A PSU for the Quickie

[the_groupie]

Hello All,

I have searched in the forum but not found the answer. I am thinking of building a Quickie however I do not wish to run it on batteries (I am lazy!). So what are the voltages I need for it to run? Is it a simple conversion?

Cheers

[earwaxxer]

You will need 2 separate voltages, 1.5V for the heaters and 30-60V for the grid (I personally like 30V but the tube can handle a range). IMO rechargeable batteries are the way to go.

[Paul Birkeland]

I built a Quickie that runs without batteries, it requires:

Two 1.5V or 3.0V DC supplies that float with respect to each other (so maybe look for a PT with two 2.5V or two 5V windings).  These must be regulated (IMO) for low noise operation.

The high voltage supply can wander a little bit, I ended up making a 105V DC regulated supply and using a CCS on the tube.  If you're going to stick with the stock circuit, 40V is a good place to start with very, very low ripple!

-PB

[the_groupie]

Hello,

thanks for the replies.

When you say 1.5 V that float you mean that they should be seperated? That I can't use a common ground or psu for 1.5 voltage?

Cheers

[the_groupie]

An aditional thought.

Can I build a 36V PSU and then connect something like this http://www.ebay.com/itm/1-5-to-29V-DC-Adjustable-Voltage-Regulator-Module-Board-Based-on-LM317-/200922412203?pt=US_Radio_Comm_Device_Power_Supplies&hash=item2ec7e8b4ab [nofollow]

To get the 1.5 V i need? Dual of these to get 2*1.5 V.

Cheers

[Paul Birkeland]

Yes, no common grounds.  This requires two separate windings for your 1.5V supplies, and you could use two of those boards to make 1.5V (one on each winding).

IIRC, there are some Hammond transformers that have two 5V windings on them, that might be a good choice.  When I built mine, I used two PT-1 transformers.  Along those lines, two Allied Electronics 6K27VF transformers would be sufficient for such a project.

-PB

[rif]

Would something like this work?  After rectifying, assume you have 6VDC.  One tube uses the 6.0 - 4.5 V tap, the other tube uses 3.0 - 1.5 V tap.  That way they don't share anything in common?

[Paul Birkeland]

I can assure you that you won't get 1.5V across any of those 1K resistors if you tried to light up two 3S4's with that supply.  Consider that the resistance of each 3S4 filament varies with temperature and from tube-to-tube, and that each filament needs separate bias.

[rif]

I just picked some random values. I was more interested to see if the concept would work - apparently it's just a bad idea. Two d-cells are looking better all the time - occam's razor and all.

[2wo]

It might be a thought to build a B+ supply and just float a D cell for the filament...John 

[earwaxxer]

I love battery powered kit. My USB to SPDIF converter runs on 9V battery power now. I use a pack of 7AA's. That thing definitely draws more amps than the Quickie. I get about 6 hours of play per charge. Improved sound over the USB power. Cost - a couple of bucks for the battery holder, a little wire and a connector, about 15 bucks for some good rechargeables. If I could run my dick off a battery I would!

[the_groupie]

Thanks for all the answers, I will think on this one a bit more....

Cheers