m0tion said:
lol that looks so much like my setup.. .or did.. look on page 22 to see mine.
I agree with just that CPU heatsink, i think the chip gets a bit to hot. Yo u can try going with just a block of Aluminum.
llmobll,
Go to settings and change it so you can see 50 replies per page, for me this only page 5, its a lot easier to read.
m0tion,
those are long secondaries and thick input wires. When is the final chassis coming? By the way, how to you like that soldering iron? Is that the $50 Weller for "hobbiests"? And it looks like you've got a few kits, nice.
Josh
Go to settings and change it so you can see 50 replies per page, for me this only page 5, its a lot easier to read.
m0tion,
those are long secondaries and thick input wires. When is the final chassis coming? By the way, how to you like that soldering iron? Is that the $50 Weller for "hobbiests"? And it looks like you've got a few kits, nice.
Josh
Josh,
This is just a test setup so the toroid wires were left as is. Chassis is the next step, I'm making it out of some hard wood (I'm thinking Walnut). I'm making two 3-channel amps. I'll use 1 for each of the 3-way active speakers I'm working on. Yes it is the $50 one, I got it as a gift from my girlfriend, one of the best presents I've ever gotten.
This is just a test setup so the toroid wires were left as is. Chassis is the next step, I'm making it out of some hard wood (I'm thinking Walnut). I'm making two 3-channel amps. I'll use 1 for each of the 3-way active speakers I'm working on. Yes it is the $50 one, I got it as a gift from my girlfriend, one of the best presents I've ever gotten.
whoa.. kits are great!
the previous amps i'v used a minimum of 10hours total on, this one wnet in a flash, 40min of soldering! 😀
lets hope it sounds decent too, although, not too good, wouldn't want it to beat my buffed lm3886 amp.. 😱
the previous amps i'v used a minimum of 10hours total on, this one wnet in a flash, 40min of soldering! 😀
lets hope it sounds decent too, although, not too good, wouldn't want it to beat my buffed lm3886 amp.. 😱
Is 15000 uF too big?
I purchased an LM3886 stereo board. The board is indeed very nice. I think that the board would be a bit more flexible if the resistors were sized to fit regular size resistors. This would allow one to use regular size resitors that they have available or possible even premium carbon comp resistors.
Anyway, to my question. I have a pair of Paccom ES Series general purpose 85 degree capacitors which are 15000 uF, 63V. A little to my suprise, they just fit on the power supply board.
So, are these capacitors suitable or is the capacitance too high? Also, is the quality of these capacitors resonable in comparison to the reccomended capacitors?
Cheers,
Gio.
I purchased an LM3886 stereo board. The board is indeed very nice. I think that the board would be a bit more flexible if the resistors were sized to fit regular size resistors. This would allow one to use regular size resitors that they have available or possible even premium carbon comp resistors.
Anyway, to my question. I have a pair of Paccom ES Series general purpose 85 degree capacitors which are 15000 uF, 63V. A little to my suprise, they just fit on the power supply board.
So, are these capacitors suitable or is the capacitance too high? Also, is the quality of these capacitors resonable in comparison to the reccomended capacitors?
Cheers,
Gio.
Re: Is 15000 uF too big?
Gio,
Most resistors should fit if you install them vertically.
As for the caps, they should work fine. The larger value should make too much of a difference. The footprint used should fit all snap-in capacitors, which have 10mm spacing and a diameter <= 35mm.
Best of luck with your project,
--
Brian
GG said:
Gio,
Most resistors should fit if you install them vertically.
As for the caps, they should work fine. The larger value should make too much of a difference. The footprint used should fit all snap-in capacitors, which have 10mm spacing and a diameter <= 35mm.
Best of luck with your project,
--
Brian
Ok i am building my LM 3886 amp kits now.
Need help, what is the difference if i do not instal the DC blocking cap. Is this setup unwise (ie dangerous to the amp). What happens if the amp see a high DC offset. Blue smoke?
I ask since i am doing my utmost with the kit to get high quailty from it, spent a fair amount on sockets, cases, transformers etc. So i would prefer not to have a cap in the input path however the amp will be used in my sitting room. This mean not only will they be used for CD and Phono stuff but they will also end up plugin into the xbox, digital TV settop box etc. Doesn this make a difference. I was hoping to go with a passive preamp at a later late for teh moment i will be splitting my NAD C350 and using the Pre in that.
Any comments gratefully received.
Phil
Need help, what is the difference if i do not instal the DC blocking cap. Is this setup unwise (ie dangerous to the amp). What happens if the amp see a high DC offset. Blue smoke?
