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

[Aaronrash]

Hi everyone,

Sorry to spam the thread with questions but I have a few more questions. I'll be building 2 EZ1073's. I went ahead and ordered the knobs (the same ones Neve uses) costed a cool $150 ouch! I'm about to order 2 kits from Collin. Here's my questions...

1) I've seen pictures of peoples builds but I'm not sure how they are doing the power switches, there's not really any detailed pictures on the back of the unit for me to follow. Regarding the switch fuse and IEC could someone give me a link to the correct parts to order? I just want to make sure they will work with my collective cases from Dan for the EZ1073

2) I read earlier that 5mm standoffs will be good for the case. Can anyone point me in the right direction for the standoffs and screws as well as how many to order. Also if there's anything else that needs to be ordered not included in the case let me know. I want to have everything here so I can build right away.

3) Lastly, what type of solder would be good for this build? I would prefer to use lead free solder, will silver solder work okay? Is there a better formula you guys would recommend?


Thanks very much everyone, I'm very excited about this being my first build. I used to have 1084s but recently had to sell them. I have a feeling these are going to make me feel right at home again.

Cheers!
Aaron

 

[sr1200]

Yes, I'm wondering what resistor values would need to be changed to make it around 30db of attenuation instead of 10db. I have very sensitive converters

Not sure what that means, everyones converters are sensitive. But if you just leave the gain at the lowest it will go and use the attenuation, unless you're sending a recording of a jet taking off or some ordnance going off, not sure why you would need 30db of attenuation. 

Any properly rated spst switch will work (depending on where you live will depend on value but since you can use a 250v min rating anywhere shouldn't really matter)
Look for nylon standoffs, I used ones that have an adhesive back on them (like stickers) really work well.
I use really fine silver bearing solder on almost all my builds.  People look down upon lead free solder, not sure why, but i've never used it.  Rosin core solder tends to leave a residue behind more than other solder i've used. Just be neat about everything and clean your board properly.

 

[Aaronrash]

Yes, I'm wondering what resistor values would need to be changed to make it around 30db of attenuation instead of 10db. I have very sensitive converters

Not sure what that means, everyones converters are sensitive. But if you just leave the gain at the lowest it will go and use the attenuation, unless you're sending a recording of a jet taking off or some ordnance going off, not sure why you would need 30db of attenuation. 

Any properly rated spst switch will work (depending on where you live will depend on value but since you can use a 250v min rating anywhere shouldn't really matter)
Look for nylon standoffs, I used ones that have an adhesive back on them (like stickers) really work well.
I use really fine silver bearing solder on almost all my builds.  People look down upon lead free solder, not sure why, but i've never used it.  Rosin core solder tends to leave a residue behind more than other solder i've used. Just be neat about everything and clean your board properly.

Thanks sr

Put it this way... On my 1084's I had to turn the output fader almost all the way down so I didn't overload my converters. I want to buy better converters when I can afford it but for now I'm gonna have to attenuate the signal somehow. I don't think it would be very hard to do... But I'll wait for Collin to chime in on that.

For the spst switch will I need to drill a hole in the back of the case for the switch or make a cut out? I'm not sure if dans case has this already but either way I'm sure it won't be a problem. Also what silver solder do you use. I might as well use exactly what you're using since you can confirm it works well.


What do you think about this? It's filtered and has a switch and fuse. Could possibly fit sideways
http://www.alliedelec.com/search/productdetail.aspx?SKU=70133406#tab=specs
With this fuse
https://www.divinelighting.com/gdc-100ma-slowblow-fuse-t100ma-250v-gdc100ma-gdc-100-ma-p-635.html
If you guys are sure a 100mA slow blow is enough!


Many thanks!

 

[tommypiper]

Guys, where to get these PCBs?  Has Gustav quit them?  (I'll ask him in meantime, but in case anyone knows additional info, please let us know.)

 

[sr1200]

Pretty sure dan has the part numbers listed in his thread for the case.  The one youre looking at at allied is too big.  The one that he normally uses is more like
http://www.mouser.com/Search/ProductDetail.aspx?R=161-0717-187-Evirtualkey11180000virtualkey161-0717-187-E

(PS allied is WAY over priced)

Radio shack .022 (i think)  silver bearing solder, its like hair lol.

For my two units i drilled a hole to the right of the trim knob below the Power LED and that did it for me power switch wise.

 

[dgoszillai]

i got a problem with 2ez1073 (!) i just built.
one (A) has no sound at all just a buzz.
the other (B) works on line (+eq) but mic gives a buzz also (no mic signal just noise)

dam ... 
they are racked so i have to dimount them all to check again any solder problem
but i was wondering if you had any way to start testing these

 

[sr1200]

Trace the schematic and follow the signal from input.  If its a voltage issue, follow the voltage from the PS section through.

 

[dgoszillai]

m... that's why when i do a DIY it has to work right away i really don't have the skills to do that
it will take me month only to know what to "trace" anyway thx for help

 

[tommypiper]

EDIT:

Are the PCBs no longer available? 

EDIT:
I found it in full kit form on AML website. 

EDIT 2:
I see Colin's reply below now too... Thanks.

 

[ubxf]

Hello Tommypiper,
i had an email exchange with Colin regarding another project of his and asking the same question.He said may be in the future but not right now . So it might be the same for this one
francois

 

[Slenderchap]

R134 (5k1) effectively sets the bottom of the trim pot signal level....just imagine if it were zero ohms, then when the pot was fully counter-clockwise the wiper would be attached to ground (through the zero ohm link) and there would be no signal going into the stage 3 amplifier.... so for 30dB attenuation it would need to be somewhere between 0 Ohms and 5k1.... I'll let you calculate that !

