DIY Dodd Buffer

Torkild · « **Reply #1160 on:** 22 Mar 2012, 08:27 pm »

Quote from: face on 21 Mar 2012, 11:25 pm

Do you mean balanced output? If so, to be fully balanced, you would need a second kit. Together, they would still need a 12V input, but the mA would be higher. I'm FYI, I'm using a 12v, 4.5A solid state power supply to feed a pair of buffers in balanced configuration.

Yes balanced output.
One kit per channel or are you saying two kit per channel?
I could live with one kit per channel.

okay i seems that i would need external power supply.

I have two Virtue M5001 iceblock with tube buffer, and the tube buffer are using the on board 12Vdc.

I would love to build some 250asx2 and use them in BTL mode with tube buffer to power my bass/sub speakers.
It would be so nice and simple just to use the on board power supply.

face · « **Reply #1161 on:** 22 Mar 2012, 08:33 pm »

One kit per channel.

TrungT · « **Reply #1162 on:** 22 Mar 2012, 08:34 pm »

^^^^^

And if you can reg. to 6V heater, you can use a bunch of 6V tube.

rodric · « **Reply #1163 on:** 22 Mar 2012, 09:28 pm »

Quote from: jk@home on 22 Mar 2012, 11:26 am

I remember reading at least one other person having a noise issue with the CTEK. There was a battery box posted in this thread or another here at AC where some power filtering was added.

I myself have an issue of leaving it plugged in all the time due to lightning storms and power surges we get around here. So my solution was to buy two 18 AH batteries and only plug in the charger when needed.

From Trung:
What's battery amp hr?

I may have to try filtering. I suspect I have some funky house wiring going on.

I'm using a UB1250 (5AH). I've also tried an Odessy car battery (55AH), but it also introduces noise for some reason. Neither will work powering the buffer with the CTEK connected.

setamp · « **Reply #1164 on:** 23 Mar 2012, 08:16 pm »

Is there a good (honest/genuine) source for nos 6H30-dr's ?

Atlplasma · « **Reply #1165 on:** 23 Mar 2012, 08:29 pm »

I bought mine at Parts Connexxion. They are advertising matched pairs, but you might want to inquire about the availability of single tubes.

xecluded · « **Reply #1166 on:** 23 May 2012, 02:44 pm »

What is the recommend battery to use for the buffer please. The answer probably in this thread somewhere but it really is too much to go through 50+ pages to find it. Thanks

TrungT · « **Reply #1167 on:** 23 May 2012, 03:15 pm »

SLA or AGM battery is the best choice.
7AH battery will last you around 3-4hrs playtime, So 2X7AH battery and C-Tek smart charger, should to the trick.

xecluded · « **Reply #1168 on:** 23 May 2012, 03:19 pm »

Any particular model # that is proven good/reliable. thanks

TrungT · « **Reply #1169 on:** 23 May 2012, 03:43 pm »

C-Tek charger http://www.amazon.com/Ctek-Battery-Charger-56158-56-158/dp/B000FQBWCY/ref=sr_1_1?s=automotive&ie=UTF8&qid=1337787461&sr=1-1
14AH Power Sonic http://www.batteryplex.com/powersonic.cfm/m/PS-12140-F2

xecluded · « **Reply #1170 on:** 23 May 2012, 07:10 pm »

Great. Many thanks Trung !!!

TrungT · « **Reply #1171 on:** 23 May 2012, 07:51 pm »

You are welcome.

jk@home · « **Reply #1172 on:** 24 Nov 2012, 03:40 pm »

This thread was fading into the sunset, so I figured I would post the pics of my passive pre plus buffer, to give it a bump. My project sat around for the summer, finally got to finished it up. Spent a little more than I could have, but very happy with the results.

The project started out as a single input/output design. I used a Goldpoint 25k attenuator, a Hammond case for the buffer, and an ammo box for the batteries (hidden in a closet). Once I found that the pre could easily drive both my main amp and a DBX crossover for my subs, I added a second output.

Just a fair warning, there definitely is a breakin period for the caps, etc. it has been obvious in my case. I found no audible effect leaving the battery charger connected 24/7, actually there is positively no noise present whatsoever. Amazing since I'm mixing consumer and pro gear together. Many thanks to Gary Dodd, TrungT and all other members for their help!

rajacat · « **Reply #1173 on:** 24 Nov 2012, 04:01 pm »

Nice work!

The Dodd buffer is next on my DIY project list.

..Roy

HAL · « **Reply #1174 on:** 24 Nov 2012, 04:07 pm »

Just sent one that I built to Forrest Dweller with a 6H30P-DR tube installed. Installed the Sonicap Platinum bypass and IR remote volume control.

Hope he sees the thread and posts his impressions.

Mine sounds wonderful with the Super-V's!

jk@home · « **Reply #1175 on:** 24 Nov 2012, 04:27 pm »

Yes the one above has the same tube, and the extra bypass caps.

TrungT · « **Reply #1176 on:** 24 Nov 2012, 05:20 pm »

^^^^^
Very nice build.

jk@home · « **Reply #1177 on:** 24 Nov 2012, 05:30 pm »

Better late than never .

Danny Richie · « **Reply #1178 on:** 24 Nov 2012, 06:02 pm »

Quote

Just a fair warning, there definitely is a breakin period for the caps, etc.

You have Platinum by-pass caps in yours. Those need a good 500 hours to settle in. Those things are just going to keep getting better.

jk@home · « **Reply #1179 on:** 24 Nov 2012, 06:22 pm »

The buffer really did sound bad "off the build table". Mainly the bass was mushy, the treble was muffled. Luckily I had some experience before with building crossovers for my MMGs, so I knew to hang in there.

After about 50 hours the buffer's bass started to settle down, so I knew I was OK. Getting close to the 150 mark now. Good thing about breaking in preamps is they can be run with the power amp off, to get them burned in quicker.