Oscilloscope and DMM Suggestions !

General Tech Discussion - Anything amp-ish goes!

Moderators: CurtissRobin, colossal, zaphod_phil, Daviedawg, Graydon

Studiocat13!
Unrated
Posts: 20
Joined: Tue 07/10/18 11:37 am

Oscilloscope and DMM Suggestions !

Post by Studiocat13! »

OK Guys, I am looking to update some of my old test gear and would like some recommendations. I currently have a very old DMM that was a very nice unit when new and has served me well along with an even older Phillips Oscilloscope which I acquired but never used. The DMM has lost its bottom line of LED and could be confusing when taking readings so I want to update it to something like the Mastech 8268, nothing crazy, just a good, reliable DMM. As far as the scope, it still powers up but I do not trust it so do I need a digital or will an older analog unit serve me better for tube related work which is all I really plan to do with it. And I do understand that I will need an isolated power supply when using the scope to take measurements which is someting else I will need to purchase. Thanks in advance for your help !
0 x

User avatar
JMPGuitars
Super Duper Admin
Super Duper Admin
Posts: 3954
Joined: Tue 09/18/12 8:00 pm
Location: South Central, MA
Contact:

Re: Oscilloscope and DMM Suggestions !

Post by JMPGuitars »

I have a few different meters. My main meter is an Amprobe TrueRMS meter (37XR-A). Whatever you get, TRMS is the way to go. You can also get ESR meters if you want to measure stuff in-circuit. I use a generic M6013 meter for capacitors. I also have a current clamp meter and a few other generic DMMs.

I don't have an oscilloscope, but I would like to invest in a decent one at some point. Honestly, I don't know enough about them to make a great choice, but I did bookmark a few I'll eventually research more.
0 x
'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright

Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info


Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook · Instagram
Items for Sale

Studiocat13!
Unrated
Posts: 20
Joined: Tue 07/10/18 11:37 am

Re: Oscilloscope and DMM Suggestions !

Post by Studiocat13! »

Thanks JMP ! I just looked at the Amprobe you suggested and it looks like a great DMM. Any limitations so far ? Also you metioned using other meters to measure capacitance, so the Amprobe will measure a cap out of the circuit but not while in the circuit ? As far as an oscilloscope, I am leaning towards the Hantek DSP 5072P. A lot of bang for the buck and has great reviews even with a lot of pros ! Would love to score a Senco PR57 for my ISO AC and Variac but haven't found a good deal yet...
0 x

User avatar
JMPGuitars
Super Duper Admin
Super Duper Admin
Posts: 3954
Joined: Tue 09/18/12 8:00 pm
Location: South Central, MA
Contact:

Re: Oscilloscope and DMM Suggestions !

Post by JMPGuitars »

The main limitations with the Amprobe are that 1. the capacitance range isn't huge (which is normal), and no, you can't measure in-circuit (also normal). There's a fuse inside the unit, which will stop the capacitance side of the meter from working if the fuse goes, but it comes with a spare fuse, so that's all good. I've had the thing for years and it's served me well. The second cap meter has a higher range, but doesn't measure in-circuit either. You need an ESR meter for that.

I'm not the guy to ask about oscilloscopes, but I remember hearing that 200 MHz was the bandwidth you want. I don't know if that's true (or why), but I remember it for some reason. If KennyO or somebody else that uses a scope was around they could help better with that. I hope somebody does chime in because I do intend to buy a scope eventually too.

I got a crazy deal on a variac, a great model too. Pay attention to eBay for those. Not totally necessary, but certainly helpful. You can always build a lightbulb test box instead.
0 x
'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright

Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info


Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook · Instagram
Items for Sale

Studiocat13!
Unrated
Posts: 20
Joined: Tue 07/10/18 11:37 am

Re: Oscilloscope and DMM Suggestions !

