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Post by Deleted on Apr 11, 2012 0:03:32 GMT
Hi Alan
Are both channels running at around 1A bias ?
i.e. around 240-250mV when warmed up, across the 4 x parallel 1 ohm resistors ?
Kind Regards
Alex
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Post by Deleted on Apr 11, 2012 8:56:32 GMT
Hi Alan could be a good idea to check the temperature of the O/P devices just to be on the safe side. if they are running @ somewhere near the same temp as the heatsinks then you are getting good heat transference.  i have big U3 beast heatsinks on my O/P devices and while they are not roasting they do get warm. likewise the Regs which are on U2 heatsinks and run warm also.  yours are probably fine but just an observation take care |
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Post by Deleted on Apr 11, 2012 9:08:54 GMT
Hi Alex,
yes I have the bias set at around 1A on both channels that's 248mv across the 4 X 1 ohms
room temp is 23c and heat sink at junction with OP is 30c
just wish my son would come across with the aluminium for the case. However I've started on my Mark II which is for my elder son, perhaps he'll get the Mark I.
Regards,
Alan
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Post by Deleted on Apr 11, 2012 10:22:26 GMT
Hi Shaun,
temp at top of OP device 31.75c temp on heat sink is same.
Regs are warmer a nice touchable temp.
Regards,
Alan
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Post by Deleted on Apr 11, 2012 11:49:02 GMT
Hi Shaun, temp at top of OP devise 31.75c temp on heat sink is same. Regs are warmer a nice touchable temp. Regards, Alan Hi Alan looking good  take care |
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Post by jeffc on Apr 12, 2012 20:36:11 GMT
DIY 15W AK SC-Class A amplifier No. 2 Lovely work Alan! I must keep chipping away at my cases and sourcing parts.  cheers.. jeffc |
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Post by XTRProf on Apr 13, 2012 5:01:50 GMT
I may look stupid without looking thru all the posts. So I declare I wanted about 10 pcs of the PS PCBs if I'm not too late and it's still being MO. Any picture of the layout? Thanks.  |
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Post by Deleted on Apr 13, 2012 5:20:30 GMT
I may look stupid without looking thru all the posts. So I declare I wanted about 10 pcs of the PS PCBs if I'm not too late and it's still being MO. Any picture of the layout? Thanks. Chong I am not sure if this is Will's final version. Alex Attachments:
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Post by XTRProf on Apr 13, 2012 5:36:26 GMT
I may look stupid without looking thru all the posts. So I declare I wanted about 10 pcs of the PS PCBs if I'm not too late and it's still being MO. Any picture of the layout? Thanks. Chong I am not sure if this is Will's final version. Alex Looking good as can do +/- or just + or - rails depending on how we connect up. Btw, how much is one? Dimension? |
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Post by Deleted on Apr 13, 2012 5:41:42 GMT
Chong I am not sure if this is Will's final version. Alex Looking good as can do +/- or just + or - rails depending on how we connect up. Btw, how much is one? Chong I can't answer that as it will depend very much on the numbers ordered. Will may be able to answer that, but he presently doesn't have much time available for these things due to his new job. Alex |
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Post by Deleted on Apr 13, 2012 7:46:11 GMT
hi Chong
i've added your name and requirements to the list
take care
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XTRProf
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Post by XTRProf on Apr 13, 2012 14:09:03 GMT
hi Chong i've added your name and requirements to the list take care You are the fastest "secretary" I have come across. You KISS me. Eh, I'm not a gay, So take note, it's KISS and not kiss. Btw, the LS352 and LS313 are the same as the matched ones as used in the Alex SC Class A HA? If is, I will also want MATCHED 2X LS352 and 2X LS313 to stock up as well. Please confirmed before I put myself in the list for that as well. Thanks. |
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Post by Deleted on Apr 13, 2012 15:42:49 GMT
Hi Chong yup those LS devices are the same as the HA/PRE so I've amended the list above. take care |
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Post by XTRProf on Apr 14, 2012 7:41:29 GMT
Hi Chong yup those LS devices are the same as the HA/PRE so I've amended the list above. take care Excellent! |
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Post by XTRProf on Apr 15, 2012 13:48:53 GMT
Hi Will, If the PS PCB can be designed as a mirror image of each + and + ve rails will be better. Just my wish list. Maybe you already have it designed that way for the final release. Thanks. |
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Will
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Post by Will on Apr 25, 2012 18:33:00 GMT
Hi Chong,
The PSU is done, and is pretty much as posted by Alex, except a terminal block is positioned next to the AC input for a remote LED out.
