[Folsom]

I have been considering this kit...

Does anyone know if the Tube comes with it? What does one cost?

It says it can run off of 12VAC... It also looks like it has diodes on it. Could I just not solder any of that stuff on and run this, with this, like Red Wine does I think for some of their stuff.

http://www.batterywholesale.com/battery-store/proddetail.html?prodID=374

with

http://www.batterywholesale.com/battery-store/proddetail.html?prodID=3105

or would it be wiser to run a 3.0AH because the DACs seem to take about 3 amps. The thing is the first one I listed is only $15, and that would give it some buffer room right, or would the DAC over draw and heat up?

Here is a 3.2AH which would be a smaller buffer

http://www.batterywholesale.com/battery-store/proddetail.html?prodID=2731

The question I am wondering is how long will the battery last? Should I go bigger? The charger is automatic... Not that I know how long it takes.

If I do build this I am going to run a Canare Belden 89259 BNC connection between it and a HagUSB. If the HagUSB does not work it will be cheap transport and home-mods.

I suppose this LARGLY depends on if I sell my Peter Daniels Chip Amp kit I partially assembled with the BG capacitors he uses, and a HEALTHY 400VAC Plitron transformer (he also uses in mono-blocks but with a slightly different output V). I just want a better, revealing DAC, as opposed to the Sharp SD-EX111's. The Sharps is not horrible but I want more; there are only so many recordings I can liten too for a lengthy amount of time. Later I will probably throw in a Marchard 24 position volume controller to clean it all up. In the mean while I will upgrade some RCA jacks and speaker terminals I think 

[chadh]

As far as I understand, the ratings (3.2 AH, 10 AH etc) refer ONLY the length of time you can run the battery.  e.g. 3.2 AH (amp hours) means the battery will give you 3.2 amps for 1 hour, or 1 amp for 3.2 hours, or...well, you get the picture.  So, if your DAC draws 3 amps, the 3.2 AH battery won't last long (about an hour). 

Chad

[Folsom]

I guess I am a little confused how Red Wine products function then... Honestly though how could a DAC take 3 amps?

There is no way that Red Wine 70wRMS mono blocks draw less.

The 3A guess is from Scott Nixon's website, where it says " 3Xac  12VAC 3A toroidal power supply for both TubeDac and USBTD " .

[ctviggen]

It might be cheaper to recreate his power supply, which looks like a 120V to 12V AC transformer in a box.  See:

http://www.6moons.com/audioreviews/nixon/tubedac.html

That, or just buy his power supply (it's only $115, which isn't bad, as you'd be hard pressed to buy the box, transformer, connections, etc. for that price). 

[SET Man]

I guess I am a little confused how Red Wine products function then... Honestly though how could a DAC take 3 amps?

There is no way that Red Wine 70wRMS mono blocks draw less.

The 3A guess is from Scott Nixon's website, where it says " 3Xac  12VAC 3A toroidal power supply for both TubeDac and USBTD " .

Hey!

   Well, if the DAC could run on 12V than yes you could run it with 12V batt.

    As for the "3A or 3amps".... it is a different thing between 3A rated transformer and 3A batt. If the recommended tranny for the DAC is 12V and 3A rated... that's mean that it will put out 36 watts. I don't know exactly how much is the DAC current drawn likely to be less than 36 watts. But you would not want to use any tranny less than recommended. You could use a higher amp rated one but nothing smaller.   You know some company like to use bigger tranny

    As for the battery. As chadh mentioned before the "Ah" rated on the batt is for "Amp per hour" not the same as the tranny rating. So, you don't have to use just 3Ah batt You could go higher like 7Ah and etc. A lower one wouldn't last last long as the higher one. I have no idea how to calcurate how how a battery last with a certain thing hook up to it.

    Well, guess what? I'm powering my "Little Buddy" DAC kit of which take a 12V with a 7Ah SLA batt. With a 10,000uf capacitor parallel across the line I haven't been keep tracking of how long it will last. But since it first charge I think it must have clocked in at 20 hours by now and it still running I do have 2 batteries so if one run out in the middle of listening I could just hook up another one BTW.... my the recommended tranny for my DAC is 12V 800ma minimum.

   Well, have fun and keep us posted.

Take care,
Buddy

[Occam]

It says it can run off of 12VAC... It also looks like it has diodes on it. Could I just not solder any of that stuff on and run this, with this, like Red Wine does I think for some of their stuff.

As Mr. Nixon's all solid state products run via a 12vdc powersupply, and his tube dac specifically requires a 12v AC ps, I'd think a comparison to the Art DI/O is a more appropriate comparison than to the Red Wine products.

There are diodes, and then there are diodes. Rather than just rectifying the ac voltage, the TDKit might be using voltage multipliers (caps and diodes) to provide multiple voltages as well as straight rectifiers to derive supplies for the digital electronics, the tube filament and the tube's B+ supply. I've no access to the schematic so this is just speculation.

The 3 amp specification of the transformer in the upgraded AC ps is not indicative of the current consumption, assuming the stock supplied supply is rated substantially less. Rather, I assume it was chosen for technical reasons, better transformer regulation, minimal leakage inductance.... that also translate into better subjective performance. This was the case with the Art DI/O of yesteryear which also had a tube (in the ADC) which required voltage multipliers, which came with a stock 1amp 9vAC powersupply. Substitution of a Stancor or Atari 9vAC 3.4amp supply was tremendously beneficial.

FWIW

[SET Man]

It says it can run off of 12VAC... It also looks like it has diodes on it. Could I just not solder any of that stuff on and run this, with this, like Red Wine does I think for some of their stuff.

