Preamp discussion

S Clark · « **on:** 2 Dec 2015, 03:54 pm »

Quote from: Davey on 2 Dec 2015, 03:24 pm

Charles, if you build the right power supply, the performance of your unit will not be degraded at all.

Dave.

Danny has experience with the unit, and therefore earned credibility. Charles is about to do the same.
I like to listen to those with experience with the units in question.

Davey · « **Reply #1 on:** 2 Dec 2015, 04:08 pm »

Quote from: S Clark on 2 Dec 2015, 03:54 pm

Danny has experience with the unit, and therefore earned credibility. Charles is about to do the same.
I like to listen to those with experience with the units in question.

Read Dave's post at the top of this page. He's correct....in my opinion.

Resorting to the first-hand experience explanation to discount opinions is silly. People with solid engineering backgrounds and experience on many types of equipment can provide knowledgeable input on subjects even though they don't have first-hand experience.

I've never driven a Ferrari, but I'm perfectly willing to acknowledge the superior engineering without first-hand experience.

Cheers,

Dave.

ebag4 · « **Reply #2 on:** 2 Dec 2015, 05:30 pm »

Quote from: Davey on 2 Dec 2015, 04:08 pm

Resorting to the first-hand experience explanation to discount opinions is silly. People with solid engineering backgrounds and experience on many types of equipment can provide knowledgeable input on subjects even though they don't have first-hand experience.

What you seem to be discounting is the gentleman who designed the equipment in question, who meets your stated criteria, made a conscious choice to drive his pre with a battery, not because it was easier, because for most, building a power supply to plug into the wall would be easier, but because he believed it sounded best this way. So yes, people including the designer with first hand experience with this equipment absolutely have credibility over those who have no experience with this unit.

Best,
Ed

Davey · « **Reply #3 on:** 2 Dec 2015, 06:04 pm »

Did you see me discounting Gary's design of this unit? If you did, I think you better re-read my posts.

Read closely and don't read anything into them that's not there.

As it happens, my own USB/DAC/preamp is currently under battery power since the original power supply developed a problem. It works just fine.....although I do have to pull the batteries off and charge them every few days.

Cheers,

Dave.

ebag4 · « **Reply #4 on:** 2 Dec 2015, 06:09 pm »

Quote from: Davey on 2 Dec 2015, 06:04 pm

Did you see me discounting Gary's design of this unit?

No, just his choice of power source.

Best,
Ed

Davey · « **Reply #5 on:** 2 Dec 2015, 06:24 pm »

Quote from: ebag4 on 2 Dec 2015, 06:09 pm

No, just his choice of power source.

No I didn't. I said there wasn't anything "inherently superior about a battery supply system."

I will stipulate that battery supplies eliminate many potential issues that might be incurred if using a conventional AC/DC supply. But, that doesn't automatically mean they will out-perform the alternative.....either subjectively or in the Lab. (Many variables at work here.)

This is the Lab Circle after all. I would be interested in seeing some comparison (lab) measurements of a Dodd preamp powered both by a battery setup and by a conventional power supply setup. That would identify any 60Hz leakage into the audio circuitry and/or other relative issues. Maybe Charles could provide these during his effort? That's objective data that would be interesting.

If PS internal resistance is the primary objective here, there are better alternatives than SLA batteries.

Subjective evaluations are incontrovertible.

Cheers,

Dave.

ebag4 · « **Reply #6 on:** 3 Dec 2015, 01:47 am »

Quote from: Davey on 2 Dec 2015, 06:24 pm

This is the Lab Circle after all.

Yes it is, carry on.

Best,
Ed

playntheblues · « **Reply #7 on:** 3 Dec 2015, 01:55 am »

I have an unopened CTEK if anyone is interested.

G Georgopoulos · « **Reply #8 on:** 3 Dec 2015, 02:08 am »

Quote from: Davey on 2 Dec 2015, 06:24 pm

No I didn't. I said there wasn't anything "inherently superior about a battery supply system."

I will stipulate that battery supplies eliminate many potential issues that might be incurred if using a conventional AC/DC supply. But, that doesn't automatically mean they will out-perform the alternative.....either subjectively or in the Lab. (Many variables at work here.)

