DIY Dodd Buffer

jtwrace · « **Reply #60 on:** 8 Apr 2010, 01:27 am »

Quote from: gld on 8 Apr 2010, 01:25 am

This is the first time I have offered a kit of any kind let alone one of my best products! I worked and worked to get it as simple and inexpensive as I possibly could. Now I am waiting to see how this first kit goes. If it goes as well as I think it will, then I will release an amplifier kit of some sort as the second kit. I have already started work on it hoping the first kit goes well!
gary

1 sold already... When can I send the funds?

Mariusz · « **Reply #61 on:** 8 Apr 2010, 01:42 am »

That would be f****n awesome

It sure would answer a lots of prayers ......
Especially those dedicated audiophiles with love for music who struggle in today's economy.

On behave of those folks - THANKS !!!

Mariusz

sl_1800 · « **Reply #62 on:** 8 Apr 2010, 01:56 am »

Gary if the amp kit resembles the current battery amp I too would be a buyer, just don't tell my wife.

gld · « **Reply #63 on:** 8 Apr 2010, 02:13 am »

Well it for sure will not be a battery amp,

way to much cost and complexity for a kit! It will probably be mono's if I can get the cost down and it will also be at least 30 watts. The battery amp is AWSOME, but it isn't enough power for a lot of people. I want the entire DIY market to be able to afford and build these kits!

It's all going to depend on the buffer kit and it's sucess.

Gary

HAL · « **Reply #64 on:** 8 Apr 2010, 02:26 am »

Gary,
The battery powered buffer kit looks great! The tube rolling idea is very cool indeed with that range of tubes it works with. I even have a nice Telefunken 12AX7 smooth plate that would be fun to try.

I do not need one with the battery preamp, but it would be a fun DIY project!

Mariusz · « **Reply #65 on:** 8 Apr 2010, 02:57 am »

Quote from: HAL on 8 Apr 2010, 02:26 am

Gary,
The battery powered buffer kit looks great! The tube rolling idea is very cool indeed with that range of tubes it works with. I even have a nice Telefunken 12AX7 smooth plate that would be fun to try.

I do not need one with the battery preamp, but it would be a fun DIY project!

Preamp/buffer kit is battery powered
Amp is in the works but it most likely will not have battery PS.

But in all honesty, I would concentrate on this kit first, since amp's future depends on IT!

I for one am familiar with Gary's work - owned his preamp ones (kind of
regret selling it). And if this kit is in 80% as good as his top of the line preamp...... you will really regret passing on this opportunity.

Side note:
its popularity will depend not only on sound quality, integrating battery power supply and price but support and clear/easy to follow instructions.
Lot of Dodd fans can be turn off by complexity of the kit or skill required to put this kit together.

Mariusz

TrungT · « **Reply #66 on:** 8 Apr 2010, 03:33 am »

Is anyone on DIY forum?
We need to spread the words of the Dodd battery buffer kit.

jtwrace · « **Reply #67 on:** 8 Apr 2010, 11:54 am »

Quote from: TrungT on 8 Apr 2010, 03:33 am

Is anyone on DIY forum?
We need to spread the words of the Dodd battery buffer kit.

http://www.diyaudio.com/forums/analog-line-level/164748-diy-dodd-audio-buffer-kit.html#post2146492

jtwrace · « **Reply #68 on:** 8 Apr 2010, 11:57 am »

Quote from: Mariusz on 8 Apr 2010, 02:57 am

And if this kit is in 80% as good as his top of the line preamp...... you will really regret passing on this opportunity.

Mariusz

Some say that the buffer actually sounds better then the preamp...

sl_1800 · « **Reply #69 on:** 8 Apr 2010, 12:48 pm »

I had the chance to A-B the preamp and buffer, I could not hear any difference in sound when the buffer was using a good NOS tube.

JohnLL · « **Reply #70 on:** 8 Apr 2010, 12:56 pm »

I am VERY interested in this also. I do not need the gain and this has got to run cool at 12 volts. Two questions. What is the current draw with the stock tube? Also I noticed mosfet in the BOM- is a CCS part of the circuit. Thanks John

jtwrace · « **Reply #71 on:** 8 Apr 2010, 01:02 pm »

Quote from: JohnLL on 8 Apr 2010, 12:56 pm

I am VERY interested in this also. I do not need the gain and this has got to run cool at 12 volts. Two questions. What is the current draw with the stock tube? Also I noticed mosfet in the BOM- is a CCS part of the circuit. Thanks John

roughly 700ma

gld · « **Reply #72 on:** 8 Apr 2010, 01:31 pm »

There is no CCS on this circuit.