...the TDKit might be using voltage multipliers (caps and diodes) to provide multiple voltages as well as straight rectifiers to derive supplies for the digital electronics, the tube filament and the tube's B+ supply. I've no access to the schematic so this is just speculation.

FWIW

Hey!

   Hmmm.... good point Occam. I don't know about that one. So, can you still use battery with the tubed DAC? No, I'm not getting the Nixon tube DAC.... but it is something I would like to know, it could come in handy in the future 

Take care,
Buddy

[Folsom]

Well I guess I will look into transformers then!

Any comment on what tube to use, or does it come with one?

[ctviggen]

I think this transformer should work:

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=122-600

Only $25.  So, if it outputs 30VA, does that mean it can produce 30/12 = 2.5 amps? 

[scottnixon]

For the record, any use of a DC supply on any of my tube buffered dacs will kill it instantly ... poof and gone.  It's 12V AC only.  The Avel toroid mentioned above is a nice doughnut to use.  Tube used is 6DJ8 or 6922 type.

[Occam]

So, can you still use battery with the tubed DAC? No, I'm not getting the Nixon tube DAC.... but it is something I would like to know, it could come in handy in the future 

Well, Scott has definitively answered that with regards to his own tube buffered DACs. Regarding other tubed DACs, that's a definitely maybe. If someone designed a dac whose tube complement's operating point(s) were for a 12.6vdc B+ (tubes plate supply), it would be easy to use a SLA battery. When I was but a wee sprat, all the car radios used miniature tubes specifically designed for 12.6v plate and filament, the 6GM8 being a common example. And many 'higher voltage' operate quite well at reduced plate voltages, if the operating points are adjusted appropriately. Note quite as common were 6.3vdc plate and filament tubes; remember, the early VW Bugs had radios.....
Multiple batteries make the choices broader, allowing for higher voltages and/or split supplies.
This doesn't answer your question specifically. Its more a question of whether the designer feels they could use a tube operating at those points that would prove optimal. Ultimately its a tradeoff between whatever benefits are to be had with a battery as a power supply, versus whatever restrictions are imposed on the tube's operating points (as well as constraining the choice of the tube itself).

Obviously, Dodd and Wellbourne have addressed these issues to their satisfaction in their preamps.

[Folsom]

Hey thanks Scott! I had no idea you were a member on this forum.

[Gordy]

A little off topic... SLA batteries really need to be kept fully charged and do not take kindly to being run down below the 12v point.  Once they've been run down below the 12v point, they will not fully charge again and life span of the battery and it's charge life are greatly diminished!  If you run the battery down to where it fails, it's toast, history, needs to be taken for a walk to your friendly neighborhood battery recycler.  Always be sure to run through a charge cycle after every use no matter how short a run that might be.   

I'm powering my DAC kit of which take a 12V with a 7Ah SLA batt.  I haven't been keep tracking of how long it will last. But since it first charge I think it must have clocked in at 20 hours by now and it still running I do have 2 batteries so if one run out in the middle of listening I could just hook up another one BTW....

[SET Man]

A little off topic... SLA batteries really need to be kept fully charged and do not take kindly to being run down below the 12v point.  Once they've been run down below the 12v point, they will not fully charge again and life span of the battery and it's charge life are greatly diminished!  If you run the battery down to where it fails, it's toast, history, needs to be taken for a walk to your friendly neighborhood battery recycler.  Always be sure to run through a charge cycle after every use no matter how short a run that might be.   

I'm powering my DAC kit of which take a 12V with a 7Ah SLA batt.  I haven't been keep tracking of how long it will last. But since it first charge I think it must have clocked in at 20 hours by now and it still running I do have 2 batteries so if one run out in the middle of listening I could just hook up another one BTW....

Hey!

   Thanks Gordy. I just want to see how many I could get on one.... Hmmm.... I guess I won't run it until it totally out than. I will measure it and see when it get to 12V point than I will use that at my reference. Well, I do have second one of which I will keep it on "trickle charger" since the first is almost done

So, can you still use battery with the tubed DAC? No, I'm not getting the Nixon tube DAC.... but it is something I would like to know, it could come in handy in the future 

Well, Scott has definitively answered that with regards to his own tube buffered DACs. Regarding other tubed DACs, that's a definitely maybe. If someone designed a dac whose tube complement's operating point(s) were for a 12.6vdc B+ (tubes plate supply), it would be easy to use a SLA battery. When I was but a wee sprat, all the car radios used miniature tubes specifically designed for 12.6v plate and filament, the 6GM8 being a common example. And many 'higher voltage' operate quite well at reduced plate voltages, if the operating points are adjusted appropriately. Note quite as common were 6.3vdc plate and filament tubes; remember, the early VW Bugs had radios.....
Multiple batteries make the choices broader, allowing for higher voltages and/or split supplies.
This doesn't answer your question specifically. Its more a question of whether the designer feels they could use a tube operating at those points that would prove optimal. Ultimately its a tradeoff between whatever benefits are to be had with a battery as a power supply, versus whatever restrictions are imposed on the tube's operating points (as well as constraining the choice of the tube itself).

Obviously, Dodd and Wellbourne have addressed these issues to their satisfaction in their preamps.

  Thanks Occam. That is why I was wondering about it since I've seen batt operated tube pre like Welborne Labs and etc.

   Well, someday if I'm going for a tube DAC.... I might look in to using battery.... maybe

  Well, as for the tubed Nixon DAC user.... If Mr. Nixon is not recommend batt for it than you shouldn't.

Take care,
Buddy