Volume can be 22K, 33K or 47K...or other value within these limits.
No watt worries needed about volume control potentiometer.... Alps brand or better, two potentiometers or a double unit, a stereo unit (two units coupled into the same axel).
If your case, or enclosure, not made with conductive material that will be grounded, do not forget to solder ground wire into the potentiometer metal case.
The output inductor can go from 5 microhenries to 10 microhenries and 70 watts of power will cross... as current will be big and resistance very low, so, do not worry too much with the inductor power, as power will not develop over it because resistance too much low to develop heat there.
Yes.... if the amplifier oscilates (very rare) you will need some power...so, select it to have coil with more than 0.5 milimeter diameter (minimum)... excelente will be 2 milimeters diameter..more than that is overkill.
This output inductor will work only if you decide to use long speaker cable, or if your speaker use passive crossover having big inductors, capacitors , big electrolitic condensers inside and resistances.... that complexity sometimes creates problems to the amplifier because of back forces entering output stage.
It "sounds"...the output coil sounds!....so, it is better not to have it, and people is removing them from modern amplifier designs.... this is dangerous if the speaker cable is very long.
The one was included into the HRII just to correct a small overshot i had into the waveform....the overshot was not something i could "listen"..but i have decided to clean the waveshape because some folks love to watch waveshapes instead of listen the music....and some of them loves to watch and listen music too... some of them are so fanatic that do that simultaneously.
regards,
Carlos
No watt worries needed about volume control potentiometer.... Alps brand or better, two potentiometers or a double unit, a stereo unit (two units coupled into the same axel).
If your case, or enclosure, not made with conductive material that will be grounded, do not forget to solder ground wire into the potentiometer metal case.
The output inductor can go from 5 microhenries to 10 microhenries and 70 watts of power will cross... as current will be big and resistance very low, so, do not worry too much with the inductor power, as power will not develop over it because resistance too much low to develop heat there.
Yes.... if the amplifier oscilates (very rare) you will need some power...so, select it to have coil with more than 0.5 milimeter diameter (minimum)... excelente will be 2 milimeters diameter..more than that is overkill.
This output inductor will work only if you decide to use long speaker cable, or if your speaker use passive crossover having big inductors, capacitors , big electrolitic condensers inside and resistances.... that complexity sometimes creates problems to the amplifier because of back forces entering output stage.
It "sounds"...the output coil sounds!....so, it is better not to have it, and people is removing them from modern amplifier designs.... this is dangerous if the speaker cable is very long.
The one was included into the HRII just to correct a small overshot i had into the waveform....the overshot was not something i could "listen"..but i have decided to clean the waveshape because some folks love to watch waveshapes instead of listen the music....and some of them loves to watch and listen music too... some of them are so fanatic that do that simultaneously.
regards,
Carlos
Carlos,
What if I make a separate box for the potentiometer and have it in a central location near the cd player but put the amps right next to the speakers?
Would the long distance between the pot and the amp be a problem?
My justification is that I would rather have the pot near the music source for ease of use but I would like to have the amps right next to the speakers since many people seem to feel it is best to have a short distance between the amp and the speaker it is driving.
So the music source and the pot would be about 2 meters from each speaker.
What do you think?
Uriah
What if I make a separate box for the potentiometer and have it in a central location near the cd player but put the amps right next to the speakers?
Would the long distance between the pot and the amp be a problem?
My justification is that I would rather have the pot near the music source for ease of use but I would like to have the amps right next to the speakers since many people seem to feel it is best to have a short distance between the amp and the speaker it is driving.
So the music source and the pot would be about 2 meters from each speaker.
What do you think?
Uriah
Hi Uriah, that is exactly the setup I use...
A seperate source and volume control box and the amp, oh and a seperate Transformer houseing, PSU boards are in amp...
just keep a finger on the 10R resistor that has the wire connection to ground when you test with long cables...if it osscilates there will be a quick heat buildup.
My dad would just laugh at the long cable worries if he were still here... He built a pretty large music/band practice room on to our house which made long cables a neccesity...
My house is small so I have the "luxury" of short cables....