Usually converters have the ability to select input sensitivity ?

Mains switches should be Dual Pole.... you should switch the live and neutral.

Gustav has never made the PCB's for the ez1073 project (cannot remember why)... they are only available as part of the AML-17-020 kit.... we do still currently sell that kit (but that may change in the future).

Colin
www.audiomaintenance.com

 

[Aaronrash]

R134 (5k1) effectively sets the bottom of the trim pot signal level....just imagine if it were zero ohms, then when the pot was fully counter-clockwise the wiper would be attached to ground (through the zero ohm link) and there would be no signal going into the stage 3 amplifier.... so for 30dB attenuation it would need to be somewhere between 0 Ohms and 5k1.... I'll let you calculate that !

Usually converters have the ability to select input sensitivity ?

Mains switches should be Dual Pole.... you should switch the live and neutral.

Gustav has never made the PCB's for the ez1073 project (cannot remember why)... they are only available as part of the AML-17-020 kit.... we do still currently sell that kit (but that may change in the future).

Colin
www.audiomaintenance.com

Thanks Collin! That pretty much answers all my questions. I will document my build and report when I'm up and running. Or if I need help (let's hope not!)

Cheers,
Aaron

 

[Aaronrash]

One last question,

If I do end up changing R134 to a lower ohm resistor, what wattage would I need to get? I will likely just stick with the originals but if I end up wanting more attenuation I will probably just experiment and put some 2K resistors at 1% for both units and that should be plenty of resistance.

 

[Sillen]

Hi
I started to build this kit and now noticed that the knobs i purchased for it does not fit the pots. Could anyone say an example of knobs that would fit really well? (As cheap as possible)
Also the lock nuts that was supposed to be for the output transformer won't tighten it up totally, obviously because of the lock nut.. Anyone else had this problem?
And one last question: What nut size and screw size would I need for the standoffs?

All the best
Isak

 

[dgoszillai]

i'm back to my 2 units.
one is working now !  ;D it was the one where the line level + eq was ok.
i figure out that the connectors i used for the XLR was not great. so i sold the wire directly to the pcb instead of using this and now it works fine.

but the second unit is still dead. i also sold the wires of XLR directly to PCB but i still have nothing just a constant tone buzz.
But i found this :
R23 = 12R is burned  :-[
i don't know if i maybe put a wrong value here .. i can't read it anymore but there's little chance because i build the 2 units side by side and i would have ended with an extra 12R and a value missing for another place.
i checked the other side of PCB no chance i did a mistake soldering here there's lots of space.
5min after unplug the VTB1847 is still very hot maybe it's damaged ?
all wires from VTB1847 are in right position.
https://lh5.googleusercontent.com/-nSV-dAtQcVE/UhZCrWJGH5I/AAAAAAAABOA/Pvg3FFAdGRQ/w958-h639-no/IMG_2285.jpg

something else bu't im not sure
the VTB9044 has a strange look one leg looks dark as if there was some heat. but i don't know if it was like this at the origin or if it happened during the problem.
https://lh5.googleusercontent.com/-1lLZFVmyi-A/UhZCreNqVqI/AAAAAAAABN8/3SPTCO-BcFM/w958-h639-no/IMG_2286.jpg
i can replace that resistor but do you guys know if i have to check other components around that could have been damaged by this ? or do i have to change it to find out ? if the problem comes from something else then it might burn again right ?

thx for help

 

[guitar4444]

I had r12 overheating on one of my units at first. I think it turned out one of  the power transistor heat sink bolts was shorting to ground. There isn't much clearance there.
But could be caused by anything that draws to much power.

cheers  Greg

 

[tommypiper]

Gustav has never made the PCB's for the ez1073 project (cannot remember why)... they are only available as part of the AML-17-020 kit.... we do still currently sell that kit (but that may change in the future).

Colin
www.audiomaintenance.com

Thanks!  If you do offer just the PCB, I'd be interested.  I'd prefer to get just the PCB, or with perhaps the inductors and possibly one or two transformers and such.  Thanks.

 

[dgoszillai]

thx Gregg,
the power transistors looks ok .. solder is fine and no sign of heat there .. but i don't know if it means they'r ok ?
did your shorted transister looked burned also ? how could i test it to know if it's ok ?

 

[guitar4444]

I don't think the transistor was actually shorted just the main power rail going to the transistor via the transformer is connected to the heat sink (I think this is right). The heat sink mounting bolts are isolated on their own pads on the board but there isn't a big amount of clearance between the pad and the board. If you have a loose fitting shake proof washer there it could easily short. The result is all the power supply power goes r12, through the transformer then through the heat sink to earth.

cheers  Greg

 

[tommypiper]

I have built 6 x EZ1073 and all have a small problem with hum.
cheers  Greg

Greg, have you tried holding a sheet of steel between the power transformer and the PCB while listening to the hum? Any piece of steel.  Doesn't have to be grounded.  Doesn't have to be thick.  You can cut open a tin / steel can and try that.  If it works, find a way to mount it against the toroid. 

PS: (Just a word of safety to anyone who reads this.  Be careful mounting metal round the toroid.  Don't use a shield that makes a complete loop connection around the toroid, or connects to the steel bolt on the inside and the chassis on the outside, as that will create a new coil around the toroid which is apparently dangerous.  If you want to mount like that, use a nylon or plastic bolt in the center of the toroid to break that conducting loop.  Others can explain further.)