Repairing an amplifier myself Hi, so theres not a channel for this, but I was wondering if anyone has experience with this. I have found an amplifier two days ago, outside in the trash. And it works! However, it has noise when you turn on the knobs. It's this amplifier: [www.retrotronics.co.nz] And as a sound-o-phile I would really like to restore this beauty to a good working state. Now, I know there are things like contact spray, but I have read that they usually do more damage than good and only *seem* to work for a short period and then they will make matters worse than they already were. So, I am not afraid of opening the machine up and replacing a few knobs, but I have absolutely no idea where to get replacement knobs and still wanted to see if someone here has another piece of advice? There might be alternatives to contact spray which don't make me replace the potmeters, but just have me clean it up a bit inside the potmeters? - Marinus https://reprap.org/forum/read.php?159,210293,210293#msg-210293 Thu, 10 Sep 2026 15:23:22 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?159,210293,338497#msg-338497 Re: Repairing an amplifier myself https://reprap.org/forum/read.php?159,210293,338497#msg-338497 REPRAP SQUAD Experimental and Hobby Fri, 11 Apr 2014 15:00:16 -0400 https://reprap.org/forum/read.php?159,210293,338441#msg-338441 Re: Repairing an amplifier myself https://reprap.org/forum/read.php?159,210293,338441#msg-338441 jzatopa Experimental and Hobby Fri, 11 Apr 2014 12:35:02 -0400 https://reprap.org/forum/read.php?159,210293,328540#msg-328540 Re: Repairing an amplifier myself https://reprap.org/forum/read.php?159,210293,328540#msg-328540
Quote
Ohmarinus
Hi, so theres not a channel for this, but I was wondering if anyone has experience with this.

I have found an amplifier two days ago, outside in the trash. And it works! However, it has noise when you turn on the knobs.

It's this amplifier:
[www.retrotronics.co.nz]

And as a sound-o-phile I would really like to restore this beauty to a good working state.

Now, I know there are things like contact spray, but I have read that they usually do more damage than good and only *seem* to work for a short period and then they will make matters worse than they already were.

So, I am not afraid of opening the machine up and replacing a few knobs, but I have absolutely no idea where to get replacement knobs and still wanted to see if someone here has another piece of advice? There might be alternatives to contact spray which don't make me replace the potmeters, but just have me clean it up a bit inside the potmeters?

- Marinus

Turn the pots to their extremes LOTS of times, probably about 50-100 cycles.
I have an old Arcam amp that does what you describe and wiping the pots works well to fix that issue.
Cheers
D]]> maddog7 Experimental and Hobby Sat, 22 Mar 2014 14:29:06 -0400 https://reprap.org/forum/read.php?159,210293,328105#msg-328105 Re: Repairing an amplifier myself https://reprap.org/forum/read.php?159,210293,328105#msg-328105 nophead Experimental and Hobby Fri, 21 Mar 2014 14:03:35 -0400 https://reprap.org/forum/read.php?159,210293,328050#msg-328050 Re: Repairing an amplifier myself https://reprap.org/forum/read.php?159,210293,328050#msg-328050 REPRAP SQUAD Experimental and Hobby Fri, 21 Mar 2014 11:34:46 -0400 https://reprap.org/forum/read.php?159,210293,214017#msg-214017 Re: Repairing an amplifier myself https://reprap.org/forum/read.php?159,210293,214017#msg-214017
I will open the machine up this evening and take some pictures
Thanks :)!]]> Ohmarinus Experimental and Hobby Fri, 31 May 2013 11:57:08 -0400 https://reprap.org/forum/read.php?159,210293,212687#msg-212687 Re: Repairing an amplifier myself https://reprap.org/forum/read.php?159,210293,212687#msg-212687
take some pics and send me the variable resistor that makes that scratchy sound, i can offer you some repair tips if it what i think is the fault :D]]> redreprap Experimental and Hobby Mon, 27 May 2013 19:52:15 -0400 https://reprap.org/forum/read.php?159,210293,210293#msg-210293 Repairing an amplifier myself https://reprap.org/forum/read.php?159,210293,210293#msg-210293
I have found an amplifier two days ago, outside in the trash. And it works! However, it has noise when you turn on the knobs.

It's this amplifier:
[www.retrotronics.co.nz]

And as a sound-o-phile I would really like to restore this beauty to a good working state.

Now, I know there are things like contact spray, but I have read that they usually do more damage than good and only *seem* to work for a short period and then they will make matters worse than they already were.

So, I am not afraid of opening the machine up and replacing a few knobs, but I have absolutely no idea where to get replacement knobs and still wanted to see if someone here has another piece of advice? There might be alternatives to contact spray which don't make me replace the potmeters, but just have me clean it up a bit inside the potmeters?

- Marinus]]> Ohmarinus Experimental and Hobby Mon, 20 May 2013 06:36:41 -0400