I ask since i am doing my utmost with the kit to get high quailty from it, spent a fair amount on sockets, cases, transformers etc. So i would prefer not to have a cap in the input path however the amp will be used in my sitting room. This mean not only will they be used for CD and Phono stuff but they will also end up plugin into the xbox, digital TV settop box etc. Doesn this make a difference. I was hoping to go with a passive preamp at a later late for teh moment i will be splitting my NAD C350 and using the Pre in that.
Any comments gratefully received.
Phil
Don't use input cap unless you need, thats the rule i usually follow. Since you are using an active pre to feed your amp, you should be good without a cap. BUT, to be sure, measure DC offset of your pre, anything higher than 200mV needs attention. Also, be sure to measure DC offset before using any new source, and also with every new source you will be using connected to your pre (xbox, tv, etc).
if you are lazy, then put the cap, sounds like this amp will be used in many different applications and not testing everytime can lead to
as for consequences, your amp will be fine, its your speakers that will let their blue smoke out.
if you are lazy, then put the cap, sounds like this amp will be used in many different applications and not testing everytime can lead to
as for consequences, your amp will be fine, its your speakers that will let their blue smoke out.
OK but what does this mean when i build the remote control passive pre amp.
By the way just measure my sources and i couldnt detect any DC off set at all. Would i be in better shape for a passive preamp with dc blocking. Sounds like it might be more advisable.
By the way just measure my sources and i couldnt detect any DC off set at all. Would i be in better shape for a passive preamp with dc blocking. Sounds like it might be more advisable.
A new pre means more testing for dc offset. i didnt see the squematic for your remote pre, so i don't know if it has caps.
it boils down to this, caps are the safest bet. do it if you dont want any bad suprises. if you want to take a risk in the name of sound quailty, drop the cap. enough said.
it boils down to this, caps are the safest bet. do it if you dont want any bad suprises. if you want to take a risk in the name of sound quailty, drop the cap. enough said.
Ok so i finished my amps last night. havent sorted out all connections as yet . Have to say that not having a manual of any osrt has cuased a few issues.
I have for example Installed the Rz and Cz as per the Photos in the Gallery. I was only when looking at them this afternoon that i realised that these are for the Zobel network, which i was really that keen on implementing. I Guess the Z should have given it away but anyway.
Briian the kits are superbly made and even without hearing and confident i will be happy with the end result. However a manual even a veyr basic one is needed soon.
A total noobe to audio building like me can get very confused even reading this wonderful forum daily, no make that hourly.
I think the main thing that you need to point out is what the input capacitor does and why you may or may not need it and also point out that the Rz and Cz parta are optional. I probably dont have much of an option now since they are in and would be a right pain in the **** to remove nad then try and reinstal if needed.
I dont mean to grumble but even having read the forums like crazy, and using the manual for the LM3875 kit, i still came up with these two issues
Anyway grumble over.
On with the build
I have for example Installed the Rz and Cz as per the Photos in the Gallery. I was only when looking at them this afternoon that i realised that these are for the Zobel network, which i was really that keen on implementing. I Guess the Z should have given it away but anyway.
Briian the kits are superbly made and even without hearing and confident i will be happy with the end result. However a manual even a veyr basic one is needed soon.
A total noobe to audio building like me can get very confused even reading this wonderful forum daily, no make that hourly.
I think the main thing that you need to point out is what the input capacitor does and why you may or may not need it and also point out that the Rz and Cz parta are optional. I probably dont have much of an option now since they are in and would be a right pain in the **** to remove nad then try and reinstal if needed.
I dont mean to grumble but even having read the forums like crazy, and using the manual for the LM3875 kit, i still came up with these two issues
Anyway grumble over.
On with the build
filholder said:
If you had properly read the LM3875 user guide, the issue about whether to install zobel or not is CLEARLY discussed.
Also, if you had read this very thread, discussion about the input cap has also been covered.
And manuals are on the way.
Look i really dont want to get into an argument abot this at all.
I love the kits, superb fun and really enjoyable.
All I meant to say is things will go a fair bit smoother for people new to this when the manual arrive.
As for not read the LM3875 manual i had read it cover to cover maybe 4 times before doing my kit.
Its just when your new to this type of thing reading about implementing a zobel network and then soldering a series of resisitors and caps to the board, some of which are labeled Rz and Cz you dont always make the connection.
Anway homer09 thanks for your swift reply to my question last night much apprecianted.
I love the kits, superb fun and really enjoyable.
All I meant to say is things will go a fair bit smoother for people new to this when the manual arrive.
As for not read the LM3875 manual i had read it cover to cover maybe 4 times before doing my kit.
Its just when your new to this type of thing reading about implementing a zobel network and then soldering a series of resisitors and caps to the board, some of which are labeled Rz and Cz you dont always make the connection.
Anway homer09 thanks for your swift reply to my question last night much apprecianted.
homer09 said:
How exactly does one measure DC offset? Is measuring the output with a voltmeter sufficient?
