Syn's offer to distribute for free is indeed a very generous gesture.
"Distribute for free" does not mean a give away.
The Diyers would still buy the PCBs and pay for post/packing and if necessary any fees due to intermediaries.
Does C2C want to continue as Steve's R+L hand man, or relinquish this part of distribution to another?
Selling off the hardware will be a big enough job for anyone.
"Distribute for free" does not mean a give away.
The Diyers would still buy the PCBs and pay for post/packing and if necessary any fees due to intermediaries.
Does C2C want to continue as Steve's R+L hand man, or relinquish this part of distribution to another?
Selling off the hardware will be a big enough job for anyone.
I'm sorry, but this thread already has 50 pages...😱
Could someone be so kind and post a link to measured specs of this astounishing amp please? 🙂
Regards
Could someone be so kind and post a link to measured specs of this astounishing amp please? 🙂
Regards
Ah, OK I misunderstood the Syn08 offer- I presume then he would be charging for board cost + shipping + expenses incurred? The only problem might be that Syn08 is in Canada, Steve is in US - would there be additional taxes + shipping?
A generous offer from Syn08, no doubt & thank you for trying to move this project along
How does Thomas/Steve feel about this is the question?
A generous offer from Syn08, no doubt & thank you for trying to move this project along
How does Thomas/Steve feel about this is the question?
AndrewT said:
Actually I was thinking to give them away for free, but then jkeny's concern is valid.
Anyway, $20 for a 6" x 9" board is really peanuts (less than it costs to manufacture in <100 pcs) so I guess the boards should now sell like hot cakes.
Ah memory always let's you down - I must go back and check my manhood, then again maybe not - I'm happy in my ignorance!
AndrewT said:
This would be Steve's decision - not mine. I'll help Steve in any way I can - but he calls the shots. As is he has his darling wife and teenage son to help ship and pack things - and as far as I know has not had any problems to date. There is a small glitch right now as he is changing his internet provider and thus a new email address will be needed. Steve is still under the weather at the moment - perhaps he will check in but if he does please go easy on him. Things are tuff right now.
syn08 said:
The boards are 5.5X6.5 (plus the diode board) or about 37 sq. in. I suppose $20 is a lot to ask. They are double sided, two oz. copper, plated, metalized holes and silk screened.
There is a schematic that matches the board (finally) for both the 50W and 100W versions. Much of the confusion about the schematic arose from my posting the first schematic in post 1 of this thread. At the time I posted that schematic, I did not know I had boards. When I discovered I had boards, I started re drawing the schematic to match the boards. This seems to have caused confusion for some.
I do not have a problem with anyone doing their own board layout. The only restriction I suggested was no commercial use. DIY at cost I do not consider a problem.
I have sent prints of the board to everyone that has E-mailed me and asked. I do not have Gerber files for the board. Those would be wherever the rest of the computer files for that project are. They are here somewhere, in storage, but I can not search for them. Thomas has prints of the board. He may post them if he chooses.
I will address some other points while I am here.
There is no link to measured specs for this amp. There is only my claimed specs.
How much will it cost you to build the amp? I have provided a BOM with sources. I give the part numbers from these sources. I suppose I could price out the whole amp (less the parts you have on hand that you plan to use) for every possible supplier for each possible builder in each country. Could you be so kind as to at least supply me with tax rates and shipping for your location?
Now the reason I am here. I have a new E-mail address. I have updated my profile with this address.
scott wurcer said:
I have to agree with the first sentence. As for the second, I feel the state of discrete simulation is, in some cases, in question. With most here using the same simulation program, why are there so many different results for such a simple circuit?
My simulations agree with my (remembered) measurements. Could someone please explain what I am doing wrong?
Steve Dunlap said:
Did you post your files, .asc and models? I forget now there have been so many version of the circuit (which I think is the problem).
