Line preamp powered by batteries.

beppe61 · « **on:** 6 Mar 2006, 03:20 pm »

Dear Sirs,

I would like to hear from anyone who has listened to battery powered line preamps.
I understand that to get the ultimate performance from audio units (as in the case of the T-Amp) a power supply based on batteries is mandatory.
Also in the case of external dacs the use of batteries could give nice improvements on sound.
In tha DACT Audio web site I read they have not been able to measure noise at all from batteries.
This must mean something after all.
Then they go on saying that a limit of SLABs is their internal impedance.
But with a nice cap at the battery output this could be well overcome.
Opinions are very welcome and appreciated.

Kind regards,

bg

konut · « **Reply #1 on:** 7 Mar 2006, 05:02 am »

Hi bg,
I do not own, or have experience with, battery powered line stages, but you asked for opinions , so heres mine. Like you, I agree that SLA powered equipment offers potential improvement over conventional power supplies. While a line stage would likely benefit from SLA power, its my opinion that with most source components have enough voltage to directly drive an amp and that a passive attenuator, with source switching, is all thats needed. The advantage of this setup is that you eliminate an active component that is essentially redundant. If I were you, I would concentrate on SLA powered source components such as the Red Wine Audio SqueezeBox 3, iMod, or other battery powered devices.

beppe61 · « **Reply #2 on:** 7 Mar 2006, 11:34 am »

Quote from: konut

Hi bg,
...
If I were you, I would concentrate on SLA powered source components such as the Red Wine Audio SqueezeBox 3, iMod, or other battery powered devices.
...

Dear Sir,

thank you so much for your very interesting reply.
What made me think about SLAB powered equipment is the belief that what makes the variious T-Amp implementations really great is the use of SLABs.
Moreover I need a dvd player as a universal source, because I am trying to use stereo for movies watching as well.
My point is, if a 12V SLAB can make a low power amp to sound exceptional it must be enough for a line pre as well.
And a truly great line preamp could give me a nice improvement in the overal sound and also flexibility of choice with different sources, if not a high end performance.
I understand that some preamps (by TRL for instance) are indeed appearing on the market, with exceptional sound.

Thank you very much indeed.
Kind regards,

bg

Gordy · « **Reply #3 on:** 7 Mar 2006, 02:51 pm »

Hello bg!

Two other battery pre's worth investigating are the new Dodd Audio pre... http://www.audiocircle.com/index.php?topic=26238&highlight=dodd+battery+preamp and the Welborne Labs Ultrapath bp... http://www.welbornelabs.com/ultra.htm

beppe61 · « **Reply #4 on:** 7 Mar 2006, 03:50 pm »

Quote from: Gordy

Hello bg!
Two other battery pre's worth investigating are the new Dodd Audio pre... http://www.audiocircle.com/index.php?topic=26238&highlight=dodd+battery+preamp and the Welborne Labs Ultrapath bp... http://www.welbornelabs.com/ultra.htm

Dear Sir,

thanks a lot for the useful information.
Very interesting application with tubes.
I wonder if some of these qualities are retained also with solid state solutions.
Thank you very much again.
Regards,
bg

Gordy · « **Reply #5 on:** 7 Mar 2006, 04:12 pm »

My only experience with sla's and solid state line level units is with my P3a dac which has been moded by Vinnie at Red Wine Audio with a battery supply... a very big thumbs up in that application!!! The usual (IMO) benefits apply... lowered noise floor which in turn allows finer detail to come through and a smoother, more musical top end.

beppe61 · « **Reply #6 on:** 10 Mar 2006, 03:25 pm »

Quote from: Gordy

My only experience with sla's and solid state line level units is with my P3a dac which has been moded by Vinnie at Red Wine Audio with a battery supply... a very big thumbs up in that application!!!
The usual (IMO) benefits apply... lowered noise floor which in turn allows finer detail to come through and a smoother, more musical top end.

Thank you very much Sir for your kind and valuable reply.
Another nice benefit of a battery PS is the isolation from the AC grid, that is very far from a clean sine wave nowadays.

