Dodd Audio Preamp / Dodd - Richie Prototype Low Wattage Amplifier

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Captainhemo



Dodd Audio Battery Preamp / Dodd - Richie Prototype Battery Powered Low Wattage Amplifier

For the past couple of years, the two main electronic components of my system have been my lightly modded Jolida JD302CRC and my Grant Fidelity Tube DAC 11. Both have done an incredible job of reproducing recording at levels typically associated with much higher priced gear, Both are over achievers,  people are always impressed when the y hear the system, once I mention the digital signal is being converted by a $300  DAC, most are simply shocked.  Both the DAC and the amp have had their power “conditioned” via a PI Audio MiniBuss and then delivered by a pair of  Marigo Audio Labs Ultra 5 power cords. The music has been delivered to the listener(s) courtesy of my GR-Research OB-7’s (91-92db w/m) with the bottom couple octaves being handled by a pair of dual 12”  servo sub H-frames.

A few months back, I saw Danny (GR-Research) start a new thread saying he had a Dodd preamp that he had purchased from Gary Dodd and was now selling it. It had been Gary’s personal piece and he had built it into a clear acrylic case.
A month went by and I was surprised to see another post from Danny stating the pre was still available…. that was my cue to give him a call and start talking  about making some changes.

The pre is a later design in the evolution of the Dodd preamps. It uses a single ECC88 but will also accept the 6H30P-DR "super tube" which apparently works exceptionally well .  The design has a lower noise floor than its predecessors and is extremely musical. In addition, it has the variable gain setting some of the Dodd pres have which can be adjusted to best suit individual system needs. There are three selectable inputs, two variable outputs and a tape / fixed output.  A motorized Alps volume pot is controlled by a remote housed in a unique clear acrylic housing to match the preamp case.

In my conversations with Danny regarding the preamp, an additional topic that came up was the new battery powered, low-wattage amps he and Gary had been working on. These little amps are extremely linear and once the signal paths are cleaned up considerably by using quality connectors such as Cardas inputs and Electra Cable Tube Connector outputs, components, and wire, they’ll perform at an extremely high level that can be difficult to believe. The linear output of these amps does have its limit which seems to be approximately 2/3 of the amps original rated power. Danny and Gary have rated their versions with regards to the linear output and not to the amps original rating or data sheet.

While I’m well past the point of listening to extreme SPL’s, I still occasionally enjoy some decent volume.  My listening room is 18’ x 12’, what I would consider a moderate sized room. The little amp Danny and I had been discussing puts out roughly 10wpc of extremely linear power….. when you do the math it just doesn’t seem like enough..I was pretty skeptical even though Danny assured me I would be amazed. I should also note that these amps are 4ch designs (this one consisting of 2 separate amps), two of the channels are full range while the second pair are rolled off into the lower octaves. This is a pretty slick setup if you’re into bi-amping a multi-way speaker, something I may try in the future with my OB7’s. For now, it’s just the two full range channels I’ll be using.

I must admit, from the posted pictures, I wasn’t overly impressed by the appearance of the clear acrylic case but at the same time, I felt I could live with it. When the package arrived and I carefully removed the contents, I was pleasantly surprised by just how cool the preamp actually looks! In fact, since setting it up, I have received nothing but compliments on the “invisible” enclosure.

As mentioned, the Dodd pre and the prototype amp are taking the place of the Jolida integrated; the Grant Tube DAC 11 is staying for now. The new pieces are both powered by a 60Ah battery which is maintained by a fully automatic CTEK  MULTI 3300 charger. I also picked up a 90’s (pre Sovtek) 6H30P-DR tube that was built using the same construction, including the large ring/halo getter, as the highly touted DR version from the previous two decades.

As soon as I began listening with the new components it was quite remarkable how much the presentation had changed. There is absolutely no noise to mask or obscure anything, it all comes through.  I had always felt (and still do) that the PI Audio Minibuss did a fantastic job at conditioning the AC power, but  the battery powered gear takes ”black” to the extreme.   Background noise is a strange thing; you really don’t even know it’s there until it’s been removed at which time you become aware of the fact that you’ve been deprived of a portion of your recordings. The clarity and detail become almost shocking. Images are extremely accurate, stable, and well defined creating plenty of air and space throughout the representation. The Dodd create a wide and incredibly deep, layered sound stage that can be strangely holographic with well recorded albums. The openness and depth are highlighted in many jazz and classical recordings, it’s all very impressive.    

Now, what about that little 10 wpc amplifier?  Well, I still can’t believe it’s only putting out that amount of clean power. There is no issue with SPL in my 18’ x 12’ room and I haven’t yet split my cross over networks to take advantage of the bi-amping capability of the 4 channel output the prototype provides.  I don’t need the additional 3db jumping to 20wpc would provide but it is always nice to have a bit more headroom.
The dynamics of this amp are just unbelievable. I am not an electrical engineer by any stretch but I assume the impressive dynamics must be in part linked to the DC power and available current of the battery. Additionally, when you’ve got such an incredibly low noise floor, the dynamic range begins lower and seems to become more extended. 

You may be asking yourself,” How much difference can a lower noise floor make?“ Trust me, it’s pretty substantial. In both cases, when I added a PI Audio Minibuss to my system and now moving to the battery powered gear, the results in each case are not subtle or difficult to hear. There is a lot of detail that becomes much more audible when everything else is removed. You become much more aware of what I suppose you’d call micro dynamics.

