Aurora Compressor from Aion

[spoontex]

Hi,

I've just finished the building of Aurora, and they don't work... is to bassy and the trebble switch don't work. I've change the transistors and check all the others components.. Any idea?!?!¿

https://vimeo.com/171801211

[whoisalhedges]

Those with the talents to help you will find it much easier if you provide the information here:

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

[spoontex]

Thanks.

I'll do the voltage list of each component and I will post them.

[whoisalhedges]

Looks like a Dyna Comp/Ross clone, right? That's a common enough circuit, lots of people here have built it. Post your voltages, and I bet someone here will have you fixing it within a couple days.

Welcome aboard, from one newbie to another!

[whoisalhedges]

Reading the project page at https://aionelectronics.com/project/aurora-ross-dyna-compressor/ it says the treble switch attenuates the highs. If the switch doesn't do anything, and it's too bassy; my money's on the wiring of the switch itself. Like there's a short somewhere which has it acting like it's in full-attenuation mode all the time, no matter where you have it set.

Might be other issues, too, but that jumps out.

[spoontex]

Ok, this are my readings:

Q1:
    C = 7.79
    B = 2.64
    E = 2.32

Q2:
    C = 9,84
    B = 3.20
    E = 2.74

Q3:
    C = 10.12
    B = 0
    E = 0

Q4:
    C = 10.12
    B = 0
    E = 0

Q5:
    C = 10.13
    B = 10.11
    E = 9.61

D1:
    A = 0
    K = 10,13

D2:
    A = 0
    K = 0

D3:
    A = 0
    K = 0

IC:

    1 = 0
    2 = 5.19
    3 = 5.20
    4 = 0
    5 = 0.63
    6 = 3.20
    7 = 10.13
    8 = 0

- I desolder D2 and D3 and check, they sems that be ok
- I replace the transistors Q3 and Q4 but still the same readings...

[whoisalhedges]

Q3:
    C = 10.12
    B = 0
    E = 0

Q4:
    C = 10.12
    B = 0
    E = 0

Q5:
    C = 10.13
    B = 10.11
    E = 9.61

D1:
    A = 0
    K = 10,13

D2:
    A = 0
    K = 0

D3:
    A = 0
    K = 0

You probably see the problem here... Q3 and Q4 have no bias on their bases. If the base isn't a diode drop above the emitter, the transistor won't work. On Q5, meanwhile, the base is almost as positive as the collector, no room to swing.

D2 and D3 are showing the same problem as Q3 and Q4 - as their anodes are tied to those transistors' bases, and the bases are at 0V, there's also 0V on the diodes.

[whoisalhedges]

For troubleshooting reference:

[spoontex]

The D1 is well mounted.

This or all others build reports ara wrong... Because Q3 and Q4 have no voltage?

https://aionelectronics.com/wp-content/uploads/2014/12/aion-aurora-ross-compressor-documentation.pdf

[spoontex]

I can't insert images in a post?!?!

I try to put some potos and I can't...

[spoontex]

I think that I found something... the GND pad of the board out 9V!!!!! with the GND pad disconeccted all the transistors show correct values...

any idea!!!??

[bluebunny]

I can't insert images in a post?!?!

I try to put some potos and I can't...

What did you try?

You need to click on Mona:

This gives you a pair of [img][/img] tags.  Put the URL of your image (which has to be hosted somewhere) in between these tags.

[whoisalhedges]

I think that I found something... the GND pad of the board out 9V!!!!! with the GND pad disconeccted all the transistors show correct values...

any idea!!!??

Is this the PCB you're using?

[whoisalhedges]

Hahaha never mind D1, that's my mistake - that's the power protection diode, it's supposed to be "backward." It won't conduct with the cathode positive to the anode; that's the whole point. Keeps your components from frying in case you accidentally put in a reverse-polarity power supply. Edited my previous posts to make me look less ridiculous.

The rest of it, Q3 & Q4's bases being at gnd, that's still a problem....

[spoontex]

Yes, this is the pcb!!

[aion]

Can you post a picture of your wiring? We might be able to see what's wrong by looking at it. Sounds like some wires are switched around someplace.

[spoontex]

No, because without the switch and jacks and only power the GND drops 9V... But if you want I send it...

[duck_arse]

what are you using to power your board, that gives you ~10.13 volts?
also, check the resistance betweeen the base of Q5 (on RG's schem) and V+.
and, photos of your built, please!

[bluebunny]

Hmmm...  Not sure I would describe that as "bassy".  Sounds more like "warbling" to me.

But if your GND pad is showing 9V, then you have a short somewhere.  Pictures of both sides of your board really would help.

[PRR]

> the problem here... Q3 and Q4 have no bias on their bases.

Schematic: http://www.geofex.com/FX_images/rosscomp.gif

With no signal, it is correct for Q3 Q4 to have "no bias". There's nothing to give them static bias. Their function is to pull-down the 10uFd at Q5 *when signal is large*. Bring signal up to +/-0.6V peaks, Q3 Q4 start to suck, 10uFd falls down from 10V, Q5 follows and reduces current through 500K+27K to '3080 pin 5 Vabc, '3080 gain drops.

"too bassy" is not likely a bias issue. A short at Q3 Q4 Base will throw the 0.01uFd on the 10K buffer and whack the highs. Many other shorts and wrong-values are possible. 470 Ohms and 470K Ohms look the same in bad light. If you are not finding it, post clear pictures and maybe some dogged bloodhound here will see it.