i have grate respect for Andrew and his curage to jump in with always proper, safe, correct , and usefull calculations We all learned something very usefull from him including me and more than once
i only dissagree that often his aspect is overdesign everything to be on the safe side ...this is another aspect of the same issue
based on the above you may understand that my answer was only a joke something you read and lough ...something funny ( i trust that we have similar sense of houmor ...or not ??? )
happy regards sakis
I am an about to retire Civil Engineer that finished his career giving something back to the community via teaching in a Special School.
I have no association with any Electronics/Electrical manufacturing or retailing company. I pay for everything I need.
A preliminary estimate of board count so far is 56. That is plenty for me to begin my order. I should have the quote tonight. Travis from Advanced Circuits called me yesterday and it has been phone tag ever since.
I initially asked him to let us have the boards at out last GB quote figure, which turned out to be a mistake in our favor, we will see.
I connected the boards I have soldered together this morning to the frontend regulator power supply and there was no smoke. Whoa!! I have yet to hook up the rail supply and the outputs.
I had initially soldered in the wrong resistor value for the voltages I am using and must go back and take the 2.2k out and solder in 4.7k. At least I caught this early. (80-40)/8.2 will give the resistor value for 80 volt frontend. These are R4 and R74 on the latest schematic.
Tad
I initially asked him to let us have the boards at out last GB quote figure, which turned out to be a mistake in our favor, we will see.
I connected the boards I have soldered together this morning to the frontend regulator power supply and there was no smoke. Whoa!! I have yet to hook up the rail supply and the outputs.
I had initially soldered in the wrong resistor value for the voltages I am using and must go back and take the 2.2k out and solder in 4.7k. At least I caught this early. (80-40)/8.2 will give the resistor value for 80 volt frontend. These are R4 and R74 on the latest schematic.
Tad
Doug,
In the last Leach 12 group buy the boards were 15.00 each. The Advanced Circuits staff made a big error in calculating the size of the pcb. They had the price figured with the width being 1.5 inches instead of 4. This made a big difference in matierial. I had a conversation with the rep last night and he explained this all to me when we discussed the new board price. This set of boards is costing closer to 19.50 each plus shipping. Granted this is a very large pcb.
As it stands now we can order 100 boards on the 4 week delivery plan at 19.50 each. This is my cost. The quality of work from this board house has always been exemplary and I have no problems using them for this order. Also, the U.S. postal rate on priority delivery has increased from 4.50 to 5.50 on domestic and closer to 13.50 international. Very close approximations these. Paypal has gone from 3.5 to 4 and change on there end which fluctuates depending on whose money is converted. Everyone is having a good time at our expense these days.
To get this off the ground I am going to have to have at least 70 percent prepaid to pay for the order. I will have faith that the final boards will eventually move. There is always someone who gets left out.
At this time there are not many full amp pcb projects being offered on DIY audio. I hope this changes.
Please let me know if this group still wishes to proceed with this endeavor. All in all a commercial amp on this scale would be many times more in money.
Tad
In the last Leach 12 group buy the boards were 15.00 each. The Advanced Circuits staff made a big error in calculating the size of the pcb. They had the price figured with the width being 1.5 inches instead of 4. This made a big difference in matierial. I had a conversation with the rep last night and he explained this all to me when we discussed the new board price. This set of boards is costing closer to 19.50 each plus shipping. Granted this is a very large pcb.
As it stands now we can order 100 boards on the 4 week delivery plan at 19.50 each. This is my cost. The quality of work from this board house has always been exemplary and I have no problems using them for this order. Also, the U.S. postal rate on priority delivery has increased from 4.50 to 5.50 on domestic and closer to 13.50 international. Very close approximations these. Paypal has gone from 3.5 to 4 and change on there end which fluctuates depending on whose money is converted. Everyone is having a good time at our expense these days.
To get this off the ground I am going to have to have at least 70 percent prepaid to pay for the order. I will have faith that the final boards will eventually move. There is always someone who gets left out.
At this time there are not many full amp pcb projects being offered on DIY audio. I hope this changes.
Please let me know if this group still wishes to proceed with this endeavor. All in all a commercial amp on this scale would be many times more in money.
