Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500

[saxmonster]

NICE!!!!!!!!!!

 

[dryman]

Hi,

i would like to build one or two EZ1073 but i can't find a source for the PCB. Audiomaintenance has no PCB or Partkit. Does anyone know, where i can get them?

 

[rob_gould]

Hi,

i would like to build one or two EZ1073 but i can't find a source for the PCB. Audiomaintenance has no PCB or Partkit. Does anyone know, where i can get them?

Audiomaintenance is the one and only source for this project.  If they're sold out there, they're sold out I'm afraid.

Colin from Audiomaintenance periodically checks this thread and may advise whether another run will happen.  If not, you may like to search for posts by user Bluzzi, who has offered a similar project in the past I believe.

 

[loganchristian]

I recently completed two of the ez1073's from partial kits. Everything checked out on both of them, proper voltages, passes audio, both sound good. When using them on a line-level stereo source I noticed that one of the units is about two line gain clicks hotter. I verified by sending an identical mono tone to both and swapping in's and out's of each. What might be suspect? Another issue I'm having with one of them is the LF gain doesn't add or subtract as much gain as my other unit. The other frequencies are matched. I used the exact same parts in both and I wonder if the bc183c's I ordered off ebay are at fault. While sourcing parts I had the most difficulty finding the right WIMA's that fit, I had to mount 5 on the bottom of the PCB. Can anyone please provide me with some places to look as I try to troubleshoot?

Thanks!

Logan

 

[Slenderchap]

i would like to build one or two EZ1073 but i can't find a source for the PCB. Audiomaintenance has no PCB or Partkit. Does anyone know, where i can get them?

Sorry, all gone.

When using them on a line-level stereo source I noticed that one of the units is about two line gain clicks hotter.

Input transformers possibly the wrong way round ?

Colin
www.audiomaintenance.com

 

[loganchristian]

Good diagnosis Colin.. of course it would happen on the second build. Line gain is fixed but LF Gain is still weak on the boost and cut, any ideas on that? Bad pot? I've looked over both boards many times now and everything appears consistent. Thanks for your help and for the great pre's!

 

[Slenderchap]

LF Gain is still weak on the boost and cut, any ideas on that? Bad pot? I've looked over both boards many times now and everything appears consistent.

Tricky to say really.... wrong pot fitted ?... duff pot ?... op-amp circuit not working properly (wrong resistor, duff transistor, bad joint).... it could be a whole host of reasons ...

Colin
www.audiomaintenance.com

 

[decentbad]

Sorry, all gone.

[/quote]

Hi, any chance for a PCB reissue?

Big thanks

 

[Slenderchap]

OK ... the ez1073 (1U version) is available again for a short while.

Colin
www.audiomaintenance.com

 

[dacapitan]

n00b question; when selecting the WIMA and ceramic capacitors is there a upper and lower limit when choosing the voltage rating? I guess this will help me understand for other projects in the future too.

How would one determine a projects component upper and lower voltage limits if not specified? I understand that it has to do with the amount of voltage it can with stand and that the component size will vary - I dont want it to be too big or blow up! Im just having trouble figuring out how to determine this, this will set me in good stead! thanks if anyone could please help I would much appreciate your help 

 

[rob_gould]

There's no upper limit to the voltage rating of capacitors; the limit there occurs because the body of the component often gets larger as voltage rating increases, meaning that a component won't fit onto the PCB.

With regard to the 1073 project, I think that 63V should suffice in most places.  The WIMAs polys don't actually increase in size that much as voltage rating increases so you can overate them and not have to worry too much about them not fitting.

 

[dacapitan]

There's no upper limit to the voltage rating of capacitors; the limit there occurs because the body of the component often gets larger as voltage rating increases, meaning that a component won't fit onto the PCB.

With regard to the 1073 project, I think that 63V should suffice in most places.  The WIMAs polys don't actually increase in size that much as voltage rating increases so you can overate them and not have to worry too much about them not fitting.

