Cheap DSO153 (not 152) or DSO154Pro for measuring amp for clipping? please help - Page 1
Forum section: electronics / testgear

author: shaolin95
author_rank: Newbie
timestamp: May 05, 2024, 03:57:33 pm
content: Hi!So I want to get a cheap oscilloscope and the use will be only to measure the speaker output of home amplifiers to make sure I am not clipping.Do notice that I am using not only speakers but tactile devices so going down to 10hz or even 1hz if possible, would be ideal so I can make sure I am not clipping any of those. I was trying the DSO 152 and it seems to not deal with anything under 6hz but not even sure if it was accurate at that point.Reading that the DSO152 is not highly regarded and that the 154 Pro is a better unit, I wanted to check about the 153 before buying the 154 Pro.Or does it even matter for my usage?Thanks!

author: wasedadoc
author_rank: Super Contributor
timestamp: May 05, 2024, 05:12:06 pm
content: Whatever scope, if you want tomeasurelevels at those low frequencies you must use DC input coupling. I can recommend the DSO154Pro for what you want to do (and more).But you should be able toseeclipping even at low frequencies with just about any scope.

author: shaolin95
author_rank: Newbie
timestamp: May 05, 2024, 05:22:19 pm
content: Quote from: wasedadoc on May 05, 2024, 05:12:06 pmSorry, I am a complete noob here. I saw that DC coupling as an option in the menu of one I was looking at. Is that all, just select the DC Coupling option and proceed?Thanks for your help..I am ordering the 154pro next

author: wasedadoc
author_rank: Super Contributor
timestamp: May 05, 2024, 08:01:08 pm
content: Quote from: shaolin95 on May 05, 2024, 05:22:19 pmAC coupling removes the DC component but also attenuates low frequencies. The magnitude of the effect varies from scope to scope. Selectitng DC coupling should produce a flat frequency response all the way down to 0Hz.

author: shaolin95
author_rank: Newbie
timestamp: May 05, 2024, 08:21:10 pm
content: Quote from: wasedadoc on May 05, 2024, 08:01:08 pmThanks for the help!!!

author: Fungus
author_rank: Super Contributor
timestamp: May 05, 2024, 09:19:11 pm
content: +1 for the Zeewei DSO154Pro

author: shaolin95
author_rank: Newbie
timestamp: May 06, 2024, 02:11:50 pm
content: A small update.So yesterday I received the 154 PRo and also two others I had ordered before asking here and was unable to cancel the order on time.While testing for a more extreme clipping, I noticed that I am unable to show the top of the wave in 2 of them no matter what I tried. I maxed out the options (at least from what I can tell) and moved it as far down as possible but it just wont show all of it.Only the LM2020 is able to let me show it very clearly. This was not my favorite device as I wanted it to be just an oscilloscope with more direct controls like the FNRSI or smaller and cheaper like the 154Pro but unless I am doing something wrong, it seems to be the only one showing me what I wanted not matter how extreme the case.Am I missing something?Here are some screenshots of all 3 devices. As you can see the LM2020 lets me get that close and detail if I wanted to and for some reason I cannot find an option to do anything remotely like this with the others. Maybe I am missing something?

author: Aldo22
author_rank: Super Contributor
timestamp: May 06, 2024, 02:38:00 pm
content: Is that really 189Vpp?I'm amazed that the scopes can withstand that at 1x. ??Try with a 10x probe.

author: shaolin95
author_rank: Newbie
timestamp: May 06, 2024, 05:12:36 pm
content: Quote from: Aldo22 on May 06, 2024, 02:38:00 pmHi.Well my issue is the 10x probe I have is this (attached photo).So I am not sure how I could connect one of those probes to the positive and negative speaker output of my amp.I have been using a probe that has a bnc to a positive and negative alligator clip for this but that's 1xThanks

author: wasedadoc
author_rank: Super Contributor
timestamp: May 06, 2024, 06:32:30 pm
content: Quote from: shaolin95 on May 06, 2024, 05:12:36 pmProbe tip to positive speaker out and croc clip negative speaker out. Advisable to run scope on battery power, ie no possibility of scope being grounded.

author: shaolin95
author_rank: Newbie
timestamp: May 06, 2024, 06:43:41 pm
content: Oh because they seem to be connected to the same piece I was concerned of shorting things but then again, that wouldn't make sense lolThanks for the clarification

author: shaolin95
author_rank: Newbie
timestamp: May 07, 2024, 02:26:54 pm
content: Quote from: wasedadoc on May 06, 2024, 06:32:30 pmThat was perfect. Now the 154Pro is my favorite by far.Thanks again!