All things G1176 - the new "repost" thread.
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Help Support GroupDIY Audio Forum:
Do you guys think a front panel like this with 4 1176 can be too busy??
INPUT, OUTPUT -> the black ones
grey in the middle is RATIO
other greys are ATTACK and RELEASE
back to drilling...
(the 2U is a Neve 1272... or will be)
:guinness:
Fabio
INPUT, OUTPUT -> the black ones
grey in the middle is RATIO
other greys are ATTACK and RELEASE
back to drilling...
(the 2U is a Neve 1272... or will be)
:guinness:
Fabio
Howdy,
I replaced my NTE177 with FDH333's. I was hoping this would fix my meter jumping when switching ratios. It did not. It seems that from 4 to 8 is the biggest jump then 8 to 12 and 12 to 20 are much smaller.
I have not recalibrated yet so I am not sure if that would make a difference.
I thought I had it once but the only thing I changed after that was Q5,6,7 cause I was worried that I may have blew them out during my previous fiasco. I ended changing most if not all of the transistors anyway so I figured what the heck. New ones won't hurt. BUT I am not sure how exactly this would affect my meter.
I have checked resistor values and cap orientations, etc and cannot find anything out of the ordinary. I also took measurements where the FDH333 diodes meet and with the ratio at 4 it was like (~ -3.x) and at 20 (-1.8x). It held steady so I dont think it is leaking anywhere.
Would you think that I still have a component that is wrong? Thanks for your help.
-Michael
I replaced my NTE177 with FDH333's. I was hoping this would fix my meter jumping when switching ratios. It did not. It seems that from 4 to 8 is the biggest jump then 8 to 12 and 12 to 20 are much smaller.
I have not recalibrated yet so I am not sure if that would make a difference.
I thought I had it once but the only thing I changed after that was Q5,6,7 cause I was worried that I may have blew them out during my previous fiasco. I ended changing most if not all of the transistors anyway so I figured what the heck. New ones won't hurt. BUT I am not sure how exactly this would affect my meter.
I have checked resistor values and cap orientations, etc and cannot find anything out of the ordinary. I also took measurements where the FDH333 diodes meet and with the ratio at 4 it was like (~ -3.x) and at 20 (-1.8x). It held steady so I dont think it is leaking anywhere.
Would you think that I still have a component that is wrong? Thanks for your help.
-Michael
When you say "meter jumping" - do you mean temporarily or permanent change to the meter indication?
The meter jumping temporarily when switching ratios is normal - it also occurs on "real" 1176's..
Jakob E.
The meter jumping temporarily when switching ratios is normal - it also occurs on "real" 1176's..
Jakob E.
radiance
Well-known member
[quote author="Bauman"]Do you guys think a front panel like this with 4 1176 can be too busy??
INPUT, OUTPUT -> the black ones
grey in the middle is RATIO
other greys are ATTACK and RELEASE
back to drilling...
(the 2U is a Neve 1272... or will be)
:guinness:
Fabio[/quote]
Yes, to me it looks buzy.
What I always do is make a cardboard frontpanel. Just cut out the meter hole, put the meter in place and start arranging those knobs (well, you did that already).
Also, put those caps on the knobs, this might look a little less buzy.
Just make it as real as possible, only from cardboard.
INPUT, OUTPUT -> the black ones
grey in the middle is RATIO
other greys are ATTACK and RELEASE
back to drilling...
(the 2U is a Neve 1272... or will be)
:guinness:
Fabio[/quote]
Yes, to me it looks buzy.
What I always do is make a cardboard frontpanel. Just cut out the meter hole, put the meter in place and start arranging those knobs (well, you did that already).
Also, put those caps on the knobs, this might look a little less buzy.
Just make it as real as possible, only from cardboard.
[quote author="gyraf"]When you say "meter jumping" - do you mean temporarily or permanent change to the meter indication?
The meter jumping temporarily when switching ratios is normal - it also occurs on "real" 1176's..
Jakob E.[/quote]
I mean permanent. It jumps and stays there.
The meter jumping temporarily when switching ratios is normal - it also occurs on "real" 1176's..
Jakob E.[/quote]
I mean permanent. It jumps and stays there.
Rob Flinn
Well-known member
Fabio
If you plan to use the ratio & meter PCB`s be careful that they don`t overlap each other behind the panel with your layout.
If you plan to use the ratio & meter PCB`s be careful that they don`t overlap each other behind the panel with your layout.
No, they shouldn't.
Your problem must be in the sidechain/metering section - Q12-13-14-15, the two diodes, and the ratio switch, point 20+21.
My primary suspect would be component values/shorts at the ratio switch.
Follow the schematic, and see if everything behaves like predicted in this section.
Jakob E.
Your problem must be in the sidechain/metering section - Q12-13-14-15, the two diodes, and the ratio switch, point 20+21.
My primary suspect would be component values/shorts at the ratio switch.
Follow the schematic, and see if everything behaves like predicted in this section.
Jakob E.
approximately what voltage should I be seeing off of Pin 6 of the TL071?
