Further to the 10000uF per rail PSU recommendation.
Have a read of this: Solid State Power Amplifier Supply Part 1
Have a read of this: Solid State Power Amplifier Supply Part 1
Agreed, Peter provides excellent support. I think the 10 uf are local decoupling on the amp board, as he lists 1500 uf caps also. It wouldn't hurt to increase either one, but as a GainClone of the GainCard, low capacitance power supplies were thought to be part of the magic. A very contrarian view that was hotly debated years ago.
I'd like to see 220 uf or so on the amp board decoupling and 4700 uf or more on the PSU. These caps are relatively inexpensive. But you can build as delivered, modify one channel and see if you hear the difference. The original Leach amp was only 12,000 uf per rail...
Enjoy your project, Tinco. Take your time and it will turn out well. The signal generator and scope can come in handy, but are not necessary unless you have an issue. There are free software signal generators that will work with your computer sound card.
Once you have your Leach amps up and running, it will be interesting to put the chip amp and Leach through their paces with a scope across a dummy load. See how they each do on square waves.
I'd like to see 220 uf or so on the amp board decoupling and 4700 uf or more on the PSU. These caps are relatively inexpensive. But you can build as delivered, modify one channel and see if you hear the difference. The original Leach amp was only 12,000 uf per rail...
Enjoy your project, Tinco. Take your time and it will turn out well. The signal generator and scope can come in handy, but are not necessary unless you have an issue. There are free software signal generators that will work with your computer sound card.
Once you have your Leach amps up and running, it will be interesting to put the chip amp and Leach through their paces with a scope across a dummy load. See how they each do on square waves.
Thanks for the recommendations guys! I read through that article mcd99uk, I didn't fully understand the article but what I gathered from it is that you need some beefy capacitors to support your transformer in handling the peaks right, and they need to be low impedance to make sure the power is supplied in time.
I'm a bit confused which caps I should replace.. the article has 10kuF capacitors directly after the rectifying bridge, the PSU in Peter Daniels' design has a very small 10uF there, but if you look at the amp board it directly after that has largish 1500uF capacitors.
If I would increase this, should I replace the 1500uF ones? or add more in parallel? And what should I replace with? the Panasonic FC series doesn't go that high in capacitance for 50V rating (it does in 10V rating though).
They aren't super expensive, so I could go for 6 1500uF ones per channel, is there any downside to having many of them? Everytime I double the amount of capacitors, the impedance halves right? Can the impedance be too low? Will something else go wrong when I do this?
I'm a bit confused which caps I should replace.. the article has 10kuF capacitors directly after the rectifying bridge, the PSU in Peter Daniels' design has a very small 10uF there, but if you look at the amp board it directly after that has largish 1500uF capacitors.
If I would increase this, should I replace the 1500uF ones? or add more in parallel? And what should I replace with? the Panasonic FC series doesn't go that high in capacitance for 50V rating (it does in 10V rating though).
They aren't super expensive, so I could go for 6 1500uF ones per channel, is there any downside to having many of them? Everytime I double the amount of capacitors, the impedance halves right? Can the impedance be too low? Will something else go wrong when I do this?
A few things:
- cheapest place to shop for parts in continental Europe is probably Reichelt.de. Be careful when ordering semi-conductors though: their parts are usually genuine if they are from ON, Toshiba and so on. But if there is no indication of manufacturers, they often come from second rate suppliers such as CDIL.
- it's a bit late now but this offer for a TO3 Symasym package could have been a nice option.
- as for PS caps, you can safely parallel 6x1500uf per channel. The downside with a lower impedance is a more abrupt draw on the diodes, so use a decent bridge. Not a big problem.
- a good article on the power supplies is here
-
- cheapest place to shop for parts in continental Europe is probably Reichelt.de. Be careful when ordering semi-conductors though: their parts are usually genuine if they are from ON, Toshiba and so on. But if there is no indication of manufacturers, they often come from second rate suppliers such as CDIL.
- it's a bit late now but this offer for a TO3 Symasym package could have been a nice option.
