8 Channel, 3U NEVE 1073 completed
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Junction
Well-known member
I am sure the answer is in these 103 pages somewhere, but does someone have the dimensions of the PCB?
Thanks
Thanks
madriaanse
Well-known member
Junction said:I am sure the answer is in these 103 pages somewhere, but does someone have the dimensions of the PCB?
Thanks
Hello,
Board Dims are: 6.500 x 3.750 inches.
M.
madriaanse
Well-known member
Hi Paul,
I have not kept track of all the changes throughout the years, but since the EZ1290 is based on the original BA183 layout, the boards are completely backwards compatible. The latest revision includes footprints for radial polypropylene caps and terminal blocks. However, you could still easily use axial polystyrene caps if you felt inclined to. Other than that, there have been a few capacitor changes throughout the different revisions based on conversations with various Neve techs.
Best,
Martin
I have not kept track of all the changes throughout the years, but since the EZ1290 is based on the original BA183 layout, the boards are completely backwards compatible. The latest revision includes footprints for radial polypropylene caps and terminal blocks. However, you could still easily use axial polystyrene caps if you felt inclined to. Other than that, there have been a few capacitor changes throughout the different revisions based on conversations with various Neve techs.
Best,
Martin
My JLM Powerstation has been giving me some odd issues as of late.
Basically, I'm getting this wwwwwhooooooooooooooommmmmmmmm whining sound on any preamp channel output that is powered and passing audio even with nothing at the input. Both 24V+ outputs from my PSU are exhibiting this, so it could be further up the line or maybe both regs took a dump??
Caps look fine (non bulgy) from visual inspection. Maybe the rectifier is taking a crap?
I thought it was heat, or regulators taking the piss but today it was there on power up, regs were cold at power up. Hrmm....
I'm gonna check my joints yada yada, and probably swap both V+ rail regs (I have a power station running 4x 1290s each)
I'll capture some audio and add here so you can hear and anyone else who runs into might be able to learn something with me.
...just went to record the noise... preamps working fine. I didn't touch the thing. It was turned off from prior to my post and just now I went and turned it on and it's working.... :-X
*further update* 4x Pres have been "burning" for a short while on one of the two 24V rails. The unused rail is warm but not hot, I can leave my thumb on the wafer and can touch the back side of heatsink without pain. I didn't think to grab the laser thermometer.
The rail regulator that is feeding the 4x burning pres is too hot to keep a finger for even a second. Still working just fine though.
Hoping it acts up today so I can grab that audio.
Basically, I'm getting this wwwwwhooooooooooooooommmmmmmmm whining sound on any preamp channel output that is powered and passing audio even with nothing at the input. Both 24V+ outputs from my PSU are exhibiting this, so it could be further up the line or maybe both regs took a dump??
Caps look fine (non bulgy) from visual inspection. Maybe the rectifier is taking a crap?
I thought it was heat, or regulators taking the piss but today it was there on power up, regs were cold at power up. Hrmm....
I'm gonna check my joints yada yada, and probably swap both V+ rail regs (I have a power station running 4x 1290s each)
I'll capture some audio and add here so you can hear and anyone else who runs into might be able to learn something with me.
...just went to record the noise... preamps working fine. I didn't touch the thing. It was turned off from prior to my post and just now I went and turned it on and it's working.... :-X
*further update* 4x Pres have been "burning" for a short while on one of the two 24V rails. The unused rail is warm but not hot, I can leave my thumb on the wafer and can touch the back side of heatsink without pain. I didn't think to grab the laser thermometer.
The rail regulator that is feeding the 4x burning pres is too hot to keep a finger for even a second. Still working just fine though.
Hoping it acts up today so I can grab that audio.
madriaanse
Well-known member
Micdaddy, that does sound like PSU woes. Be sure to put a HEALTHY heatsink on the Vreg. Maybe remote mount it if it doesn't fit.
;D It has lived in a PCU psu chassis with no heatsinks other than the thin casing of the enclosure... suppose it's time for a few chunks of aluminum.
Perhaps I've ran these so hot for so long without enough heat removal that they're burned up.
Oddly they haven't given me any trouble since I posted.
I'm going to try to reproduce the fault and capture that audio just for anyone else, then some chunkers I'll add to the regs.
Black heatsinks dissipate better than polished alum (anodized) or that is only for radiation and this is more conduction or passive convection?
Perhaps I've ran these so hot for so long without enough heat removal that they're burned up.
Oddly they haven't given me any trouble since I posted.
I'm going to try to reproduce the fault and capture that audio just for anyone else, then some chunkers I'll add to the regs.
