A new best amp ever....

Danny Richie · « **on:** 27 Jun 2009, 05:29 pm »

For some applications it really could be.

Gary Dodd has designed an all new battery powered tube amp. I have posted something about it before. I heard it last weekend when I drove down to the Lone Star Audio Fest.

Gary had it hooked up to an old pair of Alpha LS's. Not exactly an easy load for an amp to drive especially one that only produces 15 watts. It handled it great though.

Being feed a signal from one of his battery powered pre-amps there was no noise level. It was REALLY dead quiet. Resolution, detail levels, vocal region, bass response, everything was top notch. I really just couldn't believe just how good it was.

This is also a pretty simple design and the cost can be kept pretty low. Gary is shooting for a $995 cost limit. This does not include the batteries.

The batteries can be any 12 volt source. I opted for a small pair of Lithium Ion batteries. Those two little batteries will play it between 4 and 4.5 hours then they electrically shut off. It then takes 2.5 hours for the charger to bring them back up to full charge so you can go at it again.

You could go with a deep cycle marine battery (cheap) and play it for a long time between charges.

Anyway, I am totally blown away by how good this amp is and to think that what could be the best sounding amp on the market could be had for under a grand plus some batteries is just hard to believe.

I am so excited about this amp that I am really thinking about helping Gary out and buying 10 of them to resale. How many of you guys would be interested in one of these amps?

Note: Since this is really about one of Gary's new products and not one of mine, I moved it to industry ads.

mr_bill · « **Reply #1 on:** 27 Jun 2009, 06:16 pm »

I would be interested. I need to purchase an amp.
Pics would be good.
My only concern would be if 15 watts is enough.

gld · « **Reply #2 on:** 27 Jun 2009, 09:57 pm »

I just want to talk about the battery amp a bit. I do have some prototype pics I will provide, but please understand those pics DO NOT represent what the product will look like. It is just for tube layout, rear panel layout and componets will be the same, there will only be a power switch on the front, and the physical size is the same at 8.5"w x 7.5"d x 4.0"t and it weighs 9-10 pounds. Tube compliment is 2 6BQ5/EL-84's per channel along with 2 6DJ8 or equivilent tubes per channel. you have the choice of either 4 or 8 ohm taps,(not on prototype amp). That is a very wide range of tubes to choose from to tailor the sound to your liking. All amplifiers will be shipped with all JJ tubes. As always all Cardas terminations. I will provide a cable with each amp for you to connect any 12 volt battery/'s.
As Danny said his thing is just really really good,

unbeleivibly good! I am sure many of you are thinking that it's only 15 watts you need efficient speakers for this. The old Alpha's are around 90-91db and this thing palys like it's 50 or more and very dynamic and resolved. You will be floored at how much noise there really is left in systems that seem to be really quiet when you listen to this thing as it has no noise of any kind! AMAZING to say the least. I am very excited about this and I am offering it for a price that can be afforded even in this economy.

Gary

jtwrace · « **Reply #3 on:** 27 Jun 2009, 10:05 pm »

Love the PROPER use of power in connector...the powerCON 20 by Neutrik.

TF1216 · « **Reply #4 on:** 27 Jun 2009, 10:17 pm »

May I ask you guys what you think about this battery amp versus the prototype for sale? Which would be at powering a 88 dB 3-way with a calm impedance curve (6 ohm)?

gld · « **Reply #5 on:** 27 Jun 2009, 10:33 pm »

Personally 15 watts would be ok for pretty low level listening, but for the days when you just need LOUD no way.

I wouldn't use it with anything less than 90 db. However the prototype hybrid would knock your socks off! Just my 2 cents worth.
Gary

mumford · « **Reply #6 on:** 27 Jun 2009, 11:04 pm »

Powercon is awesome. Actually, Speakon is great too.

mumford · « **Reply #7 on:** 27 Jun 2009, 11:05 pm »

Do you use a SMPS to get the 300VDC B+?

gld · « **Reply #8 on:** 28 Jun 2009, 12:52 am »

I figured some one would ask that question. The answer is yes, it is a type of SMPS. It is not a typical SMPS, what I have done is I found a way to improve effiency to well over 98%, and I aint saying how I achieved it. That is the magic part of this power supply and it will be protected. aa
Gary

amandarae · « **Reply #9 on:** 28 Jun 2009, 01:14 am »

Hello Gary,

Nice amp! What is the minimum hum level at the output? Also what is the input sensitivity for full rated power and input impedance?