- as for PS caps, you can safely parallel 6x1500uf per channel. The downside with a lower impedance is a more abrupt draw on the diodes, so use a decent bridge. Not a big problem.
- a good article on the power supplies is here
-
Last edited:
Wow that's a lot to take in! But a very nice article indeed, I'll definitely read it again when I'm not in bed and should be sleeping 😛 Is the bridge in the audiosector design strong enough? I'm not sure how it should read it as it looks a bit different from the ones in that article, or is that just layout?
Both are really good articles. Looks like you picked out the main points from the one I linked to.
1) Main reservoir caps should be close to the amps they serve. The inductance of the wires limit the peak current available so keep them short.
2) Star grounding should be used for the PSU. Get a handle on star grounding. For the grounding scheme I would consider a star of stars.
3) Where you parallel film and electrolytic caps consider using a 1R in series with a 1u snubber across the power rails to potential reduce ringing.
4) You can use distributed reservoir caps. One bank next to rectifier and one bank next amplifier PCB.
5) Look up CRC PSUs. They can give good performance.
6) Several caps in parallel often gives better performance than one big cap. And often works out cheaper.
As you can see there's a lot of learning to do even just for the PSU.
Paul
1) Main reservoir caps should be close to the amps they serve. The inductance of the wires limit the peak current available so keep them short.
2) Star grounding should be used for the PSU. Get a handle on star grounding. For the grounding scheme I would consider a star of stars.
3) Where you parallel film and electrolytic caps consider using a 1R in series with a 1u snubber across the power rails to potential reduce ringing.
4) You can use distributed reservoir caps. One bank next to rectifier and one bank next amplifier PCB.
5) Look up CRC PSUs. They can give good performance.
6) Several caps in parallel often gives better performance than one big cap. And often works out cheaper.
As you can see there's a lot of learning to do even just for the PSU.
Paul
And now for a slightly contrarian point of view.
1. Yes, keep them close. Pay attention to lead dress. Twist rail leads together and run closes to the chassis, even at the expense of a couple inches of lead length. I think that lead inductance for a few inches is a red herring. It is miniscule compared to the emitter/source resistor inductance in most amps or the effect on peak current their resistance provide. My take: Keep the reservoir close to the amp, but don't obsess.
2. Absolutely necessary. Read up on grounding, several good articles here.
3. The resistor and capacitor is called a snubber. Search the forum for articles on power supply snubbers, and "snubberized." In one of the threads there is a link to an excellent article about designing snubbers. Much of the math was beyond me, but the upshot was that some serious test equipment is required to accurately design a snubber for each specific supply (your particular transformer, rectifiers and caps), and perhaps most importantly that the wrong snubber could do more harm than good. Feel free to make up your own mind, there were a lot of people who did as Paul suggests and were happy with the results. In the PSU forum here are people still using snubbers?
Agreed, a good quality film cap bypass is probably a good idea if it is 1-2% of the value of the cap it is bypassing. Below that it probably doesn't do anything but make you feel better because your wallet is thinner. Most effective bypassing the local bypass caps on each amp board.
4. Whatever makes the mechanical construction easier.
5. CRC can be great performers, but I believe they are much more effective for Class A amps. If you try it, be sure to have adequate capacitance after the R, so that there is plenty of energy available for the amp. If you approach minimum capacitance in the PSU, you'll likely get better results with a standard supply.
6. Agreed, caution that as you parallel more caps your ESR drops and peak currents will likely be higher than a single cap. Be sure your rectifier can handle it. The rectifiers in your kit are rated at 100 amp peaks, and likely will be fine. However they aren't on heat sinks, so some derating is prudent. This caution applies to any PSU, especially when you use very large capacitance (hundreds of uF).
Many years ago in a thread about how much capacitance do you need, Jan Didden advocated much lower capacitance than most, stating that going higher just shortened the charging pulses, causing higher peak currents, adding HF noise that would need to be filtered out. As for capacitance needed for power reserves, he finds the point of diminishing returns a lot lower than most. Even lower than the old 100 uf per watt for class AB rule of thumb.