Regards,
bg

Vinnie R. · « **Reply #7 on:** 10 Mar 2006, 04:21 pm »

Quote from: beppe61

Quote from: Gordy

My only experience with sla's and solid state line level units is with my P3a dac which has been moded by Vinnie at Red Wine Audio with a battery supply... a very big thumbs up in that application!!!
The usual (IMO) benefits apply... lowered noise floor which in turn allows finer detail to come through and a smoother, more musical top end.

Thank you very much Sir for your kind and valuable reply.
Another nice benefit of a battery PS is the isolation from the AC grid, that is very far from a clean sine wave nowadays.

Regards,
bg

Ciao beppe61,

In my experience, the very cleanest and most tranparent sounding preamp that I have heard is one that I built from the DACT CT101 linestage board with SLA battery power, CT2 stepped attenuator, and CT3 input select switch.

The CT101 adds nothing to the signal, just either 0dB, 6dB, or 12dB of gain (plus and high input impedance for your source and a good amount of buffering for hard to drive loads).

If you are curious, it looked something like this:
http://www.redwineaudio.com/Puri_T.html

but with this installed, along with battery power:
http://www.dact.com/html/line_stages.html

If you are a DIY'er, I highly recommend giving it a try. These parts + battery power will blow your mind! To me, it was line a "wire with gain."

If you want a battery powered preamp with some tube flavoring, the Welborne Ultrapath is the way to go!

Best regards,

Bemopti123 · « **Reply #8 on:** 10 Mar 2006, 11:35 pm »

Hi Vinnie and Peppe. That is one nice passive you have there Vinnie. As for SLA power, I have not had too much experience, but I do have the Final Laboratories Music 5 preamp, which is entirely powered by C type of batteries, about 28 of them? I cannot remember.

As it was said, battery ads 0 grain or distortion to the signal and lets not even talk about my battery powered amplifier, the Final Music 6, with 36 D batteries.

The sound signal is lighting fast, as well as being silky smooth. No grain or other noise whatsoever. As always, speaker matching is key to obtain the best sound.

Check the link to http://www.finallab.com/new_page_1.htm

Danny Richie · « **Reply #9 on:** 11 Mar 2006, 11:15 pm »

I have had some nice passive pre-amps come through our doors. Some were nothing more than stepped attenuators and some have been transformer coupled. All Copper units and all Silver units (Silver wired transformers) have been tested.

None of these sounded good to me. My old cheapy tube pre-amp sounded better than all of them.

One passive stands out though. The Stan Warren designed Superphon is by far the best I have heard. While still a passive design, it also uses an active buffer stage to match and balance output impedances.

The Superphon has sounded better than any pre-amp that I have heard except for one. That one being the new Dodd battery powered tube pre-amp mentioned above.

I don't know that the Dodd can be topped with any amount of money. Price no object, it's the best I have heard. I have even A/B'ed it against an $11,000. Aesthetix Callisto.

It sounds like it is not there in the signal path. Clean, low noise design, with extended top and bottom end, lots of drive power, etc. Plus, it has a lush midrange and a vary enveloping sound stage. It's completely smooth too. Highly recommended!

Nick B · « **Reply #10 on:** 12 Mar 2006, 01:16 am »

Danny I've been reading many posts about amps and preamps. I was on the Dodd site and the retail cost for the amp and preamp are beyond my budget, especially for the amp. At $2,800, the new preamp is reasonably priced, but doesn't have the phono section I need. A good quality separate phono section will add at least another $600 or more. Just wondering if you could recommend an alternative (with phono) based on your listening tests and exposure to some of the manufacturers, especially on the AC site. Thanks Nick

Danny Richie · « **Reply #11 on:** 12 Mar 2006, 01:19 am »

Call Gary Dodd. Tell him what you want and see what kind of a packed deal he might can make you. You might be surprised, and you have nothing to loose.

Kishore · « **Reply #12 on:** 12 Mar 2006, 01:28 am »

Gary is such a humble and honest guy- I am glad his products are getting more attention.

Highly recommend Dodd Audio

Cheers,
Kishore

beppe61 · « **Reply #13 on:** 18 Mar 2006, 08:29 pm »

Quote from: Vinnie R.

Ciao beppe61,
In my experience, the very cleanest and most tranparent sounding preamp that I have heard is one that I built from the DACT CT101 linestage board with SLA battery power, CT2 stepped attenuator, and CT3 input select switch.
The CT101 adds nothing to the signal, just either 0dB, 6dB, or 12dB of gain (plus and high input impedance for your source and a good amount of buffering for hard to drive loads).
If you are curious, it looked something like this:
http://www.redwineaudio.com/Puri ...

