Rigol DS4000 or Lecroy LC - Page 1
Forum section: electronics / testgear

author: alfred
author_rank: Newbie
timestamp: August 04, 2015, 06:35:40 am
content: Hi!I have a question. I need to replace my old trusty Rigol DS1000 and I've two choices:A brand new DS4014 or a used Lecroy LC684. The lecroy is obviously much better specced but it's a 15 year old scope. It seems to be in good condition tough.I saw bad things about the DS4000. Also, no Tek or Agilent in my country, actually Rigol is the best brand you can get here, apart from GW instek and siglent.What would you think is the better choice? prices are similar.

author: tautech
author_rank: Super Contributor
timestamp: August 04, 2015, 07:14:49 am
content: Quote from: alfred on August 04, 2015, 06:35:40 amWhat country is that? A flag placed in your profile might help with more correct advice for dealers, service etc.

author: alfred
author_rank: Newbie
timestamp: August 04, 2015, 07:20:06 am
content: Quote from: tautech on August 04, 2015, 07:14:49 amArgentina.You wont get spare parts of anything here. It's the same if it's a chinese scope or brand-name.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: August 04, 2015, 08:51:19 am
content: Quote from: alfred on August 04, 2015, 06:35:40 amStrange choice, but well, why not.QuoteMake that 15+ years, as the LC684 was EOL'd in 2000 if I remember right (and most scopes are from the 98-99 time frame as in 2000 the successor WavePro 900 was introduced which offered several improvements).QuoteThe LC Series had very few weak points, although it suffered from falling off knobs (typical LeCroy illness of those days), and after all these years might encounter failing encoders (easy to replace), but other than that is pretty solid. If it has the built-in thermo printer then there's a large capacitor which is prone to fail (and will short the PSU), either disconnect the printer or replace the capacitor (both easy to do).After all these years the LCD backlight (CCFL tube) might be getting dim but this can be easily fixed (new CCFL or LED conversion, both cheap).QuoteHard to say, and it depends on what you need.The LC Series is quite old, and the waveform update rates are pretty low (somewhere in the <20k range). On the other side, its analysis functionality is world's apart from any Rigol, and you can get all the software option enabled by inserting a cheap GAL with the unlock codes (there's a guy on the Yahoo LeCroy group who sells them cheaply). A fully loaded LC contains many options that even these days can only be found in high end scopes. The UI of these scopes is pretty simple as well. Service manuals and schematics should be available through the Yahoo LeCroy user group.The Rigol on the other hand is a typical modern low end scope: compact, low power consumption, lightweight, with only basic functionality, slow processing and pretty poor FFT. It has a large sample memory but is too slow to make much use of it (it's more a marketing figure). The DS4000 also suffered (and still suffers) from some issues which may or may not get fixed eventually, but considering that the DS4000 doesn't exactly sell in high numbers I wouldn't hold my breath. There also isn't much in the way of something that can be considered a true service manual available for it. However, it's small, uses less power and is less noisy, and since its a brand new scope it should come with warranty, which is some benefit.In terms of price, $2500 (which is what a DS4014 currently costs) is way too much for a LC684, even though its a good scope. Even the successor (WavePro 950/960) can be found for less money pretty often, and this is a newer and faster scope than the old LC684.However, if I had to choose between these two scopes only then I'd take the LeCroy over the Rigol any day, because it's a much more powerful scope. But if you need a portable/small scope, want warranty or care for high waveform rates then the DS4014 might be the better option for you.In the end, only you can decide which is the better choice for you.

