8 Channel, 3U NEVE 1073 completed

[tomas1808]

Does anyone now if I can use one of these insted of the grayhill rotary switch? :

http://www.ebay.com/itm/4P-24-Step-Rotary-switch-Attenuator-Volume-Control-DIY-/260693714311?pt=LH_DefaultDomain_0&hash=item3cb28e6587#ht_1328wt_1163

Has anyone tried one of these (on a Neve) before?

 

[sr1200]

Thats the type if switch thats on the original.  Since the resistors are on the board instead of on the switch, you may have to find a way to insert it into the circuit after the onboard resistors (if u want them on the switch) or just map the pin outs from that switch to the grayhill (honestly, the price difference w shipping isnt that far off, and the grayhills are REALLY good quality.

 

[desol]

I recommend sticking with the greyhills as well if they're the 1290 boards. Gold plated, mil spec, good quality...

 

[tomas1808]

Thanks!

Yes, I bet the quality difference is undeniable and worth the price difference in the long run .

Unfortunately money is a problem (20yo, still studying) and the only thing I want now is a good sounding preamp. I think quality switches are not my biggest priority, so I think I'll go with the true DIY spirit and see for myself if these cheaper switches are worth it. If not I can always upgrade later.

Plus customs are a big problem here, if I am unlucky the Grayhills will end up being $62 each after tax.

 

[travis]

Hello,
Im at the wiring stage and still not sure If I have the correct mic cable!  It is a 2 conductor shielded cable with a drain wire.  I know this is a stupid question, but I am pretty new to this and this is my first major project.  can the drain wire be used on pin 1 of input xlr, pin 6 to 10 on 1068 transformer, pcb board, ect?  I think thats what it says in the directions but I am scared to use the bare wire.  Could anyone confirm if it will work or not?  Thank you!   

 

[sr1200]

Yes use the bare wire. Its your friend. Just twist it and make it tight.

 

[travis]

thanks sr1200, it works!  I still have to bias, but I have a friend with a scope.  Also gonna try to silkscreen the front.  Only thing that was a little weird was that for a minute I got a strange noise...sort of like there was a cricket stuck in one of the output transformers.  It wasnt plugged into anything exept power at that point and the transformer itself was making the noise.  Yikes!  Is this normal? ???

 

[sr1200]

Ive heard of caps singing, havent heard a tx do that, but my guess would be some kind of oscillation.  How far apart do you have the transformers (input and output).

 

[travis]

Transformers are pretty much in the four corners of the box as far from each other as possible (2 channels).  I think maybe I had the gain on that channel cranked, would that cause ocsillation when un-biased?  I guess I didnt know that oscillation was something that you would hear without it plugged into some sort of speaker.  It hasnt happened again.  It sounds really good!  maybe I will post a picture if my next silkscreen attempt works out (the first one was an epic belly flop ) 

 

[sr1200]

I bought a silk screen "kit" a few weeks ago, i haven't mustered enough courage to actually try it out yet.  If you have some tips or advice, maybe w can start a new thread on that matter.

 

[travis]

Yes that is a good idea....is there one already somewhere? 

 

[kooma]

Finished 2channel unit (or so I thought). Other channel works&sounds great, the other one doesnt.
Visually everything seems to be ok, I've checked parts and will check them again

Main problem was, when I tried to adjust bias the trimmer had no effect -voltage (3055 to gnd) remained near vcc ~23,5V.
And line-N(Vcc to BA183NV) voltage(after r51) was something like 3V.
So trimmer was busted- I replaced it with 2resistors (as voltage div.) since i had no replacement in hand..
that got bias to 22.8V but still N-line was low.

I measured voltages lifting one part at a time, so when I lifted one leg off, the voltage rise up to normal;
r51->c4->r13->collector of tr5 where i gave up.

any clues?

turns out I had 3 broken bc184c transistors

 

[travis]

Hi folks,
First of all I am so glad that I chose this project ;D  Martin, if you are out there, thank you for all of your efforts!  Its kind of hard for me to decide where to dive into the diy world and the instructions on this project really made it a good starting point. 

That said I think I have wired the cases (psu and 1290) together incorrectly somehow because I get some noise at higher gain settings that goes away when I touch both cases.  does the wire that comes from the power switch to the shield and 1290 case first need to come in contact with the psu case?

 

[sr1200]

Can u post pics?  Usually the power switch is just breaking the contact to the IEC.  Shouldnt be ground there.

On a side note, id like to build another pair, but have a single rotary switch for stereo operation (i would use internal trimmers to calibrate levels where that 10K and Jumper are.  Any suggestions for a switch to do this?

 

[kooma]

f**k!  :'(

this thing works great when I test it with mics, but when I try to do sweeps/ use sw analyzer-
the same transistors 6 and 4(in BA183AV)  burn.
Can I overload these so baddly in anyways that it burns those transistors?
my other channel works perfect, but this one has some really weird sh*t going on..

 

[travis]

Thanks sr1200,  I think I have the cases connected ok now but cant go anywhere near the psu with a dynamic mic without some buzzing.  I might still have something a little off....anyone else have this happen?  Not really sure how to post a pic .  Lets see if this works

 

 

[spase]

any news about a new batch of this boards?

 

[desol]

Thanks sr1200,  I think I have the cases connected ok now but cant go anywhere near the psu with a dynamic mic without some buzzing.  I might still have something a little off....anyone else have this happen?  Not really sure how to post a pic .  Lets see if this works

 

Sounds like you have a ground issue.

any news about a new batch of this boards?

I'm still waiting for this project to be discontinued!    But that's just me. I like when things end.

 

[spase]

)) i think this is a good project , and need to be done a lot more boards for this one

 

[travis]

It is sounding good but I have a few other issues I need to sort out......just found out that none of the wall outlets in my apartment are grounded except one in kitchen   That sure doesnt help.