Having spent the past couple of years with an EL34 based amp, a tube known for its warm, lush mid-range, when I first added the Dodd pre and prototype amp to the system I did feel the mid-range was possibly a touch thin. However, after spending a couple of hours listening, it became clear that what I was hearing wasn’t the mid-range lacking, it is just presented in a more precise fashion. All the rich tones and harmonics are there, they are just more controlled and more accurate which contributes to the space and layering of the overall image.

Like the other reviews / evaluations I’ve recently posted, I think it’s a good idea to mention a couple of points that could be concerns or possibly even issues for some people. First off, as you now know, this gear is battery powered meaning you’ll “need” a decent sized battery and a high quality smart charger to keep it maintained and ready to power your gear. I say “need” because there are some good 12V power supplies out there but from what I understand, it’s just not the way to do this. I’m not sure everyone out there will appreciate such items in the living room or their family room should that be the location of your equipment. The chargers are small and the battery can be housed in an enclosure that could easily be created to go with most any decors. There are always options. Some may consider the expense of these “extra” items a burden but remember, a fairly large capacity battery paired with a decent CTEK charger will be far less of an expense to you than most quality power cords.

For those who have very large listening spaces to fill, power could be an issue with these amplifiers. I’d say the same could apply to those of you who enjoy listening levels to the extreme.  As I have already stated, this 10 wpc rated amp I’m using easily fills my 18’ x 12’ room to any SPL I’ll be listening to. There honestly isn’t a whole lot of difference in SPL compared to the EL34 based integrated. From what I understand, if /when these do go to production, they will be based on an amp that will provide the same extremely linear response, but will have a  25 wpc with 4 channels driven.

Another point that should be mentioned is that these amplifiers use Tube Connectors in place of typical binding posts. So what does that mean?  Well, first of all, if you properly terminate you cables with the tube connector male ends, the theory is there will be less “foreign” metal introduced into the signal path and you’ll be sending a cleaner signal to  your speakers.  The male ends are hollow all the way up to the very tip ensuring an uninterrupted signal path as far as possible.  Your cables need to be stripped far enough back to ensure the wire rests right up on the end before soldering. When the female sections of the connectors are installed in the amplifiers, a male end is used as a “stop” when the output wires are installed also ensuring the two wires are as physically close as possible and only an extremely small amount of material is actually between them in the signal path. Like any connector, there will of course be both proponents as well as opponents to the product and the theory behind it. I personally like these connectors and have used them in my speaker kits so seeing them used with the amp is a plus for me. The tube connectors will not accept spades and although they will accept standard .25” banana plugs, it is not the ideal situation.  Even though many may be tempted to just leave their banana terminated cables as is, it’s a simple job of installing the male tube connector terminals on your cables, I’d recommend doing so   

Although I had been somewhat skeptical of the low powered amp, I never had any doubts with regards to the capabilities of the Dodd preamp. That being said, I’m not sure I had expected such an improvement in the level of detail, layering of images, and overall musicality I’m now hearing, especially without an upgrade to my DAC, I just couldn’t be more thrilled nor more impressed. The two components have dramatically transformed my system from what I had always considered to be a very good setup into a more resolving, more refined, more enjoyable system. It’s a system that shocks and brings smiles to the faces of guests who come by to have a listen. It’s a system that is now demonstrating more of the capabilities of my speakers and the aforementioned, over achieving DAC.  But probably most importantly, it’s a system that is bringing so much more emotion to much of the music I typically listen to. In the past few weeks, I’m sure I’ve been more engaged to the music than I have been throughout the past year.  There’s been many big smiles, numerous chills and/or goose bumps, and yeah,  I even shed a tear the other night when I found myself sitting in the dark, listening to a high res  recording of “High Masecela’s – Coal Train.” The track is not only an emotional story, but it also features some demanding vocals, some great percussion, wonderful airy saxophone and some very explosive dynamics that again completely amazed me with the fact that I was listening to a 10wpc battery powered amplifier!

From the articles I’ve read and the discussions I’ve had, I always knew the Dodd Audio products were something special and obviously the product line that he and long time friend and colleague Danny Richie had been developing will be no exception.  I’m sure for many there will be some comfort in knowing that the ideas and designs Gary had recently been working on will be present in an upcoming, innovative product line.


jay

« Last Edit: 25 Sep 2015, 05:48 am by Captainhemo »

mlundy57

Thanks Jay. 

I'm holding off on a new amp for the Wedgies until these are available.

Does this amp have a preamp output for the servo subs? If not I will need to wait for the separate preamp and monoblocks. It may be awhile before the separates are available though.

Mike

Captainhemo

Thanks Jay.  I'm holding off on a new amp for the Wedgies until these are available.

Mike

They are impessive little amps... come to think of it, you  heard at a pair driving the  big monster Line Forces at Danny's didn't you  ?
I still can't believe how dynamic such a low powered amp can be, crazy  :scratch:

jay

S Clark

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  • measurement? We don't need no stinkin measurement
They are impessive little amps... come to think of it, you  heard at a pair driving the  big monster Line Forces at Danny's didn't you  ?
I still can't believe how dynamic such a low powered amp can be, crazy  :scratch:

jay
I heard a smaller variation driving the new all electrostatic and servo LS that Danny completed late last spring.  For not a whole lot of watts (7 or 8?), it had a dynamic and extremely detailed sound.  Danny has told me that the more powerful version is just as clean as the one I heard.  As we listened, Gary made some changes to the power regulation in an inexpensive dac that made it superb.  I had him do a similar mod to my dac. 
There are some pretty cool things happening for not a lot of $$.

Folsom

Your pictures are too small to see.

Captainhemo

Shawn,
If the ones you heard are the ones you sent Danny, this one is based  on the same thing, just 2 of them in one case. 

Folsom,
I made the images links and they'll open up some larger versions

jay