Sonnya,
Yes, VGS Drop is the measurement that you do. Its no big deal to do it, and has taught alot about electronics to newbies building these amps. Measuring VGS in MOSFET devices for any amplifier you are building can only make it better....equal current shared by each output device is a very good thing in any amplifier design.
My philosophy is more along Uli's where distortion measurements are pretty much meaningless, its really the final sound quality that counts.....
I'd think if that "other amp" design was soooo good that we'd all be buiding them and not the Alephs.....
Mark
Yes, VGS Drop is the measurement that you do. Its no big deal to do it, and has taught alot about electronics to newbies building these amps. Measuring VGS in MOSFET devices for any amplifier you are building can only make it better....equal current shared by each output device is a very good thing in any amplifier design.
My philosophy is more along Uli's where distortion measurements are pretty much meaningless, its really the final sound quality that counts.....
I'd think if that "other amp" design was soooo good that we'd all be buiding them and not the Alephs.....
Mark
the other amp
well it is not that old ... So not that many people could have build it..... it is less than a year, and the aleph is a production model with many years behind it....
You have said :
"where distortion measurements are pretty much meaningless, its really the final sound quality that counts" I agree a lot with you.....
Never perform the listening test yourself but get other people to do it....
well it is not that old ... So not that many people could have build it..... it is less than a year, and the aleph is a production model with many years behind it....
You have said :
"where distortion measurements are pretty much meaningless, its really the final sound quality that counts" I agree a lot with you.....
Never perform the listening test yourself but get other people to do it....
Never perform the listening test yourself but get other people to do it....
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Sonnya,
That doesn't really make sense.....I might not like the sound of an amp that somebody else likes.... Sound is too subjective......Even reviewers are pretty much meaningless most of the time.......they don't have my speakers, my room, my carpeting,,,,etc. How would they know what I like.....? Even a group review of an amplifier or other device is as meaningless...at least to me. I'd say that what makes an amp very sucessful is that it is good enough to be bought(or built for that matter) by a whole lot of people. Receiving Classic status also carries ALOT of weight with it. I will await marketing and sales of that new amplifier...if it hugely sucessful in say 5 years I might well end up owning one. I've certainly owned ALOT of other amps in the past.
Mark
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Sonnya,
That doesn't really make sense.....I might not like the sound of an amp that somebody else likes.... Sound is too subjective......Even reviewers are pretty much meaningless most of the time.......they don't have my speakers, my room, my carpeting,,,,etc. How would they know what I like.....? Even a group review of an amplifier or other device is as meaningless...at least to me. I'd say that what makes an amp very sucessful is that it is good enough to be bought(or built for that matter) by a whole lot of people. Receiving Classic status also carries ALOT of weight with it. I will await marketing and sales of that new amplifier...if it hugely sucessful in say 5 years I might well end up owning one. I've certainly owned ALOT of other amps in the past.
Mark
There's another reason I don't trust magazine reviews. Most of them don't really rely on my buying the magazine to pay their bills; It's the advertiser that they need to please. This is not only directed at the audio world, but all magazines, newspapers, radio and TV shows, etc. They might make passing mention of some products shortfalls, But they will never call a POS a POS when the often should.
By the way Mark, you're Aleph 2 was the last straw that made me start gathering parts for mine. I like it!
By the way Mark, you're Aleph 2 was the last straw that made me start gathering parts for mine. I like it!
Hi Brian,
Thanks for the kind comments. They took me about 4 months to get to this stage. I've been too busy listening to even stop and put the front panels in place.....fortunately, both my dogs have managed not stick their noses in there on the copper buss......
The sinks are what took the longest to get. About 8 weeks for them from M&M as they are not a stock sink. They did not charge me for a special run or anything though, just 22.00 or so per sink plus shippimng. They were spotless when they arrived.