Thanks for your answer Rob,

I understand that, so when it comes to the lower limit then how did you come up with 63V? and lets say for example theres a 50V Ceramic cap and a 100V in stock, you would choose the 100V? - when ideally looking for a 63V? or the 50v as 50V is closer to 63V

when overating, when does the difference or deviation in rating become too great (that the size becomes too big) ? a difference/deviation of 10V or 50v or 100v from the ideal - for example? (that the size would start impacting the ability to fit)

I know this is a simple question, but just need to wrap my head around this

 

[kante1603]

Thanks for your answer Rob,

I understand that, so when it comes to the lower limit then how did you come up with 63V? and lets say for example theres a 50V Ceramic cap and a 100V in stock, you would choose the 100V? - when ideally looking for a 63V? or the 50v as 50V is closer to 63V

when overating, when does the difference or deviation in rating become too great (that the size becomes too big) ? a difference/deviation of 10V or 50v or 100v from the ideal - for example? (that the size would start impacting the ability to fit)

I know this is a simple question, but just need to wrap my head around this

Hello and welcome to the forum.
rob_gould talks about 63v because it is a standard value for capacitors.
In general it is like this:Given you know the voltages in the circuit you simply give caps a good margin,so they are higher than the max. voltage here.Standard values are 35,50,63 and 100 volts and then their multipliers by 10,100 etc.

The keyword for capacitors is dielectric strength.

When the value is too low the cap will pop or explode.At this point a high current will flow because mostly you will have a short and will destroy surrounding parts too.
Dielectric strength depends on a lot things like the cap type and the inner construction,the surrounding temperature,age and the general charge/discharge and load conditions,on ac voltage the frequency matters too.
There's no general formula to calculate them,just give them a good margin.
Also keep in mind that caps can have high tolerances too.
Some caps like metal film types can even heal themselves ( but will loose capacitance partwhise then),others like electrolytics are polarity dependent (wrong way around means it will be destroyed) etc............

There's a lot of info to be found in the internet.

I don't know this circuit in detail and haven't built it,but 63 v versions seem to be absolutely correct in most places here.

Hope to have helped,

Best regards,

Udo.

 

[dacapitan]

Thanks for your answer Rob,

I understand that, so when it comes to the lower limit then how did you come up with 63V? and lets say for example theres a 50V Ceramic cap and a 100V in stock, you would choose the 100V? - when ideally looking for a 63V? or the 50v as 50V is closer to 63V

when overating, when does the difference or deviation in rating become too great (that the size becomes too big) ? a difference/deviation of 10V or 50v or 100v from the ideal - for example? (that the size would start impacting the ability to fit)

I know this is a simple question, but just need to wrap my head around this

Hello and welcome to the forum.
rob_gould talks about 63v because it is a standard value for capacitors.
In general it is like this:Given you know the voltages in the circuit you simply give caps a good margin,so they are higher than the max. voltage here.Standard values are 35,50,63 and 100 volts and then their multipliers by 10,100 etc.

The keyword for capacitors is dielectric strength.

When the value is too low the cap will pop or explode.At this point a high current will flow because mostly you will have a short and will destroy surrounding parts too.
Dielectric strength depends on a lot things like the cap type and the inner construction,the surrounding temperature,age and the general charge/discharge and load conditions,on ac voltage the frequency matters too.
There's no general formula to calculate them,just give them a good margin.
Also keep in mind that caps can have high tolerances too.
Some caps like metal film types can even heal themselves ( but will loose capacitance partwhise then),others like electrolytics are polarity dependent (wrong way around means it will be destroyed) etc............

There's a lot of info to be found in the internet.

I don't know this circuit in detail and haven't built it,but 63 v versions seem to be absolutely correct in most places here.

Hope to have helped,

Best regards,

Udo.

Thanks for your welcome and response Udo, very much appreciated

I understand what you mean,  that if the dielectric strength is too low it will pop and as Rob has said that with the higher voltage comes a  larger sized body thus potentially creating problems when fitting them to the PCB,

but the crux of my problem is, this good margin you speak of, what is a good margin? when do they start becoming margins that are too large? if going for a 63V ideal but 50V or 100V are the only ones to choose from is this margin too large or too small, will the 50V pop or will the 100V be too large? - do you go for the 50V or the 100V how much headroom/deviation/margin does one usually give either way?

 

[rob_gould]

There's no upper limit to the voltage rating of capacitors; the limit there occurs because the body of the component often gets larger as voltage rating increases, meaning that a component won't fit onto the PCB.

With regard to the 1073 project, I think that 63V should suffice in most places.  The WIMAs polys don't actually increase in size that much as voltage rating increases so you can overate them and not have to worry too much about them not fitting.

Thanks for your answer Rob,

I understand that, so when it comes to the lower limit then how did you come up with 63V? and lets say for example theres a 50V Ceramic cap and a 100V in stock, you would choose the 100V? - when ideally looking for a 63V? or the 50v as 50V is closer to 63V

Well, firstly I must admit to you that I'm no expert in electronics, I'm still learning so take all my advice with a pinch of salt.

