro
- Construction Tips
- 1 Replies
Hi,
Looking for a simple volume control for my subwoofer....its currently "Thumping"
The subwoofer on my Sony surround system failed,so i was gifted an active subwoofer my mate had not even opened never mind used. Some people, more £££ than .....
I was able to get sound to the sub but with a high hum(a google chk told me its normal for this particular sub), so not a wiring issue. I decided to bypass the control panel and just wire up direct to the speaker....worked fine,hum gone... just its a bit loud and with limited bass/sub adjustment on the amp im hoping i can do something like this.....
How to Build a Speaker Circuit with Adjustable Volume
The above uses a headphone jack which i would not use...just the potentiometer somewhere on the speaker cable.
Would this work? or should i be looking at something else.
Thx Jack
Looking for a simple volume control for my subwoofer....its currently "Thumping"
The subwoofer on my Sony surround system failed,so i was gifted an active subwoofer my mate had not even opened never mind used. Some people, more £££ than .....
I was able to get sound to the sub but with a high hum(a google chk told me its normal for this particular sub), so not a wiring issue. I decided to bypass the control panel and just wire up direct to the speaker....worked fine,hum gone... just its a bit loud and with limited bass/sub adjustment on the amp im hoping i can do something like this.....
How to Build a Speaker Circuit with Adjustable Volume
The above uses a headphone jack which i would not use...just the potentiometer somewhere on the speaker cable.
Would this work? or should i be looking at something else.
Thx Jack
Build: Dual mono push-push
- By MtBiker
- Subwoofers
- 12 Replies
This is not a recent build, but I have been meaning to post it for several years. It is also a precursor to a 3-way speaker build thread I intend to post that builds on this one.
Design Requirements
I was replacing an old NHT1259-based sub that had been in the corner and had sufficient output for the room, but I wanted lower distortion, more headroom and it had to be hidden. I was also planning on replacing closed cabinets with an open stereo rack that would be perpendicular to the wall, and obscured from view by a screen. This would allow me to easily access the front and back of each component, and had no doors that would trap heat. I could have built subs into the front corner wall, but this would have been an involved project entering attic space below a sloping roofline, and I decided it would be easier to push the stereo rack to the ceiling and leave room underneath it for the sub (centered on the front wall). Here is a rendering with the outgoing sub under the new rack:
Being directly under the stereo rack (but not touching it), I knew I wanted to limit vibration, so I decided to build a push-push sub. Limiting it to the width of the rack above it did not leave enough depth for back to back drivers, so they would need to be rotated and fire along the length of the room instead of left to right. However, I did not like the idea of them firing into the wall and the back of the screen, so I decided to have them face each other and radiate out a slot.
Design Details
The room is an odd L shape to the back left, and with an additional bump out and a sloped ceiling to the right. I did not try to simulate room gain or modes. I did simulate and measure the nearfield response, and I measured the response at the listening position with room gain. Coincidentally, the room gain flattened most of the low end falloff and I did not have to apply any EQ to raise the low end. The sub is crossed over to the main speakers at 80Hz and room modes are equalized out at the listening position below 150Hz.
More build photos available here.
Design Requirements
I was replacing an old NHT1259-based sub that had been in the corner and had sufficient output for the room, but I wanted lower distortion, more headroom and it had to be hidden. I was also planning on replacing closed cabinets with an open stereo rack that would be perpendicular to the wall, and obscured from view by a screen. This would allow me to easily access the front and back of each component, and had no doors that would trap heat. I could have built subs into the front corner wall, but this would have been an involved project entering attic space below a sloping roofline, and I decided it would be easier to push the stereo rack to the ceiling and leave room underneath it for the sub (centered on the front wall). Here is a rendering with the outgoing sub under the new rack:
Being directly under the stereo rack (but not touching it), I knew I wanted to limit vibration, so I decided to build a push-push sub. Limiting it to the width of the rack above it did not leave enough depth for back to back drivers, so they would need to be rotated and fire along the length of the room instead of left to right. However, I did not like the idea of them firing into the wall and the back of the screen, so I decided to have them face each other and radiate out a slot.
Design Details
- (2) Dayton Audio RSS315HF-4 12" Reference
- HF Subwoofer 4 Ohm in sealed cabinets.
- Dual drivers face each other for force cancellation, which works quite well. Cabinet vibration is almost imperceptible.
- Both cabinets are cut from a single sheet of plywood, well braced, and doubled up on some walls.
- The cabinets are joined by heavy, threaded rods which are concealed by aluminum tubing. I think the tubing is causing the high frequency ringing during sweep measurements, but it is far outside the passband.
- Rubber gaskets under large diameter washers ensure an airtight seal for the threaded rods.
- Copious use of shellac prior to priming ensures no seams are visible through the paint.
- Spray painted using rattle cans, but finished with General Finishes flat water-based poly via HVLP.
- Total dimensions (including 4” gap between cabinets) is 23” W x 19.25” H x 16.25” D
- Internal cabinet volume is approximately 30 liters with a QTC of 0.83, but as built, it measures like 20 liters with a QTC of 0.96.
- Crossover and room EQ provided by MiniDSP 2x4HD
The room is an odd L shape to the back left, and with an additional bump out and a sloped ceiling to the right. I did not try to simulate room gain or modes. I did simulate and measure the nearfield response, and I measured the response at the listening position with room gain. Coincidentally, the room gain flattened most of the low end falloff and I did not have to apply any EQ to raise the low end. The sub is crossed over to the main speakers at 80Hz and room modes are equalized out at the listening position below 150Hz.
More build photos available here.
Dynaudio Crafft Crossover schematics help!
Dear Sir,
I have Dynaudio T330D esotar tweeter and 17W75 woofer. So i want to DIY Dynaudio Crafft speaker.
I want to ask for the crossover schematics of Dynaudio Crafft speaker.
Can anyone help me?
Tks
Dynaudio Crafft:
I have Dynaudio T330D esotar tweeter and 17W75 woofer. So i want to DIY Dynaudio Crafft speaker.
I want to ask for the crossover schematics of Dynaudio Crafft speaker.
Can anyone help me?
Tks
Dynaudio Crafft: