Folsom's great little 7297 Chip Amp

skrstc · « **Reply #700 on:** 29 Oct 2016, 07:19 am »

Quote from: zek on 22 Oct 2016, 10:05 pm

Is this correct way to wire it? My DACT type pot pops with each turn.

zek · « **Reply #701 on:** 29 Oct 2016, 01:37 pm »

KR500 said:
"DACT wired backwards. I copied down a diagram from a web site on wiring connections ."

KR500 · « **Reply #702 on:** 29 Oct 2016, 04:23 pm »

Yes Zek , but it wasn't that picture , 'nother site for wiring pots which I couldn't find again ( history cleared )

BTW, I'm too cheap to go to the Dollar Store so borrowed from Mama's Kitchen when she wasn't looking and drilled pilot holes in the chassis case top with a 1/16" bit to follow up with a step bit to get them to 1/8" or 3/16"

lacro · « **Reply #703 on:** 29 Oct 2016, 05:00 pm »

Quote from: KR500 on 29 Oct 2016, 04:23 pm

Yes Zek , but it wasn't that picture , 'nother site for wiring pots which I couldn't find again ( history cleared )

BTW, I'm too cheap to go to the Dollar Store so borrowed from Mama's Kitchen when she wasn't looking and drilled pilot holes in the chassis case top with a 1/16" bit to follow up with a step bit to get them to 1/8" or 3/16"

Looking good man! Glad you finally got the issues solved, and it's up, and running....
If you finish by de-burring each hole with a countersink, it looks better. On my latest build that I am now burning in while I finish up the case, I am finding both the chip, and the big transistor are staying cold. This is my first build using the Antipole PS. My previous build used a SMPS, and the heatsinks got pretty warm (actually hot). I have vent holes drilled on the bottom of the new chassis, but I may not bother with drilling the top lid as everything is staying cold.

KR500 · « **Reply #704 on:** 29 Oct 2016, 05:31 pm »

Now I just have to cipher a way to be able to tighten , tried a rubber washer , no good . I thought about putting heat shrink over a toothed lock washer.... but that isn't the answer either.
I have some inexpensive insulated binding posts from ebay I tried that tighten, but they aren't half as well made as the Pomonas. I didn't plan ahead enough on the binding post mounting .
If you have the ability to punch a circular hole with a flat top section it would be no problem

lacro · « **Reply #705 on:** 29 Oct 2016, 06:08 pm »

Quote from: KR500 on 29 Oct 2016, 05:31 pm

Now I just have to cipher a way to be able to tighten , tried a rubber washer , no good . I thought about putting heat shrink over a toothed lock washer.... but that isn't the answer either.
I have some inexpensive insulated binding posts from ebay I tried that tighten, but they aren't half as well made as the Pomonas. I didn't plan ahead enough on the binding post mounting .
If you have the ability to punch a circular hole with a flat top section it would be no problem

Are you using bare speaker wire so tightening the nut is making the whole binding post turn? How about just using banana plugs? Or put a dab of super glue on the shoulder washers.

KR500 · « **Reply #706 on:** 29 Oct 2016, 06:18 pm »

Hey , thanks for reminding me about the counter sink after using a step bit on the holes ! Nice and smooth now
I forgot I had a cheap little counter sink set from Hazard Fraught

The Pomona Binding posts shoulder washers are for a 3/8" hole with a flat portion on one end of the circle . The flat portion of the circumference is what prevents the post from continuing to spin as you tighten .
i.e. the chassis cut out can't just be round. You can mount bare wire or banana jacks , you just can't get the posts tight to the amp case.
The super glue is my last option unless I can figure something out .
I just wanted to post something about this issue in case someone is using going to use these posts in a build.

Folsom · « **Reply #707 on:** 29 Oct 2016, 07:07 pm »

I'm so glad you got your unit working KR500. It's always a good day when some changes set a project straight; especially since some can go up in flames! (Not this one, it's nearly impossible to get the chip to do anything but simply turn off or not turn on, the protection in it works good).

BRN · « **Reply #708 on:** 29 Oct 2016, 07:16 pm »

I used Cardas binding post that have a block that holds them in place. Something like this:
http://www.soniccraft.com/product_info.php/cardas-acbp-eu-binding-post-p-5146

S Clark · « **Reply #709 on:** 29 Oct 2016, 07:23 pm »

Quote from: Folsom on 29 Oct 2016, 07:07 pm

... especially since some can go up in flames! (Not this one, it's nearly impossible to get the chip to do anything but simply turn off or not turn on, the protection in it works good).

