I don't really understand your reaction. For me diy is also about sharing and non profit stuff. This reaction is for me the same as someone posting a pie recipe on a cooking forum and complain that anybody share his recipe and cook the pie!
On the first page of the thread until today was indicated that no board were left nor going to be build again...
On this tread everyone saw different version of the build made by different peapole, some person don't have the knowledge to draw a pcb so sharing gerbers let them enjoy the amp anyway... personnaly if I post schematic, pictures, description,.... of something I'm pleased that's someone else want to reproduce/improve what I've do, if I don't want so, I don't share all the details on the web on a diy forum.
Also this tread is the best place to share gerbers of this build because here everyone know who has the credit of the original schematic and concept.
I really don't want to polemique but I wanted to explain my approach wich is in anyway the willing of stealing someone else work!
There is a line where free sharing of information ends, and piracy begins. From a fairly early stage it was reasonably well known the OPC was planning to bring this product to market, although no time lines were ever given, the reasonable thing to do would be to ask permission to reproduce his work even if 100% of it was published. It's showing respect to the original author... Does he have the legal right to stop you making a copy, perhaps not (then again he might), but the decent thing to do is at least ask since he has put so much effort into it.
it is not your place to 'help people out' replicating someone elses design without even asking. the fact this does not even compute, tells me quite a lot about you. its been well known for a long time that he was making a go at it commercially, that is why the boards werent available again and he said as much. it said no boards available on the front page, because these boards sold out in less than 24hrs and we got sick of telling people there were no boards left, there was such interest.
Even if he wasnt, its very uncool to just take it, dont say anything to him and beyond just making something for yourself, start offering it to others in a form they can replicate it with. it is not yours to share
Even if he wasnt, its very uncool to just take it, dont say anything to him and beyond just making something for yourself, start offering it to others in a form they can replicate it with. it is not yours to share
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The fact is I come more from open software and true diy spirit community and yes I understand now this is far different of what I see here....
In open source software nobody would ever think of asking the first author of a code to modify/redistribute it (i.e asking Linus Torvald to make change on or redistribute Linux kernel) and I considered the fact of publishing the hardware sources of an electronic assembly on a diy forum in the same manner, wich is almost always the case in so called DIY stuff.
Now don't worry opc won't loose customer in my fault, first because I haven't published the gerbers files (oh yes I send them to 1 person) and secondly because as you may know manufacturing one (or 2,3,4,...) pcb would cost a lot more (because of setup costs) than buying directly his new version now they are available.
Now opc i'm really sorry if i hurt you doing so...
In open source software nobody would ever think of asking the first author of a code to modify/redistribute it (i.e asking Linus Torvald to make change on or redistribute Linux kernel) and I considered the fact of publishing the hardware sources of an electronic assembly on a diy forum in the same manner, wich is almost always the case in so called DIY stuff.
Now don't worry opc won't loose customer in my fault, first because I haven't published the gerbers files (oh yes I send them to 1 person) and secondly because as you may know manufacturing one (or 2,3,4,...) pcb would cost a lot more (because of setup costs) than buying directly his new version now they are available.
Now opc i'm really sorry if i hurt you doing so...
akael there is spirit of sharing goes on here, but you need to realize that even though this is a DIY forum there are people who do have a commercial interest, even in the open source community you have to adhere to the GPL or GNU (cant remember which), which in affect is a code of conduct for sharing the software.
I am more than happy to share the software I write (mainly because I am crap) but if I wanted to sell something I wrote, I would like to think that people would respect that, and not copy my work without at least giving me credit for it.
Asking for anything in life is just polite...
I am more than happy to share the software I write (mainly because I am crap) but if I wanted to sell something I wrote, I would like to think that people would respect that, and not copy my work without at least giving me credit for it.
Asking for anything in life is just polite...
Open source (hardware or software i don't make any difference) is a big question and we start to be off topic here but what i did here is exactly in the scope of gpl or gnu (to take this license exemple), the only issue is that these sources (from opc) were not putted in this forum in the mind of open source sharing (wich I tough it was) but more to make advertising for selling products (wich I haven't understood before).