Then, all the metal work took some more time...in betwen installing projection and sound equipment in a couple of different movie theatre plex's, that kept me out of town for a while. Worked on them mainly on weekends and sometimes at night if I wasn't too tired. Fortunately,I do hae quite a bit of machining experience and was able to easily fabricate the chassis parts. Finding the time was the biggest challenge, probably in the neighborhood of about 150 man hours!
Mark
Thanks for the kind comments. They took me about 4 months to get to this stage. I've been too busy listening to even stop and put the front panels in place.....fortunately, both my dogs have managed not stick their noses in there on the copper buss......
The sinks are what took the longest to get. About 8 weeks for them from M&M as they are not a stock sink. They did not charge me for a special run or anything though, just 22.00 or so per sink plus shippimng. They were spotless when they arrived.
Then, all the metal work took some more time...in betwen installing projection and sound equipment in a couple of different movie theatre plex's, that kept me out of town for a while. Worked on them mainly on weekends and sometimes at night if I wasn't too tired. Fortunately,I do hae quite a bit of machining experience and was able to easily fabricate the chassis parts. Finding the time was the biggest challenge, probably in the neighborhood of about 150 man hours!
Mark
Mark A. Gulbrandsen said:
My experience has been that the amps I end up liking are the ones that satisfy these 2 criteria (with my speakers, offcourse):
1. Play loud before going into clipping. This should be related to power rating but not really the case. Also, note that I am not using oscilloscopes, just listening tests.
2. Sound reasonably good while in clipping.
The 2nd criteria is where most chip amps fail miserably. Note that I have not tried Gainclone. Maybe it is different but I have a hard time believing that - I have tried several commercial chip amps, but a case could be made that they are not good implementations.
The first criteria is where the low powered tube amps fail miserably (again with my 86-90dB speakers, maybe they do sound great with high efficiency speakers as others claim). Also, the tube amps do not sound all that great when in clipping (the difference is that a chip amp sounds as if it is going to kill itself, speakers, or you, for putting it through that; whereas a tube amp sounds as if it is just going to fall apart trying very hard). Pl note that I have tried only a few tube amps and probably there are others that are better.
The discrete amps seem to satisfy these criteria reasonably well - the Zen4 that I built really shines here: I have been unable to make it clip even when my pre-amp is at 3 O Clock (I have not tried pushing it any further, yet). It probably is under severe distortion but I do not hear it. I have not tried an Aleph but I am sure it also sounds great.
Best DIY Amp
Coming back to the original topic, this gets my vote for the best DIY amp. Considering effort involved in building it and subjective performance, IT IS a designer's dream.
http://www.diyaudio.com/forums/showthread.php?s=&postid=125056#post125056
Coming back to the original topic, this gets my vote for the best DIY amp. Considering effort involved in building it and subjective performance, IT IS a designer's dream.
http://www.diyaudio.com/forums/showthread.php?s=&postid=125056#post125056
No best first amp
Returning to the original question, there is no "best" first amp. So thought as to what one wan't and what skills and knowledge are already posssesd is important.
The following is based only on my experience. It may not be applicable to other people.
One thing to get out of the way first is tube vs. solid state. If you really prefer one or the other for listening go that way. If you don't know, I suggest solid state for a first attempt as the voltages are lower.
The next decision revolves around skill and experience. If you have never soldered before, get a pre made PCB. Consider www.Marchandekec.com, perhaps the 65 watt IC based design. These boards are very easy to solder as they have solder masks and the part density is not too high and the instructions are very explicit - you can even order it with a kit of parts.
If you have "stuffed" a PCB before, then something like the P3A project from sound.au.com might be considered. It does not have a large part count but the component density of the board might be a bit tight for some one who totally new to this.
I have come to find that just filling someone else's board offers little challenge and prefere to make my own. Althogh easier than one might think, that might be taking on too much the first time.