Time is very limited for me at the moment, so all my audio diy energies will be directed into getting the amp pcb done for those that want to build it.
Bear with me, guys, I'm on the case!
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Post by jeffc on Apr 26, 2012 9:12:52 GMT
Howdy Will, Glad to see you still have your head above water, hang in there.  And seeing you've found a sec to think about these PCB designs again , a reminder for a suggestion made on PSU PCBs several pages back. Can you consider an extra small mod in the way of a couple of extra holes and pads on the trace linking D3-D4, and extending traces a little for similar with D1 and D2. Although I'll most likely try some TO220 types, it might be convenient for those considering axial-leaded diodes. No big deal though, just something that might prove handy. cheers.. jeffc |
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Post by Will on Apr 26, 2012 20:14:11 GMT
Hi Jeff, I think I did have a look at doing that change, back before service was interrupted, but the diodes were very difficult to accommodate without a full re-jig of the pcb. I'm currently eagle-less  so I can't look at the files I've got. |
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Post by Will on Apr 27, 2012 20:42:41 GMT
 Evening. This is the final (barring any cock-up corrections) for the PSU pcb. Dimensions are 80mmx70mm, and the main difference between this and the previous version is that a connector has been added for a remote led, plus wire pads if you don't want to use the terminal connector. |
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Post by Deleted on Apr 27, 2012 22:10:27 GMT
Hi Will nice work on the PSU PCB. should work pretty well take care |
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Post by jeffc on Apr 28, 2012 1:34:38 GMT
Hi Will, With Shaun, looking great and thanks for the board size info again, handy to know. The bodge-up additions to your PCB layout done in Powerpoint below are what was trying to express "poorly" in words, but as stressed before, just something possibly handy for some, if pad distances suit axial diode case sizes OK. If not, then not that useful and disregard because I'm a nitwit.  cheers.. jeffc |
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Post by Deleted on Apr 28, 2012 2:07:05 GMT
Hi Jeff
It will be quite easy to mount the diodes vertically. The longer (thick) lead on one side will even result in a small amount of additional heat dissipation.
Regards
Alex
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Post by jeffc on Apr 28, 2012 6:43:32 GMT
Hi Alex, Yer I know that, but after fiddling with vertical resistor mounting in those RG-JLH PCBs I've decided I'm not a fan of vertical mounting , plus all those "very exposed" leads at the tops of the diodes could be quite dangerous if not shethed with something. As mentioned, I have 8 x MUR1520 TO220 diodes I'll try anyway so I'm as contented as anything with the layout as is, just thought this might be an easy and useful addition. If it isn't, shout out and I'll pull my head in, I'm just glad to have been allowed on the bus.  cheers.. jeffc |
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Post by Will on Apr 28, 2012 8:24:12 GMT
Hi Jeff,
I did have a look at putting in holes for the diodes you mention, but when sized to fit the diode properly, it extends off the sides of the pcb as it stands. I was going to suggest vertical diode mounting as well, but forgot.
I'm with you on the vertical mounting (especially after the JLH) it's fiddly and in my opinion does not look as neat. Still, I think that for those who wish to use axial diodes, it's the way to go.
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Post by jeffc on Apr 28, 2012 21:08:24 GMT
Hi Will, OK, suspected axial diode case size might be an issue with space available, thanks for confirming, and sorry for the distraction, I was just worried the description of what I was thinking wasn't very clear, hence the bodged-up pic. BTW, the small PSU PCB size means it will just clear the chunk of aluminium I cut for mounting transformers, so lucky guess and no recutting required . cheers.. jeffc |
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so I can't look at the files I've got.