Folsom's great little 7297 Chip Amp

KR500 · « **Reply #160 on:** 21 Feb 2016, 09:22 pm »

Today I created a cart with BOM for the amp and Antipole at Mouser. Before ordering
Does Mouser carry the heat sink or is the recommended link to HeatsinkUSa the preferred choice ?
Will the amp fit in one of the Hammond cases ?
I didn't see prices on the link for Folsoms suggested case seller at their site
Is it preferable to mount the Antipole and Antipole in separate cases ?
I have some Radio shack thermal compound , is that "good enough" or should I get something else ?
thanks

Folsom · « **Reply #161 on:** 21 Feb 2016, 09:32 pm »

Yes, I think you might struggle with that iron, Mike. You want the joint to heat up fast enough that you don't have to fry the parts.

Here's something to note, as the joint sinks the heat the iron must make up for it wattage to try and retain that same heat level. You have a 25w iron, I have a 60w station. The moment yours touches the heat will run down so fast that it won't be as effective.

I have this exact station. New replacement pieces for it are rather expensive. I've also been told this has a Hakko heater core so it's worth the gamble for the price. I hate digital button stations... But these days I'd just buy a Metcal if I were to upgrade. Their smartheat is really nice. They however are very expensive and the tips are not cheap.

Folsom · « **Reply #162 on:** 21 Feb 2016, 09:41 pm »

Quote from: KR500 on 21 Feb 2016, 09:22 pm

Today I created a cart with BOM for the amp and Antipole at Mouser. Before ordering
Does Mouser carry the heat sink or is the recommended link to HeatsinkUSa the preferred choice ?
Will the amp fit in one of the Hammond cases ?
I didn't see prices on the link for Folsoms suggested case seller at their site
Is it preferable to mount the Antipole and Antipole in separate cases ?
I have some Radio shack thermal compound , is that "good enough" or should I get something else ?
thanks

I don't know what Mouser carries for Heatsinks off the top of my head. Heatsink USA does custom sizing so I never had to think much about what Mouser carried.

I'm sure it'll fit in a Hammond case. You can base the case size off of the size of transformer for height. For planning the width you may want to consider all of the connectors on the back.

What prices are you asking about, for what?

Mounting the Antipole and transformer (I assume you meant that) in a separate case is just one way to isolate some of the radiation transformers produce, as well as the AC line. Also if the transformer has any hum at all it'll isolate that from the amp board as well. If you do have a tiny bit of hum consider using some dampening material around the transformer area of the enclosure it is in, "dynamat' type stuff. There's also Herbie Audio's products for washers and such that reduce vibrations etc.

The radioshack compound is probably just fine.

lacro · « **Reply #163 on:** 21 Feb 2016, 10:55 pm »

Quote from: mlundy57 on 21 Feb 2016, 08:20 pm

Thanks

I have an Ottlite desk lamp but was thinking of getting an LED light with a magnifying lens. Any suggestions as to a good one or what power magnification works best?

My soldering iron is a 25W Radio Shack Pro-Line with a point tip and a maximum heat output of 1003F (539C). That's a lot hotter than you are suggesting. Looks like a different iron may be in order.

For solder I use Cardas Quad Eutectic

I have one of the small black helping hands with the alligator clips but I am not fond of it. Any other suggestions for something to hold the board while working on it?

Mike

Mike,
Knowing the wood worker you are, you can make your own board holder, although this board can probably be done just as easily on a bench top.

Here's one I made:

And here's my "cheap-n-cheerful" (freebee) magnifer:

Folsom · « **Reply #164 on:** 21 Feb 2016, 11:08 pm »

How many PCB boards for two of those Larco?

mlundy57 · « **Reply #165 on:** 21 Feb 2016, 11:24 pm »

Larry,

That's sharp. Even has a adjustable and replaceable tension mechanism

Mike

KR500 · « **Reply #166 on:** 22 Feb 2016, 02:09 am »

Thanks for your reply Folsom , I'll put the Antipole and amp in 2 cases I think, and decide which Hammond cases to get for them .
I already built your Volume Control Device into a Hammond, so maybe they'll be stackable if I stay with Hammond.
Will check Mouser to see if the heat sink is available there .
My question was regarding the price for the custom cases you linked to since I couldn't find a price there , just a diagram