Actually, I have found that assembing the board is the easiest part of the whole process. Rather finding a suitable enclosure and getting the amp boards, power supply, wiring and connectors all squeezed in. I confess that I make this bit harder than it needs to be because one of my prejudices that that I hate the standard 17"x7"14" box that most audio gear seems to come in. I'm always trying to find a way to make it more compact. It doesn't help that I'm not very skilled with metal work!
You may want to think about this, if you are good with this kind of thing maybe you can take on something more ambitious on the electronic side, but if you are more like me, you may want to keep the electronics part simple until you have figure out what works for in assembling the final "product".
I suggest you don't get wrapped up in debates such as: Class A vs. ClassB, low part count vs. more complexity, BJT vs. MOSFET. You can build a good amp with any of these, but each has tradeoffs. What is more important is to understand the tradeoffs and choose what is easiest for you to deal with at first.
Since no one else has mentioned it, I'm partial to G.Randy Slone's designs. (www.sealelectronics.com) Even if these are not for you, you should check the web site to see what is available. He also has a pretty good introductory book you can get from Amazon.com that may be useful even if you never build one of his amps.
Returning to the original question, there is no "best" first amp. So thought as to what one wan't and what skills and knowledge are already posssesd is important.
The following is based only on my experience. It may not be applicable to other people.
One thing to get out of the way first is tube vs. solid state. If you really prefer one or the other for listening go that way. If you don't know, I suggest solid state for a first attempt as the voltages are lower.
The next decision revolves around skill and experience. If you have never soldered before, get a pre made PCB. Consider www.Marchandekec.com, perhaps the 65 watt IC based design. These boards are very easy to solder as they have solder masks and the part density is not too high and the instructions are very explicit - you can even order it with a kit of parts.
If you have "stuffed" a PCB before, then something like the P3A project from sound.au.com might be considered. It does not have a large part count but the component density of the board might be a bit tight for some one who totally new to this.
I have come to find that just filling someone else's board offers little challenge and prefere to make my own. Althogh easier than one might think, that might be taking on too much the first time.
Actually, I have found that assembing the board is the easiest part of the whole process. Rather finding a suitable enclosure and getting the amp boards, power supply, wiring and connectors all squeezed in. I confess that I make this bit harder than it needs to be because one of my prejudices that that I hate the standard 17"x7"14" box that most audio gear seems to come in. I'm always trying to find a way to make it more compact. It doesn't help that I'm not very skilled with metal work!
You may want to think about this, if you are good with this kind of thing maybe you can take on something more ambitious on the electronic side, but if you are more like me, you may want to keep the electronics part simple until you have figure out what works for in assembling the final "product".
I suggest you don't get wrapped up in debates such as: Class A vs. ClassB, low part count vs. more complexity, BJT vs. MOSFET. You can build a good amp with any of these, but each has tradeoffs. What is more important is to understand the tradeoffs and choose what is easiest for you to deal with at first.
Since no one else has mentioned it, I'm partial to G.Randy Slone's designs. (www.sealelectronics.com) Even if these are not for you, you should check the web site to see what is available. He also has a pretty good introductory book you can get from Amazon.com that may be useful even if you never build one of his amps.
Jag,
While I agree that those may be important things to consider there are alot more things that weigh in quite heavily on why to choose an amp.
Things I listen for and that are important to me are.......
Smearing, or blurring of high end detail...things like cymbols, and yes vibes and xylophone are also good tests.
Bottom end transient detail. Does the tympani sound correct, or does it sound like a bass drum?? This is also related to the amps control over the speakers as well. Solid state amps perform best here.
Stereo imaging.....is it nice and wide, meaning that the amp is accurately reproducing harmonics, or is the stage narrow and limited indicadive that the amp probably has a somewhat limited bandwidth, or possibly poor quality components.
Slam factor.....This is important and signifies the peak power available. Play the Telarc 1812 with real canons to do this test!! If the amp flakes out then I won't even consider it. My Aleph 2's pass(pun intended) this test with flying colors at very high playback levels. My experiennce is that tube amps normally puke out at this test.......
