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Post by Deleted on Nov 4, 2012 0:14:34 GMT
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Post by Deleted on Nov 4, 2012 1:24:37 GMT
Hi Alan They may be, but one may have an HFE 2 or >3 times higher than the other. Like you I opted out of the GB when the original supplier had a long waiting time, then the next thing you know is that Will has taken delivery of some very nicely matched devices, where even the spares aren't too far apart. Why not contact Will and see if he will send you 2 each of the spares after everybody has received their initial order ? Kind Regards Alex
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Post by Deleted on Nov 4, 2012 10:56:24 GMT
Thanks Alex, Will was on my mind but I'm still casting around to see what is commonly available to use and not overly expensive. As you say variation in HFE might be the down side, but at under £2 each delivered next day might be worth a punt. Regards, Alan
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Will
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Post by Will on Nov 4, 2012 10:56:52 GMT
Alan, it shouldn't be a problem to get you a set, as long as someone wants to sell there their share of 'duffers' - at the moment minimum hfe is 95 - with maximum 110, so a small spread, with most under 100.
Anybody fancy passing theirs on to Alan?
To clarify, I tested hfe on my atlas dca55. All devices were laid out on a AS mat on my dining room table and tested within a 1/2 hour period, with out being directly touched (I clipped the leads to the device legs and tested).
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Post by Deleted on Nov 4, 2012 11:09:20 GMT
Hi Will, just PM'd you, I'd be pleased to take a set should any one be kind enough to let me in on the buy. I might be persuaded to cut some speaker protection boards should they be required. Regards, Alan
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Post by Will on Nov 4, 2012 11:44:07 GMT
Hi Alan, replied On a general note, can you guys who have built it suggest insulating pads for the out put devices? Also a schematic drawing on how to connect up the psu case to the power amp case (showing earthing arrangement) might be a good help as well.
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Post by Deleted on Nov 4, 2012 12:20:51 GMT
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jonclancy
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Post by jonclancy on Nov 4, 2012 17:45:29 GMT
Roger that on the eBay 3296W. You can sometimes pick up bargains which have been overlooked by others.
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Post by Deleted on Nov 4, 2012 20:16:43 GMT
Hi Will With the original design, and with mine, where a separate case is used for the PSU, IEC earth is only connected to the metalwork of the PSU case. The dual outputs are not earthed to amplifier chassis until they arrive from the rear sockets near the centre of both modules. A number of solder lugs are bolted to chassis at that point. You could also use a nylon mains terminal block near there to distribute + and - 20V to the various areas if desired instead of a couple of feeds from each PSU input socket. Regards Alex
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Post by Deleted on Nov 5, 2012 22:13:17 GMT
NOT quite complete but almost there, just to wind some formerless inductors, waiting for the AD744/ LS devices and Syd's great offer of his spare output trannys. Just noticed missed R32 on one board iron's hot so after this post it'll be in. Still got a lot to do on this build but the main boards are looking good also my own cut boards for the Preamp are ready and the speaker protection board is built. So might get there for elder son's Xmas. Thanks to Will doing his stuff once again Alan
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Post by Deleted on Nov 5, 2012 22:15:25 GMT
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Post by Deleted on Nov 5, 2012 22:18:33 GMT
Almost forgot here's the underside still to clean.
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Post by Deleted on Nov 6, 2012 9:43:25 GMT
Hi Alan great work with both sets of boards. take care
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Will
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Post by Will on Nov 6, 2012 9:58:20 GMT
Indeed, nice to see them built up, rather than in a pile on my desk!
Just a quick couple of points: the pins Cfb should be linked if using the offset corrector built in. Fit a cap here if not using the offset corrector. Also, the regs suggested for the offset corrector are the tp220 types, not the to92 type. Shouldn't be a problem, but the to92 were changed to the other types after reliability problems with the to92 types.
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Post by Deleted on Nov 6, 2012 12:50:59 GMT
Hi Shaun, nice to see you active here again I do enjoy following your many audio related exploits. Will's boards rather emphasised just how much solder I use on my own hand cut jobbies.