This is the Lab Circle after all. I would be interested in seeing some comparison (lab) measurements of a Dodd preamp powered both by a battery setup and by a conventional power supply setup. That would identify any 60Hz leakage into the audio circuitry and/or other relative issues. Maybe Charles could provide these during his effort? That's objective data that would be interesting.

If PS internal resistance is the primary objective here, there are better alternatives than SLA batteries.

Subjective evaluations are incontrovertible.

Cheers,

Dave.

I agree with you dave,however simple to simple designs between ps and battery,battery has less noise..

cheers...

Davey · « **Reply #9 on:** 3 Dec 2015, 03:09 am »

Battery supplies, intuitively, have a clean concept and execution. I can understand why some folks think there are more check marks in the positive column than in the negative column relative to conventional supplies. I don't disagree with that actually, but in the engineering world it's always more complicated than it seems. You CAN achieve excellent results with a conventional power supply setup as well.

You're talking to a guy who cut his EE teeth many years ago working on silver-zinc (and a variety of other) battery systems for underwater vehicles. This is a topic I know a little bit about.

In any case, the Dodd preamp we're talking about here isn't even close to being the weak link in a listeners audio reproduction system......whether it's battery powered or AC/DC powered.

Let's keep perspective on the larger issues.

Cheers,

Dave.

G Georgopoulos · « **Reply #10 on:** 3 Dec 2015, 03:39 am »

Quote from: Davey on 3 Dec 2015, 03:09 am

but in the engineering world it's always more complicated than it seems. You CAN achieve excellent results with a conventional power supply setup as well.

I agree with you!

Danny Richie · « **Reply #11 on:** 3 Dec 2015, 04:01 pm »

Quote from: Davey on 3 Dec 2015, 03:09 am

You CAN achieve excellent results with a conventional power supply setup as well.

Dave, I agree with that as well.

My issue with using A/C is the amount of money I have to spend with conditioning and power cables before I even get to the power supply for the piece of gear.

I can buy a 100 amp hour battery and charger for less than the cost of one decent power cable.

srb · « **Reply #12 on:** 3 Dec 2015, 04:45 pm »

My issue with using battery power supplies is the additional ecological waste and toxification. I do use batteries, but only for portable devices that can't be conveniently connected to AC.

On the plus side, when AC power does get interrupted, if your entire system is battery powered you'll still be listening to tunes!

Steve

Davey · « **Reply #13 on:** 3 Dec 2015, 04:53 pm »

Quote from: Danny Richie on 3 Dec 2015, 04:01 pm

Dave, I agree with that as well.

My issue with using A/C is the amount of money I have to spend with conditioning and power cables before I even get to the power supply for the piece of gear.

I can buy a 100 amp hour battery and charger for less than the cost of one decent power cable.

It's a false narrative Danny. In my opinion.

The premise that we ALL need some sort of AC-power conditioning and/or fancy power cords and/or other gadgets is incorrect.
Grid, feeders, pole transformers, panel, house wiring, contamination from outside sources, DUT power supply design, etc, etc, are all variables.

However, I can't argue with the premise that a battery supply will give more consistent performance.....all other things being equal.

Multiple vendors/customers on AC exchanging $$$ that would disagree with my stance, I'm sure. I'm okay with that.

Dave.

rollo · « **Reply #14 on:** 3 Dec 2015, 05:06 pm »

Quote from: Danny Richie on 3 Dec 2015, 04:01 pm

Dave, I agree with that as well.

My issue with using A/C is the amount of money I have to spend with conditioning and power cables before I even get to the power supply for the piece of gear.

I can buy a 100 amp hour battery and charger for less than the cost of one decent power cable.

