DIY Dodd Buffer

dmatt · « **Reply #320 on:** 29 Apr 2010, 06:45 pm »

Any problem with using one of these since I have one lying around?

A Mazda Miata battery. A 12V sealed AGM battery with 31AH, plus a whopping 475 cold cranking amps for those audio days below freezing.

David

jtwrace · « **Reply #321 on:** 29 Apr 2010, 06:57 pm »

Not a problem at all...as long as it's a sealed AGM you're fine.

31 AH will last a looooooooong time.

I use a 28 AH.

dmatt · « **Reply #322 on:** 29 Apr 2010, 07:07 pm »

Thanks for the info.

With 31 AH, maybe I have room for battery operated tube amps sometime in the future.

Sweet.

David

jtwrace · « **Reply #323 on:** 29 Apr 2010, 07:10 pm »

Quote from: dmatt on 29 Apr 2010, 07:07 pm

maybe I have room for battery operated tube amps sometime in the future.

Sweet.

David

Depends on the efficiency of the speakers.

Mariusz · « **Reply #324 on:** 29 Apr 2010, 07:18 pm »

Quote from: jtwrace on 29 Apr 2010, 06:57 pm

Not a problem at all...as long as it's a sealed AGM you're fine.

31 AH will last a looooooooong time.

I use a 28 AH.

jtwrace
what is the max. play time with your 28Ah???
My battery is half that size - so obviously I'm curious.

As to buying 2nd unit.
This will have to wait
for just a bit. But at this (and 2-3X)
price point there is not much to choose from
which makes it NO BRAINER!

Mariusz

jtwrace · « **Reply #325 on:** 29 Apr 2010, 07:33 pm »

Quote from: Mariusz on 29 Apr 2010, 07:18 pm

jtwrace
what is the max. play time with your 28Ah???
My battery is half that size - so obviously I'm curious.
Mariusz

At 12hrs I shut it off...still more to go though.

Mariusz · « **Reply #326 on:** 29 Apr 2010, 07:37 pm »

Quote from: jtwrace on 29 Apr 2010, 07:33 pm

At 12hrs I shut it off...still more to go though.

Alright, so for 14Ah, it would be somewhere around half...... depending on ???????

jtwrace · « **Reply #327 on:** 29 Apr 2010, 07:55 pm »

Quote from: Mariusz on 29 Apr 2010, 07:37 pm

Alright, so for 14Ah, it would be somewhere around half...... depending on ???????

A lot will depend on the tube. Don't forget that I have the first version which uses two tubes. With my tubes my unit draws ~700ma. Gary says 2hrs per 1AH. I think.

Gary?

dmatt · « **Reply #328 on:** 29 Apr 2010, 07:59 pm »

Efficiency of speakers, hmm. GR Research Neo 2Xs (85dB). But I only plan to listen for at most 3 hours at a time. Plus the listening distance is only eight feet from the speakers. That means Gary's battery amp output of 15 watts would provide 92dB at the listening position.

Worst case, I suppose I could wire two of these batteries in parallel.

Thanks.

David

etcarroll · « **Reply #329 on:** 29 Apr 2010, 08:17 pm »

Is this a 1 tube or 2 tube unit?

On this thread it seems to be 1, but another thread concerning a Dodd Buffer shows 2 tubes.

I'm confused?!?

gld · « **Reply #330 on:** 29 Apr 2010, 08:20 pm »

Mariusz, with the 6N1P I ship with each kit you'll probably be able to get 12 hours or so of operation. Any other tube will not use nearly as much current and will last much longer. Example would be a 12AX7, it would go around 30 hours or so.
On another note if you are using a good smart charger you can go forever and not worry about it!

It is a 1 tube unit now.
Gary

Mariusz · « **Reply #331 on:** 29 Apr 2010, 08:25 pm »

Quote from: gld on 29 Apr 2010, 08:20 pm

Mariusz, with the 6N1P I ship with each kit you'll probably be able to get 12 hours or so of operation. Any other tube will not use nearly as much current and will last much longer. Example would be a 12AX7, it would go around 30 hours or so.
On another note if you are using a good smart charger you can go forever and not worry about it!

It is a 1 tube unit now.
Gary

12-30h !!!!!! Wow!!! Need some more LPs and coffee!

Thanks Gary

ebag4 · « **Reply #332 on:** 29 Apr 2010, 08:34 pm »

Quote from: Mariusz on 29 Apr 2010, 07:18 pm

jtwrace
what is the max. play time with your 28Ah???
My battery is half that size - so obviously I'm curious.

As to buying 2nd unit.
This will have to wait
for just a bit. But at this (and 2-3X)
price point there is not much to choose from
which makes it NO BRAINER!

Mariusz

Guys, with the 5751 installed (12V) I have been running 8 hours now and the battery is still reading 12.28 volts. I think I will easily get way over 10 hours with this tube using a 5ah battery!

Best,
Ed

TrungT · « **Reply #333 on:** 30 Apr 2010, 01:06 am »

Etcarroll
"Is this a 1 tube or 2 tube unit"
The Dodd buffer kits offer is single tube.
I think the 2 tubes version is an early one.

ebag4 · « **Reply #334 on:** 30 Apr 2010, 02:05 am »

13.5 hours on a 5ah battery before I had to shut it down tonight, it was still going strong. BTW, that is with no charger hooked up, my charger causes a hum when connected.

Best,
Ed

TrungT · « **Reply #335 on:** 30 Apr 2010, 02:10 am »

Ed
13.5 hrs, wow, Very good.
Thanks for the info.

Mariusz · « **Reply #336 on:** 30 Apr 2010, 02:14 am »

Gary
received caps & pin header.
Back in bussines.

and some pics:

ebag4 · « **Reply #337 on:** 30 Apr 2010, 02:14 am »

Quote from: TrungT on 30 Apr 2010, 02:10 am

Ed
13.5 hrs, wow, Very good.
Thanks for the info.

Yes, much more life out of the 5ah battery with the 12V tube than the 6V, of course I was using a 6V that ate a lot of current. This is probably only interesting to those who want to use a small battery so that it can live in the same case as the pre.

Best,
Ed

ebag4 · « **Reply #338 on:** 30 Apr 2010, 02:16 am »

Quote from: Mariusz on 30 Apr 2010, 02:14 am

Gary
received caps & pin header.
Back in bussines.

Looking good Mariusz, I like that box! Looks like you should be able to change tubes out easily enough, good job!

Best,
Ed

TrungT · « **Reply #339 on:** 30 Apr 2010, 02:24 am »

Mariuzs
Looking good and she may start to sing before the night is over.

I like the tube lay-out.

And the wooden knobs goes with it, oh yea, looking fine.