I thought (maybe I jumped to conclusions there) that as the boards come with 7x12's you guys might have known the voltage. My bad, I should have given all info in one post.
So I get your point. About the diy, as for getting fat etc I think almost 20 years as a bodybuilder with diets and so on will keep me from getting too fat ;-)
I set the regs to +/-12Vdc. So 12Vdc through each set of load resistors (195R).
That keeps the current around 6.15mA if my math is correct. 12/195=0.0615.
multiply Amperes by 1000 to get milli-Amperes.
i.e. 0.0615A = 1000* 0.0615mA = 61.5mA
That's the "men" speak.
Get it right, or we all get disinterested.
Less time bodybuilding and more time thinking and/or editing your posts.
P=IV, power = 12V * 0.0615A = 0.738W shared between the two 390r resistors. A pair of 500mW, or 600mW, resistors will run very hot.
I appreciate your reply.
Restistors are 1W each.
I'll read the above e few more times to make sure I got it right, I am a musclehead after all
The next part is not aimed at you, but just a general observation.
I may just be a dumb musclehead, but I have keept my posts about the matter at hand: diy. I've not called anyone lazy, or insinuating that they're stupid etc.
I am actually more used to bodybuilding forums, funny thing about them(the ones I've been on and by a funny twist compared to diy, I'm the one that knows more than most others) is that non-productive posts, posts putting someone down etc earned you a warning and if repeated it earned you a ban.
You (not you Andrew, but "you" in general) do realize that putting people down, making people uncomfortabe asking (stupid?) questions etc is very counterproductive for the diy community as new diy:ers get put off?
Just had to write that. If that earns me a ban or something, so be it.
I've felt stupid more the once asking questions on here.
Don't feel bad. I certainly did not want to offend you but tried to sting a little by comparison with the female way of describing technical matters. No more no less. It is just that people want answers without giving the right information. The people that answer then have to ask for data that should have been given in the first place. Now multiply that by a few hundred times and you'll understand the sometimes grumpy answers in such cases. Sometimes the people asking the question also have a quite persuasive way of asking and they demand answers, this all does not help of course.
There are no dumb questions, just dumb answers. So just go on asking whatever you want but give all necessary parameters when asking something. I think no one will be grumpy when supposedly stupid questions are asked. You can ask anything AFAIK. If you get the feeling you are stupid that might have something to do with the way of asking and the lack of info triggering more grumnpy questions (which is totally avoidable by yourself). I think banning is an excessive method but sure there are rules here. I recently got a sanction here for the first time so I know My feeling is that the people who are attacking others are handled quite adequately here, the people that are attacked will most likely be defended by the forum rules and the moderators. There is a kind of justice system so to speak.
Eh ? Your calculation is off Andrew: 0.0615A = 1000* 0.0615mA = 61.5mA. Should be : A to mA => 1000* 0.0615A = 61.5mA
There are no dumb questions, just dumb answers. So just go on asking whatever you want but give all necessary parameters when asking something. I think no one will be grumpy when supposedly stupid questions are asked. You can ask anything AFAIK. If you get the feeling you are stupid that might have something to do with the way of asking and the lack of info triggering more grumnpy questions (which is totally avoidable by yourself). I think banning is an excessive method but sure there are rules here. I recently got a sanction here for the first time so I know
My feeling is that the people who are attacking others are handled quite adequately here, the people that are attacked will most likely be defended by the forum rules and the moderators. There is a kind of justice system so to speak.Eh ? Your calculation is off Andrew: 0.0615A = 1000* 0.0615mA = 61.5mA. Should be : A to mA => 1000* 0.0615A = 61.5mA
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If you feel a post is offensive (please be aware you have to be able to get at least some flak here) you can click on the "warning sign" symbol in the left lower corner. That way you can file a complaint to the mods. After a few years you'll notice you have gained a phenomenon called "elephant skin" and you'll sail through posts and threads without any fear as if that button never even existed
Regarding the transformer making noise: it might be that your mains voltage is polluted and has a DC component in it. If so you will notice the noise changing continuously. There are DC blocking circuits for transformers and I challenge you to find a few yourself. My hint is to keep the 30 VA rating of the transformer in your view.
Regarding the transformer making noise: it might be that your mains voltage is polluted and has a DC component in it. If so you will notice the noise changing continuously. There are DC blocking circuits for transformers and I challenge you to find a few yourself. My hint is to keep the 30 VA rating of the transformer in your view.
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738mW shared between two 1W resistors will run very warm and should be reliable in the long term.
For adjusting the LM3x7's and bleeding the caps.
When all is in order, they will be removed and the wiring to the headamp hooked up.