Isn't this hobby fun? We may all hear the same way, but have different priorities when it comes to good sound. There are a lot of conflicting expert opinions (I'm not an expert. That's Nelson Pass, Jan Didden, Bob Curl, etc.- folks who have been making high end audio commercially for years and a good number of other hobbyists. Look for test results in their arguments, not just enthusiastic support of a viewpoint) When you do it yourself you can experiment and find what makes you happy, limited only by your time and available money.
Peter's kits are inexpensive enough that you can build several versions. Build it as presented, another using more psu capacitance and buy boards and use standard resistors to see if the caddocks matter. Under $300 extra if you re-use the case and power transformer.
If you haven't clicked on the "store" link at the top of the page, take a look there for some good looking enclosure options. I've done a lot of experimenting screwing things down to a piece of MDF, but that tends to have very low SAF. 😉
EDIT: Forgot to add in section 6 - download PSU designer 2 and simulate your supply. It allows you to model your particular transformer and caps by editing their parameters. This will allow you to determine your peak currents in the diodes and capacitors. Yes, you need to watch filter cap current to avoid overheating them.
1. Yes, keep them close. Pay attention to lead dress. Twist rail leads together and run closes to the chassis, even at the expense of a couple inches of lead length. I think that lead inductance for a few inches is a red herring. It is miniscule compared to the emitter/source resistor inductance in most amps or the effect on peak current their resistance provide. My take: Keep the reservoir close to the amp, but don't obsess.
2. Absolutely necessary. Read up on grounding, several good articles here.
3. The resistor and capacitor is called a snubber. Search the forum for articles on power supply snubbers, and "snubberized." In one of the threads there is a link to an excellent article about designing snubbers. Much of the math was beyond me, but the upshot was that some serious test equipment is required to accurately design a snubber for each specific supply (your particular transformer, rectifiers and caps), and perhaps most importantly that the wrong snubber could do more harm than good. Feel free to make up your own mind, there were a lot of people who did as Paul suggests and were happy with the results. In the PSU forum here are people still using snubbers?
Agreed, a good quality film cap bypass is probably a good idea if it is 1-2% of the value of the cap it is bypassing. Below that it probably doesn't do anything but make you feel better because your wallet is thinner. Most effective bypassing the local bypass caps on each amp board.
4. Whatever makes the mechanical construction easier.
5. CRC can be great performers, but I believe they are much more effective for Class A amps. If you try it, be sure to have adequate capacitance after the R, so that there is plenty of energy available for the amp. If you approach minimum capacitance in the PSU, you'll likely get better results with a standard supply.
6. Agreed, caution that as you parallel more caps your ESR drops and peak currents will likely be higher than a single cap. Be sure your rectifier can handle it. The rectifiers in your kit are rated at 100 amp peaks, and likely will be fine. However they aren't on heat sinks, so some derating is prudent. This caution applies to any PSU, especially when you use very large capacitance (hundreds of uF).
Many years ago in a thread about how much capacitance do you need, Jan Didden advocated much lower capacitance than most, stating that going higher just shortened the charging pulses, causing higher peak currents, adding HF noise that would need to be filtered out. As for capacitance needed for power reserves, he finds the point of diminishing returns a lot lower than most. Even lower than the old 100 uf per watt for class AB rule of thumb.
Isn't this hobby fun? We may all hear the same way, but have different priorities when it comes to good sound. There are a lot of conflicting expert opinions (I'm not an expert. That's Nelson Pass, Jan Didden, Bob Curl, etc.- folks who have been making high end audio commercially for years and a good number of other hobbyists. Look for test results in their arguments, not just enthusiastic support of a viewpoint) When you do it yourself you can experiment and find what makes you happy, limited only by your time and available money.
Peter's kits are inexpensive enough that you can build several versions. Build it as presented, another using more psu capacitance and buy boards and use standard resistors to see if the caddocks matter. Under $300 extra if you re-use the case and power transformer.
If you haven't clicked on the "store" link at the top of the page, take a look there for some good looking enclosure options. I've done a lot of experimenting screwing things down to a piece of MDF, but that tends to have very low SAF. 😉
EDIT: Forgot to add in section 6 - download PSU designer 2 and simulate your supply. It allows you to model your particular transformer and caps by editing their parameters. This will allow you to determine your peak currents in the diodes and capacitors. Yes, you need to watch filter cap current to avoid overheating them.