A seperate source and volume control box and the amp, oh and a seperate Transformer houseing, PSU boards are in amp...
just keep a finger on the 10R resistor that has the wire connection to ground when you test with long cables...if it osscilates there will be a quick heat buildup.
My dad would just laugh at the long cable worries if he were still here... He built a pretty large music/band practice room on to our house which made long cables a neccesity...
My house is small so I have the "luxury" of short cables....
Okay, I uploaded some pics to Google Albums. I am still waiting on several parts but this is how far along I am. Maybe 1/3 of the way there. Much assembly to do and I am dreading the testing. Still have to find the huge resistors for testing and some volt meters. I know where to find them, but the cost is making me wait til the last minute.
So here is the link
http://picasaweb.google.com/udailey/HRII
Uriah
So here is the link
http://picasaweb.google.com/udailey/HRII
Uriah
Attachments
![9[1].jpg](/community/data/attachments/98/98296-f2d258d06582ba57e0cbf70e8c5bf453.jpg)
I was thinking alike that Nogoodboyo, but do not know
if i was the time bomb in the last supply.
regards,
Carlos
...................................................................................................
Huge transformer Udailey!
Drivers do not need big heatsinks, a rectangle of aluminium, 2 inches long and 2/3 inch high, made into "L" shape form will be enougth to each one of the drivers.
Carlos
if i was the time bomb in the last supply.
regards,
Carlos
...................................................................................................
Huge transformer Udailey!
Drivers do not need big heatsinks, a rectangle of aluminium, 2 inches long and 2/3 inch high, made into "L" shape form will be enougth to each one of the drivers.
Carlos
Carlos, about the drivers...
Thanks, I wasnt sure how big it should be so I just decided to over do it and be safe. But I wasnt sure what I was going to do with those heatsinks anyway because they would get in the way. Will try to do what you suggest.
I bought some copper tape. I am thinking of making a cardboard circle about 5" high around each transformer and then making a screen pattern on the cardboard out of the copper tape. This way I shield everything from the transformer. I know thats a silly way to do it, but I dont see why it wont work
.
Bought 5 watt 2.2kR resistors for the PSU. WAY TO BIG LOL. I had to mount them on the bottom side and scrape away insulator near the solder pads to solder them to the board.
SO, I planned on putting this together EXACTLY the way Nordic has specified, but budget and part availability has changed my plans. I will learn more this way I think since I am sure to mess up some parts of it
Uriah
Thanks, I wasnt sure how big it should be so I just decided to over do it and be safe. But I wasnt sure what I was going to do with those heatsinks anyway because they would get in the way. Will try to do what you suggest.
I bought some copper tape. I am thinking of making a cardboard circle about 5" high around each transformer and then making a screen pattern on the cardboard out of the copper tape. This way I shield everything from the transformer. I know thats a silly way to do it, but I dont see why it wont work
.Bought 5 watt 2.2kR resistors for the PSU. WAY TO BIG LOL. I had to mount them on the bottom side and scrape away insulator near the solder pads to solder them to the board.
SO, I planned on putting this together EXACTLY the way Nordic has specified, but budget and part availability has changed my plans. I will learn more this way I think since I am sure to mess up some parts of it
Uriah
Power trannies
Hi Uriah,
Some good-looking boxes, with your HRII boards and those huge transformers. Congratulations!
The transformers are the same mine, hence my question. Have you checked the DC output voltage? I'm getting around 41V under load (about 3-4 amps), which should be loud for my listening habits.
My question -- what changes have you made to the component values to account for the higher voltage supply? (My HRII is not playing yet - have not yet found a good enclosure without big $ and work).
I was thinking of using 38 Volts on the regulators for the front-end. Any comments?
Thanks,
Francois
udailey said:
Hi Uriah,
Some good-looking boxes, with your HRII boards and those huge transformers. Congratulations!
The transformers are the same mine, hence my question. Have you checked the DC output voltage? I'm getting around 41V under load (about 3-4 amps), which should be loud for my listening habits.
My question -- what changes have you made to the component values to account for the higher voltage supply? (My HRII is not playing yet - have not yet found a good enclosure without big $ and work).
I was thinking of using 38 Volts on the regulators for the front-end. Any comments?