Don't feel bad. I certainly did not want to offend you but tried to sting a little by comparison with the female way of describing technical matters. No more no less. It is just that people want answers without giving the right information. The people that answer then have to ask for data that should have been given in the first place. Now multiply that by a few hundred times and you'll understand the sometimes grumpy answers in such cases. Sometimes the people asking the question also have a quite persuasive way of asking and they demand answers, this all does not help of course.
There are no dumb questions, just dumb answers. So just go on asking whatever you want but give all necessary parameters when asking something. I think no one will be grumpy when supposedly stupid questions are asked. You can ask anything AFAIK. If you get the feeling you are stupid that might have something to do with the way of asking and the lack of info triggering more grumnpy questions (which is totally avoidable by yourself). I think banning is an excessive method but sure there are rules here. I recently got a sanction here for the first time so I know
Eh ? Your calculation is off Andrew: 0.0615A = 1000* 0.0615mA = 61.5mA. Should be : A to mA => 1000* 0.0615A = 61.5mA
The bans where to keep the forums polite. A bunch of bodybuilders all with their own way of doing things, and many times backing claims with "internet science"..it could get rowdy if not for the rules keeping members in check.
Ofcourse you got warned first, if that didn't take you got a ban for a period of time depending on the situation.
I thought it could have something to do with the screen wire from the transformer being un-connected (will be connected when hooking up the supply wiring to the headamp). The screen wire and 115VAC wire are both properly insulated.
For now there's a 100mA fuse on the primary side. Should blow fast enough should there be a serious error somewhere.
I've dealt with transformers quite a few times before, but never R-core and never anything with a screen wire.
My preference has always been toroidal transformers. The R-core I got however is smaller in size and was very reasonably priced so I figured I'd try it.
Well, I got the headamp switched on (kind of with a stick, hiding behind a chair lol)...always nervous no matter how many times I've done the first start up.
Using a 160mA slow blow fuse on the primary side, allowing for 36,8W with 230VAC mains if my math is correct.
Transformer noise went away with the screen connected to power supply ground and a star-gnd(using the kitchen table as a workbench and there I have PE).
I have not had it on long enough to get warm yet.
DC offset was around 300mV for each channel with the trimpots (10K multiturn, 23 turn IIRC?) turned fully CCW.
With the trimpots turned 12 turns CW, I had around 280mV per channel.
I have the circuit (resistors and capacitors) for the DC-servo connected, but no opamp in the socket and no power to the circuit.
Using the dc-servo posted way back in this thread but I'll use an OPA2134.
I tried attaching the schematic for the DC-servo and the version of the "JHL" headamp I have.
I'll insert them here instead.
I have changed the 3V3 Zeners that came with my kit to 4x 1N4148 (opposite direction to the zeners)
I have also changed the output resistors to 68R.
DC-servo, I hope the designer doesn't mind, the schematic is posted here so just trying to make it easier for people to answer.
My temporary power supply
I forgot to mention that I measured DC offset with both input and output left empty, not connected.
Using a 160mA slow blow fuse on the primary side, allowing for 36,8W with 230VAC mains if my math is correct.
Transformer noise went away with the screen connected to power supply ground and a star-gnd(using the kitchen table as a workbench and there I have PE).
I have not had it on long enough to get warm yet.
DC offset was around 300mV for each channel with the trimpots (10K multiturn, 23 turn IIRC?) turned fully CCW.
With the trimpots turned 12 turns CW, I had around 280mV per channel.
I have the circuit (resistors and capacitors) for the DC-servo connected, but no opamp in the socket and no power to the circuit.
Using the dc-servo posted way back in this thread but I'll use an OPA2134.
I tried attaching the schematic for the DC-servo and the version of the "JHL" headamp I have.
I'll insert them here instead.
I have changed the 3V3 Zeners that came with my kit to 4x 1N4148 (opposite direction to the zeners)
I have also changed the output resistors to 68R.
An externally hosted image should be here but it was not working when we last tested it.
DC-servo, I hope the designer doesn't mind, the schematic is posted here so just trying to make it easier for people to answer.
An externally hosted image should be here but it was not working when we last tested it.
My temporary power supply
An externally hosted image should be here but it was not working when we last tested it.
I forgot to mention that I measured DC offset with both input and output left empty, not connected.
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Had the headamp on for well over an hour earlier.
Got about 241mV DC offset on both channels without any load and empty inputs.
Found some post I had printed out a while back where the poster used a 100R 1W wirewound resistor as load.
I didn't have that, but I put two 220R 0.6W resistors in parallell.
I made two of these and soldered them on a "test-jig", two RCA jacks each with 110R 1.2W to ground.
Now I got 0.1mV (iirc, writing from my phone), both channels still the same. Unless I've somehow misread the DMM...
Now, without having plugged in the DC-servo that's just too good to be true.