Black heatsinks dissipate better than polished alum (anodized) or that is only for radiation and this is more conduction or passive convection?
spase
Well-known member
I think there are no difference between anodized and normal heatsinks in heat dissipation .Just put a heatsink on your regulator and you gonna be fine.
critterkllr
Well-known member
I want to post about a recent issue I had with a couple of my ez1290s. Even though there are a few posts about it already, maybe somebody will find mine useful.
After a couple weeks of use the 4th channel started crackling and popping. Then it eventually turned into nothing but noise. After a few more days, the 3rd channel did the same thing.
It turned out that a vibrating psu located at the bottom of my rack managed to shake loose the nuts that held the 2N3055 down to the PCB. I tightened the nuts and added some loctite. Problem fixed.
It looks as though the 2N3055 also works as a bit of a jumper to connect two separate ground planes together. Both nuts need to make contact with the PCB. I'd suggest using some loctite or making sure the 2N3055 is screwed down very tightly to avoid some possible frustration later on down the road.
After a couple weeks of use the 4th channel started crackling and popping. Then it eventually turned into nothing but noise. After a few more days, the 3rd channel did the same thing.
It turned out that a vibrating psu located at the bottom of my rack managed to shake loose the nuts that held the 2N3055 down to the PCB. I tightened the nuts and added some loctite. Problem fixed.
It looks as though the 2N3055 also works as a bit of a jumper to connect two separate ground planes together. Both nuts need to make contact with the PCB. I'd suggest using some loctite or making sure the 2N3055 is screwed down very tightly to avoid some possible frustration later on down the road.
Potato Cakes
Well-known member
I had the same kind of issue with one of my channels when building it. I thought was a bad solder joint so I reflowed solder and retightened the nuts. I was tapping with my finger on different areas of the circuit board and when I hit the transistor it made a loud popping noise.
Never thought about the nuts coming loose during normal use. Do you travel with your EZ1290?
Paul
Never thought about the nuts coming loose during normal use. Do you travel with your EZ1290?
Paul
critterkllr
Well-known member
I've never travelled with it. It's lived in the same rack since completion. Maybe I ended up with some funky nuts and bolts?
tomnowell
Member
- Joined
- Sep 18, 2015
- Messages
- 5
First off, I want to say a big thank you to Martin! - this has been not only hugely enlightening and encouraging as a first DIY Audio project, it has been a whole lot of fun and will get a whole lot of use!!
And thank you to everyone who has contributed advice, information and help - you've all helped me a lot already .
I am a little bit stuck however, I finally got around to completing my first EZ1290 a week or so ago, and turned it on and it worked like that!, or so I thought, I was pretty happy with the sound, though I wasn't sure about it when trying to drive the pre-amp a little more.
I only have a DMM so I initially biased to 22.66v on the Collector of the 2N3055 however after doing a few recordings and analysing the waveforms it really looks as though my unit clips much earlier on one side of the waveform than the other. I have hooked up a crude signal generator from my iPad through the preamp and into my AD and analysed the sign wave with SignalScope which confirmed that the clipping is asymmetrical. So I tried turning the trimmer but couldn't get the clipping even close, I kept the signal as cold as I could to induce clipping and Im sure it was the preamp and not my AD that was clipping the signal. I have tested all my transistors and they pretty much on the money (I used BC550cs instead of BC184c), Im pretty sure my grounding is good, no crackles, cut-outs or hums.
Any suggestions? I know there were a couple of guys a while back with a similar problem, but I couldn't find the resolution except that perhaps their input signals were too hot.
Am I just using the wrong equipment? I don't have a scope but I might pick up an old analogue one if it would really help?
I noticed the trim-pot is labelled as logarithmic on the schematic and its quite possible I put a linear one in there, Would still be able to achieve correct bias?
Cheers,
Tom
And thank you to everyone who has contributed advice, information and help - you've all helped me a lot already .
I am a little bit stuck however, I finally got around to completing my first EZ1290 a week or so ago, and turned it on and it worked like that!, or so I thought, I was pretty happy with the sound, though I wasn't sure about it when trying to drive the pre-amp a little more.
I only have a DMM so I initially biased to 22.66v on the Collector of the 2N3055 however after doing a few recordings and analysing the waveforms it really looks as though my unit clips much earlier on one side of the waveform than the other. I have hooked up a crude signal generator from my iPad through the preamp and into my AD and analysed the sign wave with SignalScope which confirmed that the clipping is asymmetrical. So I tried turning the trimmer but couldn't get the clipping even close, I kept the signal as cold as I could to induce clipping and Im sure it was the preamp and not my AD that was clipping the signal. I have tested all my transistors and they pretty much on the money (I used BC550cs instead of BC184c), Im pretty sure my grounding is good, no crackles, cut-outs or hums.
