Re: Re: Re: external PS
tms0425 said:
I should have said not so great for higher current. They are made for signal, but the pins are still pretty robust. You might take a look at a Neutrik spec sheet to find out how much current. An F5 could peak 8-10amps, with 5 or 6 amps idle for two channels. While they might work electrically, I don't like mixing connectors intended for signal and quite commonly used for it with power. Someone plugs that in wrong and you have a mess (e.g. 24vdc high current shorted to ground or something)mithomas said:
The standard powercon connectors are rated at 20 amps. There is a new model that will do 32 amps at 250 volts. The standard 2 conductor Speakon connectors are rated at 30 amps and 250 volts. They also make a 4 pin speakon connector that is good for 40 amps continuous. I use these at work in a DC power generating application. Very slick and easy to use connectors. The plus to the powercons is that they make 2 versions that are keyed differently. One is intended as power out and the other as power in. I plan to use them as DC power for one cable set and AC power for the other. That way no one can plug in the wrong power type.
so ... nice weather we've been having lately huh?
yup ...
so ... does anyone know what this thing sounds like yet?
... and also cares to share that with us too?
< scurry away >
someone of course, aside from Papa
(almost 750 posts and nobody has pictures of one completed yet)
Of course, it's summer now in the northern hemisphere and I suspect Steenoe is spending his time out fishing or chasing other slippery objects of his affections
The nice thing about the Neutrik Powercon connectors is that they come in colors and the colors are mutually incompatible. That way you can have a power amp rail and a preamp rail and you need not fear that you will plug + 60V amp rails into a preamp designed for + 20V. They lock. They're inexpensive. A very tidy solution to a vexing problem.
A friend of mine has a CAT Signature preamp that has a dedicated, undetachable cable between the remote power supply and the main chassis. The thing is stiff as hell and utterly horrible to work with if you need to move the preamp, as the preamp and the power supply are each quite heavy, yet you're left with no choice but to move both at the same time. Even if you have two people and one carries the circuit, the other the power supply, it's awkward to be tethered by a mere meter or so of cable like that.
Yes, I'm well aware that you've inserted physical connections in the power supply lines that are technically avoidable; they may even deteriorate the sound to some degree. If it leads to a circuit that is impossible (or nearly so) to live with, then I can't sign off on a piece of gear that has to be assembled in situ before you can listen to it.
My subs are the last "unmovable" things I will ever build. They weigh something on the order of 250-300 pounds per side and I have no one to help me move them if I want to try a different room placement. I did it to myself. I'm not blaming anyone else. But I'm also smart enough to learn from my mistakes.
The question is: Are you smart enough to my mistakes?
Grey
A friend of mine has a CAT Signature preamp that has a dedicated, undetachable cable between the remote power supply and the main chassis. The thing is stiff as hell and utterly horrible to work with if you need to move the preamp, as the preamp and the power supply are each quite heavy, yet you're left with no choice but to move both at the same time. Even if you have two people and one carries the circuit, the other the power supply, it's awkward to be tethered by a mere meter or so of cable like that.
Yes, I'm well aware that you've inserted physical connections in the power supply lines that are technically avoidable; they may even deteriorate the sound to some degree. If it leads to a circuit that is impossible (or nearly so) to live with, then I can't sign off on a piece of gear that has to be assembled in situ before you can listen to it.
My subs are the last "unmovable" things I will ever build. They weigh something on the order of 250-300 pounds per side and I have no one to help me move them if I want to try a different room placement. I did it to myself. I'm not blaming anyone else. But I'm also smart enough to learn from my mistakes.
The question is: Are you smart enough to my mistakes?
Grey
twitchie said:
Here's a prototype with lateral MOSFET's -- it does its thermal thing just fine -- there are 3 on a side which I suspect is about one more than necessary.
An externally hosted image should be here but it was not working when we last tested it.
The lateral MOSFETs won't take the punishment which the IRFP240/9240's will.
I had the vertical MOSFET prototype working just fine, glanced over to the bench to see it smoking
The 0.47R/5W resistors are Ohmite TWW5JR47 -- DK doesn't carry them anymore (Avnet has them, and I still have a bunch on my webstore.) The feedback resistors are left over from another project -- I don't recall if they are Ohmite or Caddock 35W TO-220. I am sure that the 15W TO-126 would work equally well, or you could parallel a pair of 3W as NP suggests in his article. The TO-220 and TO-126 resistors are pretty expensive for this kind of project.
twitchie said:
OK, OK. I suppose I ought to help you poor babies.
What to compare to....
The F4 is the closest relative. They both have a clean extended
bottom and I consider them almost equivalent, with neither
having a distinct advantage.
The F4 is a little bit warmer in the mid, and might be preferred on
simple material at modest volume levels, that is to say a solo
vocal or instrument or maybe a string quartet. You could say
it's a little more tubey.