Odal3 · « **Reply #167 on:** 22 Feb 2016, 02:10 am »

Lacro - I want one of those board holders too. That looks great

Folsom · « **Reply #168 on:** 22 Feb 2016, 02:32 am »

Quote from: KR500 on 22 Feb 2016, 02:09 am

Thanks for your reply Folsom , I'll put the Antipole and amp in 2 cases I think, and decide which Hammond cases to get for them .
I already built your Volume Control Device into a Hammond, so maybe they'll be stackable if I stay with Hammond.
Will check Mouser to see if the heat sink is available there .
My question was regarding the price for the custom cases you linked to since I couldn't find a price there , just a diagram

You have to select desired sized with Landfall systems.

lacro · « **Reply #169 on:** 22 Feb 2016, 02:52 pm »

Quote from: Folsom on 21 Feb 2016, 11:08 pm

How many PCB boards for two of those Larco?

Quote from: Odal3 on 22 Feb 2016, 02:10 am

Lacro - I want one of those board holders too. That looks great

Guys: I knew I should have made several when I was making this one

Doing a one-off like this took me an entire morning, plus 3 days of staining/oiling the pieces. If you want to make your own, I can list a BOM, or the internet has several designs including one similar to this one.

lacro · « **Reply #170 on:** 22 Feb 2016, 02:55 pm »

Quote from: KR500 on 22 Feb 2016, 02:09 am

I already built your Volume Control Device into a Hammond,

Is there a thread (link) for building this Volume Control?

Folsom · « **Reply #171 on:** 22 Feb 2016, 06:05 pm »

Quote from: lacro on 22 Feb 2016, 02:55 pm

Is there a thread (link) for building this Volume Control?

It's a device that stops ground loops and noise. It helps with some devices; particularly with SMPS powered amps. Ultimately I prefer not using it unless you have a ground loops so far.

Tyson · « **Reply #172 on:** 26 Feb 2016, 06:15 am »

Just wanted to put in an update - I had this amp through here for the second time and I can attest that it's a substantial improvement over the first time (and it already sounded great the first time). More clarity, better flow, and smoother sound. This amp is a winner.

lacro · « **Reply #173 on:** 26 Feb 2016, 07:38 pm »

Question about Mouser part #80-C320C471J1G (470pF cap). I looks the board spacing for this ceramic cap is twice the lead spacing of the cap I received (5mm vs 2.5mm). This thing is really tiny, and doesn't come close to the dimensions in the Kemet spec. sheet, and it looks smaller than the one on your board. One side is labeled 471, and the other side is labeled K1J. Do I have the right part?

Folsom · « **Reply #174 on:** 26 Feb 2016, 07:50 pm »

It is small. You're welcome to substitute it for any other 470pf cap you like. It just needs to be 470pf. But recall some ceramic caps change based on voltage. MLCC's not so much, X7R/X5R do. It doesn't have to be ceramic but they're small so they fit well.

lacro · « **Reply #175 on:** 27 Feb 2016, 09:34 pm »

Made some progress today. I don't have any wire so I can't try it yet. While inspecting my solder joints, I discovered I bridged one of the chip legs to the tiny via close to it. Should I remove this bridge or ok to leave it? See second photo.

Folsom · « **Reply #176 on:** 27 Feb 2016, 10:14 pm »

It's fine. That via is really only for people that would know they need it, and what it does. It's not useful for typical operation, just like the little diode spots.

KR500 · « **Reply #177 on:** 27 Feb 2016, 10:19 pm »

a question Jeremy , the link on page 1 to HeatsinkUSA goes right to a 3.5" heatsink . Is this the one for the project ?
thanks

Folsom · « **Reply #178 on:** 27 Feb 2016, 10:49 pm »

That's what I used.

You can see larco chose something else. You almost can't go wrong here. Even the side of a 1/8in enclosure is probably sufficient for playback. But the cooler you keep it, the better you can maintain full output power.

KR500 · « **Reply #179 on:** 27 Feb 2016, 11:01 pm »

another q , I am going to order the 3.5" wide from Heatsink USA and the length is options in inches . Which is the preferred length in inches of the sink ?
thanks again