Here's the BOM. I think it's complete (went over it again this morning and made a few fixes).
Raw price per kit is $56.25.
This does not include:
- shipping charges from the vendor to me,
- the price of bags and boxes for packing the orders,
- the shipping out to you.
- PayPal fee (2.9% + $0.30) per order
This is a little lower than before, and the kit price will be ammended. I have been trying to think of how to accurately get a shipping price from the vendor before actually ordering. I think I will simply estimate $7.50 per vendor.
So 7.50 * 2 = 15/15 = $1 per order.
Currently we are at $56.25 + $1 = $57.25 per kit + paypal + shipping
Raw price per kit is $56.25.
This does not include:
- shipping charges from the vendor to me,
- the price of bags and boxes for packing the orders,
- the shipping out to you.
- PayPal fee (2.9% + $0.30) per order
This is a little lower than before, and the kit price will be ammended. I have been trying to think of how to accurately get a shipping price from the vendor before actually ordering. I think I will simply estimate $7.50 per vendor.
So 7.50 * 2 = 15/15 = $1 per order.
Currently we are at $56.25 + $1 = $57.25 per kit + paypal + shipping
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You are correct Russ.
THere are differences in the curves to suggest that the full pack version does warm up faster and cool off slower even with an almost the same thermal transfer number. The note to read is the derating factor if I remember right.
THere is only going to be some difficulty if the heatsink is on the small side and the amp is driven hard with a power supply voltage nering the max. Keep to around 30 volts after rectification or after the regulator and you will be just fine.
MArk
You are correct Russ.
THere are differences in the curves to suggest that the full pack version does warm up faster and cool off slower even with an almost the same thermal transfer number. The note to read is the derating factor if I remember right.
THere is only going to be some difficulty if the heatsink is on the small side and the amp is driven hard with a power supply voltage nering the max. Keep to around 30 volts after rectification or after the regulator and you will be just fine.
MArk
I think the schematic for this version of the amp specified 24VAC, which results in 33.6VDC for the rails.
Speaking of heatsinks, would anyone be interested in including them in the kit? Here's what I was thinking:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=31489&item=7527192673&rd=1&ssPageName=WDVW
Have him cut 3" pieces. One piece for each amp (3 x 5 3/8 inches). 3" would be $4.38 each, plus shipping charges out course. Could go to 4" for $5.84 each.
Speaking of heatsinks, would anyone be interested in including them in the kit? Here's what I was thinking:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=31489&item=7527192673&rd=1&ssPageName=WDVW
Have him cut 3" pieces. One piece for each amp (3 x 5 3/8 inches). 3" would be $4.38 each, plus shipping charges out course. Could go to 4" for $5.84 each.
BrianDonegan said:I think the schematic for this version of the amp specified 24VAC, which results in 33.6VDC for the rails.
Speaking of heatsinks, would anyone be interested in including them in the kit? Here's what I was thinking:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=31489&item=7527192673&rd=1&ssPageName=WDVW
Have him cut 3" pieces. One piece for each amp (3 x 5 3/8 inches). 3" would be $4.38 each, plus shipping charges out course. Could go to 4" for $5.84 each.
That sound like a great idea! If 4" can dissipate enough heat I would be in for that.
Any informations:
I have found any numerations not correct on the BOM and have corrected it ( only the serigraphy references, the quantities are correct ).I attach the corrected version to verify. I Creed that you did a good work, Brian.
LM3886 T now TF: The T version ( not iso ) has theoretically a better ability of dissipate of the heat ( internal ) toward the heatsink. In my LM3886 circuit it has to dissipate " theoretically " a lot of energy if the load is 4 ohms. This calculations however I am in " sinusoidal continues power" that doesn't exist in the ordinary music. I have done my test with the "T" type (not iso), but I believe that for an "moderate" use goes well the TF type ( iso ) for the reasons lists from Russ...
Heatsink: I Suggestion to use a type with 1-1.2 °C/W of Thermal Resistance, with vertical development ( like NS- AN1192 by BR100 mod. )
Ciao
Mauro
I have found any numerations not correct on the BOM and have corrected it ( only the serigraphy references, the quantities are correct ).I attach the corrected version to verify. I Creed that you did a good work, Brian.
LM3886 T now TF: The T version ( not iso ) has theoretically a better ability of dissipate of the heat ( internal ) toward the heatsink. In my LM3886 circuit it has to dissipate " theoretically " a lot of energy if the load is 4 ohms. This calculations however I am in " sinusoidal continues power" that doesn't exist in the ordinary music. I have done my test with the "T" type (not iso), but I believe that for an "moderate" use goes well the TF type ( iso ) for the reasons lists from Russ...
Heatsink: I Suggestion to use a type with 1-1.2 °C/W of Thermal Resistance, with vertical development ( like NS- AN1192 by BR100 mod. )
Ciao
Mauro
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