I am not much on garage sales but the wife forced my hand and boy am I glad that I went. IIRC I got a nice HP scanner and the speakers for the $20. Rich kids selling Dad's hand me downs. Probably to pay their cell phone bills 
I asked the young lad why? he said they have new Infinities or something like that. I said no problem, I will gladly take your junk. Funny thing, was it was late in the day, so everybody had all day to look at them. It is like you said "Zero Knowledge" I wonder if people really know the value of these things esp when they are working fine and weigh a ton. I checked, the A/L 3's were worth ~$500 new in the 70's. Work all summer for $2.65 just to afford a pair
Adding the Morels MDT32s and new "L" pads to the model 3's brought the speakers back to something of good/fine quality. I still have yet to fiddle/change the xover, LPF(woofer) inductor to be a big air core, replacing the original small laminated core, add zobels, polyprop caps in the HPF, all parts from Madisound. Found the mice had made a nest one winter, damn port holes
How is Jennifer making out?
Everyone see Mark Johnson's RingNot power supply and of course the Quazimodo transformer snubber tester?
I asked the young lad why? he said they have new Infinities or something like that. I said no problem, I will gladly take your junk. Funny thing, was it was late in the day, so everybody had all day to look at them. It is like you said "Zero Knowledge" I wonder if people really know the value of these things esp when they are working fine and weigh a ton. I checked, the A/L 3's were worth ~$500 new in the 70's. Work all summer for $2.65 just to afford a pair
Adding the Morels MDT32s and new "L" pads to the model 3's brought the speakers back to something of good/fine quality. I still have yet to fiddle/change the xover, LPF(woofer) inductor to be a big air core, replacing the original small laminated core, add zobels, polyprop caps in the HPF, all parts from Madisound. Found the mice had made a nest one winter, damn port holes
How is Jennifer making out?
Everyone see Mark Johnson's RingNot power supply and of course the Quazimodo transformer snubber tester?
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Thinking about ordering the B2109 case from eBay for this amp.
Link: B2109 Full Aluminum Power Amplifier Enclosure PSU Chassis Silver Front Case | eBay
Have any of you used this case?
It seems like a good deal for $73 shipped. Nice looking heat sinks.
I measured my 300VA antek 25Vx2 torroidal transformer and it will fit fine with about 1/4 to 1/2" clearance on top and about 1/2" clearance on each side. I could place the shared PSU board behind it in the middle and the two amp boards on each side on the heat sinks.
EDIT: It would kinda match the style of the 2205 preamp case I am using now (it's about the same width at least and same colors):
http://www.ebay.com/itm/2205-Full-a...ohone-amplifier-chassis-220x52x-/272074480176
Link: B2109 Full Aluminum Power Amplifier Enclosure PSU Chassis Silver Front Case | eBay
Have any of you used this case?
It seems like a good deal for $73 shipped. Nice looking heat sinks.
I measured my 300VA antek 25Vx2 torroidal transformer and it will fit fine with about 1/4 to 1/2" clearance on top and about 1/2" clearance on each side. I could place the shared PSU board behind it in the middle and the two amp boards on each side on the heat sinks.
EDIT: It would kinda match the style of the 2205 preamp case I am using now (it's about the same width at least and same colors):
http://www.ebay.com/itm/2205-Full-a...ohone-amplifier-chassis-220x52x-/272074480176
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the height might be one or two millimetre smaller than stated.
This is quite small available floor area.
Try assembling your working project.
Then power OFF and fold all the components into a shape that will fit an enclosure. Measure those dimesnions and THEN buy an enclosure.
BTW, will you need to fit a soft start?
will you need to fit a speaker protection isolator?
Will you need any other ancilliaries that need some space?
I am not sure what a soft start is, or if I should put one in my amp. I don't plan on any speaker protection isolator (not sure what it does.. but my speakers can't be popped from the amp -- it isn't overly powerful).
I can't think of anything I need in the amp besides the transformer, ps board and the 2 tiny amp boards.
If I could put the transformer in a separate case and feed the -25V and +25V pairs to another chassis with the rectifier /ps & amp boards, that would be great.
Then I can use two small cases and the noise from the transformer would be enclosed in its own case.
But does this pose any problems running the +-25V AC a short distance (1 foot cable) to the adjacent chasis with the ps/amp boards?
Then I can use two small cases and the noise from the transformer would be enclosed in its own case.