Thanks,
Francois
HD11 and power supply boards
HI Carlo, Nordic and Greg,
Could there be any chance there'll still be some PCBs available?
I need a pair of main board and a pair of power supply.
Thanks
Albert
BTW sorry for the mess that I forget to update my email address. I thought I'm going old and make things easy to forget.
This is why I've been struggling so long to make my decision ( I've been following the thread since day one), for I really worry about my ability to make it a finish. I only have very little experience in electronics. Wish this is a project I could show to my grandson.
HI Carlo, Nordic and Greg,
Could there be any chance there'll still be some PCBs available?
I need a pair of main board and a pair of power supply.
Thanks
Albert
BTW sorry for the mess that I forget to update my email address. I thought I'm going old and make things easy to forget.
This is why I've been struggling so long to make my decision ( I've been following the thread since day one), for I really worry about my ability to make it a finish. I only have very little experience in electronics. Wish this is a project I could show to my grandson.
Thanks FrancoisG
I am just a baby at this DIYaudio right now so its slow going for me. I do not yet have the tools to test the output of the Transformers. They came with specs from the manufacturer. It says they should output 27.2V at 19.0A and 29.6V at No Load witha 120V input at 50Hz. So your tests suprise me. This is transformer # TI-43222C from TOROID International which seems to have merged with some other European Company. Mine were made on my birthday on 06/09/2004 so hopefully there is some luck built in
Sorry I dont know any more than that at the moment. Those big enclosures are 12"x12" and cost $17 each at my local electricians supply store.
So, I guess I would be turning your question back to you
If you are certain we have the same exact transformers please keep me posted on your results and modifications. I will be doing the same but I think it will take some time. I am shooting for having working amps by May 22nd, but we will see. I have an enclosure and two speakers to finish building for my wife as well. Thankfully I have about 2 hours a day I can spend on these projects so as long as I have parts shipping to me I keep making progress. Still REALLY need to find some cheap voltmeters and big resistors for the transformer testing. Did you use the test solution that Carlos suggested? If not what did you do to test your transformer?edit: oh, ps, I am planning on covering the metal box with wood on several sides except maybe the bottom and back panel, the using the router to put a nice rounded bevel on the 90degree angles. Then veneer with some nice veneer I found on ebay. Then sand, clean, and laquer. I dont think that will be to hard. A simpler solution would be paint the whole thing matte black and put nice cherry or bit lighter colored wood on the left and right sides and have them a bit taller than the box so that it lifts a bit from the ground. Might look nice without much work.
edit: I keep editing, but another idea. Do the two sides so it is elevated from the ground, then put a bright red led in the center of the bottom facing the ground. The effect with low lights will be pretty neat
For anyone looking for huge transformers the guy I bought mine from has them for sale again but has increased his price I think by about $20 total. So you might be able to strike a deal with him.
Here is the link
http://cgi.ebay.com/Toroid-TI-04322...oryZ4660QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
The Box is by Millbank and is number 12126-SC1 . It is about $50 anywhere I see online. I would be happy to purchase and ship to you, but I am betting it would end up expensive with shipping. The pic I found online is a standard box pic and not really of the 12126-SC1. But you are in Illinois and maybe it would cost less. Remember, I am only using them for the power supply because the amp plus heatsink wont fit in there and I wanted them separate anyway.
Uriah
Those transformers are really huge, i do not think need worries about
Select zener diodes to have 3 volts less than the power output voltage, as this transformer is big enougth to sustain any need of current from the HRII.
HRII do not go more than 40 watts and 70 watts (8 and 4 ohms), but the big surprise is how loud this small amplifier can play.
Enjoy HRII, for sure you will like it.... sounds really very good..for sure you will like it.
Guaranteed!
regards,
Carlos
..................................................................................................
Dear Albertli
Try to put your order to some HRII into the Nordic's group buy, for sure he will read your mail, but for "registration" purposes, do it once again into the group buy thread opened by Nordic for this purpose.
I think he has boards for supply and boards for protection, not sure if he still have HRII boards...but having people interested, for sure he can order another bunch of boards.
regards,
Carlos
Select zener diodes to have 3 volts less than the power output voltage, as this transformer is big enougth to sustain any need of current from the HRII.