author: hendorog
author_rank: Super Contributor
timestamp: August 04, 2015, 09:29:18 am
content: I'll give you a perspective of a (relatively) positive hobbyist owner of a DS4014QuoteNo currency specified, but from memory someone stated the US price is $1999 - there is as discount available on the forums. Rigol NA have it at $2300.I think its a good scope for the price if you need the bandwidth/sample rate.I don't think there is anything available new, with that sample rate & <potential> bandwidth in 4 channels for the price. (now there's a challenge...)Hackability is 10/10 - simply enter a license code.There are bugs, and there have been quite a few bug fix releases now. Release notes are on the DS4000 thread.However it doesn't crash and generally works as you would expect. I haven't seen anything yet that is serious (that comes with a hobbyist disclaimer)(As an aside - I have observed on the forums that the people with the MSO model seem to be less happy with the scope. Also the latest firmware has a lot of MSO related fixes, so perhaps the LA/MSO is worse, I don't know.)The bits I don't like are:The update rate of the math trace is slow. It's around 1/second.The FFT resolution isn't great. I have got used to it now, although I find its fiddly to get a useful trace.Moving the knobs don't reflect on the screen rapidly - e.g. moving a measurement cursor is pretty damn fiddly.I think if you were working under time pressure (i.e. a pro) then those issues would be more serious. For me they aren't a big deal.

author: nctnico
author_rank: Super Contributor
timestamp: August 04, 2015, 11:24:52 am
content: Chances are the Lecroy use x86 processors which can be upgraded so the math functions are likely to become much faster.I think I'd choose the Lecroy over the DS4000 as well. In many cases you really need averaging and longer record lengths to do something useful with FFT. Same goes for decoding; Rigols typically decode only what is on screen which is pretty much useles for any real use.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: August 04, 2015, 05:48:52 pm
content: Quote from: nctnico on August 04, 2015, 11:24:52 amNope. The LC Series uses PowerPC processors, so no upgrade, but the processor is fast enough even for very advanced analysis setups. Also, RAM can be upgraded (32MB max IIRC).QuoteThe LC648 does not do serial decoding. This came only with the later X-Stream based scopes (Windows scopes).

author: nctnico
author_rank: Super Contributor
timestamp: August 04, 2015, 06:03:59 pm
content: Well useless decoding is as good as no decoding so no reason not to choose the Lecroy

author: dom0
author_rank: Super Contributor
timestamp: August 04, 2015, 06:08:52 pm
content: I'd expect the LeCroy to have segmented memory and probably good power analysis./e: Ah yes, 2000 segments, five time bases, smart triggers, statistics, and so on

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: August 04, 2015, 07:05:23 pm
content: Quote from: dom0 on August 04, 2015, 06:08:52 pmThis old catalog contains a nice overview of what was available for these older scopes:http://bee.mif.pg.gda.pl/ciasteczkowypotwor/LeCroy/LeCroy_2001_Catalog.pdfI haven't come across any brochures for the LC Series, however the software options for the LC are mostly the same as for the WavePro 900 Series, and is pretty expensive even by today's standards.Quote from: nctnico on August 04, 2015, 06:03:59 pmThat's true of course.

author: hendorog
author_rank: Super Contributor
timestamp: August 04, 2015, 09:24:50 pm
content: Quotemeh FUD. Decoding works fine.I'm sure there are better implementations and its been pointed out before that certain things are expected in a scope in this price range. However decoding is a long way from useless.

author: rsjsouza
author_rank: Super Contributor
timestamp: August 05, 2015, 11:57:22 am
content: Quote from: alfred on August 04, 2015, 06:35:40 amI was recently doing a research on similarly spec'd oscilloscopes and I had the following considerations.Despite the LeCroy is a fine instrument, as Wuerstchenhund points out in several other threads around this forum is that this series is built to lesser quality standards. If you have access to the equipment (and not only through photographs), I don't think it would matter much, but in my case I was purchasing online and was less inclined to take the risk.Another factor that he mentioned and it was somewhat decisive for me was the footprint. I don't have much bench space to accomodate a very large instrument, but obviously this may not be a problem for you.One additional thing to consider in the final price are the probes. The DS4000 comes with four 500MHz passive probes, but the LeCroy may not have them (or they may be busted) - I would test them or in this case you could take your chances on cheap eBay probes or some other source. Also, the extra bandwidth (above 500MHz) is useless if you can't have access to active probes.In the end I found a great price on a DS4014 on Rigol's clearance bin and ended up purchasing it. I currently like it, and I agree with all points highlighted by hendorog - including the fact the decoder works very well for my needs.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: August 05, 2015, 12:06:26 pm
content: Quote from: rsjsouza on August 05, 2015, 11:57:22 amYes, but that was in comparison to other LeCroy scopes (i.e. the later Iwatsu-built WaveRunner LT/WavePro 900 Series). And it still doesn't change the fact that the build quality of the LC is still miles above from what other manufacturers provide. Heck, the LC is still built better than most of Agilent's scopes (or any Rigol, for that matter).QuoteThe good thing with LeCroy is that their probe interface (ProBus) hasn't changed in the last 20 years, which means there is a wide range of 2nd hand probes available at often ridiculously low prices.