Tad
Well going to have to wait a bit more regardless as we don't have 70 boards spoken for yet. It might be another week or so before I'd have the money but I'd still want them for sure. Sucks that we can't get the 15 dollar price we got before though. They wouldn't do anything for repeat business? I wish I had money I could order them with the discount but this would require all or at least nearly all the boards be pre-paid for. I just don't have that kind of extra cash atm lol.
As I have said before this is a very large pcb. We have everything we need on the one board with a minimum of external wiring. Makes for better sonics, looks and potential problems.
If we just had the frontend section and hard wired the outputs as in many other projects the boards would probably be about 4.00 U.S.
I do not quite know how the error in figuring the last set of boards occurred at Advanced Circuits, but I carried it over to the community and we all benefitted. Not so this time.
I received a quote from Sunstone and it was outrageous. They have a set price for pcb's of a given dimension and this pcb did not fit in to that low price area.
I still believe with the quality and content we are getting a real bargain. These boards are way nicer than the A-75 pcb's I got from Old Colony and most of the stuff from Ebay.
If we can get about 20 more units spoken for I will place the order.
I most again remind some of you that all of the hardware, discrete components and misc. material for this amp can, if allowed to, get very expensive.
If you choose to use exotic, audiophile grade items that is of course your choice. Just remember how many you are going to need. A minimum of 24 quality output devices, if not matched, is north of 100.00 in most cases. The heatsinks should be large and heavy with adequate base dimensions.
Please take your time and assemble all of your components carefully. Test and check everything and ask a lot of questions if in doubt at all about a particular part of the construction. This forum is made of smart extremely talented qualitied individuals who give of there knowledge unselfishly.
Let's find some more constructors so we can get on with it. I want another set myself.
Tad
If we just had the frontend section and hard wired the outputs as in many other projects the boards would probably be about 4.00 U.S.
I do not quite know how the error in figuring the last set of boards occurred at Advanced Circuits, but I carried it over to the community and we all benefitted. Not so this time.
I received a quote from Sunstone and it was outrageous. They have a set price for pcb's of a given dimension and this pcb did not fit in to that low price area.
I still believe with the quality and content we are getting a real bargain. These boards are way nicer than the A-75 pcb's I got from Old Colony and most of the stuff from Ebay.
If we can get about 20 more units spoken for I will place the order.
I most again remind some of you that all of the hardware, discrete components and misc. material for this amp can, if allowed to, get very expensive.
If you choose to use exotic, audiophile grade items that is of course your choice. Just remember how many you are going to need. A minimum of 24 quality output devices, if not matched, is north of 100.00 in most cases. The heatsinks should be large and heavy with adequate base dimensions.
Please take your time and assemble all of your components carefully. Test and check everything and ask a lot of questions if in doubt at all about a particular part of the construction. This forum is made of smart extremely talented qualitied individuals who give of there knowledge unselfishly.
Let's find some more constructors so we can get on with it. I want another set myself.
Tad
To all,
Carl Huff and I have been collaborating on an alternate source for the pcb's which lowers the per board price significantly. We are still in this and trying to get the best price for all involved.
We should have something nailed done securely by this weekend and I will pass it on. We must all give thanks to Carl he is saving us mucho dinero.
So if there are any new comers please add your wants to this thread.
And remember this is just an interested parties thread at the moment.
Tad
Carl Huff and I have been collaborating on an alternate source for the pcb's which lowers the per board price significantly. We are still in this and trying to get the best price for all involved.
We should have something nailed done securely by this weekend and I will pass it on. We must all give thanks to Carl he is saving us mucho dinero.
So if there are any new comers please add your wants to this thread.
And remember this is just an interested parties thread at the moment.
Tad
Bushroot,
This is DIY audio. We have several amps on the bench at one time. I like to build them and try different layouts. You can never have too many amps. You can always give them away. The fun is in the construction and spending all of that hard earned money. The neat thing about money is you can always make some more.
Tad
This is DIY audio. We have several amps on the bench at one time. I like to build them and try different layouts. You can never have too many amps. You can always give them away. The fun is in the construction and spending all of that hard earned money. The neat thing about money is you can always make some more.
Tad
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