That's why I'm very sceptical and ask here if I've made some mistake?
The DC-servo is plugged in as far as wiring to and from it. No power to it and no opamp in the socket.
Any advice?
Btw, I can still hear a very faint buzz from the transformer, but I have to have my ear about 20cm from the transformer to hear it.
Got about 241mV DC offset on both channels without any load and empty inputs.
Found some post I had printed out a while back where the poster used a 100R 1W wirewound resistor as load.
I didn't have that, but I put two 220R 0.6W resistors in parallell.
I made two of these and soldered them on a "test-jig", two RCA jacks each with 110R 1.2W to ground.
Now I got 0.1mV (iirc, writing from my phone), both channels still the same. Unless I've somehow misread the DMM...
Now, without having plugged in the DC-servo that's just too good to be true.
That's why I'm very sceptical and ask here if I've made some mistake?
The DC-servo is plugged in as far as wiring to and from it. No power to it and no opamp in the socket.
Any advice?
Btw, I can still hear a very faint buzz from the transformer, but I have to have my ear about 20cm from the transformer to hear it.
Attachments
It was suggested earlier in this thread if you had low impedance headphones. (I have the Philips Fidelio X2).
But I just noticed that the onboard LED doesn't lit up...
Edit: strange about the un-loaded DC offset if something is very wrong(LED not lighting up)?
You'd think that would be the first thing I checked, but no...in this case I might actually be stupid.
Keeping several builds going at once might be too much for me lol
In my youth I did score in the top 4% in the military's intelligence test, it would seem that is either flawed, or I get less intelligent with age...
Never confuse intelligence with building skills
True
My fiance says that I'm very intelligent, but not very smart lol.
If there is an error somewhere on the PCB, would I get DC offset (decreasing with time) on the outputs then?
The changes made from original kit is:
All small caps are Wima film caps
100uF caps changed to 180uF Elna RJH
The caps with wrong direction on the silkscreen changed to Rubycon ZL 470uF
3V3 zeners replaced with 4x 1N4148 in series (opposite orientation than the zeners would have had)
68R output resistor instead of 2R2
23 turn trimpots instead of the ones that came with the kit.
Onboard 7x12 omitted as I use off board power supply.
10K stepped attentuator instead of included 50K cheap pot.
0R replaced by or parallell with wire Jumpers.
I take great care soldering, so cold solders etc should not be an issue. I thought I had figured out the best place to hook up power supply wires on to the PCB.
Could the issue be a faulty diode(1N4148)?
I did have to get very close to them with the iron when soldering them in series.
Got this kit dirt cheap so I figured I'd try it and see what I think about SQ.
Building a version of the BCL clone parallell with this build.
Using jfet input, CCS for the diamond buffer and a DC-servo.
I quite liked the BCL clone, so I figured I'd try to improve on it.
(Shout out to abraxalito, you're an inspiration and an invaluable help Mate).
You do have a DC bias on Q5 through R10 and R14. (with the op-amp unplugged). However it may be to high, hence your DC off-set being almost equal on both channels.
You should not have to draw the output down with a resistor/load, therefore measuring offset should be without a load.
You have a dual adjustable power supply which can be used just as easily to reduce off-set to 0VDC by.
Choose either the positive or negative side and adjust the voltage up-or-down until the off-set is close to zero.
You should not have to draw the output down with a resistor/load, therefore measuring offset should be without a load.
You have a dual adjustable power supply which can be used just as easily to reduce off-set to 0VDC by.
Choose either the positive or negative side and adjust the voltage up-or-down until the off-set is close to zero.
Yeah, I think I'll have to get the PCB out tomorrow and go over it anyway.
Getting 0.05-0.09V across 5R1. I do get 12V between the side towards rail and GND.
LED still not lit. Heatsinks not getting warm.
(Related to only 0.05-0.09V across 5R1?).
Didn't get more than <1mV DC on outputs with load disconnected just now.
I need to go over the PCB carefully. This headamp has been built when ever I had time over a couple of months when I got stuck on my modular DAC build.
In other words, I didn't really take this that serious as the other build on perf board is that much harder.
And... I do have a tendency to fudge up on the easy stuff for some reason.
Getting 0.05-0.09V across 5R1. I do get 12V between the side towards rail and GND.
LED still not lit. Heatsinks not getting warm.
(Related to only 0.05-0.09V across 5R1?).
Didn't get more than <1mV DC on outputs with load disconnected just now.
I need to go over the PCB carefully. This headamp has been built when ever I had time over a couple of months when I got stuck on my modular DAC build.
In other words, I didn't really take this that serious as the other build on perf board is that much harder.
And... I do have a tendency to fudge up on the easy stuff for some reason.