Visual Check before I turn it on - Mnats 1176 Rev D

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Biasrocks said:
canidoit said:
I have calibrated Q-Bias and Discreet Meter circuit. What problems I encountered.

Qbias points:
- When you turn the Q-bias trimmer pot, you may think it is not working because the VU meter is not moving. Keep turning it and eventually the VU meter will move and latch on depending on how far out of calibration the Qbias trimmers are. Check to see if you are turning it the right way as well, you may be going further away from getting the VU meters to move.

Discreet Meter circuit:
- If your VU meters are not moving when you turn the zero trimmer, check to see if your VU meter cabling is the right way around. My VU meters were not moving and I notice it was moving backwards so I swapped the VU cabling and it fixed the problem.
- Also if your null trimmers are so out of calibration, turning the zero trimmers will not move the VU meters. Try turning the Null trimmers CW till it is sort of at the end of its turns(it feels a little harder to turn), then CCW about 5-7 turns so that it is center of the total amount of turns it can do. Something like that. After this, turn the zero trimmers and the VU meters should start moving. Play around with that concept.

Are you saying that your meter is pegged and not responding to the adjustment?

If that's the case, I had a similar problem that was solved by moving the meter lead to the alternate place provided on the PCB. It should be right next to where you have it installed now.

Mark
I just calibrated the rest of it my own way. Put some music in, turned attack off and GR meter in and turned R44 till GR was at 0. That test tone UREI, doesn't seem to work for me. I can't do that -10db swing or whatever you call it calibration but what I have done now seems to be O.K. GR is at 0 and gain reduction is responsive.
 
The calibration process for this build needs to be improved. It's inconsistent and is frustrating. The videos are helpful for the Q-bias and Null calibration but the rest of the calibration for Gain Reduction is poor.

Whats the calibration procedure for the distortion trimmer? I was turning the R86 trimmer and I am not sure what the normal setting for this is?
 
Listening to this 1176 build in my PC speakers, it sound more like a modern 1176 so far. It's not bad, but I guess once I listen and use it properly in a recording and mixing situation, I will be able to judge better what my opinion of this unit really is.

All buttons work. A bit of a struggle to press all 4 buttons but you can do some form of all buttons by just pressing 4 and 20.

4 and 20 pressed vs all buttons give different results on my build.

Big thanks to Hairball and Skylar and other members who pitched in with help and parts to fulfil this project mission.  ;D

from
iva dunit formerly known as canidoit  ::)
 
Arno said:
I would avoid having "loose" components. for example, the caps on the xlr's, or the resistor hanging from the pcb (meter lamp series R ?? - depending on the power going through, it can become pretty hot, so watch the cables that are touching it)

O.K. I have sort of fixed it up. Made a support for the cap on the XLR and also made some breathing room for the fat resistor.
If the fat resistor gets hot, does that mean, so does the lead, cable connected to it and also the molex it is connected to? I felt that fat resistor and its very very hot.

1176done19.jpg


1176done20.jpg
 
canidoit said:
The calibration process for this build needs to be improved. It's inconsistent and is frustrating. The videos are helpful for the Q-bias and Null calibration but the rest of the calibration for Gain Reduction is poor.

Whats the calibration procedure for the distortion trimmer? I was turning the R86 trimmer and I am not sure what the normal setting for this is?

I'm very much looking forward to you acquiring the necessary understanding of the circuit and then shooting your own videos. 

Seriously though, have you any grasp of how ungrateful sounding your comments are.  I think MNats must be a complete zen master not to come on here, flame you to crispy cinder and then close up shop and never design another pcb again.  You comment on the calibration procedure as though it is your god given right to have someone hand hold you through the entire process, how about RTFM and stare at schematics until YOU get it?  I could work myself into a right old state but in the spirit of this great forum can I ask you to please consider what you are writing, being a member here and getting such fantastic help is a privilege NOT a right.

And BTW well done with your build.

Ruairi


 
Congrats canidoit,

Great encouragement for a noob like me, just as I was starting to feel a bit overwhelmed by my dual 1176 J (I am right at the beginning).

cheers,
Mac.
 
ruairioflaherty said:
canidoit said:
The calibration process for this build needs to be improved. It's inconsistent and is frustrating. The videos are helpful for the Q-bias and Null calibration but the rest of the calibration for Gain Reduction is poor.

Whats the calibration procedure for the distortion trimmer? I was turning the R86 trimmer and I am not sure what the normal setting for this is?

I'm very much looking forward to you acquiring the necessary understanding of the circuit and then shooting your own videos. 

