[BUILD] 1176LN Rev D DIY

[Echo North]

Do you have VAC between the 0V on the main PCB either of the power transformer primaries on the switch? Be VERY careful.

if the  primary wires are the ones that go from the power transformer to the middle connectors on the switch then no I do not have any power  there.

No that is the secondary. The primary goes to the power switch.  The blue, gray, purple, brown (IIRC) wires. They attach to terminals on the switch, is there AC there? Be careful.

Mike

 

[mgalimbe]

Do you have VAC between the 0V on the main PCB either of the power transformer primaries on the switch? Be VERY careful.

if the  primary wires are the ones that go from the power transformer to the middle connectors on the switch then no I do not have any power  there.

No that is the secondary. The primary goes to the power switch.  The blue, gray, purple, brown (IIRC) wires. They attach to terminals on the switch, is there AC there? Be careful.

Mike

yes those are the ones I tested and no I don't have power there

 

[Echo North]

That has to be a bad fuse. Are you sure it's good and seated correctly?

 

[mgalimbe]

I ohmed out the fuse and it was bad I put another one in plugged it in and it blew another fuse. Obvious short somewhere but I still can't figure out why it worked then the light on the meter went out. Did I burn something out causing the short?

 

[Echo North]

I ohmed out the fuse and it was bad I put another one in plugged it in and it blew another fuse. Obvious short somewhere but I still can't figure out why it worked then the light on the meter went out. Did I burn something out causing the short?

Are you using slo-blo fuses what mA rating?

Mike

 

[mgalimbe]

I ohmed out the fuse and it was bad I put another one in plugged it in and it blew another fuse. Obvious short somewhere but I still can't figure out why it worked then the light on the meter went out. Did I burn something out causing the short?

Are you using slo-blo fuses what mA rating?

Mike

Here are the specs for the fuse I'm using:

Rated Voltage        250VAC
Rated current 0.02 - 20 A
Breaking Capacity 35 A - 200 A
Characteristic Time-Lag T ( I looked this up and this is shurters way of defining their slo blo fuse type)

 

[Echo North]

I ohmed out the fuse and it was bad I put another one in plugged it in and it blew another fuse. Obvious short somewhere but I still can't figure out why it worked then the light on the meter went out. Did I burn something out causing the short?

Are you using slo-blo fuses what mA rating?

Mike

Rated current 0.02 - 20 A

That's not right. That looks like the capability of that whole line of fuses.  A fuse has a specific rating, not a range. You want something between 350mA-450mA. The fuse should have "200mA" or something on it.

Mike

 

[mgalimbe]

I ohmed out the fuse and it was bad I put another one in plugged it in and it blew another fuse. Obvious short somewhere but I still can't figure out why it worked then the light on the meter went out. Did I burn something out causing the short?

Are you using slo-blo fuses what mA rating?

Mike

Rated current 0.02 - 20 A

That's not right. That looks like the capability of that whole line of fuses.  A fuse has a specific rating, not a range. You want something between 350mA-450mA. The fuse should have "200mA" or something on it.

Mike

Yes so these fuses are 250v & 250ma. Do you think thats really the issue though?why would it blow as soon as I plug the unit in when it worked before.

 

[junkface]

Hooked up my .775v signal for calibration, and it's only showing .3v between the inside of the pins. I've double and triple checked the following:
input xformer orientation
input wiring / continuity
output wiring / continuity
missing / reversed/ visibly burnt components
solder bridges/ cold joints
resat every wire connecting to the pcb screw terminals
power supply

I've built about a dozen of these guys and I've never had this (or really any major) issue before.  tried searching this thread a while and couldn't find any problem solved with a fix I haven't tried already (see above). any advice what I should check next?

 

[Echo North]

Yes so these fuses are 250v & 250ma. Do you think thats really the issue though?why would it blow as soon as I plug the unit in when it worked before.

Absolutely yes.  250mA will blow probably 2/5 times on start up.  You need a 400mA.  Did you get those fuses from us?

We accidentally sent out 250mA for a bit.

Mike

 

[Echo North]

Hooked up my .775v signal for calibration, and it's only showing .3v between the inside of the pins. I've double and triple checked the following:
input xformer orientation
input wiring / continuity
output wiring / continuity
missing / reversed/ visibly burnt components
solder bridges/ cold joints
resat every wire connecting to the pcb screw terminals
power supply

I've built about a dozen of these guys and I've never had this (or really any major) issue before.  tried searching this thread a while and couldn't find any problem solved with a fix I haven't tried already (see above). any advice what I should check next?

