I'm known to some here for building Seventh Veil loudspeakers.
I'm now building an active mini monitor using Bandor drivers and need some advice on amplification. Per side, I'm using two Bandor 50mms for everything from 200Hz upwards and one Bandor 100m for below 200Hz. The drivers are very fast and transparent. What are the best chip amps I could use with an output of 20W to 30W into 8 ohms? I generally like a good valve amp but that wouldn't be appropriate for this application. I'm new to this area so would look at either a kit or a circuit board. Any advice would be appreciated.
Thanks in advance
Steve
PS: I know that there are plenty of relevant threads here but don't really know where to start in looking for the up to date information I need.
I'm now building an active mini monitor using Bandor drivers and need some advice on amplification. Per side, I'm using two Bandor 50mms for everything from 200Hz upwards and one Bandor 100m for below 200Hz. The drivers are very fast and transparent. What are the best chip amps I could use with an output of 20W to 30W into 8 ohms? I generally like a good valve amp but that wouldn't be appropriate for this application. I'm new to this area so would look at either a kit or a circuit board. Any advice would be appreciated.
Thanks in advance
Steve
PS: I know that there are plenty of relevant threads here but don't really know where to start in looking for the up to date information I need.
Steve,
This is another Steven and I am also new to this site and these Forums. The problem I am also having is that using the search bar here even if I get very specific in what I am looking for I get a whole rash of things that don't appear to be relevant. Can someone tell us Steve's how we can better search this site without having to read every thread to find information?
Thank,
Steven
This is another Steven and I am also new to this site and these Forums. The problem I am also having is that using the search bar here even if I get very specific in what I am looking for I get a whole rash of things that don't appear to be relevant. Can someone tell us Steve's how we can better search this site without having to read every thread to find information?
Thank,
Steven
I use the dropdown on the search to choose advanced search. This gives you a lot more options. The most valuable one I find is changing the search results to posts rather than threads.
Another thing you can try is going to google and then putting in your search term followed by site:diyaudio.com This will use googles powerful search engine but only return results from diyaudio.com
Tony.
Another thing you can try is going to google and then putting in your search term followed by site:diyaudio.com This will use googles powerful search engine but only return results from diyaudio.com
Tony.
No probs
Steve welcome back! I note your site is no longer around. I really liked the analogy (if I remember correctly) of the dance of the 7 veils with each one reveailing something more when removed. With the reference to the speakers that all 7 veils had been removed leaving only the naked truth with the sound
With respect to the amps, I've only got experience with the LM3886. I find it ok, but I've recently switched back to my 100W mosfet amp. My speakers are not that efficient and I suspect I was clipping the chipamp on transients (also if I were to do it again I would lower the gain somewhat, not easy now as I did it as a very compact p2p).
Hopefully some others can offer suggestions on other chips, but an LM3886 would do a good job for up to 50W into 8 ohms. There may of course now be better alternatives, it's around six years since I built mine!!
Tony.
Steve welcome back! I note your site is no longer around. I really liked the analogy (if I remember correctly) of the dance of the 7 veils with each one reveailing something more when removed. With the reference to the speakers that all 7 veils had been removed leaving only the naked truth with the sound
With respect to the amps, I've only got experience with the LM3886. I find it ok, but I've recently switched back to my 100W mosfet amp. My speakers are not that efficient and I suspect I was clipping the chipamp on transients (also if I were to do it again I would lower the gain somewhat, not easy now as I did it as a very compact p2p).
Hopefully some others can offer suggestions on other chips, but an LM3886 would do a good job for up to 50W into 8 ohms. There may of course now be better alternatives, it's around six years since I built mine!!
Tony.
Thanks Tony,
I am looking at doing a bridged / Parallel design with 4 of the 3886 chips on the bass channel and a single unit on the high pass circuit for the tweeter alone. That should give me enough power for the tweeter no problem with either 4 or 8 ohm load. The mid/bass is a long throw speaker of my own design and the first version was about 86db per watt. I am working on raising the efficiency by changing the motor to increase the magnetic energy in the gap and decreasing the mass of the cone that I make. It is a new composite material that I have developed. Nobody has anything like it, I do nor use a traditional matrix material. I think that the National or now TI chips look good for a self powered speaker and I am just trying to determine the best opamps to use in the active crossover which will be a 4th order Linkwitz Riley design. I see the the 5532 chips are cheap but not well liked. I am leaning towards the LM4562 but still not sure if that is the best idea. Most of the information that I have found on these chips for crossover is at least a few years old and I am not up on the latest in these parts.
Steven
I am looking at doing a bridged / Parallel design with 4 of the 3886 chips on the bass channel and a single unit on the high pass circuit for the tweeter alone. That should give me enough power for the tweeter no problem with either 4 or 8 ohm load. The mid/bass is a long throw speaker of my own design and the first version was about 86db per watt. I am working on raising the efficiency by changing the motor to increase the magnetic energy in the gap and decreasing the mass of the cone that I make. It is a new composite material that I have developed. Nobody has anything like it, I do nor use a traditional matrix material. I think that the National or now TI chips look good for a self powered speaker and I am just trying to determine the best opamps to use in the active crossover which will be a 4th order Linkwitz Riley design. I see the the 5532 chips are cheap but not well liked. I am leaning towards the LM4562 but still not sure if that is the best idea. Most of the information that I have found on these chips for crossover is at least a few years old and I am not up on the latest in these parts.