Post by Studiocat13! »

Thanks for clarification JMP. I will probably go with the Amprobe then, looks like a good deal and reviews well but not sure I need the 37XR since I will need additional meters and a scope was leaning towards the 33XR or 35XP-A. Any thoughts on that ?
Certainly hope some others chime in on the oscilloscope topic as well, would love to get some more input on that for us both.
0 x

geoff 1965
Verbose poster
Verbose poster
Posts: 1118
Joined: Mon 01/04/16 3:52 pm

Re: Oscilloscope and DMM Suggestions !

Post by geoff 1965 »

hello,
here's a youtube link showing best scopes for tube amp repair.
https://youtu.be/L0MVIvaD1BY
0 x

User avatar
JMPGuitars
Super Duper Admin
Super Duper Admin
Posts: 3954
Joined: Tue 09/18/12 8:00 pm
Location: South Central, MA
Contact:

Re: Oscilloscope and DMM Suggestions !

Post by JMPGuitars »

Studiocat13! wrote:
Fri 07/20/18 8:35 am
Thanks for clarification JMP. I will probably go with the Amprobe then, looks like a good deal and reviews well but not sure I need the 37XR since I will need additional meters and a scope was leaning towards the 33XR or 35XP-A. Any thoughts on that ?
Certainly hope some others chime in on the oscilloscope topic as well, would love to get some more input on that for us both.
The version I got is $122 on Amazon (it was $117 in 2011 when I got it). You only save about $30 buying one of the other two models, which are priced about the same on Amazon. I like the auto-ranging features on the 37, and I needed a meter that can measure inductance, which the other meters can't measure. If you don't care about those two things, you aren't missing much. If you scroll down on the amazon page there's a comparison between the models.
0 x
'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright

Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info


Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook · Instagram
Items for Sale

Studiocat13!
Unrated
Posts: 20
Joined: Tue 07/10/18 11:37 am

Re: Oscilloscope and DMM Suggestions !

Post by Studiocat13! »

Thanks for the info Geoff,
After watching the video it makes sense but I also hate the thought of buying a really old analog scope when I can have a new 70hz digital for a little more money but will certainly check on Ebay to see what's available. Thanks Again !
0 x

Studiocat13!
Unrated
Posts: 20
Joined: Tue 07/10/18 11:37 am

Re: Oscilloscope and DMM Suggestions !

Post by Studiocat13! »

Just pulled the trigger on the Amprobe 37XR per your recommendation JMP. I will also keep you posted on the Oscilloscope front as I hope to make a decision on that soon. Thanks !
1 x

geoff 1965
Verbose poster
Verbose poster
Posts: 1118
Joined: Mon 01/04/16 3:52 pm

Re: Oscilloscope and DMM Suggestions !

Post by geoff 1965 »

hello,
i'm thinking of going down the same road with an oscilloscope for testing and the video i posted was more for the range needed, i.e. pointless having an expensive 60Mhz scope if your only gonna be using around 20Khz for guitar amps. not sure about digital? would the digital sign wave be as responsive showing spikes etc when chopsticking?
i need to upgrade my DMM as well,mine does'nt have AC millivolts only DC which is helpful for leakage but no good for signal testing.
0 x

Studiocat13!
Unrated
Posts: 20
Joined: Tue 07/10/18 11:37 am

Re: Oscilloscope and DMM Suggestions !

Post by Studiocat13! »

I would think a digital oscilloscope would be just as responsive if not more, plus it has a lot of functions that a normal DMM have along with the ability to store data and presents for specific functions. The one I am looking at is less than $250.00 and is a new unit with warranty that receives great reviews from amateur to pro users. I have a friend who is a bench tech and says the digital is probably the way to go so I'm probably going to go that route. Plus the digital unit is much smaller and lighter in weight but still has a nice size display. Guess I would rather have too much scope, than not enough.
1 x

geoff 1965
Verbose poster
Verbose poster
Posts: 1118
Joined: Mon 01/04/16 3:52 pm

Re: Oscilloscope and DMM Suggestions !

