Dumb questions first.
Measure the resistance between the red and black speaker terminals. It should be 500Ω to 1000Ω. If it is a low value you have a short some where. You did insulate the terminals?
Next measure the resistance between the RCA inner and outer ring. It should be about 50kΩ. If it is less something is wrong with the input.
As Mooly says you should measure 0.9 volts between Q2 S and Q1 D. And what ever the problem is is 'common' to both builds.
Some pictures of the build would help 'us all' have a look for a problem.
Measure the resistance between the red and black speaker terminals. It should be 500Ω to 1000Ω. If it is a low value you have a short some where. You did insulate the terminals?
Next measure the resistance between the RCA inner and outer ring. It should be about 50kΩ. If it is less something is wrong with the input.
As Mooly says you should measure 0.9 volts between Q2 S and Q1 D. And what ever the problem is is 'common' to both builds.
Some pictures of the build would help 'us all' have a look for a problem.
Thanks
The resistance between the terminals is 800 ohm and between the RCA rings it is 12k Ohm. This is not enough?
And yes the Terminals should be isolated with a plastic ring. I measured the resistance between the terminals and the case and is too high to be measured.
I atached some pics... Not my best work btw... did resolder everything so many times it is uglier then bevor :/.
Black is ground and negative and Red is hot and positive.
Thanks again
Attachments
One more thing... what spearkers are you using? The sound card is not likely to have outputs for passive speakers, so that means that your speakers are:
A. active (you input line level RCA audio and it has a built in amplifier)
B. Hybrid (they have both line level AND low impedance speaker terminals), but this is very unlikely to be the case on "cheap" speakers as you put it
C. ??? No idea... but passive speakers for sure are not able to be used with a regular sound card output.
So, I am a bit confused how your speakers setup looks like. Maybe I'm completely off here. Just giving more places to check for prbolems.
Rafa.
Yeah, but he said that the card "alone" drives the speaker to louder volumes. I am wondering what sort of "cheap" speakers (as he put it) would allow both a PRE to be connected to them (active speakers) but also hold speaker terminals to connect the ACA to drive the drivers directly bypassing the internal amp? I am sure there are many such speakers, but "cheap" is not a word I would use for them.
They are some passive speakers from a cheap logitech 5.1 system. They are there to test stuff so my good speaks dont get damaged.
Something in that ballpark.
Logitech Z906 5.1 Surround Sound Speakers System
And the soundcard is the from native instruments the traktor audio 4. I choose that one for testing because it has the loudest output.
There was a very silent sound coming from the ACA when it wasnt plugged in and I was wondering how loud the soundcard is without the ACA. Just for the reference I connected the soundcard directly to the speakers and it was way louder then the ACA, even with power on.(with the wrong resistor)
Just wanted to check if the soundcard is the problem and more power is needed :
Honestly I was also astonished that it works. But wasnt that loud...less loud then people speaking.
And thanks again. Still on worktime but very very looking forward to the ACA working
EDIT: I connected the soundcard to a RCA input and connected the wires to the speakers terminal, bypassing the ACA. The speaker itself doesnt have a RCA input, only terminals.
EDIT2: The soundcard has around 2,3Vrms Output
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ACA kits now in stock at the diyAudio store!
Amp Camp Amp – diyAudio Store
Amp Camp Amp – diyAudio Store
I was all set to order an ACA kit, but the DIYAudioStore is now sold out until the fall. (Why do they have such a long restocking cycle?)
What is the collective wisdom here about instead buying the chassis, power supply and PCB board and trying to source the remaining parts myself? Would you discourage someone new to kit building audio gear like myself from attempting it?
Many thanks in advance.
-Steve
It's the "Wayne's BA-2018 Line Stage" in it's default configuration, full kit from the store...
Have to say that, on some 86dB efficient speakers. Loudness-wise, it is a bit on the lower margin—poz @ 3-4pm—but honestly it is quite ok since I don't listen very loud.
avid
Have to say that, on some 86dB efficient speakers. Loudness-wise, it is a bit on the lower margin—poz @ 3-4pm—but honestly it is quite ok since I don't listen very loud.
avid
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Question... I was told to order specific LEDs ( PE P/N 073-018)from the ampcamp store (via email support) to match the amp camp amps (I purchased my ampcamps used and they did not have the LEDs installed). I purchased the specified superbright blue 5mm 3000 mcd LEDs with voltage dropping resistors...which comes with 100 ohm and 470 ohm resistors...the instructions for the ampcamp amp say to use a 10k resistor in series with your 24V PSU. What do I use with my 24v power supply ampcamp amp, or do I need a 10k and the supplied voltagereducing resistors?
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