Any suggestions? I know there were a couple of guys a while back with a similar problem, but I couldn't find the resolution except that perhaps their input signals were too hot.
Am I just using the wrong equipment? I don't have a scope but I might pick up an old analogue one if it would really help?
I noticed the trim-pot is labelled as logarithmic on the schematic and its quite possible I put a linear one in there, Would still be able to achieve correct bias?
Cheers,
Tom
tomnowell said:
You should get a scope and set the biasing by following Martins guidance specified in the easy 1290 Build Doc
https://s3.amazonaws.com/EZ1290/assembly6.pdf
Hey guys,
Has anyone had any issues with the low end with the Ez1290? I've followed the BOM, ordering polystyrene capacitors, my transistors came from eBay and i'm using the Carnhill transformers. Just double checked my polarities and components and everything is A-OK. I'm using a JLM power plant and the voltages are bang on 24V and 48V for phantom power.
I don't have a scope so I adjusted the 5K trimmer until the 2N3055 transistor case measured 22.66V.
I tested it with a Neumann U89i and I could immediately hear there was no low end at all. I tried running a 100Hz and a 40Hz wave from my Tascam M-3700 console into it. The 100Hz was barely audible and the 40Hz was totally inaudible. Tried a different pre just to be sure and it's definitely an issue with the EZ1290.
Checked all my transistor voltages and they're pretty close to the ones specified in the build guide.
Any ideas of what to check for next before I try replacing all of my polystyrene caps with polypropylene?
Thanks,
Kris
Has anyone had any issues with the low end with the Ez1290? I've followed the BOM, ordering polystyrene capacitors, my transistors came from eBay and i'm using the Carnhill transformers. Just double checked my polarities and components and everything is A-OK. I'm using a JLM power plant and the voltages are bang on 24V and 48V for phantom power.
I don't have a scope so I adjusted the 5K trimmer until the 2N3055 transistor case measured 22.66V.
I tested it with a Neumann U89i and I could immediately hear there was no low end at all. I tried running a 100Hz and a 40Hz wave from my Tascam M-3700 console into it. The 100Hz was barely audible and the 40Hz was totally inaudible. Tried a different pre just to be sure and it's definitely an issue with the EZ1290.
Checked all my transistor voltages and they're pretty close to the ones specified in the build guide.
Any ideas of what to check for next before I try replacing all of my polystyrene caps with polypropylene?
Thanks,
Kris
Enchilada said:
Something is wrong for sure and it has nothing to do with polystyrene or propylene caps.
If all voltages are correct, What I would do is to use a signal probe, inject Music at the input, and probe it before The input transformar, after input transformer, after 1st gain stage, after 2nd gain stage, after 3rd gani Stags, before output transformer and after Out transf.
Before this I would double check the wiring to and from the input and Output transformers, please verify that again.
If you dont have a signal probe just build one its easy enough
Hi,
Just checked the transformer wiring and it's all good.
By signal probe to you mean an oscilloscope probe?
As far as I can tell the only thing I've done differently is that I've not used the shield write to connect pin 10 of the input transformer to the PCB, I've used the white wire and then used the red wire for pin 7. I wouldn't have thought that would cause an issue though.
Kris
Just checked the transformer wiring and it's all good.
By signal probe to you mean an oscilloscope probe?
As far as I can tell the only thing I've done differently is that I've not used the shield write to connect pin 10 of the input transformer to the PCB, I've used the white wire and then used the red wire for pin 7. I wouldn't have thought that would cause an issue though.
Kris
peterc
Well-known member
Audio probe data:
http://www.geofex.com/fxdebug/newfx.htm
https://www.google.com/search?q=audio+probe+geofex&newwindow=1&tbm=isch&tbo=u&source=univ&sa=X&ved=0CCkQsARqFQoTCOvdjvHA6cgCFYPsFAodyrEJ9g
Hope it helps....
http://www.geofex.com/fxdebug/newfx.htm
https://www.google.com/search?q=audio+probe+geofex&newwindow=1&tbm=isch&tbo=u&source=univ&sa=X&ved=0CCkQsARqFQoTCOvdjvHA6cgCFYPsFAodyrEJ9g
Hope it helps....
I didn't trust my eBay transistors so I picked up some BC550 transistors from Jaycar. There's a very faint, oscillating, high pitched whine now and still no low end. I'll chance them back and give this audio probing business a razz.
