1290 Build Thread

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friesdan
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Re: 1290 Build Thread

Postby friesdan » Thu Oct 10, 2013 5:08 pm


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Joe Malone
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Re: 1290 Build Thread

Postby Joe Malone » Thu Oct 10, 2013 5:17 pm

Definitely seems the TIP122 is gone faulty but strange it can still set a voltage at all. You can run both 1290 off one TREX for now as long as it is bolted to the back panel for heatsinking. We only use 2 TREX to spread the heat better. I can send you down a TIP122 in the post.
Joe :-)
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Re: 1290 Build Thread

Postby Joe Malone » Thu Oct 10, 2013 5:21 pm

friesdan wrote:Should I order this one:
http://www.digikey.com/product-detail/e ... PLA_603568
?


Yes that is the correct part. See also above post as well.
Joe :-)

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friesdan
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Re: 1290 Build Thread

Postby friesdan » Thu Oct 10, 2013 5:43 pm

Thanks for the help Joe,
No point shipping from there when I can get it here. I just ordered a couple.
Looking forward to hearing these things!

friesdan
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Re: 1290 Build Thread

Postby friesdan » Fri Oct 11, 2013 8:12 am

Hey Joe, I've got it working!
I have one last question which falls more into the "please help me understand" rather than the "I need help to make it go" category:

I've noticed that with cables which have pin 1 connected to the metal casing of the connectors, that I get a hum unless I push them straight in, and they very easily slip back to making a hum.
On the other hand, If I use an xlr cable which does not have pin 1 shorted to the casing, there is no hum. (It's a pretty high pitched one)
I'm guessing this is probably caused by some kind of ground loop off my other gear when the 1290's casing is connected to it?

I'm going to build the cables to tie this pre to my patch bay now, and I guess I won't tie pin 1 to the casing - is this generally the best practice?
Thanks Joe,
Dan

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Re: 1290 Build Thread

Postby Joe Malone » Tue Nov 19, 2013 1:45 pm

friesdan wrote:Hey Joe, I've got it working!
I have one last question which falls more into the "please help me understand" rather than the "I need help to make it go" category:

I've noticed that with cables which have pin 1 connected to the metal casing of the connectors, that I get a hum unless I push them straight in, and they very easily slip back to making a hum.
On the other hand, If I use an xlr cable which does not have pin 1 shorted to the casing, there is no hum. (It's a pretty high pitched one)
I'm guessing this is probably caused by some kind of ground loop off my other gear when the 1290's casing is connected to it?

I'm going to build the cables to tie this pre to my patch bay now, and I guess I won't tie pin 1 to the casing - is this generally the best practice?
Thanks Joe,
Dan

HI Dan
I would add a wire from the 0v on the DC connector to a bolt holding one of the output transformer to the back panel as this can sometimes happen due to how the DC connector uses the tube of the connector to link the chassis to a separate 0v terminal in the DC connector so if one isn't touching properly this can happen. Adding the wire fixes the problem with the DC connector.
Joe :-)

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tsvisser
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Re: 1290 Build Thread

Postby tsvisser » Wed Jan 08, 2014 5:50 pm

Anyone ever use the 1290 kit as the basis to build a 1272?

onday
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Re: 1290 Build Thread

Postby onday » Sun Jan 04, 2015 2:05 pm

Got the kit and final parts on friday - Thanks Joe! I have everything built and wired up for the 2ch 1290 rack. Initial testing looks ok, 24v out on each TREX kit with & without1290 connected, 48V on yellow wire.

However, I have an issue with one of the Go Between Plus boards: I can't see 48V on XLR IN pins 2 & 3 in relation to 0v on pin 1. No sound on this channel when the troubled board is in the circuit and 48v is engaged for a condenser.

Between both channels I have swapped everything around (INOUT XLR, 1290, TREX, FET DI, output xformer), so the issue is definitely on just one of the GB+ boards.
~~~~Note: Dynamic mics work fine through both go between plus boards (no 48v engaged) on both circuits.

All my dodgy soldering looks ok (to me), yellow 48V IN on Go Between Plus reads ~48v. So my thinking is that the issue has to lie with the 48v switch or the capacitor. Other switches (pad and phase) are working.

Any further troubleshooting I could do?

Cheers,

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Re: 1290 Build Thread

Postby Joe Malone » Sun Jan 04, 2015 9:28 pm

onday wrote:Got the kit and final parts on friday - Thanks Joe! I have everything built and wired up for the 2ch 1290 rack. Initial testing looks ok, 24v out on each TREX kit with & without1290 connected, 48V on yellow wire.

However, I have an issue with one of the Go Between Plus boards: I can't see 48V on XLR IN pins 2 & 3 in relation to 0v on pin 1. No sound on this channel when the troubled board is in the circuit and 48v is engaged for a condenser.

Between both channels I have swapped everything around (INOUT XLR, 1290, TREX, FET DI, output xformer), so the issue is definitely on just one of the GB+ boards.
~~~~Note: Dynamic mics work fine through both go between plus boards (no 48v engaged) on both circuits.

