8 Channel, 3U NEVE 1073 completed

[MicDaddy]

I've found a quantity of 2000+ BC184 @ $0.06USD.

Unfortunately I cannot find a noise figure spec.

The BC184 Ic is rated at 100mA as opposed to 500mA with the BC184c.

Both have hFE=130 (MIN) @Vce=5.0V, Ic=100mA

I'll pull the trigger on the lot if these would work as substitutes, otherwise apologies for the wasted post.

BC184 spec sheet http://www.fairchildsemi.com/ds/BC/BC184.pdf

BC184C spec sheet http://www.fairchildsemi.com/ds/BC/BC184C.pdf

 

[dude24man]

I fixed the poping sound when changing gain settings. I replaced the (3) 10uf 24v tants. problem solved. arty

 

[audiophreak]

Helloooo    ;D

    could a DI -unbalanced Hi-Z input be done on this project as it is in the NYDave Mila ?? 

 

[remsouille]

Hey there!
I just built a dual VPR floor box which I'm going to use to power one VPR rack, and I was wondering if I could use the 24V part of the psu to power a couple EZ1290. Would I then use the GND as a 0V?

Cheers!

 

[dmp]

I just built a dual VPR floor box which I'm going to use to power one VPR rack, and I was wondering if I could use the 24V part of the psu to power a couple EZ1290. Would I then use the GND as a 0V?

Yes I think you could.

 

[dmp]

could a DI -unbalanced Hi-Z input be done on this project as it is in the NYDave Mila ??

You could try it and see how it sounds. Though most people do a DI buffer pre  transformer.

 

[dmp]

I've found a quantity of 2000+ BC184 @ $0.06USD.

Unfortunately I cannot find a noise figure spec.

The BC184 Ic is rated at 100mA as opposed to 500mA with the BC184c.

Both have hFE=130 (MIN) @Vce=5.0V, Ic=100mA

I think the 'C' means it is a selected part from the non 'C'.  I'd pay a little more to try to get 184c if I were building another Neve. Or build one and see if the noise level is acceptable. It seems the neve design is prone to hiss, so it might not be the best place to skimp.

 

[desol]

Even my BC184c's, if I remember correctly, had HFE's down around 300...however some were above 500.

Those seem like actual prices .o6 cents. Unlike 1.00 each. Ridiculous...

I'd scoop a 'lot' MicDaddy if you can. I already bought 2 or 3 100 packs  of bc184c a long while back.

 

[muffy1975]

OK,

who has heard the EZ1290 against the real thing? Or even up against the modern AMS NEVE 1073 DPA?


Did they sound at all alike?

I compared a dpa1073 and an EZ1290 ( built as per instructions here with all the parts etc ) and it did not same the same.


The DPA sound more processed and with more of a high frequency sizzle.

The EZ1290 sounded a bit muffled by comparison.


The DPA was also noisier.


The mic used was a sm7 on vocals and acoustic guitar.


Why do these pres sound different?


If you have not compared the originals to the 1290 you won't be able to really comment i suppose.


Do you think the DPA has a different component type used? They use the ST 2n3055 but they have SMD caps don't they? Are these mica caps for all the lower pf rated caps???

Have they been biased differently? IS there a missing magic component?

regards



Michael

 

[madriaanse]

Hi Michael,

Yes, the DPA appears to be using lots of SMD components and uses a vastly different layout compared to a vintage 1073/1084 as found in 80 series consoles. I've heard people say the DPA is a very nice sounding mic pre however. I think you'll hear more resemblance between a well maintained (this is key!!) vintage 1073 and the EZ1290. In order to make the EZ1290 I had to dissect and desolder a perfectly good module to get all the details sorted out. It hurt but was worth it in the end. I'll see if I can dig up some recent clips a friend of mine recorded with an EZ1290 and Wunder CM7 and an R84 (no processing) to give people an idea of the sound.

Best,

Martin

 

[analogstud]

May be a silly question as stainless-steel IS conductive but not as conductive as aluminum. Could I just use stainless machine screws with two stacked nuts as risers for the 2N3055?

 

[MicDaddy]

May be a silly question as stainless-steel IS conductive but not as conductive as aluminum. Could I just use stainless machine screws with two stacked nuts as risers for the 2N3055?

Exactly what I did, maybe there are photos from my build way back in the thread.

 

[sr1200]

I just used 1 nut as a riser instead of trying to cut those standoffs in half.  I did that on all 6 of mine.

 

[madriaanse]

Not sure if this is helpful, but here are some test clips a friend of mine recorded with an EZ1290. Signal chain: AEA R84 -> EZ1290 -> Prism ADA-8XR -> PTHD. No further processing.

https://s3.amazonaws.com/Mixes/accgtr.wav
https://s3.amazonaws.com/Mixes/cleangtr.wav
https://s3.amazonaws.com/Mixes/crunchgtr.wav
https://s3.amazonaws.com/Mixes/morecrunchgtr.wav
https://s3.amazonaws.com/Mixes/vox.wav

Martin

PS. Using two nuts as standoffs should be totally fine. Just make sure ALL nuts are really tight.

 

[useme2305]

i finally fit my front and back panels from frank to my dual ez1290.
while doing that i rewired the whole thing thoroughly and put a nice little DC/DC board with separate regulators for each channel in the thing.

it's a fully symmetrical interface layout.

more pics:
https://picasaweb.google.com/useme2305/Neve1073Ez1290

 

[sr1200]

Love the PS!  Specs and source?

 

[useme2305]

it's a simple generic regulated psu with 48v plus a little dc/dc converter for 2x 24v which i did on vero.i'll post the vero layout when i'm at home.
coupled with a filtered ac input as seen in the pics and a simple rc-filter consisting of a 10ohms resistor and a 470uf cap after the 48v output it makes a nice and quiet psu that doesn't interfere with the trannys.

 

[useme2305]

here's the vero layout i made for the dc/dc converter 48V to 2x 24V.
i tried running both pres from one TIP121 but two regulators (one for each channel) are better. one alone can handle the current draw but it gets rather hot.
this way though it runs nice and cool if you use a big enough heat sink for each regulator.

the PSU itself is a SunPower SPS 035-48 (0,75A)

i just use the 48V from the PSU itself for phantom power and the 2x 24V for the preamp boards.

i did the interface board on vero too which i epoxied to the switches. much cheaper and more customizable than the boards i found for sale.

 

[malu]

hey diy group!

i'm running a 2 channel 1290 with an external powersupply made from a self-etched mnats pcb (30v/30va toroid).

it works fine for now but i have 2 questions (of whose i did not find answers on google):

when i turn it on it crackles sums and makes noise for about 30sec-1min, then it goes very quiet to a normal level and the preamp works like it should! is that a normal behaviour?

i used NTE123 transistors, because i could not get bc184 and kubarth suggests them as an alternative for his ten81 project.

HOW do i make the PAD, Phase Reverse and Direct Input Options? is there any documentation about these topics? maybe i search for the wrong words and DI are two letters which appear in so many words, so the search engine does not work that good.


thanks in advance and thank you martin for the wonderful project and making this possible. this pre sounds amazing

 

[North]

Hello, does it crackle on both channels or just one? check if your 2N3055 legs are touching the heat sinks. Also maybe look at caps?