And in any case I took the credit of someone else work because this is obvious on this tread that the original work was from opc, and I won't in any case sell boards or end product based on that!
Also peapole who want to sell software (to keep the comparaison) very rarely publish their source code (anyway I never saw that before!)...
Enough talk now, ...let's go design some cool stuff!
And in any case I took the credit of someone else work because this is obvious on this tread that the original work was from opc, and I won't in any case sell boards or end product based on that!
Also peapole who want to sell software (to keep the comparaison) very rarely publish their source code (anyway I never saw that before!)...
Enough talk now, ...let's go design some cool stuff!
10 x 2 layer boards costs peanuts now.
I think Owen was surprised at both the frenzied and enduring interest in this series of amps and his headphone amps, as well as at the incredible performance and at that point he would be silly to not consider making something from it; we encouraged him to.
he has given thousands of hours overall to designing and supporting boards and projects for DIYers here over the years and for sure that wasnt about money. he is a professional working in the field, in the commercial machine and made something in hobby time that looks like it might make him and his wife some money; simple as that. the fact that so many people have ignored this and continued to treat it like a free for all, has no doubt left a sour taste.
I think Owen was surprised at both the frenzied and enduring interest in this series of amps and his headphone amps, as well as at the incredible performance and at that point he would be silly to not consider making something from it; we encouraged him to.
he has given thousands of hours overall to designing and supporting boards and projects for DIYers here over the years and for sure that wasnt about money. he is a professional working in the field, in the commercial machine and made something in hobby time that looks like it might make him and his wife some money; simple as that. the fact that so many people have ignored this and continued to treat it like a free for all, has no doubt left a sour taste.
My Bad!
@ qusp & opc: Sorry if my earlier comment also caused any offence, I certainly didn't mean to encourage belligerent copying of opc's work. It was taken for granted [and expected], that people would seek permission from him before doing anything. Furthermore, regarding the info presented here, that it would be a good reference source for best practice and not be copied directly...
Personally, I did send a PM to opc, outlining exactly what was being undertaken and gave him the option to veto the project before even starting.
Now that these boards are available again, I'm more than happy to spend my money again...
Paul
@ qusp & opc: Sorry if my earlier comment also caused any offence, I certainly didn't mean to encourage belligerent copying of opc's work. It was taken for granted [and expected], that people would seek permission from him before doing anything. Furthermore, regarding the info presented here, that it would be a good reference source for best practice and not be copied directly...
Personally, I did send a PM to opc, outlining exactly what was being undertaken and gave him the option to veto the project before even starting.
Now that these boards are available again, I'm more than happy to spend my money again...
Paul
@ qusp: 
The revised LPUHP does sound very good, my recent experience has shown that I'm getting my desired listening level at about 1WATT [speakers are 8 Ohm, 85dB 1w/1m]. I'm looking at getting a miniDigi / miniDSP combo [2.1 setup] and running it balanced to the LPUHP. Looking at the whole gain structure, I hope to forgo the need of any volume control, utilising different EQ settings to give correct SPL for different music types.
Paul
The revised LPUHP does sound very good, my recent experience has shown that I'm getting my desired listening level at about 1WATT [speakers are 8 Ohm, 85dB 1w/1m]. I'm looking at getting a miniDigi / miniDSP combo [2.1 setup] and running it balanced to the LPUHP. Looking at the whole gain structure, I hope to forgo the need of any volume control, utilising different EQ settings to give correct SPL for different music types.
Paul
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Bump ...
Have a minor question ref the new LPUHP. The new power section uses 3A reg's against the old 1.5A 317/337 combo. So a slightly beefier transformer is required, suspect 2x12V 50VA would be suitable?
And, LME49600 or LME49610? The ...610's datasheet is now showing +/-750mA short circuit output current up from +/-490mA of old and on the 49600 ... I know those levels can't be relied upon as a constant current, but might they prove a little more useful for driving more difficult loads etc?
