[DaveC113]

This is particularly an issue when we'd go to a show. The A/C noise at the hotels were really bad.

The batteries were dead quiet every time.

Sure, but it doesn't cost $3k for a reasonable power conditioner or power cable either. Systems using my SurgeX have won best in show awards cost-no-object the last 2 years running, you can get them for well under $1k for a basic, stock model that will be just as effective at removing emi/rfi and eliminating surges.

I've experimented with this a bunch using an Optima deep-cycle battery and all sorts of different capacitor arrangements. The truth is batteries are not as quiet as people might assume without filtering them, batteries have significant internal resistance, and they wear out over time. IME, a good linear power supply sounds just as good if not better than an optimized battery setup and doesn't have the disadvantages of needing a charger or periodic battery replacement. A linear supply like I linked to is very likely to sound better than any battery arrangement you can come up with and costs less too.

[Davey]

Yep, it makes a difference.

My highly modified Mac Mini has it's own 100 amp hour Power Sonic battery too. And the bigger battery makes even more of a difference on it. Not all batteries are the same either. Some brands aren't as good as others. And now that battery feeds a battery buss made by Dave Elledge. Then it's plugged into my Mac Mini. And that made an improvement as well.

What are you basing the higher capacity recommendation on?  Lower internal resistance of the higher capacity batteries??

Dave.

[Danny Richie]

Sure, but it doesn't cost $3k for a reasonable power conditioner or power cable either. Systems using my SurgeX have won best in show awards cost-no-object the last 2 years running, you can get them for well under $1k for a basic, stock model that will be just as effective at removing emi/rfi and eliminating surges.

I've experimented with this a bunch using an Optima deep-cycle battery and all sorts of different capacitor arrangements. The truth is batteries are not as quiet as people might assume without filtering them, batteries have significant internal resistance, and they wear out over time. IME, a good linear power supply sounds just as good if not better than an optimized battery setup and doesn't have the disadvantages of needing a charger or periodic battery replacement. A linear supply like I linked to is very likely to sound better than any battery arrangement you can come up with and costs less too.

I am sure your power supplies are very good. Personally I have not found any to reach the level we are at with batteries and battery busses. But I don't doubt that a good linear power supply can match it.

Plus a decent power cable for the level that I play in will start at about $300 to $350. So even if you conditioner is great it will still need two power cables for one piece of gear. One leading to it and one from it. Now figure two amps, a pre-amp, a DAC, etc and it is easy to have $1,500 to $2,000 in power cables alone.

I can do much more for far less money with a battery powered system.

[Danny Richie]

What are you basing the higher capacity recommendation on?  Lower internal resistance of the higher capacity batteries??

Dave.

Hey Davey, I think you know that the lower resistance of the larger batteries is a factor.

[Davey]

What is the current draw of the Dodd preamp in question here?

Dave.

[Danny Richie]

What is the current draw of the Dodd preamp in question here?

Dave.

I don't know. I have never tried to measure it. I had a guy that handled all of that, but he is not around anymore.

[TrungT]

Single tube pre (6H30) draw little over 1A.

[Davey]

Can you post the schematic of the preamp?
This is not proprietary any longer, yes?

Charles mentioned a 12Ah battery.  Looking at the photographs, I don't see that.  I see two selectable packs each with two UB1250 (5.0Ah batteries).....wired how??
In series you still have 5.0Ah battery....in parallel a 10Ah battery.

Dave.

[TrungT]

Sorry, don't have the schematic.

[Danny Richie]

Can you post the schematic of the preamp?
This is not proprietary any longer, yes?

Charles mentioned a 12Ah battery.  Looking at the photographs, I don't see that.  I see two selectable packs each with two UB1250 (5.0Ah batteries).....wired how??
In series you still have 5.0Ah battery....in parallel a 10Ah battery.

Dave.

It is proprietary and has never been shared.

If Charles has the older version with internal UB1250 batteries then has uses two tubes and draws more juice. And that is a 24 volt version. They were originally wired on just two of those batteries so that you could run on two while the other two were charged and switch back and forth at will, and always having a fully charged pair to use. It was realized later than it sounded better with all four batteries used together.

