Nixie:
I am sure Hilbert got it from not being natively english speaking
How hard can that be to figure out
(Allthough Hilberts english is above average at that!)
Anyways, in an international place like this forum, those having english as their language of birth (I presume you are, since you dont write like a french-speaking canadian), should try and be just a little bit forgiving. A correction might be in order, but getting carried away doesnt help anyone
Steen
steenoe said:Nixie:
I am sure Hilbert got it from not being natively english speaking
(Allthough Hilberts english is above average at that!)
Anyways, in an international place like this forum, those having english as their language of birth (I presume you are, since you dont write like a french-speaking canadian), should try and be just a little bit forgiving. A correction might be in order, but getting carried away doesnt help anyone
Steen
Thank's for the kind support, steenoe! You are right, English is not my native tongue. The fact that I did not read the post properly didn't help either. It could be argued that the verb switch does not specifically imply the use of a switch, but that would be splitting hairs, since when rereading the post I realised I missread it the first time. I'm sure no offence was intended.
hilbert
Hi Hibert,
you could try to build an Aleph 0-X. This one (aleph 0) had just what you´ve described above. You can make it into an X in just the same way as a normal Aleph.
When you say you don´t mind a bit of distortion you could set the ac-current gain as high as 70-75% for some more peak capability.
My Aleph 5 ran at 65% with my Thiels and sounded better this way than with 50% and clipping.
William
you could try to build an Aleph 0-X. This one (aleph 0) had just what you´ve described above. You can make it into an X in just the same way as a normal Aleph.
When you say you don´t mind a bit of distortion you could set the ac-current gain as high as 70-75% for some more peak capability.
My Aleph 5 ran at 65% with my Thiels and sounded better this way than with 50% and clipping.
William
wuffwaff said:
Aha! Utopia does exist!
I might try Aleph 0 X eventually.
This might end in the most versatile amp ever. If I have neat sinks (heh, hrm...) that can be hooked up to a closed-loop water cooling system or just air cooled with reduced dissipation and if I include a three way switch (the physical device, not a minion with a soldering iron) that can set the amp for (1) 20W class A into 2-4 ohms, (2) 20 W class A into 4-8 ohms or (3) Full Throttle (WARNING! Use water cooling) and use the Aleph 0 topology, I can do whatever I want! For normal everyday listening at levels that will keep my neighbors (and their feline friends, sabre tooth or not) happy I'll be running pure class A, with the switch set for what ever speaker I have connected. Then when I want to crank it at the house party I can let it run into AB oblivion, or I can heat the mead and run full class A hooked to any old reactive impedance you care to throw at me.
Thank you William!
Hilbert
I am not familiar with the aleph 0-X, but I have been considering an idea for multiple bias. I have an aleph mini that I changed out the two .33 ohm resistors in series with the output devices to reduce the bias current. A simple three way switch could be installed to switch back and forth between a 1 or 2 ohm resistor and a .33.
Not sure if I would try flipping the switch hot....
BTW--what effect would this have on the ratio of CCS to gain device current -- I just started re-reading the ZV2 article to work this out, but I am sure somene already knows the answer....
Not sure if I would try flipping the switch hot....
BTW--what effect would this have on the ratio of CCS to gain device current -- I just started re-reading the ZV2 article to work this out, but I am sure somene already knows the answer....
I wouldnt worry too much about wanting to go into class A/B. Since the Aleph-X is single-ended class A, its not easy to make it do that. (The X-amps are push/pull) A 100 watt A-X does a good job, driving most speakers. Just adjust the CCS current gain accordingly (high'ish, with bad (low impedance dropping )speakers). My speakers are less than 86dB sensitive, but the A-X's can really rock them Considering the environmental aspect (you have to, these days) how many hours is the amp turned on? In general 2-3 hours a day, in my instance. Sometimes 24 hours, sometimes none Whatever, boot it up, half an hour before you want to listen seriously to it
Here is mine: http://www.diyaudio.com/forums/showthread.php?s=&threadid=93194
Steen
Considering the environmental aspect (you have to, these days) how many hours is the amp turned on? In general 2-3 hours a day, in my instance. Sometimes 24 hours, sometimes none Whatever, boot it up, half an hour before you want to listen seriously to it Here is mine: http://www.diyaudio.com/forums/showthread.php?s=&threadid=93194
Steen
steenoe said:
Hey, nice radiators Steen, I'm sure you are having a warm winter
Peltiers don't get rid of heat, they just move it around. Of course, the same is true of 'regular' heatsinks, too, but a lot of people seem to be under the impression that if you stick a Peltier on something that the heat gets slurped into the power line in some manner.
It is possible to 'X' many different kinds of circuits. The thing to remember is that you'll end up with a bridged amplifier. For the same output wattage, you'll halve the rails and double the bias current. The central element is a differential that serves as the "brain" of the thing. Once you decide on a circuit and hook two of them to the differential you'll have to hook up the feedback properly, depending on whether the circuit you've chosen is inverting or non-inverting.