Last edited:
Yes, the bridge rectifier is very strong, and those diodes (MUR860)are very fast too. you do not need heatsinks for those diodes. and yes, those diodes look different from article (solid-state diodes), but at the end they do the same job!
Last edited:
For a class AB chip amp for home audio use you can get away without heat sinks on MUR860s but they are needed for high continuous current applications like a class A amp or PA duty.
Datasheets are your friends. Learning to read them will help your understanding of the issues. http://www.onsemi.com/pub_link/Collateral/MUR820-D.PDF maximum junction temperature is 175C. The thermal resistance Junction to ambient is 73C/watt. That means at 25C ambient it can dissipate a hair over 2W and keep the Junction below rated max temperature. (2W x 73C/W + 25C ambient = Tj of 171) Looking at figure 5, we see that equates to a maximum average forward current of 2.5 amps square wave. It actually will see short spike charging the caps, so you must derate a bit. This is also operating the device at 100% of its rated capacity. For longevity, engineering prudence dictates derating a bit. Nelson Pass recommends 100C jucntion temps on MOSFETs as a good reliability point. If we use that operating point, then we are down to 1W or just over 1A average current.
So, if the chip amp's rated 50 watts RMS into 8 ohms is 2.5A RMS how can we get away without heat sinks? Partly because the diodes are in a bridge, so the average current is shared with the other side of the bridge. The main reason is that in home use and a even an inefficient 80 dB/W speaker average power is usually under 1 or 2W, so the diodes are barely carrying any current.
Datasheets are your friends. Learning to read them will help your understanding of the issues. http://www.onsemi.com/pub_link/Collateral/MUR820-D.PDF maximum junction temperature is 175C. The thermal resistance Junction to ambient is 73C/watt. That means at 25C ambient it can dissipate a hair over 2W and keep the Junction below rated max temperature. (2W x 73C/W + 25C ambient = Tj of 171) Looking at figure 5, we see that equates to a maximum average forward current of 2.5 amps square wave. It actually will see short spike charging the caps, so you must derate a bit. This is also operating the device at 100% of its rated capacity. For longevity, engineering prudence dictates derating a bit. Nelson Pass recommends 100C jucntion temps on MOSFETs as a good reliability point. If we use that operating point, then we are down to 1W or just over 1A average current.
So, if the chip amp's rated 50 watts RMS into 8 ohms is 2.5A RMS how can we get away without heat sinks? Partly because the diodes are in a bridge, so the average current is shared with the other side of the bridge. The main reason is that in home use and a even an inefficient 80 dB/W speaker average power is usually under 1 or 2W, so the diodes are barely carrying any current.
Last edited:
Response to Bob's "slightly contrarian" view. 😉
1) Agree
3) Agree but it's worth leaving space for snubbers. This is where the scope and signal generator are useful. You can feed to amplifier square waves while monitoring the power rails.
4) Agree. It's an option and also explains why the first bank of reservoir caps can be small.
5) Agree.
6) Agree.
And yes this hobby is great and addictive.
On to rectifiers....
I don't like using fast diodes for rectifiers. The fast switching can cause noise problems. My personal preference is to go for either soft recovery diodes or just a big heavy duty basic bridge.
This is the beauty of the hobby. You read different view points. Some you agree with some you don't. Eventually you come to your own preferences.
From my point of view I don't think Bobs ideas are that "contrarian". Others may disagree. 🙂
1) Agree
3) Agree but it's worth leaving space for snubbers. This is where the scope and signal generator are useful. You can feed to amplifier square waves while monitoring the power rails.
4) Agree. It's an option and also explains why the first bank of reservoir caps can be small.
5) Agree.
6) Agree.
And yes this hobby is great and addictive.
On to rectifiers....
I don't like using fast diodes for rectifiers. The fast switching can cause noise problems. My personal preference is to go for either soft recovery diodes or just a big heavy duty basic bridge.
