WTB: Analog oscilloscope for audio work - Page 1
Forum section: electronics / general

author: Mischa
author_rank: Contributor
timestamp: April 21, 2012, 08:05:28 pm
content: Hi guys,i'm new here and already introduced myself. I come from Slovenia, Ljubljana. I'm happy to see good forum like this about electronics that is not only audio oriented.Last few days i'm searcing for second hand analog osciloscope for meassuring diy audio gear (mostly with tubes) like preamps, mics, limiters and their psu. Until now i used to meassure my stuff at friends place, or at home with my cheap DMM. But now i can't bother my friend anymore with growing demand and curiosity, or hope for good results without meassuring. DMM helps me to know what's going on with DC to certain limits, but i really need to see small AC signals, precisely calculate gain, make sweeps, check for oscillations, find zobel networks for best square wave response from transformers, and other things needed to make good pro audio gear.I need at least 50Mhz BW, 2ch, 2mV sensitivity (or 5mV?), something like 400Vpp inputs, etc. So i checked eBay and some online shops for used Tektronix and HP, but shipping would be expensive because most of them are in the US. There are some threads here where users suggested Hitachis and Hamegs; from what i see they mostly have lower BW, sensitivity and less functions compared to Teks (i really trust their 2000 series, they look so well built and easy to calibrate and troubleshoot) and HP. I can spend up to 300 euros for instrument plus shipping because later i will buy signal generator too.So i need help deciding what models/manufacturers/offers to look for and if there are any essential functions i shouldn't be without for my work. Oh, as this will be my first own scope i would really like to get something that will serve me well at least for some time, so i would rather have less functions than faulty scope. So please help me decide what and where to buy and be sure i will take time to search well.Mischa

author: T4P
author_rank: Super Contributor
timestamp: April 22, 2012, 12:57:29 am
content: 20MHz would already be over the top for audio work anyway . So any 20megger scope from decent brands like HP , Tektronix , GW Instek ... whatever ! Dave knows more brands because i'm not from that era ... i wasn't even born yet .If you are interested the UT81 scopemeter might suit your purposes .

author: aghp
author_rank: Regular Contributor
timestamp: April 22, 2012, 12:29:30 pm
content: Quote from: Mischa on April 21, 2012, 08:05:28 pmIn this price class I have very good condition serviced, adjusted and tested Tektronix 2247A and 2246A.They are not "as is", they are fully working and tested and good condition!(also I have many other equipments (mostly HP and Tektronix) but I have not list and due to lack of time I have not tested all these fo ready to sell. Also some equipments are waiting final decision for sell out)Shipping cost need individually check but of course inside EU there is no any other costs.-aghp

author: tekfan
author_rank: Frequent Contributor
timestamp: April 22, 2012, 12:55:03 pm
content: I've sent a personal message if you're interested.Regards

author: Mischa
author_rank: Contributor
timestamp: April 22, 2012, 01:32:28 pm
content: Quote from: Dave.S on April 22, 2012, 12:57:29 amHi,thanks for reply. You are right, strictly for audio more than something like 100kHz isn't needed. But i was told by people from audio biz that i need to look for 50Mhz scope or more to make sure there are no oscillations up to those freq. or higher. As i'm also into AD/DA converters i would like to be able to check clocks, etcI looked at UT81; i need bench scope with bigger screen and a more intuitive controls. I don't want to loose my time setting scope and connecting it to computer, to do that i will buy good digital bench scope later. It has to be analog because i find digital scopes pretty noisy at mV levels, at least ones i tried were and didn't show small signals well. I often need to check mV levels from micropones, transformers, psu, etc. Another problem i found with some small scopes is they have low input impedance which loads source.I already checked Dave's review of 2225 Tek scope on Youtube and some posts here about similar gear. He seem to prefer them for meassuring mV levels over new digital models which are within reach of my budget (300 euros for scope and shipping). I checked eBay and some shops for second hand gear but got lost. I'm not sure what to buy to make sure it will work at least for some time. And some might have usefull features while others not. It would be nice if i get some advices from people who are into similar things i am and have more experiences.Guys, when i was writing reply i've seen new replies. Thanks a lot for helping me out, i will check this better tonight and write back.Mischa

author: Mischa
author_rank: Contributor
timestamp: April 22, 2012, 07:07:44 pm
content: Aghp: Tektronix 2247A and 2246A look like suitable scopes for my use if they come with right price and some kind of insurrance that they work well. Before making any decisions i will search a little more. For now i don't think i need more or different functions than those on 2246A, counter on 47 is nice to have but not essential at all. Maybe i could buy something cheaper and get a signal generator at the same time, depending on the price of this two scopes.If you or anyone else think there are other models that would suit my needs better please let me know even if you don't have a scope to sell.Tekfan: I'm pleased to meet someone from the same country here, i will send you a pm to talk further about options.Thanks!

