Where...or When have I ever seen a Problem Crop up AFTER the Design is Frozen?
Well...I have to admit...I've seen more than one product reach manufacturing that either didn't meet spec. (ultimately as designed) or had performance that was unstable/not to spec. under standard manufacturing processes, tolerances and conditions.
Is the plan to proto a quantity of at least one to verify performance before launching the order?
rt
Well...I have to admit...I've seen more than one product reach manufacturing that either didn't meet spec. (ultimately as designed) or had performance that was unstable/not to spec. under standard manufacturing processes, tolerances and conditions.
Is the plan to proto a quantity of at least one to verify performance before launching the order?
rt
Ever disaster is a new opportunity, blown speakers eh, sounds like a DIY refit to me! 🙂
Anthony
Anthony
It seems to be connected the the current source for the front end diff pair
The current source is on the other side of differencial pair on the PCB. The relay has probably nothing to do with the amps circuit and is some auxilary circt. for switching.
As to the board, it seams like at least 20 people will purchase it, so they all will be stuck with it. While it's very tempting to have it all and have it now😉, but why not take some extra time and try to improve it. Especially people who designed previous Aleph's boards, might bring some useful input: Brian, Dale ?
While I'm not interested in a single board, because I prefer p2p for that purpose, I might find couple friends who would like to have this amp for home theatre setup and then the boards would be handy. I would probably order 20 boards then.😉 So let's make them nice.
The current source is on the other side of differencial pair on the PCB. The relay has probably nothing to do with the amps circuit and is some auxilary circt. for switching.
As to the board, it seams like at least 20 people will purchase it, so they all will be stuck with it. While it's very tempting to have it all and have it now😉, but why not take some extra time and try to improve it. Especially people who designed previous Aleph's boards, might bring some useful input: Brian, Dale ?
While I'm not interested in a single board, because I prefer p2p for that purpose, I might find couple friends who would like to have this amp for home theatre setup and then the boards would be handy. I would probably order 20 boards then.😉 So let's make them nice.
A visionary right here our midst.
Is the plan to proto a quantity of at least one to verify performance before launching the order?
"The current source is on the other side of differencial pair on the PCB. The relay has probably nothing to do with the amps circuit and is some auxilary circt. for switching."
I believe you are right about the current source being the one with the heat sink. But the second sentence is the biggest PROBABLY I have ever read on this forum, and would even make Grey hesitate before springing that one on us. And you're a moderator to boot!
Want to roll the dice
and take your turn over again, we don't mind.
Fred
How did Ann Landers keep from shooting herself all those years?
Is the plan to proto a quantity of at least one to verify performance before launching the order?
"The current source is on the other side of differencial pair on the PCB. The relay has probably nothing to do with the amps circuit and is some auxilary circt. for switching."
I believe you are right about the current source being the one with the heat sink. But the second sentence is the biggest PROBABLY I have ever read on this forum, and would even make Grey hesitate before springing that one on us. And you're a moderator to boot!
Want to roll the dice
and take your turn over again, we don't mind.Fred
How did Ann Landers keep from shooting herself all those years?
Re: What the heck?
You might be closer to the truth than you think. I remember Fred was building Tex-X and he had it almost finished. However he doesn't say nothing about the amp recently. Is it a case of blown speaker?
😉
carpenter said:
You might be closer to the truth than you think. I remember Fred was building Tex-X and he had it almost finished. However he doesn't say nothing about the amp recently. Is it a case of blown speaker?
😉
Re: A visionary right here our midst.
I couldn't agree more. It seems like wessol build the amp, based on a board, but he didn't confirm any proper operation yet. I mean, he said that everything seemed to be fine, but he didn't connect the speakers.🙄
Fred Dieckmann said:Is the plan to proto a quantity of at least one to verify performance before launching the order?
Fred
I couldn't agree more. It seems like wessol build the amp, based on a board, but he didn't confirm any proper operation yet. I mean, he said that everything seemed to be fine, but he didn't connect the speakers.🙄
It seems like a lot space is taken now by boards discussion. Would you like me to create a new thread and move the content regarding the boards there?
Re: Not yet ready!
Gee, I could have sworn I was at work there for a minute...Fred Dieckmann said:
Hang on my friend....
Hi Peter,
If it's related to the Aleph X, it probably should stay here. Besides, we broke one record of 100,000 hits, why not go for 200,000?