Post by geoff 1965 »

sounds like a good choice,i just wondered why most of the amp tech's on youtube like D'lab & uncle doug use analog scopes.
i like the look of your build kit,do you have a pdf schematic you can post?
0 x

Studiocat13!
Unrated
Posts: 20
Joined: Tue 07/10/18 11:37 am

Re: Oscilloscope and DMM Suggestions !

Post by Studiocat13! »

geoff 1965 wrote:
Thu 07/26/18 11:42 am
sounds like a good choice,i just wondered why most of the amp tech's on youtube like D'lab & uncle doug use analog scopes.
i like the look of your build kit,do you have a pdf schematic you can post?
Yeah Geoff, I wondered the same thing about the analog scopes but would venture to say that those guys are just more familiar with the analog units and have probably been using them for years and at which point a Digital was far more expensive. But with all my research, I just can't see any cons with a new digital verses an old analog. I may even step up to another model that has a signal generator built in to it which adds even more value over needing a separate unit. BTW, Here is the schematic you requested.
1 x

geoff 1965
Verbose poster
Verbose poster
Posts: 1118
Joined: Mon 01/04/16 3:52 pm

Re: Oscilloscope and DMM Suggestions !

Post by geoff 1965 »

definately a good idea having a built in signal generator! i did'nt know they had scopes with that.yeah i've been researching and can find no benefit of an analogue only the cost!
noticed the paperwork for your build saying classic "british" with "usa" mods and would like to compare to the standard 18W schematic,can't find it,did you add it as an attachment?
british18w_schematic_v5.pdf
found it on tubedepot website,the ef86 version will be of interest,there's a good layout as well.
You do not have the required permissions to view the files attached to this post.
0 x

jobewan
Unrated
Posts: 9
Joined: Tue 07/31/18 6:33 pm

Re: Oscilloscope and DMM Suggestions !

Post by jobewan »

Hey StudioCat - just saw this. For what it is worth, I bought the Rigol DS1054Z - maybe the most ubiquitous scope on earth. Ads everywhere. But after digging through the piles of hype, I found it was the best deal. They are basically giving away all of the upgrades that people were hacking. I guess they figured it was easier to simply give it away and make it a feature. So that gets you a 100 Mhz scope with 4 channels and 24 Gigs of RAM. It is a pretty well made scope - watch the Aussie guy at EEV Blog - he does a pretty thorough teardown of it.

As far as DMMs go - I have my old faithfull Fluke, but I also picked up a Siglent SDM3055 - its a 51/2 digit benchtop meter that does quite a bit of extra stuff. I got it for the display - it is a direct ripoff of the Agilent 34461A - a classic. I can't afford that Agilent meter, as much as I would love it, but the Siglent is a nice ripoff alternative.

I don't know your budget, but that Rigol deal is very much worth the extra money. Just my $.02

JB
1 x

User avatar
JMPGuitars
Super Duper Admin
Super Duper Admin
Posts: 3954
Joined: Tue 09/18/12 8:00 pm
Location: South Central, MA
Contact:

Re: Oscilloscope and DMM Suggestions !

Post by JMPGuitars »

jobewan wrote:
Tue 07/31/18 8:10 pm
Hey StudioCat - just saw this. For what it is worth, I bought the Rigol DS1054Z - maybe the most ubiquitous scope on earth. Ads everywhere. But after digging through the piles of hype, I found it was the best deal. They are basically giving away all of the upgrades that people were hacking. I guess they figured it was easier to simply give it away and make it a feature. So that gets you a 100 Mhz scope with 4 channels and 24 Gigs of RAM. It is a pretty well made scope - watch the Aussie guy at EEV Blog - he does a pretty thorough teardown of it.
I've actually been interested in the DS1054Z.

I'd prefer a 200Mhz scope, but if I can get that running at 100Mhz for a good price, that could work. It would be nice if it was source capable too.