This is the beauty of the hobby. You read different view points. Some you agree with some you don't. Eventually you come to your own preferences.
From my point of view I don't think Bobs ideas are that "contrarian". Others may disagree. 🙂
Last edited:
Nice to have a civil discussion. Many times these types of topics incite near religious fervor. Witness many of the "benefits of xxxx" threads.
One person's miracle cure is another's snake oil. And sometimes the reason you don't hear a difference is that your speakers aren't up to resolving the difference. Once the electronics are good enough give clean output I think your mine is best spent on speakers. Until they are really good electronics and cabling are like putting high performance tires on a rust bucket that barely runs.
Tinco's chip amps should serve well until he starts getting into low impedance inefficient speakers. A Leach is nicer and double the power but you'll barely notice a loudness difference and probably not a quality difference with Insignia speakers. (Best Buy house brand)
One person's miracle cure is another's snake oil. And sometimes the reason you don't hear a difference is that your speakers aren't up to resolving the difference. Once the electronics are good enough give clean output I think your mine is best spent on speakers. Until they are really good electronics and cabling are like putting high performance tires on a rust bucket that barely runs.
Tinco's chip amps should serve well until he starts getting into low impedance inefficient speakers. A Leach is nicer and double the power but you'll barely notice a loudness difference and probably not a quality difference with Insignia speakers. (Best Buy house brand)
You'll only ever get civil discussion from me. It's no good to the OP to get into some phoney war. I'm only trying to introduce him to concepts that will help him have a successful project and avoid the mistakes I made when first starting out.
Talking about speakers. There is truth in what you say as the speakers are the biggest source of distortion. But experience shows that even the worst speakers can sound different between amps. Years ago a friend had an Aiwa mini system. we went out and bought a basic amp and CD player and used the mini system speakers. The difference was like night and day. So the difference between an ok amp vs a truly terrible amp was audible.
Another experiment between a NAD amp, Cyrus 2 and Sansui all driving a reasonable set of floor standers also revealed massive differences.
Then comparing a modified CD67 with a normal CD67 resulted in significant sound differences. Obviously the amp and speakers were kept constant.
But I digress.
Trincos chip amp should turn out very nice. They will serve very well in this very steep learning curve he's at the beginning of 🙂
If we can help him create a nice solid design that would be seen as a great success.
Talking about speakers. There is truth in what you say as the speakers are the biggest source of distortion. But experience shows that even the worst speakers can sound different between amps. Years ago a friend had an Aiwa mini system. we went out and bought a basic amp and CD player and used the mini system speakers. The difference was like night and day. So the difference between an ok amp vs a truly terrible amp was audible.
Another experiment between a NAD amp, Cyrus 2 and Sansui all driving a reasonable set of floor standers also revealed massive differences.
Then comparing a modified CD67 with a normal CD67 resulted in significant sound differences. Obviously the amp and speakers were kept constant.
But I digress.
Trincos chip amp should turn out very nice. They will serve very well in this very steep learning curve he's at the beginning of 🙂
If we can help him create a nice solid design that would be seen as a great success.
> If we can help him create a nice solid design that would be seen as a great success.
Amen to that 😉
My best speaker set is a pair of Dual CL 710. They sound very pretty. My sole bar for this project is to drive those better or as good as my Sansui does now 🙂 If these gainclones are as good as they are rumored to be, and I don't mess up soldering then I think that should be no problem 😛
I'm not sure what to do about the speakers. I listened in what I would call a reasonable hifi shop where they sold amps for ~1500 euro and speakers for ~500 per speaker and was not impressed at all. I didn't hear that much of a difference with my current set.
Then I went to the what I think is a rather outrageous store, where the guy generously let me listen to a 5000 euro per speaker set, even though I told him I could never afford that, I was absolutely blown away. It was I think this set: SCM150ASLT | ATC Loudspeakers And it was warm and smooth and clear.
The guy told me they were class A studio monitors. But if I look at that site, the class A studio monitors ATC makes look a lot different, so unless they got it customised somehow I think he was confused and they're actually class AB hifi speakers.
