Preamp discussion

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Steve

Re: Preamp discussion
« Reply #40 on: 5 Dec 2015, 04:03 am »
Davey:
Quote
Well, chokes don't regulate....they filter.

  Oops bad choice of wording thanyou for the correction without insult. Much appreciated.


charles

Actually Charles, you are correct in the sense that "swinging" chokes tend to keep the dc voltage constant, with inductance varying vs current draw. Design is such that the inductance is sufficient at minimum current draw so the filtering system does not act like a capacitor input filter, yet under maximum current draw the dc voltage does not droop unnecessarily. So the voltage tends to remain constant under varying loads. 

It is normally placed at the input of the filtering system for maximum effectiveness. Dave is correct in that one does not necessarily see such chokes used that often.

Cheers
Steve

Davey

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Re: Preamp discussion
« Reply #41 on: 5 Dec 2015, 04:25 am »
In this particular case I think we can assume the current draw from the preamp will be near constant.  (It would be very easy to measure to confirm that.)
"Regulation" generally refers to some sort of active regulation that holds output voltage constant with varying voltage input and/or varying current output requirements.
I imagine the Dodd battery preamp has no PS regulation at all in its stock form.....but somebody can correct me if I'm wrong on that.

Dave.

Steve

Re: Preamp discussion
« Reply #42 on: 5 Dec 2015, 04:34 am »
In this particular case I think we can assume the current draw from the preamp will be near constant.  (It would be very easy to measure to confirm that.)
"Regulation" generally refers to some sort of active regulation that holds output voltage constant with varying voltage input and/or varying current output requirements.
I imagine the Dodd battery preamp has no PS regulation at all in its stock form.....but somebody can correct me if I'm wrong on that.

Dave.
Yes Davey, except when the power is initiated the voltage will rise imitating a capacitive input filtering system until current draw occurs, either because of the plate current or other load such as a resistor presenting minimum current for maximum inductance of the swinging choke.

Of course you are correct as with batteries no choke is necessary.

Cheers
Steve

G Georgopoulos

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Re: Preamp discussion
« Reply #43 on: 5 Dec 2015, 04:54 am »

I imagine the Dodd battery preamp has no PS regulation at all in its stock form.....but somebody can correct me if I'm wrong on that.

Dave.

there is no need for regulation,voltage is stepped up,and it works like high tension unregulated ps (i'm guessing dont know the preamp).... :green:

G Georgopoulos

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Re: Preamp discussion
« Reply #44 on: 5 Dec 2015, 04:59 am »
voltage regulation is provided by the battery constant voltage... :green:

Davey

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Re: Preamp discussion
« Reply #45 on: 5 Dec 2015, 05:03 am »
voltage regulation is provided by the battery constant voltage... :green:

No, not really.  Battery voltage is never constant when under discharge conditions.
I've actually seen a few designs that use batteries as the power source but still employ active regulation downstream.  There are still advantages to this approach, although battery "purists" might not think so.  :)

Dave.

G Georgopoulos

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Re: Preamp discussion
« Reply #46 on: 5 Dec 2015, 05:09 am »
it's because of small batteries,Gary's preamp uses big ones... :green:

Folsom

Re: Preamp discussion
« Reply #47 on: 5 Dec 2015, 07:02 am »
Artifacts sounds good, so why not. Yes, artifacts it is.

If I defined "properly" I would have to reveal/teach electronic engineering principles and designing. I do not give away design principles cheap.

If you don't understand my description of the 11A in my previous post, it adds nothing nor subtracts nothing via years of listening testing, it does not alter the sonic/musical information. Dynamics, clarity, imaging, detail, depth, width, does not change. It reveals all the natural music that is recorded. It took decades and a lot of research/development/listening testing, and lots of money. You are more than welcome to come by for an audition.  :)

The main points I meant to address are presented in my previous post.

Cheers
Steve

Where are you located? The alternative is I improve your unit, see what you think.