Gio.
Your welcome filholder. All is good if you are satisfied with the kits, i think im yet to see someone show insatisfaction with them 
be sure to post some pics when you finish your amp 😎
be sure to post some pics when you finish your amp 😎
filholder,
I was noob a few months ago (I'm only 17), well I still am, but its amazing how much information you can learn in a single day just keep reading. Also you can desolder with your regular solding iron and a desoldering braid or buy a cheap desolding iron such as this. Obviously you don't live in America, but I'm guessing there are some cheap electronics stores to try. I ran into a problem when I was building these and I had to desolder a resistor also.
Brian and I are going to work on a guide soon, we will be sure to discuss such matters.
GG, how to measure dc offset.
Using your voltmeter or multimeter turn your dial to DC, then mili or 200m (what it says on mine). Connect the positive lead of the DMM to the positive output and the other to either the negative output or any ground on your chassis or you chassis if it is properly grounded.
Hopefully the guides will be out next week.
Thanks and please post pics,reviews, and questions/concerns when done
Josh
I was noob a few months ago (I'm only 17), well I still am, but its amazing how much information you can learn in a single day just keep reading. Also you can desolder with your regular solding iron and a desoldering braid or buy a cheap desolding iron such as this. Obviously you don't live in America, but I'm guessing there are some cheap electronics stores to try. I ran into a problem when I was building these and I had to desolder a resistor also.
Brian and I are going to work on a guide soon, we will be sure to discuss such matters.
GG, how to measure dc offset.
Using your voltmeter or multimeter turn your dial to DC, then mili or 200m (what it says on mine). Connect the positive lead of the DMM to the positive output and the other to either the negative output or any ground on your chassis or you chassis if it is properly grounded.
Hopefully the guides will be out next week.
Thanks and please post pics,reviews, and questions/concerns when done
Josh
My soldering and desoldering skills are pretty good to be honest. I have done a lot of work on motherboards etc. replacing duff caps. And have chipped a few xbox's which need a level of soldering skill far more acurate than the chipamp kits.
The thing is though once you have soldered a resistor and cap in place and trimmed the leads it is pretty difficult to put then back in isnt it.
Anyway looks like Brian used both the Zobel and Input cap is his build so if it good enough for him it good enough for me. Anyway i have been thinking that if when I get the thing up and running aint 100% i can always go buy some blackgates to replace the exhisting input caps. I guess that would have an effect.
Got to say i am having so many issues sticking this kit in
http://www.platenspeler.com/diy/amps/uk_clonekit_1.html
those cases. The PSU board is just huge compare to the LM3875 kits. Which is good!!!
If anyone is think of this combination of the Lm3886 kit and those beautiful Conrad enclosure forget it. I am sure i will get there but it is Very cramped. Might end up building something else to stick the amp boards on and using the Conrad enclosures for my preamp.
The thing is though once you have soldered a resistor and cap in place and trimmed the leads it is pretty difficult to put then back in isnt it.
Anyway looks like Brian used both the Zobel and Input cap is his build so if it good enough for him it good enough for me. Anyway i have been thinking that if when I get the thing up and running aint 100% i can always go buy some blackgates to replace the exhisting input caps. I guess that would have an effect.
Got to say i am having so many issues sticking this kit in
http://www.platenspeler.com/diy/amps/uk_clonekit_1.html
those cases. The PSU board is just huge compare to the LM3875 kits. Which is good!!!
If anyone is think of this combination of the Lm3886 kit and those beautiful Conrad enclosure forget it. I am sure i will get there but it is Very cramped. Might end up building something else to stick the amp boards on and using the Conrad enclosures for my preamp.
filholder,
For those cases I'm guessing it would be best to impliment the kit if the AC input and the toroid were on one side and the chip and input and outut are on the other side. Never dealt with that chassis before, but just a suggestion.
The guide has been started by the way.
Thanks,
Josh
For those cases I'm guessing it would be best to impliment the kit if the AC input and the toroid were on one side and the chip and input and outut are on the other side. Never dealt with that chassis before, but just a suggestion.
The guide has been started by the way.
Thanks,
Josh
I have now posted a users guide for the LM3886 kit on my website:
http://www.chipamp.com/docs/lm3886.pdf
Sorry for the delay in getting this manual out.
If you have any farther questions, drop me an e-mail, and answer them for you, and work more material into the manual.
Thanks to Josh providing me some motivation to finish this manual.
--
Brian
http://www.chipamp.com/docs/lm3886.pdf
Sorry for the delay in getting this manual out.
If you have any farther questions, drop me an e-mail, and answer them for you, and work more material into the manual.
Thanks to Josh providing me some motivation to finish this manual.
--
Brian
