[tortugaranger]

Just a quick update on the PS12B. We are finishing up our first batch of front/rear panels after which they'll be sent out for anodizing which usually takes less than week turnaround. Out latest hold up was lack of a 5 mm drill bit which apparently no hardware store anywhere carries so had to order it. Another 7-10 days should do it and we'll be ready to roll.

[tortugaranger]

We've quietly rolled out the PS12B Battery Power Supply and have received very positive responses. Here is the text from a recent email. As positive as it is the comment on the graininess being gone was a bit surprising. What graininess!!??  - LOL!!

Just wanted to let you know that the PS12B has been in place for over a week and I'm
very happy with the purchase. I was hopeful that there would be an improvement but
wasn't sure what to expect. I can say that the difference is not subtle.

All frequencies have a much smoother presentation with faster lows and crystal clear
high's. The occasional fatigue with higher volume listening due to graininess
Is also gone. I would recommend this to anyone who has or is considering the LDR3.

I know folks would be suspicious of the cost benefit (I was) but I feel this addition has
taken the pre-amp to another level. Your trial period should make this a no-brainer.

Thanks again for a great product. - Kevan

[synergy1]

Hi there,

I'm actually enquiring about your 12" Audio Nirvana AlNico speaker drivers you listed for sale delivered for $600.

I guess first off I'm really surprised no one scoffed these up as I'm sure you are. Makes me wonder too. I thought AN made some of the best

single driver full range speakers. The only thing I've heard about the Super AlNico was that the 10" version tended to have the best  sound   

across the sound spectrum from a reliable source.

I too have been toying with building a pair of single driver speakers with the AN 10" but the retail price admittedly has impeded progress.

That said just how much of a difference would AN's 12" v. 10" be overall. The 12" goes lower for one.

Because I'm don't know really a hill of beans about speaker building except it's one of the most challenging undertakings there is I think.

After building GR Research's Super V kit offering oh about 6 years ago maybe I found out how hard is really is first hand and I had all the parts

and design done for me. I even bypassed constructing the cabinets by buying pre-made cabinets from Jon ParkHurst for what I thought was a

very reasonable cost and I'm capable of building boxes.  I think he's set up for production and is fast and good at it to and is pretty easy going.

His Baltic Birch oil rubbed and then lacquer clear coated finish (I believe its what I described) is extremely well done and I know very time

consuming.  The cabinets are built very solidly and show it, they weigh over 200 lbs. each and sound incredible with the Super V design and

electrical design build-out. GR Research hit the nail squarely in the Super V design so much so I'm sure anything better sounding is posing

quite a challenge I'd think anyway.  I have a couple pairs of fairly reputable high end speakers I'd bought used of course over time that are

super in their way but I doubt are as good as the Super V's. Of course the combinations of gear driving speakers is also a big variable as you

know.
With the big 4-ways I'd say the best solid state powerhouse amps work best but with the HE 97dB Super V I've found a nifty amp I'll share with

you that has inspired me more then any other component I've come across along with the Super V is that of Urban Hi Fi's David Berning

designed ZOTL10 tube amp. It's a 10 watt OTL with a very high level designed power supply. They also have a 40 watt version that uses EL-34.

The ZOTL40 I've been told is killer and comparative to Berning's best designs in ways that are quite costly. I think a pair of mono's are $70K

whereas it's $5800 which is a lot of money too but not $70K. The ZOTL10 for 10 watts is incredibly powerful I think and will play to a nearly ear

breaking level with Super V is so desired and not clip. I listen between 62dB and 90dB at the highest probably. I also got their preamp called

MicroZOTL that can also be used as an AMP but the 1 watt per side power has been a challenge for me to even locate a reasonably priced driver

try pairing with it. I'd like to find something. I hooked it up to the super V and was totally amazed by it's sound, it lacked dynamics seriously

however but my two kids that heard it thought it was the best sounding music they'd ever heard. They have better ears too. I think they are

right.

Anyway, no worries to respond to much of any of what I wrote I just thought I'd share a few thoughts around speakers and amps etc.

I am planning on buying a different amp to use for awhile and will be putting my ZOTL10 up for sale for $2K if anyone is interested beforehand.

It sells for $2600 new. It's about 4 months old. I got a handle on another amp I'm going to try is all. Maybe there's a trade possibility here

regarding the drivers and cash? Just thought of that. I would like to try my hand at building another pair of speaker and am interested in your

the drivers you listed, if you still have them even. Let me know please. Thanks

[tortugaranger]

Please find my response here ==>  http://www.audiocircle.com/index.php?topic=144279.msg1545153#msg1545153

Hi there,

I'm actually enquiring about your 12" Audio Nirvana AlNico speaker drivers you listed for sale delivered for $600.

I guess first off I'm really surprised no one scoffed these up as I'm sure you are. Makes me wonder too. I thought AN made some of the best

single driver full range speakers. The only thing I've heard about the Super AlNico was that the 10" version tended to have the best  sound   

across the sound spectrum from a reliable source.

I too have been toying with building a pair of single driver speakers with the AN 10" but the retail price admittedly has impeded progress.

That said just how much of a difference would AN's 12" v. 10" be overall. The 12" goes lower for one.

