I wouldn't have been surprised but screwing up a 2 ohm impedance. That's amazing. Makes simulation look stupendous.
For a low power class A buffer, I could not care less of measurements, it is a no brainer to get them in the noise floor dust by designing with pencil and paper using common sense as the main tool.
Different story for a claimed <10ppm high power amplifier, that's where simulation results are usually a big pile of cow chips, the physical implementation usually controls an order of magnitude higher distortions.
And nobody needs an AP2 to measure 10ppm of distortions, a good sound card will also do for occasional measurement. Of course, one would need to know what he's doing, also understand the limitations of his setup. It's not that convenient and easy as with a Plug&Play specialized equipment.
A bit more about the scope. I moved to Shanghai January 2015. When the Chinese authorities looked at my shipment manifest, the Philips scope was listed in there along with my Rigol. They were refused entry into China and the reason given was " . . . There are no grounds for owning equipment such as this for personal use"
So, they had to remain in storage in Taiwan from were they were shipped without proper packing - just stuck in a cardboard box and airfreighted across the world. The Rigol survived.
I bought a cheap B&K in China (from Mouser mind you) and the insurance company gave me about 4 grand for the Philips back in the UK so I got a small Tek (4 channel 200 MHz 'dual mode' anslog/digital).
So, they had to remain in storage in Taiwan from were they were shipped without proper packing - just stuck in a cardboard box and airfreighted across the world. The Rigol survived.
I bought a cheap B&K in China (from Mouser mind you) and the insurance company gave me about 4 grand for the Philips back in the UK so I got a small Tek (4 channel 200 MHz 'dual mode' anslog/digital).
The AP's advantage is that it is convenient, calibrated and the results universally recognized.
I agree though that 10 ppm on a power amp is a very significant challenge. The only DIY effort I'd say got there was Edmond and Syn08 effort.
I agree though that 10 ppm on a power amp is a very significant challenge. The only DIY effort I'd say got there was Edmond and Syn08 effort.
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Wow, who are those insurance suckers? For 4k you could get about 8 second hand Tektronix 2465B 400MHz analog scopes.
I got a new scope since I figured it had to last as long as I plan to be around - and a new sig gen since that was the other item they shipped sans packaging.
The Philips scope was valued at $3.5k - very good piece of kit.
The Philips scope was valued at $3.5k - very good piece of kit.
Wow, Waly, you won't make many friends by criticizing their decisions, when you don't know all the facts. If I got it right, Bonsai got the normal airfreight insurance and he put down the list or replacement price for a device that he originally got for free! That was smart of him. What he bought after was his choice. What is the problem?
As far as solderless breadboards are concerned, I have used them for more than the last 47 years, and I like them. I even feel that the 'parasitic' nature of the breadboard's capacitance, resistance and leakage gives a reasonable worst case situation to make sure that the circuit is inherently insensitive to small things. I once designed an ultra low distortion driver amp for Sound Technology using a solderless breadboard, much to the surprise of ST. The circuit worked for them when it went into production, and SPICE was out of my league at the time. Sometimes, the old methods work as well as the newer methods of design proofing.
As far as solderless breadboards are concerned, I have used them for more than the last 47 years, and I like them. I even feel that the 'parasitic' nature of the breadboard's capacitance, resistance and leakage gives a reasonable worst case situation to make sure that the circuit is inherently insensitive to small things. I once designed an ultra low distortion driver amp for Sound Technology using a solderless breadboard, much to the surprise of ST. The circuit worked for them when it went into production, and SPICE was out of my league at the time. Sometimes, the old methods work as well as the newer methods of design proofing.
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I agree. I've built 300 MHz digital on solderless breadboards and (eventually) gotten it to work. Porting to a proper PCB was easy and the result performed beautifully on the first try, since the signal environment was so much cleaner.
No problem, just wondering who are the idiots that accepted evaluating (for insurance purposes) an old 200MHz analog scope at $4,000. Being in the same situation, I would beg for that scope to be destroyed in the transport, not being annoyed when it happens.
BTW, I don't plan to make friends on Internet forums, I have a life and real friends we gulp beers and snacks together. In fact, Mr. Bonsai, yourself, Mr. Groner, Mr. Didden, or anybody else around could well be the descendants of Tutankhamun, I couldn't care less when it comes to technical accuracy.
Digital is not analog, digital doesn't have stability issues. In fact, I agree myself that digital on a solderless breadboard can (but not always) be kind of a worst case.
Try a digital hazard on a breadboard, it may behave completely different from a PCB (in both worse or better ways). But then we no longer design digital stuff today on the breadboard, we write VHDL code and the computer generates optimal schematics with all the parasitic elements already included. Some of my colleagues are designing 10GHz digital boards (with controlled impedance traces), they usually work to the spec from the first iteration.
I was just laughing at the idea of complaining about the shortcomings of various breadboarding approaches, when I was reminded of some of the pictures of Bob Pease with his huge breadboards, using appreciable lengths of hookup wire, a bristling forest.
He did explain somewhere that the lengths of these things represented in some cases actual IC interconnect effects, at least resistively.
He did explain somewhere that the lengths of these things represented in some cases actual IC interconnect effects, at least resistively.
Sounds like people do not have to learn much about the physical aspect of parts and layout as we did back then, in modern times.
Waly, are you just a kid? I mean someone 20-25 years of age, like my grandchildren.
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Clearly with a big chip on his shoulder . . .
We were all like that once, but quickly grew out of it.
I think Waly needs to get himself a girlfriend, get out more, smoke a few joints and learn to relax a bit (this is what we mean about 'coaching' son).
😀
Indeed. Top-of-the-line equipment will never be simple, easy or intuitive. AP tried, dScope tried. Ask JC about how they tried with the SR-1.
Don't give a razor blade to a baby 😉
Jan
Don't give a razor blade to a baby 😉
Jan
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