8 Channel, 3U NEVE 1073 completed

[sgenevay]

Hi Deuce42

Look at my April 06 Post (page 38)
i recorded a 1073 DPA.... to compare...
u have links there...

Hope this will help you


Sylvain.

 

[desol]

What people call the phenomenon of Neve 'haze', doesn't have anything to do with noise. It's the overall buildup of low - mid frequency in a mix. I don't think there's ever been a consensus on whether such a thing actually exists. The grounds are supposed to be seperate with 10ohms between them, which means the pcb Ov should not be connected to case ground. Other problems such as placement of components, etc are causing oscillation.

As to what the problem is on the switch you'd probably have to trace the audio signal with a scope to see where/what is happening throughout the stages.

 

[MicDaddy]

Can I skate by with this power trafo?  I plan to use with 1x JLM powerstation for 8x preamps.

http://www.mouser.com/ProductDetail/Triad-Magnetics/VPT24-2080/?qs=wkKrz7WmEgMMEIeVWR4gGA%3d%3d

24VAC ct @ 2.08A  not enough??

Anybody recommend anything else?  I think Desol sent me the part# for the toroidal used but I can't find them anymore.

 

[sr1200]

Gonna need a bigger boat....

I believe the JLM is good to power a pair of boards. (probably can do 3 but its gonna get toasty!!)  Gonna need 4 of them JLMs for that task im thinkin...

 

[desol]

I have eight 1290's running off a single powerstation with the larger rectifier upgrade. Although it has been modified further to disable the neg power rails as well as provide full wav rec. I posted about it earlier on in this thread. The onboard 317's are bolted to the case and are barely warm to the touch. The toroid i used was the avel lindberg  3.33 amp 80va unit. I have thought of putting in a bigger supply but this seems to be working fine.

I did a quick amp test tonight with my AC meter. On start, they pulled around 2.71 amps, then settled at 740mA idle(with phantoms engaged). DC did about the same...with idle a little lower at ~610mA.

 

[erikb1971]

Hi All

I have designed a front panel for my 2 channel 1290 (based on MatthewF's kindly supplied design - tnx!). I have attached a picture for you to take a look at. If anyone has any comments / tips /things I have overlooked, your input is highly appriciated. I would also like to know how to add another font type in front panel express, so I can match the font to my other builds. I have the font on my pc, but it is not showing up in front panel express...

Als I would like to take the opportunity to repost my previous question, since you guys might have overlooked it, and Iam stuck with my built without answers (no preassure though):

Iam finished soldering the parts on my EZ1290s but I have run into two little problems:
1. I did not recieve R56 (resistor 12 Ohm 1W). But I got two extra R98 (resistor 10 Ohm 1W).
Can I use the 12 Ohm in place of the 10 Ohm?
I have bought in a local shop two 12Ohm 1W resistors, but they are twice the size ...will fit though, but Iam wondering.. are they a different kind of resistor?

2. I have an empty space on both boards labelled 3k3. I do have two 33Kohms resistors, but they are not the ones right? Or can I use these anyway?

Thanks a lot


Erik

 

[MicDaddy]

hey desol, would you take a peek at the model number of your toroidal?

The largest 12+12 I found was only 30VA for an Avel.

Thanks again!!

 

[desol]

Micdaddy: have a look at the y23 range 80VA. 12+12 @ 3.33A.

Erik: Use the resistors specified. A larger 1 watt doesn't matter. 33k is not 3.3k.

 

[erikb1971]

Desol: thank you!

I have spotted an error in my front panel design! The DI was much too close to the gain, those boards (DI & 1290) would be completely in each other's way! Attached the new version, for this the DI board has to be mounted upside down, but otherwise the DI is much too far from the gain...

 

[MicDaddy]

Hey thanks, who sells them?    

Avel Lindberg Y236351


edit:  Avel Lindberg of course  ;D
Awesome, thanks!!

For future reference,

Avel Lindberg Sales 

800-979-1022, x 1, or fax 860-354-8597

 

[desol]

You order direct from them..

 

[statzern]

Hey Statzern, to narrow down the problem can you measure the level at the L-P junction of each pre-amp?
This is the point where a trimmer would be inserted if used and would allow you to see if the different level is due to the second or third amplification stage. I don't think the first amp stage is at fault as this only kicks in for the higher gain settings and you are observing the difference across the whole scale. Cheers, Briomusic

Yeah, I can give that a try. Thanks for the advice. Will report results ASAP.

 

[statzern]

Hey Briomusic,

I measured the voltage at the L-P junction at the negative side of the 10 uF/25V tantalum cap. The voltages are very different at that point. The gain was set to 35 dB.

What do you think might be going on to cause this difference?  ??? ???

 

[erikb1971]

HI All

Iam nearing completion of my 2 channel 1290 + gobetween + JLM DI. It being my first build, Iam starting to get a little nervous. I have three questions:

1. Iam "missing" three jumpers per board if I compare to some other pictures here on the forum... should I solder those in?

2. Should I move the output transformer in to indicated position? Wich would mean further away from input transformer, but the output cable would be crossing the power cable

3. can I attach all transformers directly to the case or should the be insulated as well?

Hope you can help this newbee...


cheers

Erik

 

[sgenevay]

For me transformers has to be linked to the ground ... so to the case...

Sylvain

 

[briomusic]

HI All

Iam nearing completion of my 2 channel 1290 + gobetween + JLM DI. It being my first build, Iam starting to get a little nervous. I have three questions:

1. Iam "missing" three jumpers per board if I compare to some other pictures here on the forum... should I solder those in?

Those are not really jumpers, they are pcb copper traces and vias. A 'via' is a connection of the top layer to the bottom layer of the pcb. the only jumper you need is already installed if I see correctly. if you are using an output trim, install it at that point INSTEAD of the jumper.

2. Should I move the output transformer in to indicated position? Wich would mean further away from input transformer, but the output cable would be crossing the power cable

Not a thang as that power cable is DC if I understand correctly (PSU in seperate case - very good idea). but current position is ok too.

3. can I attach all transformers directly to the case or should the be insulated as well?

As sgenevay said, don't insulate - you want them to be grounded!

 

[erikb1971]

Thank you!

First estimated testdrive tomorrow evening.. exciting!

 

[0dbfs]

I think that dark-burgundy-slightly-wrinkled colour would look nice for a front panel with these.

Cheers,
JoBu

 

[briomusic]

Hey Briomusic,

I measured the voltage at the L-P junction at the negative side of the 10 uF/25V tantalum cap. The voltages are very different at that point. The gain was set to 35 dB.

What do you think might be going on to cause this difference?  ??? ???

hi statzern, sorry for the late reply hadn't seen your post.
Just to clarify you are measuring AC/sound levels with a scope right? if levels are already different at that stage then it is a sign that the problem is before the BA183AM stage, so either in the gain switch or in the (second) BA183NV. To further narrow down the problem, can you measure the level at the negative side of C8 for each gain setting. be carefull, this C8 exists twice, one shouldn't show any ac voltage except for the very high gain settings. I am talking about the other one! This point is inbetween the gain switch and the first amp. Let me know what you find, especially at the lower gain settings! cheers briomusic

 

[letterbeacon]

HI All

Iam nearing completion of my 2 channel 1290 + gobetween + JLM DI.

This is pretty much exactly the same as what I'm planning to build.  Do you have the front panel dimensions handy so I can see how far apart the Go Between and the DI have to be from the 1290 PCB?

Is it ok to have the ribbon cable that goes from the DI to the Go Between so long?  It's an unbalanced signal, right?  Is there a risk of it picking up any unwanted noise?