Thanks,
Josh
0 x
'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright

Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info


Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook · Instagram
Items for Sale

User avatar
JMPGuitars
Super Duper Admin
Super Duper Admin
Posts: 3954
Joined: Tue 09/18/12 8:00 pm
Location: South Central, MA
Contact:

Re: Oscilloscope and DMM Suggestions !

Post by JMPGuitars »

I decided to go ahead and order the thing. One of the authorized dealers automatically includes all the "upgrades" free in the shopping cart (they say they'll email the serial). I chatted with them online and got a few bucks off too. ;) It was $331 with free shipping.

I wouldn't bother paying more for a unit with a signal generator built in, as it looks like they all cost at least twice as much. I'm going to try out the Tenma 72-505, which is available brand new for $34 at Newark (for some reason it's twice as much on Amazon). I read a few reviews and plenty of people use it for audio tube amps and tube radio repair. I'll see how it is.

Thanks,
Josh
0 x
'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright

Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info


Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook · Instagram
Items for Sale

Studiocat13!
Unrated
Posts: 20
Joined: Tue 07/10/18 11:37 am

Re: Oscilloscope and DMM Suggestions !

Post by Studiocat13! »

geoff 1965 wrote:
Fri 07/27/18 11:54 am
definately a good idea having a built in signal generator! i did'nt know they had scopes with that.yeah i've been researching and can find no benefit of an analogue only the cost!
noticed the paperwork for your build saying classic "british" with "usa" mods and would like to compare to the standard 18W schematic,can't find it,did you add it as an attachment?
british18w_schematic_v5.pdf
found it on tubedepot website,the ef86 version will be of interest,there's a good layout as well.
Yeah, I tried to attach the schematic of the circuit I'm building, wonder why it didn't show up ? Either way, its the one on the Tube Depot site and I am building the standard circuit not the EF86. I will be doing a couple mods like the choke and changing a couple caps for better bass response but nothing major until I play it for a while. Still looking at scopes and may go with this Siglent SDS1052DL+ over the Hantek although both are nice scopes for the money. Also looking at ESR Meters too !
0 x

Studiocat13!
Unrated
Posts: 20
Joined: Tue 07/10/18 11:37 am

Re: Oscilloscope and DMM Suggestions !

Post by Studiocat13! »

jobewan wrote:
Tue 07/31/18 8:10 pm
Hey StudioCat - just saw this. For what it is worth, I bought the Rigol DS1054Z - maybe the most ubiquitous scope on earth. Ads everywhere. But after digging through the piles of hype, I found it was the best deal. They are basically giving away all of the upgrades that people were hacking. I guess they figured it was easier to simply give it away and make it a feature. So that gets you a 100 Mhz scope with 4 channels and 24 Gigs of RAM. It is a pretty well made scope - watch the Aussie guy at EEV Blog - he does a pretty thorough teardown of it.

As far as DMMs go - I have my old faithfull Fluke, but I also picked up a Siglent SDM3055 - its a 51/2 digit benchtop meter that does quite a bit of extra stuff. I got it for the display - it is a direct ripoff of the Agilent 34461A - a classic. I can't afford that Agilent meter, as much as I would love it, but the Siglent is a nice ripoff alternative.

I don't know your budget, but that Rigol deal is very much worth the extra money. Just my $.02

JB
Thanks for the info JB. The Rigol looks like a nice scope indeed but may be more than what I need, so I am looking at the Siglent SDS1052DL+ right now but would love to see how you like the Rigol once you get it. So far the Amprobe JMP suggested is working out well but I am looking at ESR Meters so would like to know what everyone prefers in that department. Keep me posted on the new scope !
0 x

Studiocat13!
Unrated
Posts: 20
Joined: Tue 07/10/18 11:37 am

Re: Oscilloscope and DMM Suggestions !

Post by Studiocat13! »

BTW, I decided to ditch the idea of having a scope with a Signal Generator when I was reminded that I already have a nice Loftech TS-1 Signal Generator, just need to get it back from a friend of mine !
1 x

Post Reply