Try:
http://groupdiy.com/index.php?topic=20058.msg769979#msg769979

 

[mgalimbe]

Yes so these fuses are 250v & 250ma. Do you think thats really the issue though?why would it blow as soon as I plug the unit in when it worked before.

Absolutely yes.  250mA will blow probably 2/5 times on start up.  You need a 400mA.  Did you get those fuses from us?

We accidentally sent out 250mA for a bit.

Yes I did get those from you when I ordered the kit but no worries I will go to radio shack and get 400mA fuses today. Then maybe we can revisit the other issue i was having.

Mike

 

[Echo North]

Yes so these fuses are 250v & 250ma. Do you think thats really the issue though?why would it blow as soon as I plug the unit in when it worked before.

Absolutely yes.  250mA will blow probably 2/5 times on start up.  You need a 400mA.  Did you get those fuses from us?

We accidentally sent out 250mA for a bit.

Yes I did get those from you when I ordered the kit but no worries I will go to radio shack and get 400mA fuses today. Then maybe we can revisit the other issue i was having.

Mike

A  400mA slo-blo would be perfect.

Mike

 

[mgalimbe]

I just looked online they have 500mA is that too much?

 

[Echo North]

I just looked online they have 500mA is that too much?

It's not ideal, but you certainly won't blow it.

However if there is an issue with your build it might not blow to prevent on PCB damage. I'd use it in a pinch, but it's your call.

Mike

 

[mgalimbe]

I just looked online they have 500mA is that too much?

It's not ideal, but you certainly won't blow it.

However if there is an issue with your build it might not blow to prevent on PCB damage. I'd use it in a pinch, but it's your call.

Mike

Well theres definitely an issue with my build.  :'(The only other size they have in stock is 315ma which might be too small. I'll just order some from mouser. unless you think the 315 will work for now.

 

[Echo North]

I just looked online they have 500mA is that too much?

It's not ideal, but you certainly won't blow it.

However if there is an issue with your build it might not blow to prevent on PCB damage. I'd use it in a pinch, but it's your call.

Mike

Well theres definitely an issue with my build.  :'(The only other size they have in stock is 315ma which might be too small. I'll just order some from mouser. unless you think the 315 will work for now.

You could try it. Personal I would just use the 500mA.  Any major issue is going to blow 500mA.

 

[mgalimbe]

I just looked online they have 500mA is that too much?

It's not ideal, but you certainly won't blow it.

However if there is an issue with your build it might not blow to prevent on PCB damage. I'd use it in a pinch, but it's your call.

Mike

Well theres definitely an issue with my build.  :'(The only other size they have in stock is 315ma which might be too small. I'll just order some from mouser. unless you think the 315 will work for now.

You could try it. Personal I would just use the 500mA.  Any major issue is going to blow 500mA.

Whereas this is my first build and I really don't know what is wrong with my build I'd rather get the right fuse so that we can figure out whats going on without complicating things. I just ordered a bunch, so I will post up once they arrive in a few days.

 

[junkface]

"Try:
http://groupdiy.com/index.php?topic=20058.msg769979#msg769979"

thx, I saw that post but since I couldn't get the .775 to even show correctly on the input xlr (across 2/3 it's around .3) I figured it wouldn't be of much help. anyhoo, here's my readings VAC testing to ground with a .775 vac 1khz signal sent into it.

1. T-Pad input =  .155
2. T-Pad output =  .095
3. Input transformer primary = .095
4. Input transformer secondary = .03
5. At the Input + terminal at the main PCB = .03
6. C7 + pad = .645
7. C7- pad = .645
8. Blue wire on output transformer = .07

hope that helps diagnose the problem, or at least point in the right direction

 

[JingleDjango]

Currently my 1176 is losing a lot of low end information when I pass audio through it, with or without compression. This link should go to a folder containing two recordings of an 808 kick sample.

https://drive.google.com/folderview?id=0BxIj2f8qKoJ2cDBCYWRTZ1ZKd2s&usp=sharing

One is dry from the DAW, and the other is passed through the 1176 and back in to the DAW. Attack is turned CCW and switched off.  Any ideas what might be causing this?