Seriously though, have you any grasp of how ungrateful sounding your comments are.  I think MNats must be a complete zen master not to come on here, flame you to crispy cinder and then close up shop and never design another pcb again.  You comment on the calibration procedure as though it is your god given right to have someone hand hold you through the entire process, how about RTFM and stare at schematics until YOU get it?  I could work myself into a right old state but in the spirit of this great forum can I ask you to please consider what you are writing, being a member here and getting such fantastic help is a privilege NOT a right.

And BTW well done with your build.

Ruairi
I have nothing against Mnats, but you have to remember, he didn't want to sell me the boards in the first place. I had to basically bug him for those boards. I am just sharing my experiences and opinions on this build process and it's not intentional to degrade anyone, just my experience mixed with positives and negatives coming from a newbie point of view.
 
I had a quick trial in the studio with the unit. I am pretty happy so far with the results running some pre-recorded vocals, guitars and synths. Though it does not have such a prominent mojo as the UA La3a, it still has that 1176 signature to it in my opinion.

I noticed the zero metering do drift in GR mode, hence why some people have the zero adjust at that little hole at the front of the 1176. I noticed it came back to zero eventually.
 
canidoit said:
I have nothing against Mnats, but you have to remember, he didn't want to sell me the boards in the first place. I had to basically bug him for those boards. I am just sharing my experiences and opinions on this build process and it's not intentional to degrade anyone, just my experience mixed with positives and negatives coming from a newbie point of view.
"The calibration process for this build needs to be improved. It's inconsistent and is frustrating." is accusational and demanding. You could have shared your experiences by saying something like "The videos are helpful for the Q-bias and Null calibration but the rest of the calibration for Gain Reduction lacks the level of guidance needed by a beginner".

mnats had reasons for not wanting to sell you the boards, and your frustrations at the calibration process entirely validate his apprehension. To come back and say the project docs are inadequate after their writer had previously given you clear warning that your knowledge was inadequate for the project is laughable.
 
gswan said:
canidoit said:
Kingston said:
Apart from sticking a Urei logo in a unit that is blatantly NOT Urei?
I got that from Purusha. I paid good money for that case.  :)

It's fraud. Do you also pay good money for counterfeit credit cards too?
LOL, it's an 1176 mate.  ;)
The whole design circuitry is not an original idea?  ???

Some of you people may not like Purusha, but don't spread the hate to me. Keep your DIY politics to yourself.  ;D

I ordered an 1176 case and he sent me one with a logo on it. It's done.

I will be inviting you to my Birthday this year so that you can cheer me up ::)
 
canidoit said:
gswan said:
canidoit said:
Kingston said:
Apart from sticking a Urei logo in a unit that is blatantly NOT Urei?
I got that from Purusha. I paid good money for that case.  :)

It's fraud. Do you also pay good money for counterfeit credit cards too?
LOL, it's an 1176 mate.  ;)
The whole design circuitry is not an original idea?  ???

It is NOT an 1176. It is a compressor based on the 1176 circuitry. You have blatantly copied a trademark without permission. At some stage in its life, maybe 20 years from now it may be misrepresented as a UREI 1176 and sold as such. There's a lot more to building an 1176 than just copying the circuitry and putting it in a box.
 
gswan said:
canidoit said:
gswan said:
canidoit said:
Kingston said:
Apart from sticking a Urei logo in a unit that is blatantly NOT Urei?
I got that from Purusha. I paid good money for that case.  :)

It's fraud. Do you also pay good money for counterfeit credit cards too?
LOL, it's an 1176 mate.  ;)
The whole design circuitry is not an original idea?  ???
It is NOT an 1176. It is a compressor based on the 1176 circuitry. You have blatantly copied a trademark without permission. At some stage in its life, maybe 20 years from now it may be misrepresented as a UREI 1176 and sold as such. There's a lot more to building an 1176 than just copying the circuitry and putting it in a box.

Kingston

[/quote]

Dfer,

Please Explain........?
gswan said:
canidoit said:
gswan said:
canidoit said:
Kingston said:
Apart from sticking a Urei logo in a unit that is blatantly NOT Urei?
I got that from Purusha. I paid good money for that case.  :)

It's fraud. Do you also pay good money for counterfeit credit cards too?
LOL, it's an 1176 mate.  ;)
The whole design circuitry is not an original idea?  ???

It is NOT an 1176. It is a compressor based on the 1176 circuitry. You have blatantly copied a trademark without permission. At some stage in its life, maybe 20 years from now it may be misrepresented as a UREI 1176 and sold as such. There's a lot more to building an 1176 than just copying the circuitry and putting it in a box.
 
canidoit said:
LOL, it's an 1176 mate.  ;)
The whole design circuitry is not an original idea?  ???

Some of you people may not like Purusha, but don't spread the hate to me. Keep your DIY politics to yourself.  ;D

Now, you laugh at everyone here that has helped you?