Anyway, I guess that's the next bar! 😀 I'd have to teach myself some woodworking then though >_>. They seem to have an amplifier for each driver in the speaker, pretty crazy!
Amen to that 😉
My best speaker set is a pair of Dual CL 710. They sound very pretty. My sole bar for this project is to drive those better or as good as my Sansui does now 🙂 If these gainclones are as good as they are rumored to be, and I don't mess up soldering then I think that should be no problem 😛
I'm not sure what to do about the speakers. I listened in what I would call a reasonable hifi shop where they sold amps for ~1500 euro and speakers for ~500 per speaker and was not impressed at all. I didn't hear that much of a difference with my current set.
Then I went to the what I think is a rather outrageous store, where the guy generously let me listen to a 5000 euro per speaker set, even though I told him I could never afford that, I was absolutely blown away. It was I think this set: SCM150ASLT | ATC Loudspeakers And it was warm and smooth and clear.
The guy told me they were class A studio monitors. But if I look at that site, the class A studio monitors ATC makes look a lot different, so unless they got it customised somehow I think he was confused and they're actually class AB hifi speakers.
Anyway, I guess that's the next bar! 😀 I'd have to teach myself some woodworking then though >_>. They seem to have an amplifier for each driver in the speaker, pretty crazy!
Do your research. Do not rush. Consider each and every decision you make.
An amp for each driver. That's an active setup. Well within your grasp with the chip amps. It's not crazy at all.
My current system is exactly that. I have two XLS10s in sealed boxes equalized down to 17Hz running off two 500W plate amps. The fullrange speakers are 8" aluminium cone + 1" ceranic tweeter driven off 4 leach amps. It sounds lovely to me and can go to club levels (I like my trance).
But walk before you run. Get this amp done first and done well. There's a whole mass of options available to you in this hobby and there's no reason why in time you can't better that super expensive setup for a lot less money.
What sansui do you have? Mine is an AU517. It's the best dance music amp I've ever heard.
An amp for each driver. That's an active setup. Well within your grasp with the chip amps. It's not crazy at all.
My current system is exactly that. I have two XLS10s in sealed boxes equalized down to 17Hz running off two 500W plate amps. The fullrange speakers are 8" aluminium cone + 1" ceranic tweeter driven off 4 leach amps. It sounds lovely to me and can go to club levels (I like my trance).
But walk before you run. Get this amp done first and done well. There's a whole mass of options available to you in this hobby and there's no reason why in time you can't better that super expensive setup for a lot less money.
What sansui do you have? Mine is an AU517. It's the best dance music amp I've ever heard.
It's the AU-D33, there's a fun review of it here (not so positive 😛) Sansui AU-D 22? - AudioKarma.org Home Audio Stereo Discussion Forums.
I suspect you will like the GainClone with your speakers..
As for speakers, when you're ready you probably already know that I will suggest DIY for anything better than basic big box store speakers. At $200 a pair you can't compete with economy of scale, go buy them. At $3-400 you can do as well as a lot of $1,000+ speakers. There's lots of concepts to explore there, too. Traditional multi way, full range, waveguides, dipoles, dipoles with waveguides...
As with amps, start with a proven design, preferably a simple one, like a two way. Of course, I started with a design of my own, a 4 way plus sub. That it sounded decent and impressed friends was likely equal parts luck and pride of ownership.
There are kits available if you want to do it easily, some include cabinets ready cut so virtually all you have to do is wire it up. When you're ready, check the speaker threads here and over at HT Guide's "Mission Possible DIY" section. John Krutke also has some nice designs at zaphaudio.com He has an arrangement with Madisound to distribute drivers and kits he has designed. He uses a lot of drivers that are likely to be available to you. Dayton drivers are popular at HT Guide, they are great value drivers and the parent company Parts Express was a forum sponsor.
Geez, what a coincidence, Paul. I am heading to a partially active system. I have been fully active, but simplified for a while. Time to go back to max performance. I have a custom Zaph design MT, to which I will add bass bins.