John Inlow
By the way, the prototype cost of a single pcb is $242.00..........
Hi Peter,
If it's related to the Aleph X, it probably should stay here. Besides, we broke one record of 100,000 hits, why not go for 200,000?
John Inlow
By the way, the prototype cost of a single pcb is $242.00..........
But etching one prototype at home from a transparent printout is less than one hour of work. If there should be produced a serios amount of PCBs it is worth the time to make a serios and prooven design. Including shelfmadepototype for maybe 5$ material costs and one hour of time. Or is one of your hours worth 237$ + ?
wessol has manufactured a pcb using current artwork, till.
It works.
Manufacturing a prototype involves many parameters that aren't covered by home diy processes. If the manufacturer wants $242.00, then why not order enough pcbs to lower the cost per board?
I've stated my position. If anyone else wants to modify the prints and perform the necessary follow ups, be my guest.
I'm going to obtain a manufactured pcb, anyone that wishes to join me is more than welcome.
John Inlow
It works.
Manufacturing a prototype involves many parameters that aren't covered by home diy processes. If the manufacturer wants $242.00, then why not order enough pcbs to lower the cost per board?
I've stated my position. If anyone else wants to modify the prints and perform the necessary follow ups, be my guest.
I'm going to obtain a manufactured pcb, anyone that wishes to join me is more than welcome.
John Inlow
Sigh
"Fred, are you trolling, or, are you attempting to be a wet blanket? If you're truly concerned, wonderful. You appear to be very cautious, have you had an unhappy experience with an unstable amplifier?"
Yep, as has anyone who fools with amplifiers long enough......
I 've blown up speakers before by screwing around by not testing the amp adequately before playing through speakers. I fried some of my favorite tweeters messing around with the decoupling on the current sources of my hot rod Aleph 3 in a biamp set up and I have a EE and enough test equipment that it should have never happened, IF NOT FOR THE FACT THAT I WAS IN A HURRY TO FINISH IT WITHOUT TAKING ENOUGH TESTING. I believe the astronauts used to call this "Go Fever" It took about ten minutes of testing how the amp powered up with the new mods to figure out what went wrong in the one minute it took for the tweeters to melt. The amp had been turned off and burnt the tweeters when it was powered back up. I had origionally hooked up the tweeters with the amp powered up and had listened for a week before all the fun started. I thought Grey had blown up his amp at some point during testing but did not find the post on my quick trip though about 40 pages of this fun. I am curious why he hasn't finished but I will leave that up to him. I just got tired of messing with mine for awhile and will finish when I get motivated and not to get back in the middle of all this. I will standback and let you guys finish this. I am just trying to save some speakers and keep people from getting seriously pissed off in this project. I have read a ton of "shooting from the hip" stuff here (some of it absolute B.S.) and not much modeling, measurements , or serious observations from the major players on this project. There have been a few exceptions but mostly everybody is trying to get to the end result with doing much of the work. I am interested in this of course but I don't feel I owe anybody a debuged final design. It is too much work and I get too much crap for not telling everyone what they want to hear. Go read the first 10 or 15 post of mine in this thread and the fear and loathing it inspired. I got bitched at for refering someone to a web reference on phase margin instead of giving a half *** explantion the would not have enlightned any one. Talk about killing the messenger! I leave the task of finishing this design up to someone else more heroic than I. I would never turn pcbs for other people without hard wiring and testing one channel. It is not too complicated a design to do this and Peter and I have supplyed pictures of breadboard techniques in this very thread. As I said it is a matter on doing the work. Does everyone want to hack PCBs to debug for themselves, or will they wait for a debugged layout? And there is merit in either approach by the way just so everyone knows what they are getting into. Most of my engineering development projects called for pretty close PCBs with mods on them, but time is money in the real world. I talked a guy into 15 PCBs instead of a 100 once and we ended up with 30 wires and about 25 parts tacked on those guys before the next PCB turn. Guess who would have had to mod all hundred of them?Foesight is a wonderful thing but much harder than hindsight. Grey, you started this thing and even got behind the scences advice from Nelson Pass, as well as inspiring him to offer an incredable amount of input here. Why why not finish it out?
They say "Fools rush in, where angels fear to tread."
I'm no angel, but I am not rushing either,
Fred
"Fred, are you trolling, or, are you attempting to be a wet blanket? If you're truly concerned, wonderful. You appear to be very cautious, have you had an unhappy experience with an unstable amplifier?"