I'm thinking it's not supposed to be 17 v, which is what I'm getting.
Tom
** Updating my saga: with careful manipulation of R55, I can get the meter zeroed momentarily. But if I shift into bypass mode or turn the unit off, the calibration goes away. Plus, for some reason it takes 30 seconds or so for the voltage to the meter to get up to its final value.
Also as well: I'v only got maybe 5 or 10 degrees of play on R55 before I go down to -7 volts or up to 17 volts. Is this normal? Should I check the value of the trimpot, or maybe put in a 10 turn trimmer instead of a single turn?
***
More updating: I figured out I had the wrong trimmer at R54--2K instead of 100K. Fixing that goof got the vu needle to zero up in a lovely fashion. Now I think I'm actually ready to put audio through it.
Thanks
Tom
I'm thinking it's not supposed to be 17 v, which is what I'm getting.
Tom
** Updating my saga: with careful manipulation of R55, I can get the meter zeroed momentarily. But if I shift into bypass mode or turn the unit off, the calibration goes away. Plus, for some reason it takes 30 seconds or so for the voltage to the meter to get up to its final value.
Also as well: I'v only got maybe 5 or 10 degrees of play on R55 before I go down to -7 volts or up to 17 volts. Is this normal? Should I check the value of the trimpot, or maybe put in a 10 turn trimmer instead of a single turn?
***
More updating: I figured out I had the wrong trimmer at R54--2K instead of 100K. Fixing that goof got the vu needle to zero up in a lovely fashion. Now I think I'm actually ready to put audio through it.
Thanks
Tom
Doug,
Yep, that's what happens. For a calculation of resistor ratio versus output voltage, see the manufacturer's 78XX data sheets..
Jakob E.
Yep, that's what happens. For a calculation of resistor ratio versus output voltage, see the manufacturer's 78XX data sheets..
Jakob E.
Cheap, simple, available, and does the job well enough..
radiance
Well-known member
What is a good way to drop the voltage from the "VU lamp out" from 37V to 9V?
I've never done this before so I'm a bit unsure but what I read from the books is two resistors (with the right value) in series between the two poles.
Is this correct? and should I use 1W or higher resistors for this?
I want to use the "VU lamp out" to power 4 LED's in series instead of using a lamp.
My power transformer is 0,6 A so I guess there's enough juice...
I've never done this before so I'm a bit unsure but what I read from the books is two resistors (with the right value) in series between the two poles.
Is this correct? and should I use 1W or higher resistors for this?
I want to use the "VU lamp out" to power 4 LED's in series instead of using a lamp.
My power transformer is 0,6 A so I guess there's enough juice...
To drop voltage, use a resistor in series with the LED's. The LED's should also be connected in series.
To find resistor value, you need to know voltage drop and current draw.
Give the LED's e.g. 10mA.
There is a voltage drop over each led of say 2V. 4LED's make 8V
You now have 37V that needs to be dropped to 8V - that is a drop of 29V @10mA
U/I=R - 29V/0.01A=2900Ohms. Make that 3.3K, that's close enough.
Power rating - 29V x 0.01A=0.29W - use 0.5W or 1W to have a safe margin..
Jakob E.
To find resistor value, you need to know voltage drop and current draw.
Give the LED's e.g. 10mA.
There is a voltage drop over each led of say 2V. 4LED's make 8V
You now have 37V that needs to be dropped to 8V - that is a drop of 29V @10mA
U/I=R - 29V/0.01A=2900Ohms. Make that 3.3K, that's close enough.
Power rating - 29V x 0.01A=0.29W - use 0.5W or 1W to have a safe margin..
Jakob E.
radiance
Well-known member
Thanks Jakob. Can I do the same for powering two 12V relay's in series? (with a different resistor value obviously)
Also: how about this for powering the relay's..
Also: how about this for powering the relay's..
Nope, you shouldn't use a divider for that. The load parallels the lower side of the attenuator.
Figure out the current and needed voltage drop, and calculate like above..
Jakob E.
Figure out the current and needed voltage drop, and calculate like above..
Jakob E.
martthie_08
Well-known member
hey, I just found this on evilbay:
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=7315367734&fromMakeTrack=true
It is a 1176 with jensen trannies, maybe that would be another nice option in addition to the oeps and lundahls. I sent the auctioneer an email asking about the exact model numbers, will post them here, if I get a reply!
And if you have some 3 grand to spend this blue 1176 looks quite nice
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=7314524100&fromMakeTrack=true
Is that an overload or a threshold led on above that meter?
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=7315367734&fromMakeTrack=true
It is a 1176 with jensen trannies, maybe that would be another nice option in addition to the oeps and lundahls. I sent the auctioneer an email asking about the exact model numbers, will post them here, if I get a reply!
And if you have some 3 grand to spend this blue 1176 looks quite nice
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=7314524100&fromMakeTrack=true
Is that an overload or a threshold led on above that meter?
radiance
Well-known member
Thanks again Jakob. It works like a charm :grin:
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