This hobby can become all consuming and interfere with interpersonal relationships. 😉
As for speakers, when you're ready you probably already know that I will suggest DIY for anything better than basic big box store speakers. At $200 a pair you can't compete with economy of scale, go buy them. At $3-400 you can do as well as a lot of $1,000+ speakers. There's lots of concepts to explore there, too. Traditional multi way, full range, waveguides, dipoles, dipoles with waveguides...
As with amps, start with a proven design, preferably a simple one, like a two way. Of course, I started with a design of my own, a 4 way plus sub. That it sounded decent and impressed friends was likely equal parts luck and pride of ownership.
There are kits available if you want to do it easily, some include cabinets ready cut so virtually all you have to do is wire it up. When you're ready, check the speaker threads here and over at HT Guide's "Mission Possible DIY" section. John Krutke also has some nice designs at zaphaudio.com He has an arrangement with Madisound to distribute drivers and kits he has designed. He uses a lot of drivers that are likely to be available to you. Dayton drivers are popular at HT Guide, they are great value drivers and the parent company Parts Express was a forum sponsor.
Geez, what a coincidence, Paul. I am heading to a partially active system. I have been fully active, but simplified for a while. Time to go back to max performance. I have a custom Zaph design MT, to which I will add bass bins.
This hobby can become all consuming and interfere with interpersonal relationships. 😉
Last edited:
Yes. We'll soon have similar setups. Sounds like you know a lot more than me when it comes to speakers. I decided to keep it simple and went with sealed enclosures.
However, the one thing I dispute is that I reckon you can better the $200 speakers even considering the economy of scale. At least that's the case over here, the offerings at that price level are pretty poor. The only company that ever produced a good low price speaker, in my opinion, was Mordant Short but these days even they are suspect.
I remember one party night we had my homemade stuff combined with some off the shelf hifi. The only bit of the off the shelf stuff to survive was the CD player. 😱
All consuming is an understatement. My latest project has become almost an obsession. It's a challenge I MUST succeed at. I've been spending about 5 hours every evening working on it.
The good thing about this forum is that it brings us nutters together. Before I used to be a lone mad man.
Don't go dis'ing my Insignia speakers now.😀 You can do a lot worse. For a $79 pair of speakers they sound pretty sweet and would meet the needs of all but the most discriminating audiophile. 🙂 One of my other pairs is the Pioneer bookshelf set designed by the renown Andrew Jones. Interestingly enough, I like the overall sound of the Insignia's better. A tad more bass - such as it is.
Rick
OK, Rick, I stand corrected. 😉 I already was thinking to get a pair as my rear surrounds to see if I want to step up from 5.1 to 7.1 without hurting my wallet too much. I'm sure they'd be more than adequate bedroom speakers.
My son is a Geek Squad member, so Insignia was the first thing that came to mind when I wanted to talk about an inexpensive speaker. At least I didn't say B@$e. 🙂
Glens Falls, where upstate are you?
My son is a Geek Squad member, so Insignia was the first thing that came to mind when I wanted to talk about an inexpensive speaker. At least I didn't say B@$e. 🙂
Glens Falls, where upstate are you?
Last edited:
Is there a way I could test the rectifier diodes with a multimeter? I tried measuring by setting the multimeter to 200ohm and then measuring first left to right, then right to left, as I think you would test a diode, but the multimeter always says 1 for infinite resistance.
I have soldered the first rectifier portion of the psu, I get the transformer tomorrow so I can't measure anything yet.
When I get the transformer, can I test the power supply like I would test any, by measuring the DV between G+ and V+? It should just be a constant voltage right?
Since I'm doing point to point making lines is a bit tricky, and I had to mess around for a little until I found out how to do it quickly, so I'm afraid I may have overheated a diode.. how fast would that happen? The diodes very quickly got too hot to touch.
I have soldered the first rectifier portion of the psu, I get the transformer tomorrow so I can't measure anything yet.
When I get the transformer, can I test the power supply like I would test any, by measuring the DV between G+ and V+? It should just be a constant voltage right?
Since I'm doing point to point making lines is a bit tricky, and I had to mess around for a little until I found out how to do it quickly, so I'm afraid I may have overheated a diode.. how fast would that happen? The diodes very quickly got too hot to touch.
- Status
- Not open for further replies.