Steven
Moondog,
I guess I wasn't very clear here. I am planning on an active cross-over and then the gain clone amp and all inside the enclosure. I haven't seen much that can compete with the National Semi chip before going for a class D circuit which I don't want to do. I just am questioning the best chips to implement the xo. Some like to use the 5532 chip for price reasons and others just hate that chip, but others also don't seem to think much of the LM4562 I see some other low noise chips but some of the prices are just plain crazy. I don't mind the price of the 4562 but if something is in the same range and is better why not use it...
Steven
I guess I wasn't very clear here. I am planning on an active cross-over and then the gain clone amp and all inside the enclosure. I haven't seen much that can compete with the National Semi chip before going for a class D circuit which I don't want to do. I just am questioning the best chips to implement the xo. Some like to use the 5532 chip for price reasons and others just hate that chip, but others also don't seem to think much of the LM4562 I see some other low noise chips but some of the prices are just plain crazy. I don't mind the price of the 4562 but if something is in the same range and is better why not use it...
Steven
You may find the NatSemi application note 1192 worth a look or two, if you haven't done so already.
Somebody likes them; they're quite popular. The data may be a few years old (or more), but it's still valid. IMO a very good active xover could be built from either of those op amps you mention.
OPA2134's for the filter circuit would probably be a good choice. They are low noise, low distortion, fet input, have enough bandwidth (without being finicky about the circuit). Generally a good allround chip I's say http://www.partsconnexion.com/prod_pdf/opamp_64156.pdf
Tony.
http://www.partsconnexion.com/prod_pdf/opamp_64156.pdfTony.
Sofaspud,
I have looked at the National Semi information and actually have it sitting next to me printed out. I see that some people seem to use the circuit as drawn and others do not seem to want to use the servo portion of the design. I don't want to hand trim every amplifier that I would produce and so it seems like the servo is probably the easier if not more expensive method.
WinterMute,
I took a quick look at the OPA chip and didn't realize that it was a Burr-Brown design. I'll have to take a closer look at in and see the differences between it and the National chip. I know that spec sheets don't tell the whole story so I will keep that in mind. I actually had a friend who worked with Burr-Brown when they started many years ago and he gave me the very first solid state variable tone generator that they ever built. I have it in storage, don't know if the electrolytic caps are still any good though.
Steven
I have looked at the National Semi information and actually have it sitting next to me printed out. I see that some people seem to use the circuit as drawn and others do not seem to want to use the servo portion of the design. I don't want to hand trim every amplifier that I would produce and so it seems like the servo is probably the easier if not more expensive method.
WinterMute,
I took a quick look at the OPA chip and didn't realize that it was a Burr-Brown design. I'll have to take a closer look at in and see the differences between it and the National chip. I know that spec sheets don't tell the whole story so I will keep that in mind. I actually had a friend who worked with Burr-Brown when they started many years ago and he gave me the very first solid state variable tone generator that they ever built. I have it in storage, don't know if the electrolytic caps are still any good though.
Steven
Thanks Tony. Seventh Veil Loudspeakers are no more and I will be building these under the 7V brand. I plan to build just two systems to start with (sell one, keep one) and then see how it goes.Steve welcome back! I note your site is no longer around. I really liked the analogy (if I remember correctly) of the dance of the 7 veils with each one reveailing something more when removed. With the reference to the speakers that all 7 veils had been removed leaving only the naked truth with the sound
50W/8 ohms will be plenty for my requirements. I only need 20-30W.
Do others have any suggestions for other chips and/or suggestions for the best way to go with the LM3886? That was my purpose in starting this thread. I'm confident that the new mini-monitors will be of a high quality and need power to match.
Thanks Al, long time no post.
I'm considering the chipamp.com board for simplicity. Is that inverted? Is there a thread here that discusses the 'invertion' aspect?
Also, I'm using active crossovers and wonder if I can use these somehow instead of the buffers you mention. I hope my questions aren't too dumb but my electronics knowledge is dire! My speakers are good, honest!
I'm considering the chipamp.com board for simplicity. Is that inverted? Is there a thread here that discusses the 'invertion' aspect?
Also, I'm using active crossovers and wonder if I can use these somehow instead of the buffers you mention. I hope my questions aren't too dumb but my electronics knowledge is dire! My speakers are good, honest!
Yup, the crossovers will do the job. Don't think the Chipamp board is inverted off the top on my head, but that is just a good version of the datasheet circuit, so download that and have a look at the suggested implimentations.
As for the general implications of inverted op-amps, that's a bit long winded to get into here, but google is your friend, there's lots of good stuff out there on the interwebs.
As for the general implications of inverted op-amps, that's a bit long winded to get into here, but google is your friend, there's lots of good stuff out there on the interwebs.
before any new builder or beginner even considers parallel (PA) or bridged (BA) or bridged parallel (BPA) build a single chip implementation and learn how it works, learn what needs to be done to make it perform as expected.
Only after that start the research on what might lead to improvements on the basic "fully implemented" chipamp.
Hint:
DO NOT build the stripped down version shown as fig1 in the National datasheet for the 3886 !!!!!!!!!
Only after that start the research on what might lead to improvements on the basic "fully implemented" chipamp.
Hint:
DO NOT build the stripped down version shown as fig1 in the National datasheet for the 3886 !!!!!!!!!
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