DBX 160x sounds like 500hz high pass

[TRJanuary]

If it were on my bench, I would check audio path capacitors first. Old caps often cause a low end roll-off.

[dualflip]

Originally Posted by TRJanuary

If it were on my bench, I would check audio path capacitors first. Old caps often cause a low end roll-off.

My exact same thoughts, replace the caps and see what happens

[mjrippe]

+1, thought that just from reading the post title ;-)

[Fhl]

Excellent, thank you

[Ruairi]

Instead of lifting legs and measuring you can just bypass each audio path cap with a crocodile cable while listening and if your low end returns you've found your culprit. Of course if one electrolytic is on it's way out they'll all likely need replacing.

[Fhl]

Originally Posted by Ruairi

Instead of lifting legs and measuring you can just bypass each audio path cap with a crocodile cable while listening and if your low end returns you've found your culprit. Of course if one electrolytic is on it's way out they'll all likely need replacing.

Great advice, thank you! I might just change them all. A couple of the disc capacitors have a white residue on them, although they look intact. The electrolytic ones look just fine, but I guess they are dried out.

[jensenmann]

Better don´t do that shorting-electrolytics thing. There´s only one foil cap in the audio path, IIRC (just had a look: C112 + C113 are in the signal path for feedback purpose). Most electrolytics sit between rails. You´d damage the PSU by shorting any of these.
Recapping won´t do no harm anyway.

[Fhl]

Originally Posted by jensenmann

Better don´t do that shorting-electrolytics thing. There´s only one foil cap in the audio path, IIRC (just had a look: C112 + C113 are in the signal path for feedback purpose). Most electrolytics sit between rails. You´d damage the PSU by shorting any of these.
Recapping won´t do no harm anyway.

Thanks for the warning, jensenmann. I'm afraid I shorted a few caps before I noticed the small spark. Also, I found one that wasn't between any rails, and it improved the sound. Can't tell if it was only an increase in volume or a bass boost though.
Have I damaged the PSU? Any parts in particular I should check out?

Also, should I buy any specific caps (brands etc)? I know there are a thousand different types, but I don't want to make the unit sterile either. The filter caps 470uF/35V are of the brand nichicon, and the other electrolytics look similar esthetically (color etc). Locally I can order Nippon Chemi-Con, Jamicon, NIC Components, Panasonic, Rubycon and Suncon caps. At least for the aforementioned values.

As you can tell I am very new at this, but I'm eager to learn. Thanks

[Ruairi]

Originally Posted by Ruairi

Instead of lifting legs and measuring you can just bypass each audio path cap with a crocodile cable while listening and if your low end returns you've found your culprit.....

[Ruairi]

Originally Posted by Fhl

As you can tell I am very new at this, but I'm eager to learn. Thanks

Please send your unit to a competent tech, there are voltages inside that chassis that can kill. If you are not able to read a schematic and work out which caps are in the audio path and which caps are in the PSU section you are not ready to work on this gear. I mean this in the nicest possible way.

I regret giving you the advice I did as you were not ready for it. By all means keep studying and learning (I am) but please don't mess around with live equipment until you know what you are doing.

A good local tech will talk you through the issue and you'll learn much in the process.

Good luck.
Ruairi

[Fhl]

Originally Posted by Ruairi

Please send your unit to a competent tech, there are voltages inside that chassis that can kill. If you are not able to read a schematic and work out which caps are in the audio path and which caps are in the PSU section you are not ready to work on this gear. I mean this in the nicest possible way.

I regret giving you the advice I did as you were not ready for it. By all means keep studying and learning (I am) but please don't mess around with live equipment until you know what you are doing.

A good local tech will talk you through the issue and you'll learn much in the process.

Good luck.
Ruairi

You are right, I'll bring it to a tech and ask if he can talk out loud while working, if he's ok with that.
I did not try to short the filter caps. It was the only caps physically big enough to fit a brand name so that's why I mentioned them. I figured I could change all the electrolytics when first at it. I would've drained the caps with a high watt cement resistor. And I checked the voltages with my DMM. I am well versed in personal safety, however, as you point out I am not good enough when it comes to reading schematics and could easily damage the unit. Thank you for your help. I really do I appreciate it.

[Ruairi]

Excellent, and thank you for taking my post in the spirit it was intended. Good luck getting the unit up to speed, I've been looking at picking up a few 160X myself for mixing.

[Fhl]

Originally Posted by Ruairi

Excellent, and thank you for taking my post in the spirit it was intended. Good luck getting the unit up to speed, I've been looking at picking up a few 160X myself for mixing.

Thanks again The working unit is really nice on bass and snare (haven't tested it on anything else yet). And for me it's a lot of joy to work with analogue knobs and being able to close my eyes for a couple of seconds. Good luck picking up a unit or two

[Fhl]

Update: The problem was not with the capacitors at all. The output transformer had a broken winding wire, and two of the switches were bad. The only problem with the other unit was a bad switch, resulting in only the input volume being reflected through the LEDs and not the output. Thanks for the help!

[Ruairi]

Glad to hear you found the issues! Enjoy your now working compressor.

[mjrippe]

And thanks for coming back and sharing the results!

[Fhl]

Originally Posted by Ruairi

Glad to hear you found the issues! Enjoy your now working compressor.

Thanks again! It's a lot of fun using it.

Originally Posted by mjrippe

And thanks for coming back and sharing the results!

You are quite welcome!