All my dodgy soldering looks ok (to me), yellow 48V IN on Go Between Plus reads ~48v. So my thinking is that the issue has to lie with the 48v switch or the capacitor. Other switches (pad and phase) are working.

Any further troubleshooting I could do?

Cheers,


Send me a top and bottom photo of the GO between plus PCB to my email so I can see if I can spot the problem. Check you have not cut into a 6k8 resistor with the sharp bottom edge of the OEP can.
Joe :-)

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onday
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Re: 1290 Build Thread

Postby onday » Mon Jan 05, 2015 7:10 pm

I haven't had the chance yet to take photos in decent lighting - will do that now.

Also, here are some voltages taken from the IDC socket on GB+ w/ 48v ON (0v on board as reference)

Working GB+:
PIN VOLTS
9 - 47.5
7 - 47.5
5 - 47.5
3 - 47.5
1 - 47.5

2 - 0
4 - 0
6 - 0
8 - 0
10 - 0


Problem Child has incorrect voltages on pins 1, 3, 5 and 7 (IN+, IN-):
PIN VOLTS
9 - 47.5
7 - 0
5 - 0
3 - 0
1 - 0


2 - 0
4 - 0
6 - 0
8 - 0
10 - 0

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Re: 1290 Build Thread

Postby Joe Malone » Mon Jan 05, 2015 7:43 pm

onday wrote:I haven't had the chance yet to take photos in decent lighting - will do that now.

Also, here are some voltages taken from the IDC socket on GB+ w/ 48v ON (0v on board as reference)

Working GB+:
PIN VOLTS
9 - 47.5
7 - 47.5
5 - 47.5
3 - 47.5
1 - 47.5

2 - 0
4 - 0
6 - 0
8 - 0
10 - 0


Problem Child has incorrect voltages on pins 1, 3, 5 and 7 (IN+, IN-):
PIN VOLTS
9 - 47.5
7 - 0
5 - 0
3 - 0
1 - 0


2 - 0
4 - 0
6 - 0
8 - 0
10 - 0


From above voltages it would seem to be a solder short around the 48v switch or 470R or 10uF cap on the GO Between Plus or broken 48v switch. But also check all 10 pin headers and cable plugs are on the correct way around.
Joe :-)

JLM Audio

Capturing Audio without Injury

onday
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Re: 1290 Build Thread

Postby onday » Wed Jan 07, 2015 6:15 pm

I have found the solution :)

I pulled out one leg of each 6k8 for IN+ and IN- and found that there is a short on pin 5 and IN- (!!!)

On the IN- terminal solder joint, there was a little solder which had bridged over the pad edge onto the rest of the pcb (See pic). I cleaned the joint and made it smaller: now all works well :) What a silly mistake, I'm glad it's over.

Thanks so much for helping with everything - much appreciated! Onto the next build :)
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Hwidow
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Re: 1290 Build Thread

Postby Hwidow » Sun Jul 26, 2015 6:02 am

Hello, I just started to build 1290 everything kit and noticed that on 1290 PCB there goes 4 double plastic connectors on the edge of the pcb for power connection and input. I only got 2 double connectors per kit. Was wondering can I take triple ones from DI kit as the DI don't really need them?

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Re: 1290 Build Thread

Postby Joe Malone » Mon Jul 27, 2015 11:40 am

Hwidow wrote:Hello, I just started to build 1290 everything kit and noticed that on 1290 PCB there goes 4 double plastic connectors on the edge of the pcb for power connection and input. I only got 2 double connectors per kit. Was wondering can I take triple ones from DI kit as the DI don't really need them?


Yes correct last batch of 1290 were missing 2 x 2 way terminal blocks and 1 x 3k6 resistor

Yes you can use the 2 x 3way terminal blocks from the DI kits with 1 x 2 way terminal blocks to make a 8 way. They will tongue and groove together the same as the 4 x 2 way ones to make one block of 8.
Joe :-)

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Hwidow
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Re: 1290 Build Thread

Postby Hwidow » Wed Jul 29, 2015 1:39 pm

Here's the update. First unit is assembled, calibrated voltage, and tested with different microphones, dynamic, condenser and ribbon as well as bass guitar direct to DI inputs. And it sounds excellent ! No hiccups or unpredictable behaviour. I just hope I will have the same results with second unit. Will post the results soon as missing parts arrive. Thanks Joe, great work and great customer support!
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