I have 100 dB speakers and hum is its enemy.

regards,

Abe

gld · « **Reply #10 on:** 28 Jun 2009, 01:58 am »

Output hum??

?? Whats that? There is no noise at all, it's like hey man turn it on! With some tubes there is tube hiss if you got your ears in the speaker.
Input impedance is 100K and it will go to full power with 1 volt in
gary

mumford · « **Reply #11 on:** 28 Jun 2009, 02:00 am »

Quote from: gld on 28 Jun 2009, 12:52 am

I figured some one would ask that question. The answer is yes, it is a type of SMPS. It is not a typical SMPS, what I have done is I found a way to improve effiency to well over 98%, and I aint saying how I achieved it. That is the magic part of this power supply and it will be protected. aa
Gary

I think it will be truly magical if you can get rid of the switching noises. 98% efficiency is not that big of a deal.

So, square waves or pure sine waves? Switching frequency?

Audiovista · « **Reply #12 on:** 28 Jun 2009, 02:20 am »

Quote from: mumford on 28 Jun 2009, 02:00 am

....98% efficiency is not that big of a deal....

Not sure I understand... not a big deal as in "easy to achieve" or "not critical for the application" ?

If 98% indeed, I think it's a huge deal. Especially if from 12V to 300V and low power (100-200W).

Boris

mumford · « **Reply #13 on:** 28 Jun 2009, 02:27 am »

I guess I just care about sound quality rather than efficiency. Class A amps have never been about efficiency. In order to get 15W from a pair of EL84, I suspect that we are stepping onto Class AB push pull territory here.

gld · « **Reply #14 on:** 28 Jun 2009, 02:36 am »

Ok, first off it is a cla aass A push-pull amp. And the efficiency thing is very big indeed! I did mention well above 98%. What makes it even better is that it is totally noise free as far as humans go. Operating frequency is above 100khz!
Just for fun a little bit ago I connected my Grado SR80 headphones directly to the amp and I shorted the inputs. The grado's are rated 98DB. With the JJ tubes that all units will be shipped with you could hear a slight tube hiss and absolutely no other kind of noises! aa Now, maybe with speakers 100db and above you may actually hear a tube hiss if you stick your ears in the speaker, with 98db phones right on my ears It was very slight.

gld · « **Reply #15 on:** 28 Jun 2009, 02:37 am »

yes, in the upper end of the power range it is in B. So We can call it a class AB amp.

JackD201 · « **Reply #16 on:** 28 Jun 2009, 05:55 am »

Quote from: amandarae on 28 Jun 2009, 01:14 am

Hello Gary,

Nice amp! What is the minimum hum level at the output? Also what is the input sensitivity for full rated power and input impedance?

I have 100 dB speakers and hum is its enemy.

regards,

Abe

Hey Bro! This one has definitely got your name on it! aa aa aa aa

amandarae · « **Reply #17 on:** 28 Jun 2009, 09:17 am »

Quote from: JackD201 on 28 Jun 2009, 05:55 am

Quote from: amandarae on 28 Jun 2009, 01:14 am
Hello Gary,

Nice amp! What is the minimum hum level at the output? Also what is the input sensitivity for full rated power and input impedance?

I have 100 dB speakers and hum is its enemy.

regards,

Abe

Hey Bro! This one has definitely got your name on it! aa aa aa aa

Hello Boss JackD "the man",

I did not know that you check upon the AudioCircle forums at all ! I was very surprise!! In a good way of course. The thread "Best Amp Ever" is too exciting not to check out.

Nice to see you here sir!

Gary,

Thanks for the reply. I will keep an eye on this thread and see if I can afford the amp.

regards,

Abe

JackD201 · « **Reply #18 on:** 28 Jun 2009, 01:00 pm »

Always on the lookout for goodies to bring home buddy. If you get a pair of these amps gimme your impressions. You know I trust your ears

I have some 95dB speakers with impedance variances less than 1 ohm that would benefit from really quiet operation (Crimped Aluminum ribbons with massive Neodymium mag structures). This amp looks very promising indeed.

Besides, I've always had a soft spot for the EL-84's boogie factor.

Audiovista · « **Reply #19 on:** 28 Jun 2009, 02:04 pm »

Quote from: mumford on 28 Jun 2009, 02:27 am

I guess I just care about sound quality rather than efficiency. Class A amps have never been about efficiency. In order to get 15W from a pair of EL84, I suspect that we are stepping onto Class AB push pull territory here.

Good reasoning, I can only agree 100%.

This is going to be an interesting product.