Altmann dac and RWA battery enclosure

denjo · « **on:** 15 Jul 2006, 10:24 am »

Geoff
I have both the Altmann Attraction DAC (full monty) and Vinnie's seamless RWA battery enclosure which he custom built to power the Altmann. If you are going the Squeezebox route (which I plan to), you might want to customise the RWA battery enclosure to be able to accommodate the SB as well. I also requested Vinnie to add inputs for wall power supply for background and less critical listening! Vinnie is a great guy to deal with and his RWA works very well with the Altmann!

Paul_Bui · « **Reply #1 on:** 15 Jul 2006, 11:39 am »

Quote from: denjo on 15 Jul 2006, 10:24 am

Geoff
I have both the Altmann Attraction DAC (full monty) and Vinnie's seamless RWA battery enclosure which he custom built to power the Altmann. If you are going the Squeezebox route (which I plan to), you might want to customise the RWA battery enclosure to be able to accommodate the SB as well. I also requested Vinnie to add inputs for wall power supply for background and less critical listening! Vinnie is a great guy to deal with and his RWA works very well with the Altmann!

Can't agree more: Vinnie is a great person to deal with, let alone his excellent skills and resilient energy.

I'm also curious about the Altmann DAC and looking forward to a listen. Asking Vinnie to customize a battery enclosure is a very good idea. Which battery are you using with the DAC?

By the way, if you're planning to go the SB (or Olive music server) route modded by Vinnie, you'll be in for a pleasant treat. Both of my RWA SB2's have been playing flawlessly for over a year while reproducing wonderful music that I would think really hard before replacing them with anything else, at least for a long time to come. I find myself listening to violin and strings a lot, something that I wanted to but couldn't tolerate due to the early set in fatigue.

denjo · « **Reply #2 on:** 15 Jul 2006, 01:06 pm »

Paul
I believe Vinnie uses a Universal 10 Ah Sealed Lead Acid battery. The Altmann would be the perfect choice if you value natural, non-fatiguing sound. The timbral accuracy and decay of notes is what the Altmann excels in spades. I have heard the DAC through wall and SLA power supply and the latter removes any hint of digitatis, giving CDs a wonderful analog sound not unlike vinyls. In fact, IMHO the Altmann closes the gap between CDs and vinyl: I no longer crave for a turntable! Let me know if you have any further queries.

Dennis

geofstro · « **Reply #3 on:** 15 Jul 2006, 05:00 pm »

denjo,

I didn't realise Vinnie had already built an SLA power supply for the Altmann. That's great news.

I certainly know Vinnie's a great guy to deal with. I'm doing a lot of catching up on this circle after a few months absence though, and things have moved on quite a bit. I need to do some more reading before posting

...and thanks for the tips on the SLA/Altmann options. I too am getting the full monty Altmann, which Charles is building for me right now. Your description of it ties in exactly with my expectations.

geoff

dburna · « **Reply #4 on:** 16 Jul 2006, 09:35 pm »

Denjo (or perhaps Vinnie),

When Vinnie build you a battery/custom case for the Altmann DAC, did he have the DAC in-house (at RWA) or just shipped you a case into which you inserted the DAC?? Just wondering if Vinnie has now had a chance to hear what the Altmann DAC can do. If so, Vinnie, would you care to comment on how the Altmann sounds relative to some of the other DACs that have passed through your workshop?

Thanks in advance, -dB

geofstro · « **Reply #5 on:** 16 Jul 2006, 09:50 pm »

I know the question would have been addressed to Denjo, though as I'm an interested party, so to speak, I can definately answer on this point, that it would be an external SLA battery power supply that Vinnie would have made here. Similar to, (perhaps identical?) to the one he supplies for the SB2 and 3 mods.

One of the design criteria of the Altmann DAC is that it doesn't sit within any type of enclosure. Instead it is simply mounted on a piece of laxqured spruce to minimize resonance, and it gets its power from an external 12 volt battery.

Denjo, I am interested in what kind of lead you use between the DAC and Vinnies SLA. Did you fabricate a custom lead yourself or did Vinnie include one with the SLA?

Thanks

geoff

denjo · « **Reply #6 on:** 17 Jul 2006, 12:17 am »

Dburna
The battery enclosure (not unlike the one he builds for the Squeezebox) came with the SLA but no DAC since I did not need the DAC. Two toggle switches control on/off and charge on/charge off.
Geoff
Charles Altmann provided the cable to feed the DAC but I did not use his cable. Instead, I used the one Vinnie provided. Not sure if it is silver or silver plated but it sounds great! At some point in the future, I might custom make a pair once I have done some due diligence. The cables are thin and twisted. The Altmann DAC has a connector with a pair of screws (- and +) to swop cables, as you desire. as for digital cables, I have found the DAC (not surprisingly) to be quite revealing of the quality of cables you use. I started with a Hishagao but switched to Belden 1506 with Canare connectors. The Belden's are the el cheapo that have been pretty well reviewed. The improvements were significant. I wonder what the DAC would sound with premium digital cables like Kimber D-60. If price was not an issue I would have invested in Stealth's Sextet (you can buy another Altmann at that price!).
I have also tried the optical input of the Altmann and was quite surprised to observe that it did not sound too different from the digital input (I was using a cheap Toshiba TOSLINK). My plan is to connect the SPDIF to the SB3 and switching between CD and wireless music would be as easy as the flick of a switch!

geofstro · « **Reply #7 on:** 17 Jul 2006, 09:50 am »

denjo,

Thanks again. I'll ask Vinnie if he can make one up for me exactly the same as yours. I didn't realize the power supply cables for the Altmann could be changed so easily. That's good news. I'm going to be using an old (but good) Harmonic Tech digital cable for Coax. For Toslink there was some talk around here a while back about the benefits of true glass Toslink, so I may try that out.