Hi Will, I had noted the chat about the regs and how some had problems with the to92 however both my AKHA/pre and AK 15 watt power amps have not given me any problems with to92 type and as I've stock left over from the first build it suited me to use them. Thanks also on the cfb pointer, yes I'd also noted that link was required but it's great that you have picked up on it, needless to say I will use the offset corrector. With regard to the boards they are very easy to populate I had no problems with solder flow and was quite amazed how little solder was required at each joint. When you posted your BOM I realised I'd a few resistors to change and found removal of the ones with altered values as per Alex's latest schematic not too difficult. With regard to the terminal blocks, although I intend to hard wire the power and audio inputs and outputs I have fitted them and added on the underside small eyelets soldered to the stubs of the terminal pins for that purpose. Regards, Alan
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Post by Deleted on Nov 6, 2012 17:43:40 GMT
Hi Alan ''nice to see you active here again I do enjoy following your many audio related exploits. Will's boards rather emphasised just how much solder I use on my own hand cut jobbies''. and nice to see you still producing such fine work so now let's hope for a really bad winter so i can get some peace just that Bl**dy green house to put up and job is jobbed outside wise this year. then come spring it all starts again with internal house stuff (planning permission pending) and a double car port. mmmmmmmmmm i just can't wait. nice work again Alan take care
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Post by Deleted on Nov 6, 2012 20:59:52 GMT
Hi Shaun, that's a big greenhouse you have in mind, I thought mine was big when I built it at 20 feet by 10 feet. Grew a load of stuff in it until I partitioned it into a ten by ten workshop and the other half MGLW took over for the wintering of the garden furniture now the only green thing about it is the paint on the exterior. Enjoy the fact that you can do what you do, and when you cant there's always the sit down weaving with the iron to keep you young at heart. Regards, Alan
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Post by Deleted on Nov 7, 2012 2:23:47 GMT
For Aussies. This month Altronics has the Loudspeaker Protection kit on special for $25. Also, if any Aussie constructors of this project require 2 x dual Greg Erskine newly designed JLH PCBs, please contact me. Alex
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Post by Deleted on Nov 7, 2012 10:36:47 GMT
Hi Shaun, that's a big greenhouse you have in mind, I thought mine was big when I built it at 20 feet by 10 feet. Grew a load of stuff in it until I partitioned it into a ten by ten workshop and the other half MGLW took over for the wintering of the garden furniture now the only green thing about it is the paint on the exterior. Enjoy the fact that you can do what you do, and when you cant there's always the sit down weaving with the iron to keep you young at heart. Regards, Alan Hi Alan yes it's big but we had a falling down wooden job there before so the choice was have a big patch of empty space or fill it with something useful. a truly great post on inductor winding by the way. just superb take care
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Will
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Post by Will on Nov 9, 2012 20:35:26 GMT
Hi Chaps,
Had an email today, the last parts (LS devices) have been posted, so should be here in the next couple of days.
If they are here tomorrow, I should be able to get everyone's parcels out. If not, it's going to be another week on, as I'm out the country with work for a week.
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Post by Deleted on Nov 11, 2012 12:12:24 GMT
Hi Chaps, Had an email today, the last parts (LS devices) have been posted, so should be here in the next couple of days. If they are here tomorrow, I should be able to get everyone's parcels out. If not, it's going to be another week on, as I'm out the country with work for a week. Hi Will That’s great news. I’m looking forward to others having the chance to listen to Alex’s super quality amp and those boards do look superb. Thanks Take care
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Will
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Post by Will on Nov 11, 2012 20:36:57 GMT
Hi Chaps, sorry no bits delivered yesterday, so it'll be a week or so now.
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Post by Deleted on Nov 11, 2012 21:33:25 GMT
No probs (for me anyway ) Will so don't let it spoil your trip. And thanks for keeping us in the picture. Dave.
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Post by Deleted on Nov 21, 2012 0:31:25 GMT
Well feel good tonight just got two more PSU JLH Combo boards to cut and stuff and this second build with Will's boards will be almost there. Hi Syd, Xmas was a little optimistic I think considering that November is almost gone, however here's a pic of the state of play tonight. I see Photobucket has upgraded their site, hope I got the url right for this pic. Bugger!! wish they'd leave things alone that didn't work back to PB for another go.
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Post by Deleted on Nov 21, 2012 0:35:34 GMT
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