author: aghp
author_rank: Regular Contributor
timestamp: April 23, 2012, 07:57:21 am
content: Quote from: Mischa on April 22, 2012, 07:07:44 pmThis CT is not just counter timer if compare to separate counter/timer.In 24xx models this is expensive option but 2247A it is factory default (and 2246A do not have it)It is deeply integrated to oscilloscope functions and it make it different as separate equipment.It is working in rise/fall time measurements, delta time etc... nearly just with all time related measurements you do with oscilloscope using example A and B times.It is big value if need it but nearly nothing if not need.In professional use one very important thing is money. How long time need to do some work. Just with simple and fast settings this can measure things what need much more work if use separate equipments for this. If do not need measure accurate times between signals or accurate times inside one signal then do not need this or it can use just as simple separate frequency counter ot pulse counter.For simple things with normal analog audio etc this is over what really need.But this is very good 100MHz analog professional oscilloscope and it is useful for many things.Here is combined datasheet for 2247A (be careful and note what things are for 2247A and what for other models in datasheet)http://www.mediafire.com/?i0j3px2sjl0k1ioThis is in good condition. But I can not give warranty. It is over 20 years old.Inside and outside condition is very good and all works perfect. Fan is new Panaflo FBA08A12M-1A.(btw also new fans are littlebit noisy, due to high airflow and construction where fan is assembled inside middle of scope but not (audio)isolated from base. And whole case and inside is aluminium. And I do not recommend lower airflow becouse some components run hot in power supply and on the processor board and in the main board.I have serviced/ repaired and also sold lot of Tektronix oscilloscopes and with this experience and with also whole more than 40 year experience with hobby and industrial professional electronic I can not see any problem in this oscilloscope. It is just as normal in accuracy and good /exellent woking condition.If I sell oscilloscope with claim that it is without fails/problems and works normally it is really it when it start from me to buyer. I really do not want destroy my name with some hundred euro doing some kind of fraud - fake to some buyer.Everyone know that if lamp work and I turn it off, I can not be anymore sure it is still working.But also, in case it example arrive as defect/failed and different condition what I have promize.With second hand equipments it is good and common practice to reduce both of parts risk but also littlebit split this risk for both parts. I have always promizede my main selling area (Finland) that if unit is not as promised buyer send it back and I change it or refund but excluding shipping. So buyer is responsiple both direction shipping costs and I am responsible about equipment price. This is simple here locally becouse shipping is not so expensice.For foreign countries but reduced only to EU area I do not know what is real good practice.What I can do before deal.I can arrange many kind of pictures including also pictures about tests / measurements. Of course in this price class it need be somehow related to amount of work and equipment price.Still this is business- or is it. I buy equipments. Then I use more or less hours of real work, always also testing work, carry some risks.Some time I buy equipment (or example take equipment as partial payment for more expensive some buy) and then I find that this equipment can never sell as good working condition after I have done 20 hour repair work...Now we talking around 300 euro (without any accessories, manuals, probes etc) Tektronix what I have serviced, made calibration adjustments explained in Tek service manual, fully tested etc..It is not same what you can see in ebay "we have not knowledge how to test, we have not euipments for test or just simple "as is".This is good or exellent working condition but how to proof itSome test pictures? What kind of test?How to give a guarantee that the buyer feels secure?I will listen good reasonable opinions.2247A weight alone is around 8.7kgI can not make real safe package under 10kg. Next step in Postal Priority Parcels is 15kg. This is possible. With this, whole shipping and package total is 63 euro (after 10kg price jumps up lot of).This is expensive but I think total price including shipping is only meaningful.After this information and with more details I will continue private if you are still interest.you can send PM or directly using this email:-aghp---picture is just from unit what I have sold short time ago.Just same condition in all meanings, cosmetic and functionality. Just as identical.(Front panel looks lot of better in real life than this picture, and same is focus. There is available better quality pictures but I have not in this computer so I copy this from internet from my other sales ad.)