Geoff

Vinnie R. · « **Reply #8 on:** 18 Jul 2006, 02:26 am »

Quote from: dburna on 16 Jul 2006, 09:35 pm

Denjo (or perhaps Vinnie),

When Vinnie build you a battery/custom case for the Altmann DAC, did he have the DAC in-house (at RWA) or just shipped you a case into which you inserted the DAC?? Just wondering if Vinnie has now had a chance to hear what the Altmann DAC can do. If so, Vinnie, would you care to comment on how the Altmann sounds relative to some of the other DACs that have passed through your workshop?

Thanks in advance, -dB

All,

Thanks for all your kind words about your experiences working with me. It has certainly been a pleasure dealing with you guys too and I'm thankful to have this forum for everyone to share their ideas and experiences.

I decided to do a "split topic" and take these last few posts from the "Sig 30 thread" and move them to a new topic called "Altmann dac and RWA battery enclosure." Hope nobody minds

Hi dburna,

Welcome to Audiocircle and the RWA forum!

When I built the battery power supply for denjo, I do not have the opportunity to actually listen to the Altmann but I wish I could have! I have read lots of favorable comments about it.

The SLA power supply that I made for denjo was very similar to the one that I make for the Squeezebox mods (same enclosure, same 10Ah battery, On/charge switch, charger jack, etc.). denjo mentioned that he is considering using a SB3 later on, so I made separate jacks on the back to power the RWA modded SB3 and the Altmann.

Best regards,

dburna · « **Reply #9 on:** 18 Jul 2006, 07:30 pm »

Vinnie,

Thanks for your reply. It's good to be "in the fold". Looking forward to hearing how well the Signature 30 amp will control my Horning Perikles speakers.....I love these speakers and they produce a tremendous realism, but they do need a low-end "iron hand". One reason why I may dispense with tube amps altogether......and why I ended up reading the RWA Forum in the first place.

I agree with the other posters -- take your time w.r.t. cranking out your amps......right after mine ships.

Good things come to those who wait.....

For anyone/everyone else: I've been looking for a new DAC. I know this has been posed in several guises on several of the AudioCircle forums, but as yet a concise assessment of the following questions eludes me:

1. Has anyone been able to do a direct comparison between the Altmann vs. Lite Audio DAC-60 (modified and/or unmodified) vs. the Monarchy D24? Since this is an RWA forum, lets throw Vinnie's modified Olive into the mix as well....

2. For anyone who has listened to the above DACs, would you care to comment on any problems/limitations they have with high-frequency hardness/harshness? I don't know if any of these DACs exhibit this problem, but I am particularly sensitive to this issue. Having been to a few audio shows (and audio showrooms), this problem is one that can drive me out of their listening environment almost immediately. And the list of "cuplrits" that exhibit this problem is a long and inglorious one...

3. Can anyone help me get over my Altmann "it's just a freekin' circuit board on a piece of wood" anxiety enough so that I can take the plunge? Mind you, this is from someone who already has an AudioSector 1543-based DAC on a board. Of course, the difference in cost is more than $1k, plus the need to add a battery power supply. I'm sure that, despite some configuration similarities (choice of some parts), that the Altmann DAC can improve on the AudioSector (aka: 47 Labs) implementation.

4. Can anyone comment on their findings regarding NONOS DACs and their susceptibility to jitter? Dick Olsher references that view in his latest Enjoy the Music article, but I'd like to get a reference to someone who addresses this in more detail. From a technical standpoint it sounds plausible, but usually the devil is in the details. I was hoping that someone had some direct experience.

Thanks in advance for any additional help as my quest continues.

-dB (a unit measure of noise)

Paul_Bui · « **Reply #10 on:** 18 Jul 2006, 09:33 pm »

Having used a AS NOS DAC, I recently learned about a person in San Francisco who has two Altmann DAC/amp setups. Once I get connected and we get together, I'll be happy to post my impressions in comparison with my RWA SB2/ AS DAC combo. San Francisco is about one hour driving away.

dburna · « **Reply #11 on:** 18 Jul 2006, 09:52 pm »

Thanks, Paul. I would be delighted to hear your impressions. I can wait a little while to hear before making my purchasing decision.....I think.

Best, -dB

dburna · « **Reply #12 on:** 25 Oct 2006, 01:56 am »

And????......And?????? aa

Paul_Bui · « **Reply #13 on:** 25 Oct 2006, 02:22 am »

Forgive me, wifey just got home and my typing got interrupted. Will follow up soon.

Paul_Bui · « **Reply #14 on:** 25 Oct 2006, 02:45 am »

Quote from: dburna on 25 Oct 2006, 01:56 am

And????......And?????? aa

Let's move to the more appropriate Multichannel & Digital Domain circle.