Paul
Have a minor question ref the new LPUHP. The new power section uses 3A reg's against the old 1.5A 317/337 combo. So a slightly beefier transformer is required, suspect 2x12V 50VA would be suitable?
And, LME49600 or LME49610? The ...610's datasheet is now showing +/-750mA short circuit output current up from +/-490mA of old and on the 49600 ... I know those levels can't be relied upon as a constant current, but might they prove a little more useful for driving more difficult loads etc?
Paul
Hi Paul,
A 50VA transformer is pretty much ideal. I've been using the AS-0515 from Antek.
The secondary voltage really depends on how high you want the rails to be. I would suggest +/-18V which means you pretty much need +/- 15V secondaries if you want to keep the voltage on the high side of the regs sufficient enough maintain regulation under full load. If you don't need that much voltage swing, then you can certainly go for a lower voltage secondary.
I've been using the LME49610 pretty much exclusively since they are the same price and perform a little better while giving you the flexibility of higher rail voltages.
The new supply configuration is significantly more robust than the previous version, so RMS and peak power are both a little higher
Cheers,
Owen
A 50VA transformer is pretty much ideal. I've been using the AS-0515 from Antek.
The secondary voltage really depends on how high you want the rails to be. I would suggest +/-18V which means you pretty much need +/- 15V secondaries if you want to keep the voltage on the high side of the regs sufficient enough maintain regulation under full load. If you don't need that much voltage swing, then you can certainly go for a lower voltage secondary.
I've been using the LME49610 pretty much exclusively since they are the same price and perform a little better while giving you the flexibility of higher rail voltages.
The new supply configuration is significantly more robust than the previous version, so RMS and peak power are both a little higher
Cheers,
Owen
Cool ... they're going to be powering a pair of Mark Audio A7.3. Am aiming for 8Watt output, so +/-15V rails should do the trick ... can set the gain appropriately once decided on either SE or Bal input.
Shame your not making the power section available as a stand alone board. I hope to use 2 x 'The Wire' Power Amp with a pair of 8 Ohm helper woofers and the LPUHP's PS section would've be idle for the output stage [looking at either +/-10V or 15V]
Paul
Shame your not making the power section available as a stand alone board. I hope to use 2 x 'The Wire' Power Amp with a pair of 8 Ohm helper woofers and the LPUHP's PS section would've be idle for the output stage [looking at either +/-10V or 15V]
Paul
Hey guys,
could anybody help me with the transformer? The recommended 25VA Amgis transformer is not deliverable till feb. 2014. Is there another transformer that fits the form and the holes? What about voltage, which voltage is usable above 12V? I red about 15V, what about 18V? Just for interest...
Is it possible to increase gain to about 40?
I have another amp which should be used together...
Thanks,
Stammheim
could anybody help me with the transformer? The recommended 25VA Amgis transformer is not deliverable till feb. 2014. Is there another transformer that fits the form and the holes? What about voltage, which voltage is usable above 12V? I red about 15V, what about 18V? Just for interest...
Is it possible to increase gain to about 40?
I have another amp which should be used together...
Thanks,
Stammheim
Is capable of driving 4ohm load, power reduces into lower impedance because the buffer current output is limited. I did some calcs on it a while ago because I was looking to use these on 4 or 6ohm tweeters in an active system. I went with compression drivers in the end so ... didn't have that problem in the end
Hi Do,
As Chris mentioned, 4 ohm loads are no problem, but you will get less power. I have measured about 9W RMS into 4 ohms before the current limiting kicks in.
I feel like the amp actually sounds a little better current clipping than it does voltage clipping, but that could just be me
Either way, at 91dB efficiency, 9 watts should be enough for some pretty loud listening!
Cheers,
Owen
As Chris mentioned, 4 ohm loads are no problem, but you will get less power. I have measured about 9W RMS into 4 ohms before the current limiting kicks in.
I feel like the amp actually sounds a little better current clipping than it does voltage clipping, but that could just be me
Either way, at 91dB efficiency, 9 watts should be enough for some pretty loud listening!
Cheers,
Owen