Aion Electronics Stratus OD - no gain, no volume boost

[suryabeep]

I just checked it again with the pot turned somewhere in between the two extremes:
1 and 3 - open
2 and 3 - 0
2 and 1 - open

[EBK]

I measured resistance between the drive lugs as well:
Anti Clockwise - 0 ohms between 2 and 3 as well as 2 and 1.     I think this is the problem?
clockwise - 0 ohms between 2 and 3, 1 between 2 and 1.

Well, let's revisit this.  This seems ok, potentially.....  Depends on the meter.

[EBK]

I just checked it again with the pot turned somewhere in between the two extremes:
1 and 3 - open
2 and 3 - 0
2 and 1 - open

Your meter sure likes giving yes/no answers.  Could you show us a picture of it?  (If it's a Magic Eight Ball, I'm outta here.  )

[suryabeep]

I know, it's weird. The voltage functions are fine, just resistance is very finicky.


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[EBK]

Manual ranging, so when you see that overflow 1, turn clockwise to the next higher range.  Likewise, whenever you see 0, turn the knob counterclockwise to the next lower range.

[suryabeep]

Thanks for the instructions, I guess I didn't really understand this before.
Now I'm using it on the 200M setting:
all the way clockwise I'm getting 0.8 for 3&2, 1.6 for 2&1
in the middle im getting 0.8 for 3&2, 1.4 for 2&1
all the anti-clockwise I'm getting 0.8 for both.
Am I even doing this right? If I am, what does this mean? I really am a total noob with all this stuff

[EBK]

One more piece of info.  You have to pay attention to whether your mode has a 'k' or 'M' and, if so, stick that on the end of your number.

[suryabeep]

ah i see.
all the way clockwise I'm getting 0.8M for 3&2, 1.6M for 2&1
in the middle im getting 0.8M for 3&2, 1.4M for 2&1
all the anti-clockwise I'm getting 0.8M for both.

[robthequiet]

What is the resistance from pin 1 to pin 3 again? In 2M mode, probably.

[suryabeep]

What is the resistance from pin 1 to pin 3 again? In 2M mode, probably.

I'm getting 0 all the way anti-clockwise and overload everywhere else


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[robthequiet]

OK, now I would suggest measuring the pads on the PCB and make sure you don't have a dead short across any of them. If not, I would then take a resistor of say 100K and place it across the pads for pins 1 and 3, to simulate having a pot at a fixed setting. This will tell us if the circuit will do gain.

[EBK]

I would suggest pausing and grabbing a handful of different resistors and measuring them until we can be totally confident in the meter use.  There is some learning going on that we shouldn't gloss over.  It will help with all future builds.   

[suryabeep]

@EBK I tried what you suggested, the multimeter works. I tried with resistors of different values too to test out the ranges on the meter.
@robthequiet the 100K resistor didn't do anything.

The odd thing is that the meter measures the volume pot perfectly in both 2M and 200K modes. However when I try to measure the drive pot it's the same as before.


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[duck_arse]

I'll take two steps back and ask: are you doing your resistance measure with the power to the circuit off? this is most important for ALL resistance/continuity measuring, and voltage in the circuit will mess the results.

and: can you read the DC VOLTAGEs across that pot, obvs with power back on.

[suryabeep]

I'll take two steps back and ask: are you doing your resistance measure with the power to the circuit off?

You're right! I was measuring with the power on! I did the measurements again with power off, here's what I found: resistance from 1 to 2 and from 1 to 3 changes proportionally to the knob being turned. 2 to 3 is always 0. The maximum resistance from 1 to 2 and from 1 to 3 I got was 875K.


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[Les Turnbull]

Make sure that the input socket is not shorting to  the chassis when it springs open. Turn the input same as you have the output socket .

[ElectricDruid]

I did the measurements again with power off, here's what I found: resistance from 1 to 2 and from 1 to 3 changes proportionally to the knob being turned. 2 to 3 is always 0. The maximum resistance from 1 to 2 and from 1 to 3 I got was 875K.

This is pretty good. 2+3 are connected together in the schematic, so 1 to 2 and 1 to 3 *should* give the same result, and they do, so that's good. Similarly, 2+3 are connected together, so the resistance between them *should* be zero, and it is, so that's all good.

The maximum resistance is 875K, which is within the +/-20% for a typical "1 Megohm" (=1000K) pot. So that's also good.

Whatever's wrong with it, it doesn't seem to be the drive pot.

HTH,
Tom

[robthequiet]

Hm, just to confirm: If you check resistance between IC1 pins 6 & 7, do you get the same result as when you turn the drive pot? Just want to confirm we don't have any problems in the diode/feedback area.

[suryabeep]

Hm, just to confirm: If you check resistance between IC1 pins 6 & 7, do you get the same result as when you turn the drive pot? Just want to confirm we don't have any problems in the diode/feedback area.

It somewhat matches the drive pot, but I consistently get 16K more on the IC than on the pot. For example the pots at 0 but the IC is at 16K, pots at 569K ICs at 585K.


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[suryabeep]

Just want to confirm we don't have any problems in the diode/feedback area.

I somewhat guessed the diode section. The RTO variant uses transistors in this section, but the orientation for the transistors wasn't given in the documentation, so I pretty much just matched it up with the Diode options given in the doc.


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