DIY Dodd Buffer

HAL · « **Reply #220 on:** 22 Apr 2010, 07:06 pm »

If you guy's don't stop

you will short something out!

Mariusz · « **Reply #221 on:** 22 Apr 2010, 07:19 pm »

Quote from: jtwrace on 22 Apr 2010, 07:01 pm

No secrets...just more drool with the bypass caps.

How $ are those upgrade caps?
Might get some of those and others to roll.
Any other recommendations???

jtwrace · « **Reply #222 on:** 22 Apr 2010, 09:56 pm »

Quote from: Mariusz on 22 Apr 2010, 07:19 pm

How $ are those upgrade caps?
Might get some of those and others to roll.
Any other recommendations???

They're $40. I had a long talk with gary over using something more exotic. He suggested I stick with these.

Mariusz · « **Reply #223 on:** 22 Apr 2010, 11:29 pm »

I know Gary likes those.

•••••••••••••••••••••••

Gary
I preped eveything and it is coming along pretty nice.
My first DIY preamp.

Seems like I got everything except for 1 - AXICOM 12V relay

I might get those bypass caps after all.

Also
I haven't seen any reference to non motorize volume control (stock) instalation.
And wire to board wireing for that and motorized alps.
It would help rookies like myself.

gld · « **Reply #224 on:** 23 Apr 2010, 12:33 am »

Mariusz on the instructions page under diagrams there are 2 items. 1 of them is the main wiring diagram and it shows the wiring for the non remote pot. The other diagram shows how to wire the remote volume board into the buffer.
Did you get the second package that had a relay and a switch in it along with a small heatsink and some tie-wraps? Also there is the 3rd package with the fully built and tested remote control kit you ordered.

Gary

Mariusz · « **Reply #225 on:** 23 Apr 2010, 12:58 am »

Just double checked and you were right, 12V relay is there along with the switch, heat sink, 10 piner & ties.

I think that is all.

Pictures on your website are really helpful and they make the assembly a snap.

Mariusz

sl_1800 · « **Reply #226 on:** 23 Apr 2010, 01:13 am »

Gary,

There is a switch in the kit.......wiring diagram shows it as 6V - 12V. Does this mean the unit can run on a 6V source or a 12V source?

Also I have all of by parts and pieces soldered and ready to put into the chassis. Looking forward to getting this baby up and running.

TrungT · « **Reply #227 on:** 23 Apr 2010, 02:04 am »

Steve
The switch is for your tube, switching between 12v and 6v tube.

gld · « **Reply #228 on:** 23 Apr 2010, 02:15 am »

Thanks Trung, yes, it is for switching the filament voltage from 6 volts to 12 volts.

gld · « **Reply #229 on:** 23 Apr 2010, 02:58 am »

Hey all ,the requested changes to the instructions have been finished. Check it out and please let me know if there is anything else I need to change to make it easier to build this thing.

Gary

Robert F. · « **Reply #230 on:** 23 Apr 2010, 09:40 am »

Quote from: jtwrace on 22 Apr 2010, 05:59 pm

I agree 1,000,000%!

I also see that you did the Sonic Platinum bypass upgrade. Good idea as I was shocked at the difference. I purchased mine when they first came out (assembled) and then did the bypass upgrade. I have even more

I HIGHLY recommend this to all.

What is the "Sonic Platinum bypass upgrade" ? What is bypass cap value?

I think I need to keep this in mind for when I build my own kit. If there are upgrades and tweeks that make this buffer better, then I will go for it.

Robert

gld · « **Reply #231 on:** 23 Apr 2010, 02:06 pm »

The upgrade to Sonicap Platinums as a bypass cap . It wires across the original 3.3uf Sonicap. The value of the cap is .01uf and it's a Sonicap Platinum. It DOES make nice differences sonically. The best part is , it is a nice improvement for cheap ($40) for a pair of them

gary

Mariusz · « **Reply #232 on:** 23 Apr 2010, 03:29 pm »

Quote from: gld on 23 Apr 2010, 02:06 pm

The upgrade to Sonicap Platinums as a bypass cap . It wires across the original 3.3uf Sonicap. The value of the cap is .01uf and it's a Sonicap Platinum. It DOES make nice differences sonically. The best part is , it is a nice improvement for cheap ($40) for a pair of them
gary

That's pretty good deal.
But let me touch on that....a bit.

So why use a bypass caps at all?

- will .01uf SP smooth out the top end, remove some edginess, clean things up or add some benefitial coloration?

Just curious

Mariusz

gld · « **Reply #233 on:** 23 Apr 2010, 05:42 pm »

They will do all of that and then some.

But DO NOT expect ANY colorations!

Gary

Mariusz · « **Reply #234 on:** 23 Apr 2010, 06:39 pm »

Thanks Gary
that's what I though.

So, (more or less) the only coloration will be associated with tube choice.
Sounds good to me.

P.S
that is how I remember your top of the line preamp.
Transparent as far as the circuit is concern but telling and revealing in tube characteristics.

Mariusz

ebag4 · « **Reply #235 on:** 23 Apr 2010, 09:04 pm »

Gary,
Would it be possible for you to tell us what specs we need to look for to determine whther or not a tube is suitable for the buffer? Also, it would be good to have the equation to determine the output impedence. I know I have a number of 6 volt tubes I pulled from an old console years ago, I'm sure others have stock as well. Of the tubes I have one is on the list on your website. I wouldn't want to bother you with looking them all up to determine compatibility.

Thanks,
Ed

gld · « **Reply #236 on:** 23 Apr 2010, 10:23 pm »

Ed that would be quite tough to tell you the equation. I use a spice modeling software and the computor to determine the output impedance.

I really don't mind inputing all the specs and giving you an answer on any tube as lond as I can find the spec on it. Heck that way even I get to learn something and build a better tube info base

Gary

ebag4 · « **Reply #237 on:** 23 Apr 2010, 11:00 pm »

Quote from: gld on 23 Apr 2010, 10:23 pm

Ed that would be quite tough to tell you the equation. I use a spice modeling software and the computor to determine the output impedance.
I really don't mind inputing all the specs and giving you an answer on any tube as lond as I can find the spec on it. Heck that way even I get to learn something and build a better tube info base
Gary

Understood, thanks for the reply. Once I get mine up and running and have put some hours on it I will hit you up for some tube info.

Thanks Gary,
Ed

Mariusz · « **Reply #238 on:** 23 Apr 2010, 11:21 pm »

Dodd remote arrived.
Love it.
Feels like a brick.

Gary, thank you for assembling the board and transmiter + housing for me.
It's a huge help.
•Q•. - Is the wooden remote shell pre-finished or not?
(it sure feels like it has been "licked" )

Mariusz

gld · « **Reply #239 on:** 23 Apr 2010, 11:41 pm »

No finish. I left that for you to do.
gary