Davey

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Re: Preamp discussion
« Reply #48 on: 5 Dec 2015, 03:45 pm »
it's because of small batteries,Gary's preamp uses big ones... :green:

Well, in this case it's irrelevant anyways since Charles is interested in getting rid of the batteries.  :)

It seems Steve has ideas for this application, but he's not going to offer up anything without getting paid for it.
So, what type of supply would you recommend?  Some sort of series-regulated scheme?  Some sort of shunt-regulated scheme?  Maybe a supply without active regulation?  Reconfigure the Dodd preamp circuitry so a low volt supply is not required?  Or maybe some other option???

Dave.

Steve

Re: Preamp discussion
« Reply #49 on: 5 Dec 2015, 07:31 pm »
Where are you located? The alternative is I improve your unit, see what you think.

How are you going to improve upon perfection???? You are not making sense.
(I am retired and taking care of mom, so not selling.) Just one string.

http://www.audiocircle.com/index.php?topic=114637.0

Char1 is a phd who was a college professor and reviewing for PBS in Florida.

Cheers
Steve

Folsom

Re: Preamp discussion
« Reply #50 on: 5 Dec 2015, 08:31 pm »
Only one way to find out :thumb:

Steve

Re: Preamp discussion
« Reply #51 on: 5 Dec 2015, 09:04 pm »
Only one way to find out :thumb:

We all know that is not true by definition. :roll: Of course if one can dice the 11A, then one can falsely claim
batteries are superior. However, since the 11A is perfect/natural, there is no distortion from the power supply,
no need for batteries, and no need for expensive power cords.

Cheers
Steve

Folsom

Re: Preamp discussion
« Reply #52 on: 5 Dec 2015, 09:34 pm »
Ok Steve, whatever.


Davey, first do you have any idea what the ampere requirement is on the unit? That's important.

You can bet that it can handle a small range of voltages, but it needs proper current (ampere). There's numerous low noise regulated and unregulated power supplies abound. Some of the better ones that have exceptional performance only have small output current; hence knowing what you need is important.

Some regulated designs have much lower noise than other designs, but some don't. So that's not an easy question. I don't see any point in changing the voltage of the appliance. In fact if it varies too far it might create biasing problems with the tubes, or blow capacitors. How about some questions that will help us help you.

1. What are the ampere requirements
2. What's your budget?
3. What level of DIY would be interested in?
 a. I'll build anything with a schematic, and put it in a box
 b. I can solder PCB's that have an easy layout and put it in a box
 c. If it's modules I can put it in a box
 d. I can probably change the end of a supply cable to mate to my preamp

Jonathon Janusz

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Re: Preamp discussion
« Reply #53 on: 5 Dec 2015, 09:40 pm »
I've actually seen a few designs that use batteries as the power source but still employ active regulation downstream.

Not knowing all of its inner workings, isn't this what a product like the BatteryBUSS from P.I. Audio does for the battery supplying power to the preamp?  I just wanted to make this noted, as the impression was made earlier that a battery and charger eliminates everything else needed in a power conditioning chain to optimize sound quality gains,  but like everything else in audio it looks clear to me that the whole debate between AC vs. battery power is a discussion of approaching the same problem from two different directions where it again is the complete solution that ultimately matters.  Like many wiser men than I have told me and said before me, "Everything has an effect on everything, and everything matters."

I'm just as interested as anyone in finding a way of getting all the benefits of batteries without the batteries.  I was very impressed by Vinnie's LIO implementation as a way, if not debatably to get all the way there, to get very close.  Other than adding more fiddly bits with a battery solution, financially, my other objection to it has been that unless you run the whole system on batteries, something is still going to be on the AC power, needing all the expense of managing that AC power, so theoretically if chasing the last 1% of sound quality, it just seems like adding on top of the total cost of entry instead of bringing the whole cost down.

We all know that is not true by definition. :roll: Of course if one can dice the 11A, then one can claim
batteries are superior. However, since the 11A is perfect/natural, then there is no better, by definition.
But just as important, no distortion from the power supply and no need for batteries.

Cheers
Steve

Respectfully, reading the references you provided, I would not argue that the 11A may be very, very good.  I don't know first hand, as I have not heard one, but it is regarded in very good company. 

