Rigol Ds1054 Z o-scope.

[rockman627]

I see the guy in Psionic Audio uses this and at this price ($349) I think my boss will spring for it. Can I use it right out of the box to troubleshoot amps? Or do I need special probes etc?

[x-pro]

Quite.
But if it will be necessary to repair the primary part of switching power supplies, it would be desirable to have a galvanically isolating transformer in the power supply of the device.

[x-pro]

However, there is an exception.
This device is not very sensitive to noise in low-signal circuits.
Its own, at a level higher than....
In such cases, it is better to use an ordinary analog oscilloscope.

[Helmholtz]

Are you sure you need 4 channels? Readouts with 4 channels can be confusing.
I think with analog circuitry 2 channels are sufficient.

I like to have 2 channels (e.g. to see phase differences between signals) but I rarely use the second channel of my Siglent SDS 1202X-E (love it).

New scopes typically come with a set of probes allowing measurements up to 400V peak.
For higher voltage points you need an x100 probe.

[Mick Bailey]

I would use an additional voltage divider on the input if working on tube amps as extra protection from accidental high voltages, especially if scoping around the output tubes. I think J M Fahey published a handy circuit here a while ago.

[Helmholtz]

There are actually 2 voltage limits.
One is for the scope input, the other for the probe.
A voltage divider after the probe cannot increase the probe's limit.
A 1500V probe needs to have larger leakage and creepage distances and use materials having a higher dielectric strength than a 400V probe.

Probing power tube plates is best avoided because voltage peaks can exceed 1500V in extreme cases like with oscillation.

[rockman627]

I hardly know anything about o-scopes. When I took my tech course back in 1980, the teacher showed us you can inject a signal and use the scope to trace along the circuit until you see no signal or one that is weak, jittery etc. I have been able to fix quite a bit by looking at the schematic and figuring out which component might be defective or from guidance from guys like you. But we have a few amps where I can't figure it out and will have to trace and see where the signal goes awry. But now I want to look into that Siglent.

[Helmholtz]

Rigol and Siglent specs and prices (over here) are quite similar.
I just liked the display and readouts on the Siglent better.

I typically buy from online dealers offering money back after 2 or 3 weaks testing.

[rockman627]

Just to be sure, is " waveform generator " the same as "signal generator" ? I'd hate to get this and then tell my boss I need a separate signal generator.

[Helmholtz]

Just to be sure, is " waveform generator " the same as "signal generator" ? I'd hate to get this and then tell my boss I need a separate signal generator.

I guess so. My Siglent doesn't have that. I already had a sig gen.
I'm sure there's a model having that feature.

[The Dude]

FYI: Though I have a signal generator, it's often easier to use YouTube test tones. You can find just about anything you need, from single frequencies to sweeps to isolated guitar tracks, etc. Easy to switch from one to the other. Just run a line out of your PC sound card, or even a phone/tablet.

[Mick Bailey]

A waveform generator can be a different device to a signal generator; a signal generator usually allows the choice between fixed waveform types (mine just does sine and square), but a waveform generator can produce user-defined, custom waveform shapes in addition to standard types. Also numerous modes of operation.

[Helmholtz]

.... but a waveform generator can produce user-defined, custom waveform shapes in addition to standard types. Also numerous modes of operation.

That is often called an "Arbitrary Waveform Generator".

I use a "Function Generator" providing sine, square and triangular signals. All 3 waveshapes are useful for amp testing.

[gui_tarzan]

My son got me a Siglent SDS1202X-E for father's day. I haven't used it much yet but I really like it so far.