Voice test.........Louis Armstrong and Ella Fitzgerald work really good for this test!
Listening Fatigue....listen over a period of time to see if any fatique sets in........after a while you may not be able to stand how the amp sounds. I've noticed this problem alot with I.C. based designsbut it can happen with all types of amps to some extent.
Mark
While I agree that those may be important things to consider there are alot more things that weigh in quite heavily on why to choose an amp.
Things I listen for and that are important to me are.......
Smearing, or blurring of high end detail...things like cymbols, and yes vibes and xylophone are also good tests.
Bottom end transient detail. Does the tympani sound correct, or does it sound like a bass drum?? This is also related to the amps control over the speakers as well. Solid state amps perform best here.
Stereo imaging.....is it nice and wide, meaning that the amp is accurately reproducing harmonics, or is the stage narrow and limited indicadive that the amp probably has a somewhat limited bandwidth, or possibly poor quality components.
Slam factor.....This is important and signifies the peak power available. Play the Telarc 1812 with real canons to do this test!! If the amp flakes out then I won't even consider it. My Aleph 2's pass(pun intended) this test with flying colors at very high playback levels. My experiennce is that tube amps normally puke out at this test.......
Voice test.........Louis Armstrong and Ella Fitzgerald work really good for this test!
Listening Fatigue....listen over a period of time to see if any fatique sets in........after a while you may not be able to stand how the amp sounds. I've noticed this problem alot with I.C. based designsbut it can happen with all types of amps to some extent.
Mark
Mark A. Gulbrandsen said:
Agreed, agreed, agreed, agreed, agreed, and agreed. But, what I found (and this was a surprising conclusion for me) is that an amp that performs good on all these criteria has a good clipping performance (the 2 criteria that I described before) as well and vice versa. The advantage of this conclusion is that where it takes days or weeks to perform listening tests on all the criteria described above it only takes a few minutes to perform the clipping tests.
I guess it can be argued that having come to this conclusion my judgement is now clouded and I would call an amp bad (or good) based on clipping tests which otherwise really provides a good (or bad) performance...
Well, the clipping tests alone really don't necessarily mean that an amp will pass on Vocal tests, high end blurring and detail resolution, and imaging capability.
I've owned amps that were good at the above but were poor in the clipping and slam test. The BAT VK-60 is one that comes to mind. Overall a really expensive but great sounding amp till it came to slam factor. It clips fairly gracefully thougjh. Another was the ARC D-115. This thing sounded great till it ran out of steam and clipping was not so graceful. Bear in mind that both these are tube amps. Other amps I've had that don't hold up in high end detail and vocal but had great slam and graceful clipping were the Boulder 250AE Monoblocks. Very pricy amps that after owning them for a while I began to become really disappointed in. They always had a bothersome glare to them that I wasn't able to tweek out...even if left on all the time.....
Overall....its really difficult to judge an amp by only a couple of parameters, ya gotta live with it a while. I guess thats the part that helps keep the likes of Krell and BAT in buisness.
Mark
I've owned amps that were good at the above but were poor in the clipping and slam test. The BAT VK-60 is one that comes to mind. Overall a really expensive but great sounding amp till it came to slam factor. It clips fairly gracefully thougjh. Another was the ARC D-115. This thing sounded great till it ran out of steam and clipping was not so graceful. Bear in mind that both these are tube amps. Other amps I've had that don't hold up in high end detail and vocal but had great slam and graceful clipping were the Boulder 250AE Monoblocks. Very pricy amps that after owning them for a while I began to become really disappointed in. They always had a bothersome glare to them that I wasn't able to tweek out...even if left on all the time.....
Overall....its really difficult to judge an amp by only a couple of parameters, ya gotta live with it a while. I guess thats the part that helps keep the likes of Krell and BAT in buisness.
Mark
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