Some of them will behave dramatically different. Let me state as simply as I can one issue. As andy_c proposed take just the output devices running at 25mA and hold their Vbe's constant and alternately source and sink 2.5A there is considerably more than 50ppm of non-linearity at the output. This is basic device physics 101 it has nothing to do with simulators. The voltage at the output can be computed by hand.
ctc2thomas is building the 50 watt version. I am building a 100+ watt version on Steve's boards.
The parts cost of Steve's BOM on post #809 is $140 from Mouser for the 50W stereo version. My project list on Mouser differs from Steve's in the capacitors. I priced out Nichicon Muse for the electrolytics and WIMA film caps instead of the Panasonic caps from Digi-Key that Steve specified.
The single most expensive line item is the 10,000uF/50V cap at $66.40 for the Nichicon Muses which were a few dollars each more expensive than the Panasonic, Mallory or "regular" Nichicon capacitors.
This list does not include any hardware, heatsinks, transformers, etc. Just the items listed on the BOM.
Phil
The parts cost of Steve's BOM on post #809 is $140 from Mouser for the 50W stereo version. My project list on Mouser differs from Steve's in the capacitors. I priced out Nichicon Muse for the electrolytics and WIMA film caps instead of the Panasonic caps from Digi-Key that Steve specified.
The single most expensive line item is the 10,000uF/50V cap at $66.40 for the Nichicon Muses which were a few dollars each more expensive than the Panasonic, Mallory or "regular" Nichicon capacitors.
This list does not include any hardware, heatsinks, transformers, etc. Just the items listed on the BOM.
Phil
I am an idiot
But sitting in the supermarket carpark today I happened upon an article in a June 91 wireless world about chaos in electronics by Jim Lesurf.He expounds on the difficulties in modelling non linear electronics and used phase plots showing patterns of bifurcations and other stuff I don't understand
regards
Max
edit] ps just 2 cents & coincidents
pps I feel like an idiot because before we went to shop I read Cargo Cult Science by RPF
pps thanks to Ostripper.
But sitting in the supermarket carpark today I happened upon an article in a June 91 wireless world about chaos in electronics by Jim Lesurf.He expounds on the difficulties in modelling non linear electronics and used phase plots showing patterns of bifurcations and other stuff I don't understand
regards
Max
edit] ps just 2 cents & coincidents
pps I feel like an idiot because before we went to shop I read Cargo Cult Science by RPF
pps thanks to Ostripper.
Hi Steve,
during some simulations, I perceived cross conduction between output transistors ( 10kHz and so on....maybe less ). Installing R10=100 as atached file solves that and decreases THD.
What you think about it ?
regards
Ed
during some simulations, I perceived cross conduction between output transistors ( 10kHz and so on....maybe less ). Installing R10=100 as atached file solves that and decreases THD.
What you think about it ?
regards
Ed
Juergen Knoop said:
For the 100W amp, ( I did not produce a 50W amp commercially) the THD at rated power into 8 ohms was 0.01% or less measured at 1KHz. Not really such outstanding specs, but some dispute my claim.
Steve Dunlap said:
Steve,
Care to clarify which is correct and final? There's quite a gap here...
http://www.diyaudio.com/forums/showthread.php?postid=1752556#post1752556
scott wurcer said:
I have not posted my files. I do not use LT4 or any of the other programs I have seen mentioned here.
My question was simple enough. Other than actual mistakes, any of the "many versions" of the circuit posted vary only in transistor updates (to newer part numbers with similar specs) or small changes in resistor values. Each and every one can be built and will work. Use the last posted schematic for the 50W amp. When everyone gets the same results in their simulation (without posting one file for everyone to run) I will accept the results. Even if they are incorrect.
As andy_c proposed: The problem here is that the Vbe's of the outputs do not remain constant. If you make them constant, then you are correct. The Vbe of the "off" device increases as the "on" device conducts more current.
EDDELARUE said:
If you feel this resistor improves the circuit, then use it. Could you build and test one each way to compare the measured THD?
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