But does this pose any problems running the +-25V AC a short distance (1 foot cable) to the adjacent chasis with the ps/amp boards?
Hi Jen
that's another nice case, too bad your transformer is a lil too big (again).
wont you still need to do some metal work for this?
no not really , best to include the big smoothing caps and rectifiers near the transformer. why? b/c the AC secondary is now composed of short bursts of very high current with some EMI/RFI (noise) due to snappiness (fastness) of the diodes charging the main caps. If the wires between the 2 boxes can be perfectly balanced pairs you'll get some cancellation with careful twisting and RC snubbers. edit> This is hard to do , even after the rectifiers. on some chip amp builds depending on grounding strategy, DC power needs 2 pairs per chip amp channel (umbilical = 4 pairs for stereo)
IMO 2 nice boxes with added umbilical cabling ( thick wire w/ new heavy duty DC connecters) will always be fugly & more expensive than doing it properly in one.
that's another nice case, too bad your transformer is a lil too big (again).
wont you still need to do some metal work for this?
no not really , best to include the big smoothing caps and rectifiers near the transformer. why? b/c the AC secondary is now composed of short bursts of very high current with some EMI/RFI (noise) due to snappiness (fastness) of the diodes charging the main caps. If the wires between the 2 boxes can be perfectly balanced pairs you'll get some cancellation with careful twisting and RC snubbers. edit> This is hard to do , even after the rectifiers. on some chip amp builds depending on grounding strategy, DC power needs 2 pairs per chip amp channel (umbilical = 4 pairs for stereo)
IMO 2 nice boxes with added umbilical cabling ( thick wire w/ new heavy duty DC connecters) will always be fugly & more expensive than doing it properly in one.
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saw this a couple of days ago http://www.diyaudio.com/forums/audi...kit-building-instructions-41.html#post4545835
seems easyish with buying Al extrusions and angle stock
once the metal yard cuts the extrusions they can cut the top/bottom panels exactly with same setup!
besides that a pretty lady in the metal yard outta get anything she wants.
seems easyish with buying Al extrusions and angle stock
once the metal yard cuts the extrusions they can cut the top/bottom panels exactly with same setup!
besides that a pretty lady in the metal yard outta get anything she wants.
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What do you guys think about this case?
Full Aluminum Enclosure Mini Amp Case Power Amplifier Box Chassis | eBay
It's 203mm wide inside, 300mm deep and like 4 inches tall. Seems plenty big enough and I can situate the shared heat sink under the back vent row inside.
It's only $70 including shipping. ANd it's the exact same width, faceplate and style as my preamp I just built.
Full Aluminum Enclosure Mini Amp Case Power Amplifier Box Chassis | eBay
It's 203mm wide inside, 300mm deep and like 4 inches tall. Seems plenty big enough and I can situate the shared heat sink under the back vent row inside.
It's only $70 including shipping. ANd it's the exact same width, faceplate and style as my preamp I just built.
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Do I see a DIY DAC there too ?
This can be an addictive hobby
Next up, some DIY speakers!
Question about Dissipante 3U
I am needing to get a chassis for my chip amp. The Dissipante 2U or 3U both look good for my needs--I see them for sell here at the store.
My only question is about the "base plate".. They ask if I want a baseplate.. and I am not sure what they mean. Yes I need a bottom to the amp to screw the transformer and boards to.
I am needing to get a chassis for my chip amp. The Dissipante 2U or 3U both look good for my needs--I see them for sell here at the store.
My only question is about the "base plate".. They ask if I want a baseplate.. and I am not sure what they mean. Yes I need a bottom to the amp to screw the transformer and boards to.
Jennifer:
You don't really need the external heat sinks on the Dissipante; I've built several LM3875 chip amps in Galaxy enclosures, drilled my holes through the bottom panel (and not an internal panel) and mounted the heat sinks inside the chassis. Depending on the particular chip you choose, you might consider chassis alternatives.
Regards,
Scott
You don't really need the external heat sinks on the Dissipante; I've built several LM3875 chip amps in Galaxy enclosures, drilled my holes through the bottom panel (and not an internal panel) and mounted the heat sinks inside the chassis. Depending on the particular chip you choose, you might consider chassis alternatives.
Regards,
Scott
I'd love a link to the enclsoure you chose. Mine is stereo with a huge antek 300va transformer. I have lm3886
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