Dear Sir,

I sincerely hope you will excuse me for my late reply but I had a big problem with my PC.
Thank you sincerely for your very kind and valuable reply that I understand comes from an extremely talented audio designer.
I know that DACT module and attenuator.
On the DACT's site they state to have overcome the problem of noise in PS with their own latest design (even if between the lines they confirm the intrinsic superiority of batteries on noise.

Thank you very much again for your very valuable advice.
Kind regards,

beppe

beppe61 · « **Reply #14 on:** 18 Mar 2006, 08:35 pm »

Quote from: Bemopti123

Hi Vinnie and Peppe.
That is one nice passive you have there Vinnie. As for SLA power, I have not had too much experience, but I do have the Final Laboratories Music 5 preamp,
...
The sound signal is lighting fast, as well as being silky smooth.
No grain o ...

Thank you very much Sir.
Another point for batteries then.
Kind regards,

beppe

beppe61 · « **Reply #15 on:** 18 Mar 2006, 08:48 pm »

Quote from: Danny

1) I have had some nice passive pre-amps come through our doors.
Some were nothing more than stepped attenuators and some have been transformer coupled.
All Copper units and all Silver units (Silver wired transformers) have been tested.
None of these sounded good to me.
2) My old cheapy tube pre-amp sounded better than all of them.
3) One passive stands out though.
The Stan Warren designed Superphon is by far the best I have heard. While still a passive design, it also uses an active buffer stage to match and balance output impedances.
The Superphon has sounded better than any pre-amp that I have heard except for one.
4) That one being the new Dodd battery powered tube pre-amp mentioned above.
I don't know that the Dodd can be topped with any amount of money. Price no object, it's the best I have heard.
I have even A/B'ed it against an $11,000 Esthetix Calisto.
It sounds like it is not there in the signal path.
Clean, low noise design, with extended top and bottom end, lots of drive power, etc.
Plus, it has a lush midrange and a vary enveloping sound stage.
It's completely smooth too. Highly recommended
...

Thank you Sir again for your advice.
Let me please put ather questions to you.
1) Very interesting (no question here by the way)
2) Which was it?
3) So it is not a strictly passive pre (the buffer is active I mean).
Any idea about its general schematic ? is it fet based or bjt based?
4) Thank you for the valuable suggestion. I will get some more info from the site.

Thanks a lot again and kind regards,

beppe

Danny Richie · « **Reply #16 on:** 19 Mar 2006, 03:58 am »

Quote

2) Which was it?

Something that Gary Dodd threw together from parts he had laying around.

Quote

3) So it is not a strictly passive pre (the buffer is active I mean).
Any idea about its general schematic ? is it fet based or bjt based?

See info on it here: http://www.superphon.com/

Quote

4) Thank you for the valuable suggestion. I will get some more info from the site.

I just picked up some heavy quilted Maple today for mine. I can't wait.

Curly Woods · « **Reply #17 on:** 19 Mar 2006, 04:47 am »

Danny,

It was great to finally meet you today. I am glad that the wood meet your expectations and I look forward to seeing and hearing your preamp. I am sorry that I missed the get together this afternoon. When I left the shop all that I could think of was an ice pack and some pain relief

That preamp of Gary's is beautiful. As I said, if it sounds half as good as it looks and feels, I have to have one!

beppe61 · « **Reply #18 on:** 19 Mar 2006, 09:33 am »

Quote from: Danny

Quote
2) Which was it?

Something that Gary Dodd threw together from parts he had laying around.
Quote
3) So it is not a strictly passive pre (the buffer is active I mean).
Any idea about its general schematic ? is it fet based or bjt based?

See info on it here: http://www.superphon.com/
Quote
4) Thank you for the valuable suggestion. I will get some more info from the site.

I just picked up some heavy quilted Maple today for mine. I can't wait.

Thank you very much Sir for the kind and valuable advice.
Kind regards,

beppe

tigzstudio · « **Reply #19 on:** 19 Mar 2006, 08:34 pm »

danny have you compared the new dodd pre to a modwright swl?