The link given to my stories earlier is both incomplete and out of date; that's only about half of what I've written.
Grey
It is possible to 'X' many different kinds of circuits. The thing to remember is that you'll end up with a bridged amplifier. For the same output wattage, you'll halve the rails and double the bias current. The central element is a differential that serves as the "brain" of the thing. Once you decide on a circuit and hook two of them to the differential you'll have to hook up the feedback properly, depending on whether the circuit you've chosen is inverting or non-inverting.
The link given to my stories earlier is both incomplete and out of date; that's only about half of what I've written.
Grey
GRollins said:
That is true, but they do transfer the heat away from the FETs, thereby at least lowering the junction temp somewhat. Still need good dissipation from the sinks of course. Maybe I should follow the trend and steal myself a copper church roof. That should be enough copper for a pair of decent heat sinks.
Has anyone tried heatpipes, btw?
Yes, that took me a while to figure out. It helped a lot to read the SOX article at passdiy.com. He is one smart feller, that Mr Pass!
I suppose you could X an AB cirquit as well, but maybe that would be futile.
Is there an updated list somewhere else, perhaps?
Nixie said:
"When you assume, you make an *** of u and me". I would say that Steen's remark was kind of flattering, though, don't you think? It's not bad to be passing as natively writing English, when you've only known the language half you life. Please excuse us of lesser linguistic talent if we misinterpret what is being written. The main goal, I'm sure we all agree, should be to get the message across, right?
Hilbert
jacco vermeulen said:
Yes, that is of course a problem... Maybe some resourceful diy:er should start manufacturing them for Class A amp use?
No, at least at my university we have to write in English, so yes, I do get some extra practice, although the people proof reading my papers are also Swedish, so it might be a case of blind leading blind, in some sense.
Hilbert
jacco vermeulen said:Okidoki, then you have permission to read some of Mr Rollins's short stories first
Thank you! I am doing way too much procrastination as it is, but I might rotate between different types of it. Reading posts or reading short stories, for example.
See! I have no clue what I'm saying. Here people actually read what I write. My thesis will be read by my supervisor and my oponent. That's it. If they suck at English, I'm home free!
Hilbert
voltage question
I am bringing up my a-x's (stereo pair) and had a question about the rail voltages...
I am using a C-R-C power supply and using thermistors for the R
I am seeing a slight difference between the positive voltage rail +15.2 (WRT ground) and the negative voltage rail -15.6 (WRT ground). I am not finished dialing everything in with the housing panels in place, so these values will probably move around a bit. (as the bias currents change, the thermistor's resistance changes)
My question is what would be an acceptable/desirable difference for the + and minus rail voltages?
Thanks,
Jeff
P.S. I will post pictures as I finish up.
I am bringing up my a-x's (stereo pair) and had a question about the rail voltages...
I am using a C-R-C power supply and using thermistors for the R
I am seeing a slight difference between the positive voltage rail +15.2 (WRT ground) and the negative voltage rail -15.6 (WRT ground). I am not finished dialing everything in with the housing panels in place, so these values will probably move around a bit. (as the bias currents change, the thermistor's resistance changes)
My question is what would be an acceptable/desirable difference for the + and minus rail voltages?
Thanks,
Jeff
P.S. I will post pictures as I finish up.
Re: voltage question
Not being one of your hellfire-'n-brimstone religious folks, perhaps I'm getting this wrong, but if the topic is religion and you've got as much heat as a class A amp dissipates, then wouldn't that be hell instead of heaven? Perhaps it would be more appropriate to steal the copper off a Satanist church?
Yep, so futile that's it's the basis of the entire "X" line at Pass Labs.
The last I saw, there was a search function at www.analogsf.com that stayed fairly current. That should cover 99% of everything I've ever had published.
Thermistors aren't as tightly matched as you might wish. Some evening when you're bored, sit down and match them. That should get rid of the problem. In the meantime, I wouldn't lose any sleep over a .4V difference in the rails.
Grey
hilbert said:
Not being one of your hellfire-'n-brimstone religious folks, perhaps I'm getting this wrong, but if the topic is religion and you've got as much heat as a class A amp dissipates, then wouldn't that be hell instead of heaven? Perhaps it would be more appropriate to steal the copper off a Satanist church?
Yep, so futile that's it's the basis of the entire "X" line at Pass Labs.
The last I saw, there was a search function at www.analogsf.com that stayed fairly current. That should cover 99% of everything I've ever had published.
yup said:
Thermistors aren't as tightly matched as you might wish. Some evening when you're bored, sit down and match them. That should get rid of the problem. In the meantime, I wouldn't lose any sleep over a .4V difference in the rails.
Grey