Folsom DIY7297 Amp & Antipole PSU

[Big Cheese]

Discharge resistor for Antipole

Hi Jeremy,

I am planning to order the parts from Mouser coming weekend, but I have two questions on the discharge resistor:

1. Would mouser p/n 71-PTF5610K000BYEK be suitable (I just picked the first 10K through hole resistor I could find),or can you give me a recommendation?

2. Does the discharge resistor go on to the Antipole board on the resistor symbol next to the diodes? (I know it is the only available location, but noobs need confirmation...).

Thanks and take care,

Laurens

 

[Destroyer OS]

1. I would go 1/4w to 1/2w

2. Yes, where the resistor symbol is at near the big caps

 

[pistollero]

this discharge resistor interfere with the quality of sound??
why isn´t it on the boom list?

thks..

 

[Big Cheese]

1. I would go 1/4w to 1/2w

2. Yes, where the resistor symbol is at near the big caps

Thanks Jeremy!

 

[Destroyer OS]

Anyone got some build pics to post?

This one is looking pretty nice, over at AC.

this discharge resistor interfere with the quality of sound??
why isn´t it on the boom list?

thks..

No ill effects. The amp usually discharges the caps VERY quickly, but some may have circumstances. The Antipole is designed to be used in lots of applications, not just the DIY7297.

 

[Big Cheese]

Hi Jeremy,

My heatsink and thermal paste are supposed to be delivered to me today / tomorrow, so I will be populating the boards this weekend.

So by Sunday, I will have music - or magic smoke...

I will try to post some pictures once the amp is up and running.

Cheers,
Laurens

 

[pistollero]

Anyone got some build pics to post?

This one is looking pretty nice, over at AC.




No ill effects. The amp usually discharges the caps VERY quickly, but some may have circumstances. The Antipole is designed to be used in lots of applications, not just the DIY7297.

Very nice build...but the caps don t seem oscon sepf....

 

[Destroyer OS]

Very nice build...but the caps don t seem oscon sepf....

They are Nichicon FP series. In the notes about building they are an option. They sound different, but not "better", just different. Some describe them as more open.

 

[pistollero]

They are Nichicon FP series. In the notes about building they are an option. They sound different, but not "better", just different. Some describe them as more open.

Did you eard united chemicon psc/ psf?
I found a japanese blog where they they sound better than oscon and nichicons...
In a dac aplication.

 

[Destroyer OS]

I have not. But I've been looking to try Kemet's in another application because of their wide range of voltages.

 

[Big Cheese]

My build: good news and bad news

So this weekend I built my Folsom 7297 Amp and Antipole

The good news:
Everything came together without major issues
I haven't let any magic smoke escape
No breakers were tripped

The bad news:
Hardly any sound from either speaker using my phone as a source. Only when the volume is on maximum, you can hear music very, very softly.

I ordered the standard BOM from Mouser, I only added the discharge resistor 71-RN65D-F-10K. I simply soldered this on to the board, no switch or nothing.

Now, can anyone help me with trouble shooting? I have 18.5V AC coming into the Antipole, but I do not get a consistent DC voltage coming out of it (I assume the rectification takes place within the Antipole).

I have attached some pictures of the current status, in the trial setup.

Any help would be appreciated,

Laurens

 

[Destroyer OS]

Can I get some bottom pictures?

It is possible the epcos naked silver caps are shorting the antipole.

Your input caps are mounted at the wrong end, the blue ones, dont know about the mkp's under it. Basically on the top ones they are connected to the same trace. The very first hole thag is not the inout for wires, is the hole connected to input wires. All proceeding holes are connected to the chipamp.

 

[Big Cheese]

Thanks Jeremy,

Yeah, now that you point it out, it is pretty obvious the input caps are mounted in the wrong holes . I will start by repositioning them.

For the Antipole, I am now wondering if I actually put my DMM to DC setting when measuring the output...

Will make the changes this evening an post and update plus some pictures of the underside.

Cheers,

Laurens

 

[Big Cheese]

SUCCESS!!!

Jeremy,

Many thanks for your sharp eye. After I got home I de-soldered the input caps and put them in the correct position, hooked everything up, and...
-
-
-
-
MUSIC!!!

After you pointed my foolishness out I really don't understand what I was thinking to put them where I did...

The amp has been playing in my living room for about an hour now, and I am really surprised and impressed with what 2 x 15 Watts can do.

Tomorrow I will hook my pre-amp up for decent volume control. Will report back in the weekend.

Thanks for a very nice product and for all your support.

Take care,

Laurens

 

[pistollero]

Just to share that on mouser the main nichicon kz are out of stock....

 

[Destroyer OS]

The BK are available:

LKG1H472MESCBK
.

 

[wcwc]

Ah, yes, the D45H11G will be fine.

Any other suggestions? That one and the other one you mentioned as a replacement are out of stock until 2018. Any other suggestions or should I look elsewhere?

 

[Destroyer OS]

512-D45H11

 

[wcwc]

512-D45H11

Can we use Keratherm instead of the mica and thermal paste? I used on an ACA build and it seemed less messy.

 

[Destroyer OS]

For the chip? Sure! Just make sure to use that shoulder washer.