Because I'm don't know really a hill of beans about speaker building except it's one of the most challenging undertakings there is I think.

After building GR Research's Super V kit offering oh about 6 years ago maybe I found out how hard is really is first hand and I had all the parts

and design done for me. I even bypassed constructing the cabinets by buying pre-made cabinets from Jon ParkHurst for what I thought was a

very reasonable cost and I'm capable of building boxes.  I think he's set up for production and is fast and good at it to and is pretty easy going.

His Baltic Birch oil rubbed and then lacquer clear coated finish (I believe its what I described) is extremely well done and I know very time

consuming.  The cabinets are built very solidly and show it, they weigh over 200 lbs. each and sound incredible with the Super V design and

electrical design build-out. GR Research hit the nail squarely in the Super V design so much so I'm sure anything better sounding is posing

quite a challenge I'd think anyway.  I have a couple pairs of fairly reputable high end speakers I'd bought used of course over time that are

super in their way but I doubt are as good as the Super V's. Of course the combinations of gear driving speakers is also a big variable as you

know.
With the big 4-ways I'd say the best solid state powerhouse amps work best but with the HE 97dB Super V I've found a nifty amp I'll share with

you that has inspired me more then any other component I've come across along with the Super V is that of Urban Hi Fi's David Berning

designed ZOTL10 tube amp. It's a 10 watt OTL with a very high level designed power supply. They also have a 40 watt version that uses EL-34.

The ZOTL40 I've been told is killer and comparative to Berning's best designs in ways that are quite costly. I think a pair of mono's are $70K

whereas it's $5800 which is a lot of money too but not $70K. The ZOTL10 for 10 watts is incredibly powerful I think and will play to a nearly ear

breaking level with Super V is so desired and not clip. I listen between 62dB and 90dB at the highest probably. I also got their preamp called

MicroZOTL that can also be used as an AMP but the 1 watt per side power has been a challenge for me to even locate a reasonably priced driver

try pairing with it. I'd like to find something. I hooked it up to the super V and was totally amazed by it's sound, it lacked dynamics seriously

however but my two kids that heard it thought it was the best sounding music they'd ever heard. They have better ears too. I think they are

right.

Anyway, no worries to respond to much of any of what I wrote I just thought I'd share a few thoughts around speakers and amps etc.

I am planning on buying a different amp to use for awhile and will be putting my ZOTL10 up for sale for $2K if anyone is interested beforehand.

It sells for $2600 new. It's about 4 months old. I got a handle on another amp I'm going to try is all. Maybe there's a trade possibility here

regarding the drivers and cash? Just thought of that. I would like to try my hand at building another pair of speaker and am interested in your

the drivers you listed, if you still have them even. Let me know please. Thanks

[Jim Hamley]

Hi Morten,
I recently purchased an LDR3v2 from you and am loving it Well done!
I've been thinking about a 12V power supply for my Mytek Brooklyn, so now I'm considering powering the Tortuga as well.
With a nod to Vinni Rossi, who is a pioneer in off-the-grid audio, I ask the following:
Since you are using two 12V batteries, did you consider a charger/load switching scheme that seamlessly switched a charged battery to the load and the charger to the other battery?
Would the LDRv2 benefit from low series effective resistance ultracapacitors provided power-either alone or in parallel with the batteries?
Thanks, Jim

[tortugaranger]

Since you are using two 12V batteries, did you consider a charger/load switching scheme that seamlessly switched a charged battery to the load and the charger to the other battery?

No, did not consider that. But I can definitely see the benefits of this approach. It wouldn't take that much of a design change from our current version to accomplish this but it would indeed require new circuit boards etc.

By way of some background, the PS12B was originally conceived as a 24 volt battery PS that would serve as a split voltage (+12/-12) battery power supply with virtual ground for powering of a solid state buffer with the ultimate in low noise DC power. This is still in the works and with some minor part changes and reprogramming the PS12B can become the PS24B.  In the interim we decided to simply run the 2 12V batteries in parallel and released it as a nominal 12 VDC power supply that could be used with our existing LDR passive preamps.

Would the LDRv2 benefit from low series effective resistance ultracapacitors provided power-either alone or in parallel with the batteries?

In my view there would be no advantage to this with our LDR preamps. While our current passive preamp design benefits from a quiet (low noise) power supply (used to drive a pair of op amps) they do NOT use this power dynamically. By that I mean the power supply is used to do some very modest amplification/buffering of control power signals that are themselves constant DC (i.e. static) at any attenuation point and only change briefly when volume level changes. This type of system would not benefit from improved dynamic response which is what caps are usually there to provide in conventional audio preamps.

Every now and then someone will point out that our preamps are really not "passive" preamps because they use a power supply. To which I'm happy to concede that they're probably more accurately described as "actively controlled passive preamps". The key distinction between our passive preamp and a true active preamp is the power supply is NOT electrically touching the audio signal, plus there's no gain (amplification) and there's no (impedance) buffer. The power supply does statically control the resistance levels of the LDRs but this is done optically with photons (LEDs) and not electrons.

[khill]

Disregard. I got my answer. Ugh


I apologize if this question has been asked and addressed "I Googled key words"...but would this battery supply/charger power a Dodd Audio battery buffer with the powerCON female receptor on the buffer?

Thank!