Hello.
Sorry for another oscilloscope thread...
It's been a while that i'm building things following schematics and without looking what I was doing, just listening the final product: No hum? good!
Now I want to bring the hobby to the next level (from dummy to beginner) and for that I'm searching an oscilloscope.
Is just for tube amplifiers, no knowledge at all how digital things work.
I was considering a pc oscilloscope (Picoscope 2205a) for multiple reasons: little (don't have anymore space in my house, my gf will kick me out is she see a big white box with a screen), multifunction, relatively cheap (trying to keep it under 200€).
But I saw that in most of the threads you guys do not recommend that kind of oscilloscope.
Do you think that for the basic works it can be enough or not at all?
Best regards to you all!
Sorry for another oscilloscope thread...
It's been a while that i'm building things following schematics and without looking what I was doing, just listening the final product: No hum? good!
Now I want to bring the hobby to the next level (from dummy to beginner) and for that I'm searching an oscilloscope.
Is just for tube amplifiers, no knowledge at all how digital things work.
I was considering a pc oscilloscope (Picoscope 2205a) for multiple reasons: little (don't have anymore space in my house, my gf will kick me out is she see a big white box with a screen), multifunction, relatively cheap (trying to keep it under 200€).
But I saw that in most of the threads you guys do not recommend that kind of oscilloscope.
Do you think that for the basic works it can be enough or not at all?
Best regards to you all!
There is no PC Oscilloscope which can handle tube power supply measurements.
An voltage probe for any oscilloscope, capable for isolated volt and signal measurements comes in a price of 400-500$
An modern Oscilloscope able to really help in power supply troubleshooting, this has a price of 1000-1200$.
There is no words and workarounds to substitute the results which a real tool can offer.
An voltage probe for any oscilloscope, capable for isolated volt and signal measurements comes in a price of 400-500$
An modern Oscilloscope able to really help in power supply troubleshooting, this has a price of 1000-1200$.
There is no words and workarounds to substitute the results which a real tool can offer.
If you think you want a scope, you need a scope.
Luckily there's never been better scopes available for such little money.
https://www.youtube.com/watch?v=ETCOhzU1O5A
Luckily there's never been better scopes available for such little money.
https://www.youtube.com/watch?v=ETCOhzU1O5A
I bought a couple of PC scopes for work. I didn't buy them as scopes, but as feedback loop analyzers for power supplies. They knock out gain/phase plots in a couple minutes and super accurately. AND! they're scopes. Cleverscope is the brand. A bit over your budget, but you also get gain/phase plots. We got them loaded at $2000 each, but compare to Ridley for $20,000, Venable at $30,000 and Keysight at $40,000. The plots come out way nicer than the others too.
If you don't have the space for a hardware model a "PC scope" is a good alternative. I have one which I use mainly if I need to save measurements.
The Picoscope 2205A looks like a good choice.
You probably should get a 100x (or perhaps 1000x) probe for tube work (I don't think it needs to be isolated, as likely your circuits are grounded anyway. Isolated probes are mainly for switched power supply design, where the primary side is not reference to safety ground). With a bit of searching you should find a decent second-hand model from Tektronix on e-Bay.
Samuel
The Picoscope 2205A looks like a good choice.
You probably should get a 100x (or perhaps 1000x) probe for tube work (I don't think it needs to be isolated, as likely your circuits are grounded anyway. Isolated probes are mainly for switched power supply design, where the primary side is not reference to safety ground). With a bit of searching you should find a decent second-hand model from Tektronix on e-Bay.
Samuel
Thank you for all the answers!
Reading at that I feel kinda demoralized...
I looked up at the Rigol and other entry-level scopes and I more or less understand the advantages.
Then I will need proper probes and then a signal generator... i think there's no way out under 1000€ or so.
For the space I can eventually manage it.
But thing is that will require me a really long time to have that money, and at that point I have the equipement but can't do anything with it (no money for components and projects).
I suppose there's no way out of that unfortunately.
I still have a little confusion: a pc scope will blow up my laptop/project/himself, is not gonna work at all or is just not so precise?
Is a pc scope better than nothing?
Have a nice day and thanks for the help!
Patrizio
Reading at that I feel kinda demoralized...
I looked up at the Rigol and other entry-level scopes and I more or less understand the advantages.
Then I will need proper probes and then a signal generator... i think there's no way out under 1000€ or so.
For the space I can eventually manage it.
But thing is that will require me a really long time to have that money, and at that point I have the equipement but can't do anything with it (no money for components and projects).
I suppose there's no way out of that unfortunately.
I still have a little confusion: a pc scope will blow up my laptop/project/himself, is not gonna work at all or is just not so precise?
Is a pc scope better than nothing?
Have a nice day and thanks for the help!