Do not forget the Batterybuss cost. An essential part IMO. Granted one Uberbuss is $1100 plus PC of choice [ TWL 7+] then six PC to components adds up.
Besides the money which is a factor to some which is better in sonic retrieval is the issue here. I will find out soon.

charles

TomS · « **Reply #15 on:** 3 Dec 2015, 05:32 pm »

Quote from: rollo on 3 Dec 2015, 05:06 pm

Do not forget the Batterybuss cost. An essential part IMO. Granted one Uberbuss is $1100 plus PC of choice [ TWL 7+] then six PC to components adds up.
Besides the money which is a factor to some which is better in sonic retrieval is the issue here. I will find out soon.

charles

Charles,

Since this is the lab circle I have to emphasize what some have already mentioned, that the quality and implementation of the DC supply matters a lot. The typical off the shelf 3 terminal chip regulator (LM12xx, LM317, etc) implementations just aren't going to get it done. As Danny said, the necessary level of elegance for a proper LPS can get expensive.

I'm not recommending this guy's stuff at all as I haven't tried them, but the articles provide interesting perspective for sonics
http://www.coreaudiotechnology.com/batteries-vs-linear-power-supply/
http://www.coreaudiotechnology.com/faqs-about-our-power-supplies/

I've used the KECES DC-115 power supply (since superceded to DC-116) with success for various low voltage applications like the Squeezebox and a Linux server, and have been quite happy with it at modest cost.
http://www.keces.com.tw/5_english/index_5_english.htm

DaveC113 · « **Reply #16 on:** 3 Dec 2015, 05:41 pm »

IMO, there are pros and cons to a battery based PS... but the biggest pro is marketing, people have a lot of misconceptions that a battery is noise and impedance free, which, unfortunately, is far from the truth.

Batteries require additional filtration and storage caps to reduce their impedance and clean up the power, plus the cost of batteries and replacement batteries, plus a charging system. The AC supply may require a power cable but at least the power cable isn't as toxic as the battery and won't need to be replaced every year or three...

IMO, given the same budget and taking a few sets of replacement batteries into account, an AC power supply would end being cheaper in the long run and differences in SQ wouldn't be much of a factor if both were designed competently.

Of course, then there are the supercapacitors as used by Vinnie.... I have not looked into building a PS with them yet....

DaveC113 · « **Reply #17 on:** 3 Dec 2015, 05:47 pm »

Quote from: TomS on 3 Dec 2015, 05:32 pm

Charles,

Since this is the lab circle I have to emphasize what some have already mentioned, that the quality and implementation of the DC supply matters a lot. The typical off the shelf 3 terminal chip regulator (LM12xx, LM317, etc) implementations just aren't going to get it done. As Danny said, the necessary level of elegance for a proper LPS can get expensive.

I'm not recommending this guy's stuff at all as I haven't tried them, but the articles provide interesting perspective for sonics
http://www.coreaudiotechnology.com/batteries-vs-linear-power-supply/
http://www.coreaudiotechnology.com/faqs-about-our-power-supplies/

I've used the KECES DC-115 power supply (since superceded to DC-116) with success for various low voltage applications like the Squeezebox and a Linux server, and have been quite happy with it at modest cost.
http://www.keces.com.tw/5_english/index_5_english.htm

From your first link, I think this is a good summary:

Quote

Linear power supplies are going to be larger than batteries. But unlike batteries they can be built to a much higher bandwidth that functions consistently. A well-designed linear power supply can be considerably lower noise, faster, and higher bandwidth than any battery. Linear power supplies can filter the incoming AC noise, eliminate ripple to exceptionally high frequencies, and have much higher slew rate and current output. This means their sound will always be consistent and their potential much greater.

Comparing a battery to a SMPS or entry-level power supply will put a battery ahead as the clear winner. It will be much lower noise than a SMPS. But a well-crafted Linear power supply has several advantages and should be the only consideration when looking for the ultimate power solution.

Davey · « **Reply #18 on:** 3 Dec 2015, 05:57 pm »

Tom,

What's in that KECES power supply? All I can see is a transformer and multiple capacitors.

Dave.

TomS · « **Reply #19 on:** 3 Dec 2015, 06:00 pm »

Quote from: Davey on 3 Dec 2015, 05:57 pm

Tom,

What's in that KECES power supply? All I can see is a transformer and multiple capacitors.

Dave.

Sorry, I haven't taken the time to dissect it and it's packed up at the moment