As the volume rises and the complexity of the material increases,
the F5 pulls ahead by retaining more clarity - specifically less
IM type distortion. As a result it does a better job with
articulation of instruments - there is a little less smearing,
If you have a pair of full range drivers, Lowther PM6A or
Feastrex D9nf, the F5 brightens the top end up just a bit,
adding a touch of tintinabulation that we all like, although it also
heightens the perception of response peaks a little more.
In this category, if you find the high efficiency full rangers too bright
with the F4 or F5, the F3 is perhaps the more appropriate amp.
The imaging is very good with both of these amps in my system,
and I haven't heard enough difference to make a decision on that,
but the localization is pleasing. The open baffle speakers I'm
using already have a big ambient sound stage, and would
probably do that with any decent amplifier.
The F4 is a little more relaxed all round, the F5 carries a little more
detail.
Now go out and play.
twitchie said:
so ... nice weather we've been having lately huh?
yup ...
so ... does anyone know what this thing sounds like yet?
... and also cares to share that with us too?
< scurry away >
someone of course, aside from Papa
(almost 750 posts and nobody has pictures of one completed yet)
Of course, it's summer now in the northern hemisphere and I suspect Steenoe is spending his time out fishing or chasing other slippery objects of his affections
look
HERE
and few posts down
more than 2 yrs ago ;
made by my friend Oly , as result of mine hysteric Babelfish J conundrum ;
as you can see - with all differences , most important one (of many) certainly is difference in feedback arrangement , which is in F5 natural implementation of feedback from toob world
I'm pretty sure that F5 sounds pretty simillar to little Oly's symmetric amp , or vice versa .
so - my conclusion is - it sings pretty much in same league as Babelfish J ( or Aleph J ,whatever ) with minor difference - it's more capable to drive more demanding spks ;
you can place here usual mumbling about preferences/taste for odd vs. even harmonics in THD spectra .....
one more time - you can see what Papa's lateral thinking is ;
ordinary amp designer always look and chase equal impedances on both sides of diff stage ; Papa just neglected diff stage ( or LTP , in any of incarnations ) , making space for something not new , but certainly not seen so lately .
I can write more , but I'm lazy ....... don't count on my awareness what I'm actually writing
edit:
Papa- this time you spoiled my answer ....... while I'm typing .....
Zen Mod said:
look
HERE
and few posts down
more than 2 yrs ago ;
made by my friend Oly , as result of mine hysteric Babelfish J conundrum ;
as you can see - with all differences , most important one (of many) certainly is difference in feedback arrangement , which is in F5 natural implementation of feedback from toob world
I'm pretty sure that F5 sounds pretty simillar to little Oly's symmetric amp ....... while I'm typing .....
Hey Zen Mod did you (or little Oly) build this symmetric amp.
Ot you just
Zen Mod said:
I prototyped that circuit once upon a time, and I was a little
disappointed, but I can attribute that mostly to IR P channels
operated Common Source. Other P channel parts will work better
for this.
Still, I don't expect that it will sound that similar - the diff pairs on
the input do have a different character to them. Relying on (bad)
memory, I think that the F5 has a more extended top end.
Nelson Pass said:
yeah,Papa , I learned that lesson form you ; in fact - used parts were IR IRFP140 and Fairchild IRFP9240 ( sorta better complement ? )
Nelson Pass said:
I meant that I expect that F5 is similar , and certainly better ( what I wrote , if I can trust my bad memory ........ ) ; what one can expect from that Baldrick-like
clever feedback arrangement...... I remember - when I was a kidoe - making my first OP based preamp ; first one was anemic ; just later - when I change (maybe even just by mistake , not because of any lucida intervala ) feedback net to low impedance one , funny little OP based thingie almost started to sing ... maybe these audio electrons just prefers easiest paths
so - my conclusion is that - even if I didn't make your (our?) newest toy , I think that I have slight idea how it sounds .... better than little Oly's amp , but similar in character .
regarding Oly's , Plantefeve's and similar amps ...... for me - electronics is somewhat as Jazz - take already well known tune (standard) , make it by your way - you have your tune ; better or worse that other interpretations - another issue , but certainly your
F5 is jewel ; not exactly break-trough as Alephs and SUSY , but certainly example of cunningness .........
is it really easiest to see Buda in details ?
I am gathering parts for the F5 from Digikey and two issues come up:
1. Digikey carries Dale RN resistors, but at 0.1 and 0.05 W. So, it is better to use these or to use the ones from Yageo?
2. What part number should I use for the thermistors?
Sorry for the questions, but this is not my expertise after all
I remember when I made a Zen V4, parts list included in the article
1. Digikey carries Dale RN resistors, but at 0.1 and 0.05 W. So, it is better to use these or to use the ones from Yageo?
2. What part number should I use for the thermistors?
Sorry for the questions, but this is not my expertise after all
I remember when I made a Zen V4, parts list included in the article