Yep, run 24V and a bunch of amps into these amps backwards, and I can attest that they are not completely idiot proof!

lacro · « **Reply #710 on:** 29 Oct 2016, 08:55 pm »

Quote from: KR500 on 29 Oct 2016, 06:18 pm

Hey , thanks for reminding me about the counter bore after using a step bit on the holes ! Nice and smooth now
I forgot I had a cheap little counter-bore set from Hazard Fraught

The Pomona Binding posts shoulder washers are for a 3/8" hole with a flat portion on one end of the circle . The flat portion of the circumference is what prevents the post from continuing to spin as you tighten .
i.e. the chassis cut out can't just be round. You can mount bare wire or banana jacks , you just can't get the posts tight to the amp case.
The super glue is my last option unless I can figure something out .
I just wanted to post something about this issue in case someone is using going to use these posts in a build.

I understand about the D-punch opening in a chassis to prevent the post from turning, but you should still be able to tighten the post unless the 3/8" alignment steps (AKA shoulder) on the washers are greater than your chassis thickness. If so, try turning one around so the step is facing away from the chassis, and only one is centering the post in the 3/8" hole. The total amount of the step (shank length in drawing) must be less than the chassis thickness.

KR500 · « **Reply #711 on:** 29 Oct 2016, 10:14 pm »

Hey , worked GREAT turning one washer the other way round. Thanks Larry , I owe you
When I was dinking around with it this morning I pondered doing that..... but didn't.
One washer shoulder almost makes it through the chassis, but not quite . Getting the other washer's shoulderless face side up against the chassis gave it something better to grip
Now I can button it up and get listening

BRN , thanks for the link to the Cardas posts at Soniccraft
They were on my BOM originally but budget considerations made me opt for the Pomonas, which are less money but still well made
I did wind up getting the Furutech IEC receptacle from Soniccraft though . As Jeremy says , it's a nice piece . I'm glad I skipped the OEM cord that came on the NABU chassis . I'll probably wind up getting a Panagea power cord for this from Audio Advisor

S Clark · « **Reply #712 on:** 30 Oct 2016, 01:43 am »

With the wife out of town, the bar in the kitchen became the soldering center, and my second Folsom amp has come to life. Between soldering, smoking some BBQ pork,and a bottle of Muscadet sur lies, it was a great day in the kitchen.

BRN · « **Reply #713 on:** 11 Nov 2016, 05:34 pm »

I wanted to know what speakers Folsom amp owners are using? I'm using Blumenstein Orca speakers with an old Yamaha 8" down firing sub.

KR500 · « **Reply #714 on:** 11 Nov 2016, 06:26 pm »

At the moment Klipch MTM speakers while breaking the amp in ( if needed ? )
Next I'm going to try it in my listening room with my Seas FA 22 Full Range speakers

lacro · « **Reply #715 on:** 11 Nov 2016, 06:27 pm »

Just completed my latest Folsom amp. I couldn't find a case I liked, so I built my own. I am totally blown away by the sound quality of this one. It's my fourth build, but this one has the Antipole PS with a Lundahl transformer powering it. The amp has the stock BOM except the input caps are Clarity ESA. I have about 100 hours on it, and it is by far the best sounding yet. I have previously only used an SMPS to power these amps. I just can't get over how good this new one sounds. I can listen for hours without fatigue. Jeremy: This is one great design, and I hope you decide to offer another batch of cards so many others can build, and enjoy this superb sounding amplifier!

Folsom · « **Reply #716 on:** 11 Nov 2016, 06:37 pm »

Damn! Nice job Larco, I doubt the pictures even due to full justice (funny lighting). What are the black and white things above the PowerCon inlet?

lacro · « **Reply #717 on:** 11 Nov 2016, 06:51 pm »

Quote from: Folsom on 11 Nov 2016, 06:37 pm

Damn! Nice job Larco, I doubt the pictures even due to full justice (funny lighting). What are the black and white things above the PowerCon inlet?

Thanks! The Blk/Wh connectors are 10VAC output that powers a DAC that requires 10VAC. The 5.5# 300VA transformer has 4) 16V secondaries that I paralleled, and it has 2) 10V secondaries so I used them to power the DAC instead of a cheap 10VAC wall wart.

nik.d · « **Reply #718 on:** 11 Nov 2016, 07:07 pm »

Congratulations Lacro, another phenomenal build. And a 300VA Lundahl transformer... What to say!

KR500 · « **Reply #719 on:** 11 Nov 2016, 08:10 pm »

Wow , that is a nice looking piece of gear !