HRII do not go more than 40 watts and 70 watts (8 and 4 ohms), but the big surprise is how loud this small amplifier can play.
Enjoy HRII, for sure you will like it.... sounds really very good..for sure you will like it.
Guaranteed!
regards,
Carlos
..................................................................................................
Dear Albertli
Try to put your order to some HRII into the Nordic's group buy, for sure he will read your mail, but for "registration" purposes, do it once again into the group buy thread opened by Nordic for this purpose.
I think he has boards for supply and boards for protection, not sure if he still have HRII boards...but having people interested, for sure he can order another bunch of boards.
regards,
Carlos
hahhahahhah
I had finished my Vanilla Uncle!
But one channel first, to know how much the BASS.
Fisrt power on, D**n the protective resistor almost burn my finger. even i just turn on, few second the temperature is pretty HOT
So i check the voltage across the protective resistor is 15V!
I just turn the pot until 1V and everything seems ok, so i turn the pot to get lower DC output -> 1,8mV.
BUT uncle, I have check the vBE on output transistor is just 570mV? I read in your picture about voltage had 700mV? Is my amp is ok?
Maybe Tomorrow, I will bought the picture of my Vanilla.
Thank's
La Ode
I had finished my Vanilla Uncle!
But one channel first, to know how much the BASS.
Fisrt power on, D**n the protective resistor almost burn my finger. even i just turn on, few second the temperature is pretty HOT
So i check the voltage across the protective resistor is 15V!
I just turn the pot until 1V and everything seems ok, so i turn the pot to get lower DC output -> 1,8mV.
BUT uncle, I have check the vBE on output transistor is just 570mV? I read in your picture about voltage had 700mV? Is my amp is ok?
Maybe Tomorrow, I will bought the picture of my Vanilla.
Thank's
La Ode
Hi Albert I will contact you tommorrow with ordering instructions.
Carlos that amp is comming on nicely, the torroids make me jealous...
CRT if nothing gets too hot to touch and it sounds fine it likely is!!!
I figured out the P1 would be overkill for a guitar amplifier, whereas the plain old DX with a bit more gain and a valve preamp, which I kind of pirated from a good design that is no longer in business, I think it is going to kick some butt when it is done.
Haveing a clean channel only going through a triode with volume control and a distortion channel going through another 2 triodes for gain, distortion and volume control. It is a simple design with a rich variety of sounds from few controls, not the stupid fender boxes where the knobs are almost only for show.
I think the DX will love the simple crossoverless speaker, I allready have a completed DX channel, just have to make some time to start on the pre section.... I did tinker a bit with layout, but Ihave to save up a bit for the valves, sockets and transformer hunt. Thinking I might use 2 2x22V baby torroids on a voltage doubler for about 240VDC and a PCB mount tranny for the heaters.
This is a picture of my HRII's guts, please note everything is OVERSIZED to be and INDESTRUCTABLE unit (performance wise), you certainly don't need to go that far overboard...
Carlos that amp is comming on nicely, the torroids make me jealous...
CRT if nothing gets too hot to touch and it sounds fine it likely is!!!
I figured out the P1 would be overkill for a guitar amplifier, whereas the plain old DX with a bit more gain and a valve preamp, which I kind of pirated from a good design that is no longer in business, I think it is going to kick some butt when it is done.
Haveing a clean channel only going through a triode with volume control and a distortion channel going through another 2 triodes for gain, distortion and volume control. It is a simple design with a rich variety of sounds from few controls, not the stupid fender boxes where the knobs are almost only for show.
I think the DX will love the simple crossoverless speaker, I allready have a completed DX channel, just have to make some time to start on the pre section.... I did tinker a bit with layout, but Ihave to save up a bit for the valves, sockets and transformer hunt. Thinking I might use 2 2x22V baby torroids on a voltage doubler for about 240VDC and a PCB mount tranny for the heaters.
This is a picture of my HRII's guts, please note everything is OVERSIZED to be and INDESTRUCTABLE unit (performance wise), you certainly don't need to go that far overboard...
- Status
- Not open for further replies.