Loud buzzing noise
Hi,
when nothing connected to input ACA is dead silent. When I connect output from my PC soundcard I get loud buzzing noise (sounds like sawtooth wave).
I didn´t have this problem when I was using linear power supply. Now I am using laptop smps adapter. Everything is star ground - same as before I was using linear PS.
Any ideas?
Hi,
when nothing connected to input ACA is dead silent. When I connect output from my PC soundcard I get loud buzzing noise (sounds like sawtooth wave).
I didn´t have this problem when I was using linear power supply. Now I am using laptop smps adapter. Everything is star ground - same as before I was using linear PS.
Any ideas?
Problem solved. My smps adapter doesn´t have third ground pin on ac mains connector, so I need to ground chassis to to safety ground via another wire.
I haven't been able to get my ACAs to work. And I fear I'm not likely to get the free time to troubleshoot them. So I think, sadly, I'm going to throw in the towel. I'd be willing to sell them both for $99. They are fully assembled (tho not working), red/black chassis, with the two power supplies. PM me if interested.
Don't throw in the towel yet - are they completely dead? Is the LED lighting up? Can you take any well- lit, in-focus photos and post them here?
Output impedance
Hi,
is there a way how to increase output impedance to 4 Ohms without adding 1.5R resistor to output and wasting the power?
Hi,
is there a way how to increase output impedance to 4 Ohms without adding 1.5R resistor to output and wasting the power?
different amp , then
different gain and most probably no way without wasting the power
besides converting upper Mu half to plain CCS (Rout goes to some 1R7 , with lower gain ) , that demands inclusion of substantial Rs for lower mosfet , to further increase Rout
so , gain will go down , same as efficiency
try what you're getting with some 2R7 to 3R connected in series
different gain and most probably no way without wasting the power
besides converting upper Mu half to plain CCS (Rout goes to some 1R7 , with lower gain ) , that demands inclusion of substantial Rs for lower mosfet , to further increase Rout
so , gain will go down , same as efficiency
try what you're getting with some 2R7 to 3R connected in series
simple proportion with load impedance
if load is 8R , with series connected 8R you'll waste 50% of power
if load is 8R , with series connected 8R you'll waste 50% of power
Like 6L6 said, take a clear photo (or a couple to show all the component values) and post it in the thread. That both amps don't work is a very good sign-probably there's the same problem on each..
6L6 and Variac, here are some photos of one of the amps, as requested. I'm grateful that you're willing to look at them. When I power up this one, I get a tiny flash from the LED, and that's it. Any ideas?
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
What Version is the Amp Camp and how to upgrade from there?
Still not getting a reply that helps and yes, I have read all the articles.
What version of all the Zen Amps is the Amp Camp?
What is the best way to experiment with the different Zen Amp versions? Breadboarding or modifying the AMP Camp PC boards?
All help appreciated.
Still not getting a reply that helps and yes, I have read all the articles.
What version of all the Zen Amps is the Amp Camp?
What is the best way to experiment with the different Zen Amp versions? Breadboarding or modifying the AMP Camp PC boards?
All help appreciated.
flohmann - your photos look good. I think the next step is to grab your DMM and make sure you have voltage (+19V, or close) at the +V on the PCB. Red probe on blue wire, black on black, meter set to DC volts.
docrob - The ACA is approximately the original Zen.
The best way to expirement is to get a heatsink and transformer, a handful of other pats, read the original zen articles, specifically 1-4, and start building/breadboarding. Listen to the ACA while you read/solder/build. 🙂 🙂 🙂
If you want to jump right into the deep end, build an Aleph J or F5. 😀
docrob - The ACA is approximately the original Zen.
The best way to expirement is to get a heatsink and transformer, a handful of other pats, read the original zen articles, specifically 1-4, and start building/breadboarding. Listen to the ACA while you read/solder/build. 🙂 🙂 🙂
If you want to jump right into the deep end, build an Aleph J or F5. 😀
I find it pretty hard to see, but 6L6's advice to check the voltage at the board input is good. People have mixed up wiring the power jack. One of the tabs is disconnected when the PSU plug is inserted, so the only sure way to know is to insert the PSU plug into the jack and then measure the tabs, or even better, measuring as 6L6 mentions makes sure you have the right polarity right at the board also!
I think his jack really might be wired wrong. Here's the photo from the Build Guide, and it is correct (as it matches my amps ! ) Red is positive of course.
If so do we need to give Mike a prize?!
If so do we need to give Mike a prize?!
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I built the original Zen amp years ago and made a stupid mistake -- it took another pair of eyes to see it. Would like to build the ACA, does anyone know if the whole kit will be offered again anytime soon?
Cheers!
Vinnie
Cheers!
Vinnie