Later versions used an external battery.

[Davey]

It is proprietary and has never been shared.

I'm just curious....How is the high-voltage generated with this design?

Dave.

[Danny Richie]

I'm just curious....How is the high-voltage generated with this design?

Dave.

Gary designed something to step up the voltage.

He did something similar but to a higher level with his battery power tube amps.

[rollo]

  I have two one [ variable gain  and Gary's latest] with single 6H30 and external battery and one with [4] 12Bh tubes with external battery. Both sound great.
  Think a linear PS is worth a try at least. Direct comparison is the only way for me to find out for myself. While I respect Danny's ear big time  and his recommendation my nervosa is peaking. 
  If and when I get or build one I will post my findings and solve this issue for your interest. Keep ya posted.


charles

[S Clark]

Direct comparison is the only way for me to find out for myself.
charles

Absolutely! Your own ear has the final say. 

[Davey]

Battery supplies provide a differentiation from other products on the market in that they catch the eye of fickle audiophiles.  Some audiophiles like to make statements with the products they purchase.  I get that. 
However, there isn't anything inherently superior about their design relative to a good linear power supply.  Just like conventional power supplies they have issues/trade-offs....although a different set.

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

Dave.

[Steve]

Battery supplies provide a differentiation from other products on the market in that they catch the eye of fickle audiophiles.  Some audiophiles like to make statements with the products they purchase.  I get that. 
However, there isn't anything inherently superior about their design relative to a good linear power supply.  Just like conventional power supplies they have issues/trade-offs....although a different set.

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

Dave.

I totally agree David. Nice post. Charles, besides the 11A, there is deHavilland, Herron and probably more who make a nearly perfect preamplifier that uses an AC power supply and requires no expensive power cords. So AC power supplies are not inherently bad, but take your time and find or design a good one.

Cheers
Steve

[adminRH]

The thread has been split after the relevant replies to the OP.

The split-off thread, retitled "Preamp discussion," is still in Quarantine pending further filtering of posts with personal attacks.
http://www.audiocircle.com/index.php?topic=139259.0

You may post in the new thread while it is in Quarantine. But if the bickering continues the thread will be trashed without any effort to filter it.

Thanks to 'The Lab' facilitator sts9fan, and to the contributors to these threads.

[bodhiboy]

Just a little public service announcement regarding Dodd Battery Powered Preamps (the 4 onboard battery type):

Using the charger and batteries identified below, the batteries NEVER discharge! There is an LED display on the charger that indicates 5 levels of charge with 5 being fully charged, which with these batteries is 26.9 volts. In an effort to discover how much play time it would take for the charger to drop to level 4, I let the system play around the clock (volume at zero overnight) and after 3 days and nights, it still hadn’t dropped from fully charged level 5. So I got out my trusty multimeter and the battery bank was still at 26.9 volts!

The batteries actually charge faster than they discharge!

This is awesome! All of the benefits of battery power with none of the liabilities. These batteries also provide 12 Ah instead of the 10Ah that SLA or GEL batteries do.

Anyhoo, just a public service announcement for anyone with a Dodd Battery Powered Preamp or for anyone who was previously unwilling to accept a limited run time with one of the best sounding preamps of all time...well, that concession is no longer required!

https://www.amazon.com/gp/product/B09L1C6LCL/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1


https://www.amazon.com/gp/product/B07TKD4DCH/ref=ppx_yo_dt_b_asin_image_o05_s00?ie=UTF8&psc=1

[S Clark]

Any idea if the provided charger will charge those 6 AH batteries?

[bodhiboy]

Any idea if the provided charger will charge those 6 AH batteries?

It will not.  LiFePO4 batteries need to be charged by a charger that is designed to charge LiFePO4 batteries.  The original charger is rated at 0.5 amp and the referenced Victron charger is rated 10 times that at 5 amps...presumably a big reason why the batteries never discharge on this charger.