DIY Dodd Buffer

TrungT · « **Reply #1100 on:** 6 Jan 2012, 02:58 pm »

^^^^^
100K Pot value is a good match for the kit.

jk@home · « **Reply #1101 on:** 7 Jan 2012, 01:53 pm »

Thanks T. I'm sending you a PM.

jk@home · « **Reply #1102 on:** 12 Jan 2012, 05:09 pm »

Ordering a CTEK charger today, and we have a Batteries Plus store down the road, so I can check out if they have something in stock I can use.

I have some questions regarding the 12 volt power supply. Have a closet on the back wall that has some of my equipment in it, hidden from view. I've seen the gorgeous battery boxes some have done here, but if I can throw the battery and charger in the closet, I won't need to go there.

Can I do a 6'-8' 12 VDC cable run from battery to buffer? If so, what gauge wire should I use? If not, what's the max length? Does the cable need to be shielded? Thanks

TrungT · « **Reply #1103 on:** 12 Jan 2012, 05:15 pm »

^^^^^
Buffer only draw 1A, so 12G wire should handle, make sure you add on an extra fuse close to the battery possible, just for extra safety.

jk@home · « **Reply #1104 on:** 12 Jan 2012, 05:43 pm »

Good news, thanks

siava1018 · « **Reply #1105 on:** 18 Jan 2012, 11:09 pm »

I emailed gary the other day for a vol pot and knob but he hasnt replied. Where else can i get a blue alps, is there anything else to use?

TrungT · « **Reply #1106 on:** 18 Jan 2012, 11:29 pm »

^^^^^
Try email Gary again, he had problem with his email last few days.

face · « **Reply #1107 on:** 18 Jan 2012, 11:30 pm »

A Goldpoint stepped attenuator would be better, if not an Alps pot would work.

usp1 · « **Reply #1108 on:** 19 Jan 2012, 01:11 am »

Or try the Warpspeed LDR.

HAL · « **Reply #1109 on:** 19 Jan 2012, 01:28 am »

Gary has on his website that he is working on a remote LDR volume control for his preamps.

Might be worth seeing if he plans a retrofit kit for the existing buffers.

face · « **Reply #1110 on:** 19 Jan 2012, 01:29 am »

Anyone know what this mess is?

HAL · « **Reply #1111 on:** 19 Jan 2012, 01:32 am »

I would say it is a balanced Dodd Audio Buffer being driven by a piece of sculpture.

TrungT · « **Reply #1112 on:** 19 Jan 2012, 02:22 am »

^^^^^
Sculpture made it balanced.

and sound good too

jk@home · « **Reply #1113 on:** 24 Jan 2012, 01:26 pm »

Starting to get my parts together, thanks Trung for helping me out there

Ordered some Sonicap Platinums for bypass caps and M/F neutrik powercons. Got the Power Sonic 18 AH battery and CTEK 3300.

Picked up a small, inexpensive panel mount analog 0-15 VDC meter from a local ET shop, to use on a temporary breadboard board I am first building the buffer on, need to start breaking in the caps ASAP. Later will get one of those nice ones from JD for the finished chassis. I want to be able to monitor the voltage right on the buffer.

I see on the standard buffer kit, it uses a power switch/mute board. But on the single I/O buffer pictured on the Dodd site, it appears he uses a standard toggle switch. Can this be a SPST switch, or does it need to be DPST (w/both plus and minus controlled)?

I assuming the mute function is to prevent turn on/off thumps?, Is that going to be an issue when using just a toggle? In my system I turn the power amp on last / off first (manually), so I should be OK, right?.

Also is the signal grounded to chassis, same as/tied into the 12 VDC ground, or should they be isolated? I'm using an Aragon 8008ST amp, and have had DC offset problems with it before.

Edit: Emailed Gary, SPST switch OK, all grounds go together. Onward

TrungT · « **Reply #1114 on:** 25 Jan 2012, 07:26 pm »

^^^^^
Glad you got email from Gary.

jk@home · « **Reply #1115 on:** 5 Feb 2012, 01:05 pm »

I was up in the garage attic the other day, found an old surplus ammo case laying around. Thought that it might make a decent battery box (as long as it's hidden

). Do these gel batteries in this type of app need any ventilation at all? The metal ammo box is air tight, although that could be remedied with a drill and drill bit.

Also when checking into some more Neutrik powercons, for the above box, discovered on their web site that the gray colored connectors are designated as "power-out", vs the blue color as "power-in". But yet folks here use the gray ones on their buffer chassis (power-in). Is this a non-issue, or am I missing something here?

http://www.neutrik.com/en/lighting/powercon/powercon-20-a/

TrungT · « **Reply #1116 on:** 5 Feb 2012, 02:29 pm »

^^^^^
SLA > Seal Lead Acid
So your armmo case should work great (great ideal)

You can use either Neutrik powercon, just make sure you get the right male plug for it.
Gray powercon is corrected power in.
NAC3FCB + NAC3MPB-1
You can add an inline fuse closed to the battery possible (more safety)

tenantman · « **Reply #1117 on:** 5 Feb 2012, 02:36 pm »

Quote from: siava1018 on 18 Jan 2012, 11:09 pm

I emailed gary the other day for a vol pot and knob but he hasnt replied. Where else can i get a blue alps, is there anything else to use?

Try hifi collective in UK for the ALps pot

jk@home · « **Reply #1118 on:** 5 Feb 2012, 03:04 pm »

Quote from: TrungT on 5 Feb 2012, 02:29 pm

^^^^^
SLA > Seal Lead Acid
So your armmo case should work great (great ideal)
You can use either Neutrik powercon, just make sure you get the right male plug for it.

I"m going to have a couple Ms & Fs of each color, so I'm good there.

Right now have a standard 50 cal box, may look for a "fat" 50, in town, which will give me a little more room. Thanks to all the military bases around here, we have a "surplus" of surplus stores to choose from.

TrungT · « **Reply #1119 on:** 5 Feb 2012, 04:48 pm »

^^^^^

If you drill few holes for vent, you can mount the C-Tek charger inside, on the lid.

The lid can become a heat sink.