Building a symmetrical psu B1 buffer

[jleaman]

I'm going to buy a nice alps

[JeroenR]

Originally Posted by woodturner-fran

Cases are the bane of every diyers life. I gave up ages ago trying to make my own and now always re-purpose a chassis from something else. My current one for the dcb1 is a broken cd player. Key problem is the very high cost of nice chassis and I don't ever see them getting cheaper.


Fran

For Europe this seems a good alternative : Hi-Fi 2000 contenitori per l'elettronica, case modding HTPC, Galaxy, rack, DIYaudio, computer cases, knobs,milled Handles, milled fronts, hi-end,

There are a lot of sizes and they seem not too expensive, approx EUR50 including shipping.

edit : EUR50 based on a 23x17cm case for the B1.

[gabanyayaya]

Originally Posted by Salas

1. Don't know specifics about your transformer ratio and reflected impedance needs of your circuit. Very general a question.

2. Nothing smothers pot subtleties in a DC super low parts count circuit like this one if you are about to investigate pot qualities. There is not that much between cheap carbon and better conductive plastic beyond the obvious mechanical quality and longevity gains, a cheap switched is a very good value, but ultimately look to make a Lightspeed.

Salas,

the traffo ratio is 500:500, Freq responds is 10-50K....I think it's a utc a-20 if not mistaken......hope this info could give you some clue.

[Salas]

1:1 then. 20-25k pot will do.

[gabanyayaya]

Originally Posted by Salas

1:1 then. 20-25k pot will do.

thank you very much....but what should it be if i use output transformer (1:1) then a tube output...?? is 50K as mention on the DC Coupled B1 Shunt PSU V4.3.pdf ?

[Salas]

If you feel like employing in your additional tube circuit after the transformer some smallish output capacitor (no less than 2.2uF), then you can use 50k pot and change the 220k input to ground resistors on DCB1S to 560-680k.

[gabanyayaya]

Originally Posted by Salas

If you feel like employing in your additional tube circuit after the transformer some smallish output capacitor (no less than 2.2uF), then you can use 50k pot and change the 220k input to ground resistors on DCB1S to 560-680k.

note that...thanks salas

[massimo]

Originally Posted by JeroenR

For Europe this seems a good alternative : Hi-Fi 2000 contenitori per l'elettronica, case modding HTPC, Galaxy, rack, DIYaudio, computer cases, knobs,milled Handles, milled fronts, hi-end,

There are a lot of sizes and they seem not too expensive, approx EUR50 including shipping.

edit : EUR50 based on a 23x17cm case for the B1.

I'm working on it. If you chose the 28 cm deep version, you could also fit a suitable xfrm.
My idea is to hold the pcb (Hyp or Mez) with some 3 x 3 cm L shaped alu bars 5 cm apart from the back panel. The bars will also provide heatsink for the mosfets and hold the selector sw and volume pot for Hyp board.
The xfrm (Hammond 229D24) will be placed close to the front panel with other 1,5 x 1,5 alu bars.

Stay tuned

[udailey]

Massimo,
I am not sure about this but if I am right you will short a turn on the transformer by mounting it to the chassi with an aluminum bar on each side if you will be attaching it by the core that sticks out the sides of that transformer. I would mount the transformer on some perf board or similar then mount the board to the chassis. I could be wrong about shorting the turn. But thought I should warn just in case.
Uriah

[massimo]

The Hammond 229 series are PCB mounting xfrm. Thus a pcb (or two small pieces of prefboard) will be used to hold the xfrm and it(they) will be bolted to the alu bars.
Wait and see....