Patrizio
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A PC scope doesn't blow up anything, will work fine and is not fundamentally less precise than purely hardware-based models (Think about it--if the display is built-in or not doesn't do anything about precision. That's determined by the analog front-end/data converts.). There are certain limitations which stem from the limited USB data rate/PC processing power, but I wouldn't worry about this too much for basic audio work.
Every oscilloscope has an input voltage limitation. Typically this is +/- 20 V. Using a standard 10x probe you can extend this to +/- 200 V. Unfortunately, many tube circuits involve higher voltages than this, so you need a 100x probe, which is a considerably more specialized item. If the projects you're interested in have supply voltages below 200 V (and/or if you can manage either with external AC coupling or not probing high-voltage nodes at all) you should get away with standard 10x probes (which perhaps are included with the Picoscope).
Samuel
Try to buy this one:
https://www.picotech.com/accessories/active-oscilloscope-probes/25-mhz-700-v-differential-probe
is not cheaper but good to use with tubes and picoscope.
the BW is very high and you have two options for voltage.
Walter
https://www.picotech.com/accessories/active-oscilloscope-probes/25-mhz-700-v-differential-probe
is not cheaper but good to use with tubes and picoscope.
the BW is very high and you have two options for voltage.
Walter
Generally speaking this is medium to Low quality advice, untested and used equipment they totally need a fresh calibration certificate in both items so them to be trusted.
These certificates would come for a price of additional 400$.
And even so, the equipment will still be old.
The golden advice here is starters to never buy used equipment.
I don't know what planet you live on, but that is very unhelpful advice for beginners doing DIY.
No-one needs a ($400?) certificate to debug a valve amp. It is really easy to check that the 'scope is within (say) 5% by using simple comparison techniques.
I have two s/h TEK scopes, a 5000 series that does differential sub-mV measurements and a 100Mhz general purpose one. As far as measurements on the screens are concerned, they have been "spot"-on for 15 years without calibration. Both scopes cost about $100 equivalent, plus probes.
If ever I make a measurement that doesn't seem correct, I always doubt the accuracy and find a way to back it up. Good advice in ANY electronics area.
I have come across a few guys who blindly believed a piece of test gear because it had a cal sticker on it!
If you can succeed working with electronics in a workbench which nothing works absolutely correct, then name your planet so to never visit it.
Sorry for my really late answer.
Thank you all for the comments! I lost sleep a couple of nights and I arrived at the conclusion that for the moment I have to live without an oscilloscope.
I can't afford to buy a decent one, and even if I could right now the expense is not justified.
It has just to wait.
Anyway I think you helped me avoid making a purchase that I'll probably regret; when you see it on paper it is so tempting for the price, but there is always a downside.
Thank you!
Patrizio
Thank you all for the comments! I lost sleep a couple of nights and I arrived at the conclusion that for the moment I have to live without an oscilloscope.
I can't afford to buy a decent one, and even if I could right now the expense is not justified.
It has just to wait.
Anyway I think you helped me avoid making a purchase that I'll probably regret; when you see it on paper it is so tempting for the price, but there is always a downside.
Thank you!
Patrizio
It is a property of the real world that absolutely nothing ever works absolutely correctly.
Even calibrated equipment is certified to have errors that are within stated bounds, but it still has the errors.
Requiring a calibration certificate for every piece of gear is a unnecessary luxury in most repair and development shops. Its nice, but it is not an absolute necessity in most cases.
Hi all,
I'm still without a scope
I've found a Tektronix TAS 250 with probes close to where I live for a modest price (170), so I can go in person to check if is in good shape.
Anyone owns/owned one or knows if is a good scope? (as a reminder, I'm really amateur, is for tube amplifiers)
Thank you!
I'm still without a scope
I've found a Tektronix TAS 250 with probes close to where I live for a modest price (170), so I can go in person to check if is in good shape.
Anyone owns/owned one or knows if is a good scope? (as a reminder
, I'm really amateur, is for tube amplifiers)Thank you!
THe biggest problem with tube amps is that you will be dealing with VERY high voltages. Most scopes have very fragile inputs that will get destroyed at the voltages tube amps throw at them. A 100x scope probe can help, IF you keep the system ground at the same ground as the oscilloscope. Also, remember the voltage rating on the front of the scope is for DC or close to it, the higher the frequency the lower the tolerated voltage. You can find this information in the user manual. Usually, if the rating is 400Vpp then by the time you reach 100Mhz it is closer to 40Vpp.
Also, you can venture outside of Tek and HP/Agilent, don't forget names like Hameg, Rhode & Shwartz (sp?) and even the old Fluke/Phillips scopes. These names are not mentioned as much because these forums tend to be USA centric but those names are more common in Europe.
Also, you can venture outside of Tek and HP/Agilent, don't forget names like Hameg, Rhode & Shwartz (sp?) and even the old Fluke/Phillips scopes. These names are not mentioned as much because these forums tend to be USA centric but those names are more common in Europe.
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