Yep, as has anyone who fools with amplifiers long enough......
I 've blown up speakers before by screwing around by not testing the amp adequately before playing through speakers. I fried some of my favorite tweeters messing around with the decoupling on the current sources of my hot rod Aleph 3 in a biamp set up and I have a EE and enough test equipment that it should have never happened, IF NOT FOR THE FACT THAT I WAS IN A HURRY TO FINISH IT WITHOUT TAKING ENOUGH TESTING. I believe the astronauts used to call this "Go Fever" It took about ten minutes of testing how the amp powered up with the new mods to figure out what went wrong in the one minute it took for the tweeters to melt. The amp had been turned off and burnt the tweeters when it was powered back up. I had origionally hooked up the tweeters with the amp powered up and had listened for a week before all the fun started. I thought Grey had blown up his amp at some point during testing but did not find the post on my quick trip though about 40 pages of this fun. I am curious why he hasn't finished but I will leave that up to him. I just got tired of messing with mine for awhile and will finish when I get motivated and not to get back in the middle of all this. I will standback and let you guys finish this. I am just trying to save some speakers and keep people from getting seriously pissed off in this project. I have read a ton of "shooting from the hip" stuff here (some of it absolute B.S.) and not much modeling, measurements , or serious observations from the major players on this project. There have been a few exceptions but mostly everybody is trying to get to the end result with doing much of the work. I am interested in this of course but I don't feel I owe anybody a debuged final design. It is too much work and I get too much crap for not telling everyone what they want to hear. Go read the first 10 or 15 post of mine in this thread and the fear and loathing it inspired. I got bitched at for refering someone to a web reference on phase margin instead of giving a half *** explantion the would not have enlightned any one. Talk about killing the messenger! I leave the task of finishing this design up to someone else more heroic than I. I would never turn pcbs for other people without hard wiring and testing one channel. It is not too complicated a design to do this and Peter and I have supplyed pictures of breadboard techniques in this very thread. As I said it is a matter on doing the work. Does everyone want to hack PCBs to debug for themselves, or will they wait for a debugged layout? And there is merit in either approach by the way just so everyone knows what they are getting into. Most of my engineering development projects called for pretty close PCBs with mods on them, but time is money in the real world. I talked a guy into 15 PCBs instead of a 100 once and we ended up with 30 wires and about 25 parts tacked on those guys before the next PCB turn. Guess who would have had to mod all hundred of them?Foesight is a wonderful thing but much harder than hindsight. Grey, you started this thing and even got behind the scences advice from Nelson Pass, as well as inspiring him to offer an incredable amount of input here. Why why not finish it out?
They say "Fools rush in, where angels fear to tread."
I'm no angel, but I am not rushing either,
Fred
Fred, HH or how ever. As you have experience with this:
I´m not EE and i have not tons of test equipment. If i read what you wrote i feel very uncmpfortable, because i´m going to use some really expensive loudspeakers in near future - see my horn experiments thread in Loudspeakers section. So the question: If i test positive a new amp has no oscillation. If i test a new amp for about 2 hours on an old loudspeaker playing music and including switch on and off without damage of the old loudspeaker, is it still dangerous to hook it at the expensive driver? What else may happen?
I´m not EE and i have not tons of test equipment. If i read what you wrote i feel very uncmpfortable, because i´m going to use some really expensive loudspeakers in near future - see my horn experiments thread in Loudspeakers section. So the question: If i test positive a new amp has no oscillation. If i test a new amp for about 2 hours on an old loudspeaker playing music and including switch on and off without damage of the old loudspeaker, is it still dangerous to hook it at the expensive driver? What else may happen?
Till,
I would suggest to continue testing until the amp has reached thermal stability. Depends on the heatsinks how long this will take. Why not run it for half a day or so? And always have a look at the idle current of the output stage. When it doesn't change any more you should have been waiting ling enough.
---
Holger
I would suggest to continue testing until the amp has reached thermal stability. Depends on the heatsinks how long this will take. Why not run it for half a day or so? And always have a look at the idle current of the output stage. When it doesn't change any more you should have been waiting ling enough.
---
Holger
I have hooked the amp up to some cheap test speakers.
Even heard the CD I had playing
The only issues I had where a slight hum which may be due to the way I am hooking up my unbal inputs.
