NP, Bill. 🙂
So - another 'panel' lover! 🙂
I had owned Maggies for nearly 30 years, before my new spkrs. I don't miss them at all!
Aah, that's a shame. 🙁 I agree the AN is exceptionally resolving ... but I'm not finding any problems with my sources - merely hearing more! 😀
Andy
Well darn looks like i honestly have to say I no longer know what I'm doing.
I have a dual rail SMB running at 32v with a single AN.
On the output side low distorted audio and the large transistors stay cool to the touch.
let me know if someone can help.
Best,
Shane
I have a dual rail SMB running at 32v with a single AN.
On the output side low distorted audio and the large transistors stay cool to the touch.
let me know if someone can help.
Best,
Shane
It’s not biasing properly if the MOSFETs are cool. Please measure voltages at all transistor legs and redline the schematic. Take a photo and post here. That’s the best way for us to diagnose remotely. It’s like a full blood test and X-rays and vitals ordered by an emergency room physician when they don’t know what is causing a patient to be sick. It’s work to collect that, but worth it as the fault can be precisely pin pointed.
At minimum, voltages (with respect to GND) at all pins of output MOSFETs and across the source resistors. Generally when the amp is not biasing properly with the circa 1.3A current - a cold solder joint, loose connection, or incorrect resistor is loaded. Sometimes it is a bad electrolytic cap.
At minimum, voltages (with respect to GND) at all pins of output MOSFETs and across the source resistors. Generally when the amp is not biasing properly with the circa 1.3A current - a cold solder joint, loose connection, or incorrect resistor is loaded. Sometimes it is a bad electrolytic cap.
Happily just be for the i take these measurements i may need to look at the Daul SMB on the output i have 29.6 and -30.6 no of palying with the trim pots can make this better
I can see nothing amiss, but I might miss something.......
You should use some heatshrink on all the wire/semi connections, particularly near the heatsinks.
I'd suggest you switch off, then trace all the wire from semis back to the intended point pcb; if your outputs are not producing heat it indicates either a connection is open OR the current sensor across base/emitter on the output resistors is miswired or even the wrong gender.
There is no easy to way fixing these issues and they happen even with seasoned pros. You can't see, smell or hear electricity, you need to check all the connections with a meter.
HD
You should use some heatshrink on all the wire/semi connections, particularly near the heatsinks.
I'd suggest you switch off, then trace all the wire from semis back to the intended point pcb; if your outputs are not producing heat it indicates either a connection is open OR the current sensor across base/emitter on the output resistors is miswired or even the wrong gender.
There is no easy to way fixing these issues and they happen even with seasoned pros. You can't see, smell or hear electricity, you need to check all the connections with a meter.
HD
UP AND WORKING!!!!
I have a test 12in coaxial Wharfedale speaker thumping with high clarity.
I cleaned up some wiring and check the values of every single component.
I found a cold solder joint on the one of the legs on the KSA992.
now to move towards stereo!
Thank for the help
I have a test 12in coaxial Wharfedale speaker thumping with high clarity.
I cleaned up some wiring and check the values of every single component.
I found a cold solder joint on the one of the legs on the KSA992.
now to move towards stereo!
Thank for the help
Great news! It’s always something like that - cold solder joint gets us all. Better than forgetting to even solder a joint. That’s happened to me a few times.
The other AN board working flawlessly. (I wish i had started with that one but no smoke so im very happy) now a i can dig into my Yarra build
Great news, Shane........
Now, enjoy the sound but marvel at the heat produced. Class A amps are a thermal challenge.
Hugh
Now, enjoy the sound but marvel at the heat produced. Class A amps are a thermal challenge.
Hugh
Well done - but why don't you completely finish the amps - so you can start listening to them - before starting yet another build?
You did very well to have just one or two dry joints - it took me many months to get my 2 amps working as they should, after finishing the soldering. 🙁
But as Hugh posted ... you will be amazed by how much they heat the room. 😀 I built the 4R version - which means that each stereo amp puts out 240w of heat. I believe this is a bit more than the 8R version (180w?) but I'm resigned to only running my ANs during non-summer months - due to their heat output. 🙁
Andy
The amp is now 100% completed.
At the time of troubleshooting i did not want to power up both channels in hopes to minimize damage.
Yeah they sure do give off a good amount of heat but that's the price we pay for class A.... its worth it!
Congrats, Shane! May we see some photos of the build?
What speakers are you currently driving with the AN’s?
What speakers are you currently driving with the AN’s?
Id like to think of this as a simpler build.
I need to do some wire management (don't judge me to harshly)
I'm toying with the idea of adding 2 VU meters and power switches for each side, something looking like the HH Scott alpha line.
sadly I haven't found any meters that have blown me away.
On the speaker front I test with a pair of 12in wharfedale coaxial.
In the study i have a pair of Sansui Stereo Speakers SP-1500.
It all sounds great honestly. It maybe time for and upgrade but I don't have any plans at the present.
I need to do some wire management (don't judge me to harshly)
I'm toying with the idea of adding 2 VU meters and power switches for each side, something looking like the HH Scott alpha line.
sadly I haven't found any meters that have blown me away.
On the speaker front I test with a pair of 12in wharfedale coaxial.
In the study i have a pair of Sansui Stereo Speakers SP-1500.
It all sounds great honestly. It maybe time for and upgrade but I don't have any plans at the present.
Attachments
Nice work, Shane!
Could you give us a short review of the sound quality after running through a few albums?
Good case, too.
HD
Could you give us a short review of the sound quality after running through a few albums?
Good case, too.
HD
Congrats on the new build, Shane! Very nice neat work. If you like round gauges, these VU meters I am trying out right now with my new 600w class D amp driven by a tube buffer is very nice. Kind of Nagraesque looking.
Ha, I have a pair of those vu meters, was going to put them in my Alpha Nirvana but just could not make them fit in my case.
What's the obsession with VU meters? 😕 The AN already incorporates a very useful red 'clip LED' in each channel. If this never flickers on when you're playing music ... you ain't clipping! 🙂 So who cares whether you're actually outputting 3w ... or 23w!
Andy