author: Stray Electron
author_rank: Super Contributor
timestamp: August 05, 2015, 07:27:33 pm
content: "The good thing with LeCroy is that their probe interface (ProBus) hasn't changed in the last 20 years, which means there is a wide range of 2nd hand probes available at often ridiculously low prices."This.I've bought plenty of LeCroy PP-005 500Mhz probes for $50 each from a certain auction site. I really love the features on that model probe and they're now my go-to probes. I even used them on my HP scopes.I'd take a LeCroy scope over a Rigol any day of the week! They're end of life by the manufacturer but the manufacturer has released all of the manualsincluding the service manualAND all of the software option enabling codes and there is a very active LeCroy support group on Yahoo. I currently have 4 LeCroy scopes and two HP DSOs.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: August 06, 2015, 05:33:24 am
content: Quote from: Stray Electron on August 05, 2015, 07:27:33 pmI bought some 500MHz and 1GHz active probes for little money on ebay. Aside from the standardized probe interface (which makes finding probes easy), the fact that most punters are searching for Agilent and Tek probes generally keeps LeCroy probe prices low.

author: alfred
author_rank: Newbie
timestamp: August 13, 2015, 02:03:00 pm
content: Thanks everybody! It seem I asked in exactly the best place in the internet. I have no space problems but analyzing stuff like rs232 is something I do very often. Anyways, I'll try to get an used Lecroy 9xx, and failing that, the Rigol.Your answers were very educative, btw.Thanks you again, and best regards,Alfredo

author: rsjsouza
author_rank: Super Contributor
timestamp: August 13, 2015, 09:57:33 pm
content: Alfredo, RS232 decoding is pretty standard with a dirt cheap PC-based logic analyzer from eBay, therefore you should consider that.Also, two additional details I forgot to mention that I took into consideration:- a brand new instrument has warranty, while an older instrument may be reaching the end of its lifetime (or not, depending on how it was built);- a brand new instrument does not have service manual (or it is unusable given the level of integration), while older equipment may be more repairable (unless you run into a custom ASIC as mentioned onthis nice thread).Wuerstchenhund points out onthis other threadthe LeCroy 9000 series is not terribly great for modern days, but he may have additional comments.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: August 14, 2015, 11:26:12 am
content: Quote from: rsjsouza on August 13, 2015, 09:57:33 pmI agree, and many of the USB LAs are much more flexible than what can be found in a low-end scope like a Rigol.QuoteI believe Alfredo means the WavePro 900 (WP940/WP950/WP960, successor of the LC6xx Series) and the old 9300 Series with monochrome CRTs. But yes, I'd not recommend the 9300 Series unless it's really cheap, or you've some particular interest in the most powerful oscilloscope of the early '90s.@Alfredo: if you don't need the high bandwidth and sample rate of the WavePro 900 Series and want something more compact then have a look at the LeCroy WaveRunner2 LT. They're smaller than the huge LC and WavePro Series but offer most of the advanced functionality that can be found in the larger scopes. Plus all these LeCroy scopes (9300, LC, WP900, WR2 LT) operate the same.