And I have not ran the little guy long enough to reach thermal stability. About two hours, But the dc offset changes where slow.
Even heard the CD I had playing
The only issues I had where a slight hum which may be due to the way I am hooking up my unbal inputs.
And I have not ran the little guy long enough to reach thermal stability. About two hours, But the dc offset changes where slow.
I do not know exactly what is going on. It however suddenly reminds me of this. It's only a theory...!?!?
---------------------------------
“It’s only a theory.”
Theory and experiment play complementary roles in physics.
What are the hallmarks of a good theory?
(From a book, Physics)
---------------------------------
“It’s only a theory.”
Theory and experiment play complementary roles in physics.
What are the hallmarks of a good theory?
- It must work. It must agree with experiment. But the limitations of experimental test and the range of applicability must always be recognised.
- It has an extensive area of applicability.
- It relates a wide variety of disparate phenomena.
- It is simple, and therefore beautiful. The grand theories of physics have been extraordinarily simple, and it is both an esthetic preference as well as an act of faith for physicists to believe that when a theory is right it is also simple and elegant.
(From a book, Physics)
Hello jh6you,
Would you care to elaborate? The statements read well, but, what do they mean to you?
Would you care to elaborate? The statements read well, but, what do they mean to you?
Hrm...
Well, I hadn't planned on offering my PCB for others to use, as I can do without the hassle, and get them at a flat rate in small quantities anyway... but for anyone interested in waiting until I'm ready to have more fabbed (late Feb?), I will be able to offer an alternative Aleph-X PCB. It will be more expensive (approx. $35-40 each?), but "deluxe" version, and fully tested for stability, with stuffing footprints included for stabilizing capacitors on the feedback network, Q2 and Q11, and in the current sources. I will <i>not</i> provide gerber files or other layout artwork, schematics only (although I would provide layout previews of some sort so people can see what the board looks like).
Basic specs are (not yet finalized, BTW...):
- smaller form factor than wessol's board
- double sided, plated through (no ground plane)
- silkscreen & solder mask
- modified diff pair current source - set up to allow various options, at least for the prototype. Final version will probably use something resembling HH's current source with LM329/FET reference.
- power transistor footprints along one side of the board
But, anyone who wants one will have to be patient and wait till I have time to finish building and testing the prototype. Like Fred, I positively will not release boards until they are fully tested.
Well, I hadn't planned on offering my PCB for others to use, as I can do without the hassle, and get them at a flat rate in small quantities anyway... but for anyone interested in waiting until I'm ready to have more fabbed (late Feb?), I will be able to offer an alternative Aleph-X PCB. It will be more expensive (approx. $35-40 each?), but "deluxe" version, and fully tested for stability, with stuffing footprints included for stabilizing capacitors on the feedback network, Q2 and Q11, and in the current sources. I will <i>not</i> provide gerber files or other layout artwork, schematics only (although I would provide layout previews of some sort so people can see what the board looks like).
Basic specs are (not yet finalized, BTW...):
- smaller form factor than wessol's board
- double sided, plated through (no ground plane)
- silkscreen & solder mask
- modified diff pair current source - set up to allow various options, at least for the prototype. Final version will probably use something resembling HH's current source with LM329/FET reference.
- power transistor footprints along one side of the board
But, anyone who wants one will have to be patient and wait till I have time to finish building and testing the prototype. Like Fred, I positively will not release boards until they are fully tested.
(sorry for the long post, but I am just starting to catch up in this thread)
Well... I can get pcbs made for myself for free from my school, since I am doing a special topics audio engineering class with Dr. Leach, so if you need someone to test an Aleph-X board layout before making a mass order, I could do that.
board quality looks like this:
front:
http://brian.darg.net/aleph/aaq
back:
http://brian.darg.net/aleph/aao
They are just done on a milling machine. The silkscreen layer is etched into the substrate, and the bottom is etched into the copper. Double sided boards are possible (without plate through holes) as I have done for my leachpcb design:
http://brian.darg.net/albums/leachamppcb/abp.sized.jpg
I have been considering making a layout for myself and trying the Aleph X before I finish both channels of my Aleph 2, and have one channel of each to compare. I have my Aleph 2 monoblock chassis that I am working on that has 4 heatsinks with 3 IRFP240 devices on it. I can use this chassis now to test the Aleph-X
Here is a pic:
http://brian.darg.net/aleph/aaj
If a layout is decided on (I haven't followed the status of the circuit very much, besides looking at gray's circuit).