Your arrogance is astounding!  :eek:

Now that you've revealed yourself, I for one while not continue to help you.

Mark
 
canidoit said:
Whats the calibration procedure for the distortion trimmer? I was turning the R86 trimmer and I am not sure what the normal setting for this is?

It's the preamp linearity setting. Usually setting it approximately midway will be sufficient, however if you want to set it correctly them you will need to invest in some equipment (at least an oscilloscope, signal generator and THD measuring setup). Apply a 500Hz -30dBu signal to the input, set the input to fully CW and the output to about 2 o'clock and measure the THD of the output. Tweak R16 for minimum THD.
 
gswan said:
canidoit said:
Whats the calibration procedure for the distortion trimmer? I was turning the R86 trimmer and I am not sure what the normal setting for this is?

It's the preamp linearity setting. Usually setting it approximately midway will be sufficient, however if you want to set it correctly them you will need to invest in some equipment (at least an oscilloscope, signal generator and THD measuring setup). Apply a 500Hz -30dBu signal to the input, set the input to fully CW and the output to about 2 o'clock and measure the THD of the output. Tweak R16 for minimum THD.
Thanks  :)
 
mac said:
Congrats canidoit,

Great encouragement for a noob like me, just as I was starting to feel a bit overwhelmed by my dual 1176 J (I am right at the beginning).

cheers,
Mac.
Mac, Im not sure how different the Rev J is, but I have some excel sheets I built for this Rev D that you may find useful. I can send it thru to you and you can alter it if you think it could help.

I set up the case first before installing the components to the board, that way, the components installed would not get damaged while I played around with the positioning of the internals and externals. Like I mounted the empty boards into position in my case, transformers, etc. and drilled and cut out parts of the case for connectors and that. Then when I got that done, I then soldered the components.

building1.jpg


building2.jpg


I also printed out an exact scan of the boards I received and marked each component off with a pen or highlighter and placed subnotes on the print out as I went thru and soldered or wired the components or section or as I gathered notes from peoples posts or information collected, so that I know what to watch out for when I soldered that component.

eg.
matched fets, on the board print out, I put a note in there so that when I got up to it, that I have to make sure it is matched.

Also be wary that the large caps may need to be soldered last on some sections of the board because you will have trouble soldering components smaller than the caps in some positions, I discovered.

Very, very useful is to download as many pics of the unit you are actually building for visual reference. I am talking internals overall, close ups, etc. This is such a massive help especially when you are not electronically educated and like to build visually. It will give you options on how to position your internals and some form of guidance in wiring and soldering but always refer to whatever final documented info you have. The visual is more for assurance and confirmation. Email me and I will send you off the collection I have.

I think the key to this DIY thing, is planning and prep work.

Check out some of my posts, maybe theres some info in there you may find useful since I am coming from a newbie also.

Good luck mate! The Rev D unit sound pretty good so far, I will be recording with it more when I have time. I am off to finish Drips La2a, check this guys builds out http://dripelectronics.com. Also check out Hairball, http://www.hairballaudio.com/shop
He sells some of the parts for the 1176 and also has the customer support and service to back it up.
 
gswan said:
canidoit said:
Whats the calibration procedure for the distortion trimmer? I was turning the R86 trimmer and I am not sure what the normal setting for this is?

It's the preamp linearity setting. Usually setting it approximately midway will be sufficient, however if you want to set it correctly them you will need to invest in some equipment (at least an oscilloscope, signal generator and THD measuring setup). Apply a 500Hz -30dBu signal to the input, set the input to fully CW and the output to about 2 o'clock and measure the THD of the output. Tweak R16 for minimum THD.

It's perfectly possible to do this very accurately "on the cheap". All you need is a decent sound card and a VST plugin host (like the free Reaper), and some software to generate a 500-1000hz sine. And an FFT display plugin, like this great quality free one http://www.voxengo.com/product/SPAN/

Send the sinewave, let's say 1khz to your 1176 input at 0dBu. Set 1176 to bypass, then max output, and set input so you have unity gain.

Look at the resulting audio in the FFT plugin (that voxengo span). You will very accurately see the 2nd harmonic moving when you tweak the distortion trimmer. Set it where it's lowest.

But then, some people like this distortion. Set it where you like it best (if you can even hear it).
 
Hey Kingston,
Can you recommend a good free software signal generator also?? I am assuming I would need two PC's and soundcards to have one produce appropriate test signals and one with the voxengo fft plugin to analyse what my 1176 is doing?? Yes?? or did I misunderstand???

cheers,
Mac.
 
I think he ment that you need one pc&soundcard :)
I think that most sequencer hosts have some kind of signal generators inthem.(ie.logic has it and even adobe audiotion has it:)
 

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