Considering the many opinions here on AudioCircle as a start, the challenges continuously debated in objectively measuring everything having to do with an admittedly not completely understood science of sound reproduction and the resulting human interaction with it, and the completely subjective positions of people filling in the missing pieces as best they can, saying any audio device (or anything created by human hand for that matter) is "perfect" is a stretch to put it politely and casting a hard line in the sand suggesting otherwise probably isn't going to go very far in backing that claim.

ebag4

Re: Preamp discussion
« Reply #54 on: 5 Dec 2015, 09:51 pm »
Considering the many opinions here on AudioCircle as a start, the challenges continuously debated in objectively measuring everything having to do with an admittedly not completely understood science of sound reproduction and the resulting human interaction with it, and the completely subjective positions of people filling in the missing pieces as best they can, saying any audio device (or anything created by human hand for that matter) is "perfect" is a stretch to put it politely and casting a hard line in the sand suggesting otherwise probably isn't going to go very far in backing that claim.
+1, well said.

Best,
Ed

Folsom

Re: Preamp discussion
« Reply #55 on: 5 Dec 2015, 10:02 pm »
Measurements are good indicators for what you might hear. Sometimes I get people asking for measurements, and my first thought is, who cares? :lol: Everything that sounds good to me sounds the same even after I measure it. Important things are impedance and power matching.

Sure, experimental stuff gets plugged into LTspice to find out of it's going to work at all, but that's not the end game. My Walkman from when I was 10 years old had an output signal that appears the same as the sources signal, and low distortion. Anyone want to borrow it? No... But it's got lower distortion than a pair of Lamm M2.2 amplifiers! Nope... no one cares.

Steve

Re: Preamp discussion
« Reply #56 on: 5 Dec 2015, 10:23 pm »
Respectfully, reading the references you provided, I would not argue that the 11A may be very, very good.  I don't know first hand, as I have not heard one, but it is regarded in very good company. 

Considering the many opinions here on AudioCircle as a start, the challenges continuously debated in objectively measuring everything having to do with an admittedly not completely understood science of sound reproduction and the resulting human interaction with it, and the completely subjective positions of people filling in the missing pieces as best they can, saying any audio device (or anything created by human hand for that matter) is "perfect" is a stretch to put it politely and casting a hard line in the sand suggesting otherwise probably isn't going to go very far in backing that claim.

Jonathon, if you had actually read my previous posts on this string, you would have seen that the 11A has been listening tested for years. In fact I mentioned using speakers up to 28 grand. (Interesting you would not quote me.) In fact I have not mentioned measurements once in my posts on this string, so why the claim that I stated the exact opposite of what I actually posted.   :roll:

And what is your opinion of no perfection based on? Amateurs/diyers claiming to be industry participants? Dodd made a good move by using batteries as he eliminates the mistakes of almost all designers in building a power supply.

Just because most cannot do it, doesn't mean no one can.

Our purpose here is to help the public.

Cheers
Steve
« Last Edit: 8 Dec 2015, 10:40 pm by Steve »

Davey

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Re: Preamp discussion
« Reply #57 on: 5 Dec 2015, 11:23 pm »
Davey, first do you have any idea what the ampere requirement is on the unit? That's important.

Obviously it's important.  That's why I asked the question back on page 2 of this thread.  :)
http://www.audiocircle.com/index.php?topic=139075.msg1481241#msg1481241
Apparently, nobody has made this simple measurement on one of the units.  :)  I can estimate it pretty well, but it would be nice to have an actual measurement.

Dave.

Folsom

Re: Preamp discussion
« Reply #58 on: 5 Dec 2015, 11:35 pm »
It's a bit harder to measure than voltage. You can figure it out if you know the values of the parts (I do not).

The other questions are important too. It's possible to have it evaluated (PM me), but is it worth the $? For example maybe just try an Astron because it'll work fine.

Davey

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Re: Preamp discussion
« Reply #59 on: 6 Dec 2015, 12:05 am »
It couldn't be easier to measure.  You just put your ammeter across the fuse clips and then pry one end of the fuse up.

Dave.