AMP4 DAC Sub Mini Tube Hybrid Awesomeness

[teflondon]

Hey all,

I finally got started on my project today. I wanted to get my soldering skills warmed up so I assembled the easy tube kit that I am using for my preamp. Plus, I am saving up a few bucks for the amp4.

It went super smoothly. My new weller station (christmas present!), panavise, and what I learned on my amp6 all made this time around a breeze. Not that all the solders are flawless...

I used some of my sockets and pins to create a base for the tubes. I was going to cut a 10pin IC socket to use, but I wanted to get going today.

I know it's not an amp4 (yet!), but this thread will be very soon.







This board is not yet tested. The two crappy trimpots were included in the kit, and those and the pins on the IN/OUT are just for getting the thing working. The fine people over at diyaudioprojects have discussed many upgrades for this kid. I just built it to stock, but will be swapping a burr brown opamp with the one it came with.

This will be between the amp4 and the remote input module in my system. In the near future I will be asking the experts about powering this thing with a TREAD ps, without toasting it since it's made for a 9v battery.

[krilli]

Very cool. You're on a roll, I'd say.

[V-bro]

Super cool! Those sockets sure make life easy don't they?

Nice project, will be following this!

[teflondon]

Hey yeah, the sockets / pins are awesome.

However, these particular ones are pretty light weight. The pins are tiny - perfect for a breadboard, but otherwise kind of tinsy.

Some of the wires in my cigar box kit that are more rigid cause a little problem with pulling the pins out of the board / sockets. Also, I thought I was being clever buying rounded ones because they seemed like they would fit better, male to female. But I can't use them on existing pins / boards because they are mostly all square. So I will have to either buy some square sockets as well, or replace the pins with my own.

[V-bro]

The round ones for headers do fit on square header pins and are in fact MUCH better quality than the square ones... The ones you have there look like the ones with smaller holes, designed for component leads...

[teflondon]

So are these sockets actually supposed to be soldered in-to?

[teflondon]

Hey All!

Man, I can't believe it's been 7 months since I was last in here. A lot has happened around these parts.

I have been slowly working on my amp4 project. Very Slowly.

My tube pre never sounded very good. Rather, the sound quality was good but it was riddled with hiss and picked up crazy EMI. I am probably going to scratch that.

My bantamDac didn't work when I turned it on. I am planning to buy another CMOY chip and try again. It was my first major SMD with those little pins, and I probably screwed it up.

But my amp4 is mostly done, and I am about to wire it up for step #14 testing in the amp4 instructions.

I have a nice modushop enclosure, of which I have already drilled and mounted the rear panel.

I want to get the transformer affixed and wired to the power entry before I test so I only have to do it once. I just wanted to get clarification on wire it up before I go and do it wrong.

My trafo is the antek 2215. My understanding is that I am going to pair up the primaries (2 red, 2 black) because I live with 115v mains. I am clear on how to wire up the switch, fuse, and entry.

My question has to do with the secondaries. The amp4 has no center tap, so I want to wire the secondares in paralell, correct? There are 2 blue wires and 2 green wires. Does that mean I want to attach the blue to blue, green to green? Or do I want to match the correct phase of blue / green and blue / green?

I have the mv-02 remote module I got on ebay. I have a tread PS which I may use to power it, or I may wrap my own lead around the trafo.

Thanks for the help. Pictures are on the way.

[tuo]

My trafo is the antek 2215. My understanding is that I am going to pair up the primaries (2 red, 2 black) because I live with 115v mains. I am clear on how to wire up the switch, fuse, and entry.

My question has to do with the secondaries. The amp4 has no center tap, so I want to wire the secondares in paralell, correct? There are 2 blue wires and 2 green wires. Does that mean I want to attach the blue to blue, green to green? Or do I want to match the correct phase of blue / green and blue / green?

Parallelled secondary yes. And that exactly what you are already doing with the primary, so connect blue to blue and green to green. Other way around you would connect them in exactly opposite phases and that would negate the output to zero.

[V-bro]

To parallel you need to know the phase of the windings, but first what wires ARE windings... You can use your DMM to measure resistance. If there is a connection there is a winding...

There is a way to determine the phase as well..Otherwise you do not only get zero output voltage, but also effectively short either the flux or the output voltage... You can connect a single wire from a secondary winding in series with the primary and measure if the output on the other secondary wire is mains+ output voltage or - output voltage... But that does involve a bit of fairly dangerous mains measuring... It would be easier if the manufacturer had marked them somehow... Another way is to take a bulb in the voltage rating of the output and see if it lights up or not, when it lights up you have current flowing and chose the wrong connections which cause them to short...

I would wind some extra windings for the pre... around 35 windings usually gives a pretty nice 12Vac voltage... Then off course rectify and regulate it well!

[Scratchy]

Of course V-bro is correct about the polarity (phase), but you could always check the wiring diagram on the manufacturers website:
http://www.antekinc.com/pdf/AN-2215.pdf