I would prefer a design that takes the aleph form factor (4x3 banks of devices) and changes the aleph 2 monoblock into a alephX monoblock. How much power of an Aleph-X could you run on a chassis capable of dissipating 300W? 50W? I think that would be a good target.
I was planning on doing a circuit layout myself and trying it in the aleph2 chassis, but I just haven't had time to start on this yet, and I have many other projects I need to finish first.
I realize that the design isn't exactly verified and testing. I have been waiting for Peter's to be done before starting mine.
I would like to see a fully expanded drawn out circuit for an Aleph-x with 4 banks of 3 devices and see how dissipation and power is calculated for this design. I assumed that it was simply twice the heat dissipation of the Aleph, since you have two halves. Does each half of the X circuit see half the output impedence? (wondering if it will run an 4 ohm load, meaning that the aleph leg would be driving a 2 ohm load possibly). When I get around to it, I will work on an expanded schematic. I just haven't put much time into looking over schematics, except for the first one posted by grey.
I should finish a few more of my projects this week, clearing the shelf for a new one.
If anyone can help me with dissipation and power figures for an aleph-X in an aleph 2 chassis, I would appreciate it. Are there any new schematics since the one grey posted, that can be used for a starting point?
edit: one more thing... I have access to a few labs of test equipment and a distortion analyzer. I will be able to run any tests on the finished design. I love having access to the school's ee labs.
--
Brian
Well... I can get pcbs made for myself for free from my school, since I am doing a special topics audio engineering class with Dr. Leach, so if you need someone to test an Aleph-X board layout before making a mass order, I could do that.
board quality looks like this:
front:
http://brian.darg.net/aleph/aaq
back:
http://brian.darg.net/aleph/aao
They are just done on a milling machine. The silkscreen layer is etched into the substrate, and the bottom is etched into the copper. Double sided boards are possible (without plate through holes) as I have done for my leachpcb design:
http://brian.darg.net/albums/leachamppcb/abp.sized.jpg
I have been considering making a layout for myself and trying the Aleph X before I finish both channels of my Aleph 2, and have one channel of each to compare. I have my Aleph 2 monoblock chassis that I am working on that has 4 heatsinks with 3 IRFP240 devices on it. I can use this chassis now to test the Aleph-X
Here is a pic:
http://brian.darg.net/aleph/aaj
If a layout is decided on (I haven't followed the status of the circuit very much, besides looking at gray's circuit).
I would prefer a design that takes the aleph form factor (4x3 banks of devices) and changes the aleph 2 monoblock into a alephX monoblock. How much power of an Aleph-X could you run on a chassis capable of dissipating 300W? 50W? I think that would be a good target.
I was planning on doing a circuit layout myself and trying it in the aleph2 chassis, but I just haven't had time to start on this yet, and I have many other projects I need to finish first.
I realize that the design isn't exactly verified and testing. I have been waiting for Peter's to be done before starting mine.
I would like to see a fully expanded drawn out circuit for an Aleph-x with 4 banks of 3 devices and see how dissipation and power is calculated for this design. I assumed that it was simply twice the heat dissipation of the Aleph, since you have two halves. Does each half of the X circuit see half the output impedence? (wondering if it will run an 4 ohm load, meaning that the aleph leg would be driving a 2 ohm load possibly). When I get around to it, I will work on an expanded schematic. I just haven't put much time into looking over schematics, except for the first one posted by grey.
I should finish a few more of my projects this week, clearing the shelf for a new one.
If anyone can help me with dissipation and power figures for an aleph-X in an aleph 2 chassis, I would appreciate it. Are there any new schematics since the one grey posted, that can be used for a starting point?
edit: one more thing... I have access to a few labs of test equipment and a distortion analyzer. I will be able to run any tests on the finished design. I love having access to the school's ee labs.
--
Brian
I currently have my X warming up to see how long it takes to stablize.
I am using Carpenter's pc board layout.
In place of the original 4.7k resistors I am using the
suggested 1k, otherwise all parts are the same as Grey's
original design.
If anyone would like any mesurments
I have a scope meter and would be willing to provide
them.
I am using Carpenter's pc board layout.
In place of the original 4.7k resistors I am using the
suggested 1k, otherwise all parts are the same as Grey's
original design.
If anyone would like any mesurments
I have a scope meter and would be willing to provide
them.