The mosfet is for the timer circiut for turn on delay. If you notice in the pics of the kit the important parts I don't want anyone to know about are potted. There are 2 potted modules in the kit.
Don't ask I'm not telling what I have done.

Believe me it's quite unusual what I have done.
The entire kit runs very cool in fact I doubt that anyone will even notice.
The current draw depends on the tube being used. The older units like Jason's that have 2 tubes in them use about 700 ma depending on the tube used. The new units like the kit have only 1 tube and therefore the current goes down to half or less depending on which tube is being used. The thing will play hundreds and hundreds of hours on a small 26 AH battery.

Gary

TrungT · « **Reply #73 on:** 8 Apr 2010, 01:54 pm »

Jason
You are "THE MAN"

brother love · « **Reply #74 on:** 8 Apr 2010, 02:41 pm »

Quote from: gld on 8 Apr 2010, 01:31 pm

...The new units like the kit have only 1 tube and therefore the current goes down to half or less depending on which tube is being used. The thing will play hundreds and hundreds of hours on a small 26 AH battery.
Gary

I'm a little confused (OK, a lot

). Your battery config for Dodd Audio pre-amp (& one you offer thru Danny @ GR Research) is (4) 12v 5 amp batteries run in series & parallel to achieve 24v & 10 amps. Correct? Recognizing that single tube passive buffer has greatly reduced current draw, what are you recommending battery-wise for this wonderful DIY unit? [Edit: I see a 12v DPDT relay in BOM, so assume this unit needs a 12v battery only].

I understand there are different battery options, but was hoping that I could utilize (2) 12v 7 amp SLA batteries in series (24v 7 amp net) to operate both the tube buffer & a Virtue Audio One.2 amp (amp draws 7 amps I believe & up to 30v PSU). A 24v 1.8 amp charger would stay hooked-up to batteries. Is this feasible, or does the proposed combo increase demand/ needs?

gld · « **Reply #75 on:** 8 Apr 2010, 02:56 pm »

No,

you cannot use the Virtue amp battery supply for the buffer. The Virtue amps run on 24 volts, the buffer runs on 12 volts. The battery preamp runs on 24 volts. You could use 1 12 volt 7 AH battery on the buffer and it would play around 50-60 hours or so depending on what tube is being used.

ebag4 · « **Reply #76 on:** 8 Apr 2010, 03:04 pm »

Quote from: gld on 8 Apr 2010, 02:56 pm

You could use 1 12 volt 7 AH battery on the buffer and it would play around 50-60 hours or so depending on what tube is being used.

That is incredible Gary!

Best,
Ed

jtwrace · « **Reply #77 on:** 8 Apr 2010, 03:22 pm »

Quote from: TrungT on 8 Apr 2010, 01:54 pm

Jason
You are "THE MAN"

I'm just a fan of "Triple D Audio"

dBe · « **Reply #78 on:** 8 Apr 2010, 03:24 pm »

Quote from: jtwrace on 8 Apr 2010, 11:57 am

Some say that the buffer actually sounds better then the preamp...

Before the Buffer that I have I had a Cary SLP-50B that I modified to the hilt - HexFREDs for HV, Schottkys in the heater supply, HUGE B= power supply capacitance as well as filament supply, a 317 filament regulator, a HV mosfet regulator instead of the zeners, Sonicaps with Platinum bypasses, a few Rikens here and there all working with Amperex Orange label 7308 tubes. It was big, beefy, bold in sound. The Dodd on the other hand is just honest - it gets out of the way of the music. Truly amazing in it's transparency. Like I said at diyAudio: Awesome is only a word............

Dave

TrungT · « **Reply #79 on:** 8 Apr 2010, 03:29 pm »

Jason
Are you talking about battery size? AA AAA and the DDD?

Dave
Hurry to fininishing your V speakers, then Dodd gears really ... really AWESOME