But in the case of this circuit, the highest voltage on the PCB will be around the 48V phantom power section.  Other parts of the circuit are lower than this, and the audio sections will never approach this voltage, so 63V is higher than 48, plus a bit of margin too.  As Kante also explained, these parts don't come in every single unit - look up E6, E12, E24 etc resistor values if you don't know what I mean.

To answer the second question, if I understand you right, there's no correlation between voltage, or any other, rating and size.  You can't say for sure that a 100V rated cap will be twice as big as a 50V rated cap.  It just doesn't work like that I'm afraid.

The way you have to learn this is simply by diving in and, dare I say it, making a few mistakes as you go.  I've definitely bought components which haven't fitted the board in the past but you can always use them for something else - it's all a learning process.  Fortunately, there are also resources like this incredible forum to help out new members and ensure that hey don't waste too much money!

You don't say where you're based, but this sample of my order for this project (purchased from rapid electronics in the UK) will at least allow you to compare part numbers and datasheets to see the sizes of the components that I used even if you don't order from there :

14 10-2208 22nf 63v Mks2 Mini Poly Capacitor Case A

15 10-2216 Wima 100NF Polyester Capacitor Case A 63V MKS2

16 10-2212 47nf 63v Mks2 Mini Poly Capacitor Case A

17 10-2204 10nf 63v Mks2 Mini Poly Capacitor Case A

18 10-2206 15nf 63v Mks2 Mini Poly Capacitor Case A

19 10-2220 220nf 63v Mks2 Min Poly Capacitor Case B

20 10-2222 330nf 63v Mks2 Min Poly Capacitor Case C

21 10-2224 470nf 63v Mks2 Min Poly Capacitor Case D

22 10-2228 Wima Mini Polyester Capacitor (Case E) 1UF 63V

23 08-0935 47pf 2.5mm Npo Ceramic Capacitor

24 08-0940 100pf 2.5mm Npo Ceramic Capacitor

25 08-0904 180pf 2.5mm Npo Ceramic Capacitor

26 08-0945 220pf 2.5mm Npo Ceramic Capacitor

27 08-0955 470pf 2.54mm Npo Ceramic Capacitor

28 08-0950 330pf 2.54mm Npo Ceramic Capacitor

29 08-0906 680pf 2.5mm Npo Ceramic Capacitor

30 08-0275 100nf 2.5mm Y5v Dielect Ceramic Capacitor

31 10-1410 220pf 100v Polypropylene Capacitor

32 10-1425 680pf 100v Polypropylene Capacitor

37 11-3822 1000uf 50v 105 Deg Radial Electrolytic Capacitor

I'm not sure that this will be everything.  If I recall correctly I had to get some bits from Farnell as well, but there's enough here to get you started...

Hope this helps...

 

[rob_gould]

only ones to choose from is this margin too large or too small, will the 50V pop or will the 100V be too large? - do you go for the 50V or the 100V how much headroom/deviation/margin does one usually give either way?

There is a fairly simple answer to this :

overrate them until A : they become too big for the board or B : they become much more expensive.

Just to reiterate, electronically speaking there's no problem using a 630V capacitor when a 63V one is called for.

I'm sure someone much wiser than I will be able to provide a calculation or rule of thumb for this, but I don't have one, and I've never had an issue overrating them by a sensible margin and leaving it at that.

 

[dacapitan]

Thanks so much for your answers, this definitely gives me some more understanding.

So lets say with the 48V being the highest voltage a component is likely to be subjected to and overating to 63V provides enough margin, but there are only 50V and 100V available you would choose the 100V (provided it fits) as this provides a greater margin.

but lets say for arguments sake; if the 100V didn't fit and the 50V fitted but has less margin, its still okay as its marginally higer? - even though not by a large amount

what margin is considered safe.... I know it may not be the case here..... but just for my better understanding and potentially other people who may come across this.

 

[rob_gould]

I wouldn't use a 50V part in a 48V circuit. Again someone else may correct me on this but I wouldn't.

In the case of the Wima caps in this circuit it isn't an issue anyway because the footprint is small irrespective of the voltage rating.

 

[kante1603]

I wouldn't use a 50V part in a 48V circuit. Again someone else may correct me on this but I wouldn't.

In the case of the Wima caps in this circuit it isn't an issue anyway because the footprint is small irrespective of the voltage rating.

Agreed absolutely,one must remember the caps tolerance.....no margin left anymore.
63 volts is the next step.

Udo.

 

[dacapitan]

Great, yeah that makes sense, thanks so much for your input, the tolerance factor definitely explains that!