author: Mischa
author_rank: Contributor
timestamp: April 25, 2012, 07:56:42 pm
content: Hey guys,i'm still in need for a scope. I'm considering aghp's offers (thanks for explanations!) but i would rather buy something like 2225 which is simpler inside, lighter and if i'm not wrong fan is quieter. If anyone of you guys from the US who bought 2225 scopes from that auctions want to sell them, please let me know. I can offer 111$ for a scope (i think it's fair price), pay 10$ for packaging and shipping with 200$ insurance. You will not have any expenses and get 111$ for a scope. But you would have to go to a post office, so please think about it before you are offering me something, i'm short with time. I would also buy other Tek scope that is built and silent like 2225.Cheers,Mischa

author: Chet T16
author_rank: Frequent Contributor
timestamp: April 25, 2012, 08:05:06 pm
content: $10 shipping from the US to Slovenia?

author: Mischa
author_rank: Contributor
timestamp: April 25, 2012, 08:09:50 pm
content: No, i wanted to say seller gets 111$ for a scope and 10$ for packaging, i pay the rest. Thanks for remainding me!

author: zoltm
author_rank: Contributor
timestamp: April 29, 2012, 03:18:51 pm
content: Just curious if analogue scope works better for audio application? Would the well discussed digital scope like Rigol DS1052E also works for audio application? I am new to scope, sorry if I happen to be asking stupid question.Thanks.

author: Mischa
author_rank: Contributor
timestamp: July 13, 2012, 10:17:27 am
content: Hi guys,as there seem to be some people interested in buying analog scopes i would like to let you know how my buying journey ended.I bought Tektronix 2247A from user AGHP and i couldn't be happier with deal and scope i gotEverything went smooth, he replied to all my questions (with lots of patience) regarding functions and other models i could possibly buy, took photos i asked for, describe what i will get in details, and calibrated the scope. I payed 300 eur for scope and 50 eur for shipping, he included two probes. From day i payed scope arrived in about 4 days in very good package and he kindly replied to my further questions. I know 350 eur seems expensive, but it's still quite a bit cheaper than eBay deals from the US or EU. And it was not "as is", "no means to test", "lights up"; we agreed for 14 days return if there was anything wrong or not as described. Yeah, it arrived as described and very clean (not used much it seems). So thanks Kari (aghp), it was a real pleasure to buy from you.I also have to say thanks to Tekfan, he gave second opinions about pictures Kari sent and kindly invited me to his home to test a scope with his instruments. Everything was as promised, i would say even better. We tested some obvious things and also looked at extensive triggering (for analog scope), voltmeter-counter/timer and cursors. At first i didn't really care about this extra functions, but since i got them i feel like i couldn't live without them. Specially voltmeter and cursors are very useful for my needs. Voltmeter works well even at very low levels which is very nice because i'm often having mV levels and need to calculate gain, transformer ratios and things like this. Ohh, btw, Tekfan's house is "audio treasure", i don't think i've seen so many highly regarded audio devices at one place! Ask him about it, you won't regret itSo this is it, i think i wrote what's important, if anyone have questions let me know, maybe Tekfan will also write a comment. It's good to know that good analog scopes can be bought in EU. Prices are not very low, but still good when i take in account trust, calibration, communication and very good instrument.Thanks to all of you for replies, i appreciate it.Regards from Mischa

author: nctnico
author_rank: Super Contributor
timestamp: July 13, 2012, 12:08:35 pm
content: Quote from: zoltm on April 29, 2012, 03:18:51 pmA digital scope is often more complicated to use compared to older analog scopes therefore some people like analog scopes better. There is not much difference between using an analog or digital scope for audio. Actually a digital scope will show low frequencies way better than an analog scope can. I used to have a Tek 2230 and an Iwatsu DS8617 which both could be used as an analog or digital scope but I never used them in analog mode.

author: Mischa
author_rank: Contributor
timestamp: July 14, 2012, 05:59:35 pm
content: I can see low frequencies well with mine, and find it simpler to use for basic work. Yeah, it depends what you like. I wanted good analog scope in good shape, and it was pretty hard to find it in Europe, or prices were way too high with shipping from reputable US sources.For further analysis, which i don't need often, i can use other instruments.

author: Simon
author_rank: Unknown
timestamp: July 14, 2012, 06:33:38 pm
content: Yes you want decent bandwidth, I could not work out why my amp ran so hot and poor quality sound until I put a scope on it and found 6 MHz oscillations.