D-scope vs ap?

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pucho812

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New hire Part of  the design team is talking that we need to dump the ap's on our service benches in favor of a d-scope.  As lead bench tech I have my concerns. Anyone have d-Scope and ap experience?  Possible to shed some light on this?
 
Hey Pucho,

I have a dScope and have experience with the AP Sys 1, SYS 2722 and a little second hand experience with the APx515.  I should also go on the record and say that I do some repair work for Prism / Maselec and am affiliated with the company.

I think both are excellent platforms, and I see the newer APx systems as a response from AP to Prism's feature set.  AP's new "bench mode" for example is something that Prism have had for quite a while (live FFTs etc).

For absolute state of the art distortion measurements only the Rohde & Schwarz UPV can come close to the flagship AP. (Edit - adding that this level of distortion measurement is not typically needed in day to day bench QC and repair work, if you are designing cutting edge AD/DA then that's a different story).

I've yet to find something I couldn't do with the dScope, but my experience with the APs has been good too although the software add ons can get expensive.  For day to day bench work there is nothing I feel I am missing.

I think it would be useful for your new hire to explain in bullet points what he feels the dScope would bring to the table.  A demo unit can easily be arranged once you are clear on what dScope might offer you.
 
I agree. I think the big  idea was we can replace the portable one's we use now for day to day bench work in favor of automated dscopes. Having looked at programing a scope, my AP515 that I have for my home bench is more streamlined then the dscope.  I system one I got from you was upgraded to a 515 for home and the system one went into audio use elsewhere. :) The one feature I need to spend more time with is the FFT aspect. We currently have a separate FFT machine at work, an sr770 by srs. I have yet to get any Ap to behave like that or any other test system for that matter.  I am probably doing something  to cause that but boy for 1980's tech the sr770 is still a heavy contender in 2017.
 
pucho812 said:
I agree. I think the big  idea was we can replace the portable one's we use now for day to day bench work in favor of automated dscopes. Having looked at programing a scope, my AP515 that I have for my home bench is more streamlined then the dscope.  I system one I got for you was upgraded to a 515 for home and the system one went into audio use elsewhere. :) The one feature I need to spend more time with is the FFT aspect. We currently have a separate FFT machine at work, an sr770 by srs. I have yet to get any Ap to behave like that or any other test system for that matter.  I am probably doing something  to cause that but boy for 1980's tech the sr770 is still a heavy contender in 2017.

I didn't realize that you guys were using Portable Ones on the bench.  The dScope is in a whole other league, it's not a comparable class at all.  A portable one is great for quick sig gen and go/no go tests but that's about all IMO.

The FFT on the dScope is excellent and I use that more than any other feature, it was limited on the older AP systems but seems much better on the newer.  I use the live FFT for trimming distortion on circuits, positioning toroids etc.

I haven't used the Stanford FFT but the advantage of something like a dScope is getting all of the information in one place - levels, THD and viewing individual harmonics.  I have a preset configuration that i use for day to day work that has everything I need across two  screens. 
 
Hi Pucho
I worked for AP for many years. I used Tek, Amber, SoundTek, HP, dScope and several others. Each system had the good & bad points.  For the service bench it sometimes it is not easy to have a PC, monitor, mouse & keyboard on the bench. The simple P1 or equiv in good enough. The final check of the system under test may require many other tests to verify all is to spec and a AP or other scripted machine is an excellent tool for the job.

As for the new hire "Design Engineer" it is his preference and not the service bench preference. Keep an open mind and look at it as it may be a better tool.

Duke
 
Howdy duke, The mind is open and and willing just making sure we going in the right direction.

ruairioflaherty said:
I haven't used the Stanford FFT but the advantage of something like a dScope is getting all of the information in one place - levels, THD and viewing individual harmonics.  I have a preset configuration that i use for day to day work that has everything I need across two  screens.

Yes all in one place is key. That's what I like about the 515. I can generate a PDF of every result... I am sure dscope is capable
 
Hi Pucho
I don’t shotgun problems as they may not be the real problem.

Make a list of GOOD/POSITIVE & POOR/NEGATIVE of your observations of the problems. Now you should be able to good decision to the best solution.

At AP and other company’s I work for, I would review any new problems with manufacturing / service department. This was a great tool as it leads to better and serviceable new products. After development of the new products, I would sit with them as we both learned new things through this process.

Duke
 
Thinking a little further on this, I know that I couldn't do the repair work I do for Prism / Maselec / PMC with a Portable one.  Trimming for lowest IMD, live bin centers frequency response for tuning HF limiters, FFTs for trimming distortion and even the fact that some of the gear has lower distortion than a P1 could measure.

That said that doesn't mean you have to get a dScope but stepping up from the P1s to something more powerful sounds like it could yield results.
 
Well that's the thing,  we have had the portable one's on the bench since I stated and were used  for as long as  I am aware of. 

For what we do, they work well even though there is a lot of hands on adjustment  for different phases of testing and measurement.

from what I have seen so far, the main thing is to have a more automated process. So in in APX land it would be a sequence. I find them very easy to put together in APX land.  So have a sequence  myself and the other techs can run from top to bottom on any unit at any time and see what is what, less chance for error that way.
 
the verdict is the following

1. we currently have ap portable one's on the test, qc and repair benches.  They do us well but lack one function we get out of an sr-770 from SRS systems.  The 770 we use for real time FFT analysis on eq's.  So for example if I hook up to the 770 and engage  an eq, with  eq controls at center detent(boost/cut) I should see a flat line or as close to a flat line. If I do a boost I will see the curve happen in real time. any control adjustment gets reflected on the 770.

2. The d-scope is going back whenever it gets picked up. We no longer need the demo unit.

3. we picked up 2 X dscopes which  for what we are doing, does what the 770 does as well as the AP portable.  Are there ways around what the 770 does with the portable one? Sure, we can do frequency vs gain sweeps from 0hZ to whatever but it's not real time. Sweeps take time to do. When doing production batches where we don't have all day  for testing the bin centre testing is crucial for saving time.

4. I have an ap515 at home running apX. it's similar to d-scope but not the same.  They both have their pros and cons.  For me at this point the APX software is much easier to program as far as  making test  and measurement sequences that you repeat for the same piece  again and again. But d-scope will get that way in time.

 
I have an AP Portable One and a new fancy test set isn't in the cards. I take the AP output into  a Studio Six Digital interface and use their FFT software on an iPad. It works well enough for me. Probably too much of a kludge for a business.
 
Gold said:
I have an AP Portable One and a new fancy test set isn't in the cards. I take the AP output into  a Studio Six Digital interface and use their FFT software on an iPad. It works well enough for me. Probably too much of a kludge for a business.

No more kludgy then we had before  with the srs770.  ;)
 
bruno2000 said:
What model(s) did you buy?
Thanks!
Best,
Bruno2000

Of the d-scope? We got the IIIA+. We don't do digital around here so it was the best option for us. We still have the AP portable one on the bench.  as well.  they measure close to one another but are slightly off.  In the thousandths decimal point. so cool
 
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