8 Channel, 3U NEVE 1073 completed

[skal1]

Hi madriaanse


This might be a stupid ? , is this pre amp the same used in the neve mic pre 1272 .

regards

skal1

 

[junkmaster]

so beautiful....

 

[madriaanse]

Sorry for the delayed responses guys - been busy:

in number 1 the pot has a centre ident at 12oclock position where it says 0dbs.

number 2 it's exactly the case you described all the way it's 0dbs.


is it possible to have a pot that acts like the example in picture 1?

Hi Whoops
You can print anything you want on the front panel. The pot is an attenuator only (gain comes from the gain switch) and cannot be made to add gain without significant departure from the original design.

I searched for alternatives to the P&G 120€ pot,
what do you think of these ones?

http://www.banzaieffects.com/PEC-MIL-MO-LOG-5k-pr-26690.html

http://uk.farnell.com/vishay-sfernice/p11vyn-5k0-10-l/potentiometer-5k-log/dp/1141609?_requestid=236522

If you really don't want to use P&G, I would start by searching for some "decent" conductive plastic potentiometers and trying them to see how they sound and feel. My resentment for cheap pots comes from their poor operation over time, the way they degrade sound/add grain, and how rough they feel. If you come to find out that none of the pots work out you can always switch back to "faderless" by putting the resistor back in - shouldn't take more than a minute.

if your not too busy PM me when you get the chance, I've been trying to get ahold of you for 2 or 3 weeks but your box is full.

Hi Richard, please email me at: 1290preamp [at] gmail.com

hello Martin, i received 4 pcb 3 days ago

thanks; thanks; thanks!!!!

Hi Nikonet, you're very welcome and enjoy, enjoy, enjoy!!!!

is this pre amp the same used in the neve mic pre 1272 .

Hi Skal1, up to 50dB a (correctly wired) 1272, a 1290 and a 1073 (w. eq disengaged) should sound absolutely identical because their inards (BA183, 10468, LO1166) are absolutely identical WITH THE EXCEPTION OF: an additional pre-stage (BA183NV) in the 1290 and 1073. (the 1073 also has EQ of course) A 1272 was designed as a bus amplifier, and was never meant to have more than 50dB of gain. To get more than 50dB of gain without adding significant distortion, the 1290 and 1073 switch in this extra pre stage. Any 1272 with more than 50dB has been "hacked/cranked" and should not be taken serious past 50dB. (IMHO)

so beautiful....

Thanks!! They are great fun to record with and get used all the time!!

Hope this helps!!

M.

 

[skal1]

Thanks for response, have you got a self etch pdf ,or do i have to buy the boards from you .


regards

skla1

 

[madriaanse]

Hi Skal1,

See first post

All the best,

M.

 

[okgb]

it's so worth it , just to have someone offering boards
the EZ version really is so
thanks Martin

 

[Neil]

This is on my list of get-to projects. Thanks for offering this Martin!!

Is it possible to build a 2-ch version into a 1 RU case? All of the ones I've seen are 2 RU high, but would like to start with just 2 channels and conserve rack space. Is using a 1 RU case not advisable because of the proximity of the transformers to each other, or can it be done fairly easily? Ideally I'd like to have the PSU in the same case, but I realize that may not be good. Has anyone done such a thing? I will probably be using an ACDC for power.

 

[madriaanse]

Thanks for the kind words Greg and Neil!!

You can certainly fit everything in a 1U. With a bit of creativity you can even fit 4ch into a 1U (deep case, w. external PSU). Check out the most recent finished EZ1290 build: http://www.groupdiy.com/index.php?topic=32196.0 You'll want to order the Narrow Board output transformers from Audiomaintenance: http://www.audiomaintenance.com/acatalog/CA-18-VTB1148_extended_info.html
Also, use a low profile heatsink on 2N3055, and you may have to mount the 470u caps on their sides.

I am not a fan of having the PSU inside the case, but it should be ok if you have audio and PSU components on far opposite sides inside the case.

Best Regards,

M.

 

[zachs]

ALl that's left for mine is to get my FP made and then put it on! I fired it up today for the first time and audio was all messed up, then I realized I forgot the jumper  :-\ Once I put those in, sonic glory. I don't currently have the pots wired but will probably add them, not sure yet. Pretty stoked it worked first time up. Completed unit pictures coming soon.

 

[Whoops]

thanks for explaining Martin,
I will try the Vishay conductive plastic pots,
they seem to be the best option in terms of quality / price !!

 

[zachs]

Along the pot lines I asked Mark at Brent Averill today what he uses for the 1272's and he said he uses 5k Panasonic Plastic Conductive.

 

[Whoops]

Cool.

I know that Phoenix Audio use 10K Vishay plastic conductive also.

 

[zachs]

Do you have a part # for the pots you're using Whoops?

 

[mitsos]

I think Whoops is talking about the Vishay-Sfernice pots.. Very nice, yet a bit expensive... If you can get your hands on some OMEG ECO pots in the resistance/taper you need, you'd save yourself some serious $$. They too are conductive plastic and nice quality so should last a bit longer than run-of-the-mill carbon pots.. Can't comment on the quality difference between the vishay and omegs though. I would assume the vishay-sf are more rugged.

 

[Whoops]

Do you have a part # for the pots you're using Whoops?

I will use this ones:

http://uk.farnell.com/vishay-sfernice/p11vyn-5k0-10-l/potentiometer-5k-log/dp/1141609?_requestid=236522

They are Vishay, and are quite affordable.
I would not go with anything cheaper than this.

 

[kml23956]

Martin,

Do you have any boards left?

 

[madriaanse]

I have more coming in soon; shoot me an email at 1290preamp [at] gmail.com

M.

 

[stitch-o]

Do you have a part # for the pots you're using Whoops?

I will use this ones:

http://uk.farnell.com/vishay-sfernice/p11vyn-5k0-10-l/potentiometer-5k-log/dp/1141609?_requestid=236522

They are Vishay, and are quite affordable.
I would not go with anything cheaper than this.

in the US, I found this for trim:
http://www.mouser.com/Search/ProductDetail.aspx?R=6187R5KL1.0virtualkey57700000virtualkey858-6187R5K

 

[4toes]

does anyone know how you would wire a phase and pad for this build?
is there a kit somewhere, or is it easy enough to do it myself?

 

[trancedental]

does anyone know how you would wire a phase and pad for this build?
is there a kit somewhere, or is it easy enough to do it myself?

Igor has a preamplifier universal input board kit available here with Pad / DI & 48V http://www.groupdiy.com/index.php?topic=29771.0

I've ordered one of those myself, looks easy enough ;D

Just waiting for a few parts on my EZ1290 to finish off, missed the post today. Still at least I've managed to build & test my JLM AC/DC power supply without mishaps!