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Folsom DIY7297 Amp & Antipole PSU

Destroyer OS

Member
Paid Member
2005-11-14 11:09 pm
PNW
Hey Guys! I figure it's about time. I get requests fairly often. Here's the deal I need a commitment of 25 pairs to get the ball rolling. And those that participate in the GP get a few bucks off the normal price.

If you're not familiar here's a long thread over at AC about them.

These next print of boards will feature a BOM with an updated TL431 that's even lower noise. The old TI one sounds a little warmer for who's ever interested. The amplifier boards will be larger to accommodate the option of Jantzen capacitors (1.5uf). The Antipole boards will be a little shorter with the removal of the now unnecessary hexfred board provisions.

Price for GB:

$22 Amp board ($24 normally) (high grade BC337 transistor included, NOS)
$19 Antipole board ($21 normally)
$8 USPS priority shipping, contact for international.



How to join:

Just update the attached txt document, I need an email and how many pairs of boards you'd like. Once we hit 25 I'll send out an email with payment information.
 

Attachments

  • diy7297&antipole.txt
    29 bytes · Views: 494
This is a great amp. I have one.

Usually I like just keeping a running list as a regular post. If someone wants to add their name - they quote the last one or use the quote function. Name and number of boards.


Having to download and upload txt file is too cumbersome and not easily visible.

Like this:
John Doe - 4 amp and 4 antipole boards
Jane Jones - 6 amp boards only
 
When I built this amp, I did not have a huge stash of OSCONs on hand. I might try rebuilding it with the huge oscon array and see how it sounds. Although I really do like my discrete mosfet Class AB amps overall for maximum bass authority over any chip amp.

This thread needs some pics. Here is my implementation: I used a small GPU heatsink with fan and 7812 for powering the fan (drop speed with resistors to keep quiet), I have a mishmash of caps on the array, I added an LED - can't have an amp without a light. :) there is no case it's just mounted on a wooden board along with banana multiway output jacks.

555573d1466356331-what-heck-its-less-than-lunch-image.jpeg
 
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Destroyer OS

Member
Paid Member
2005-11-14 11:09 pm
PNW
The 7297 can be light in the bass if a speaker is ported/vented with too low of QES (too much physical dampening is bad too). The simple solution is to take the speaker impedance (4 , 6 , 8 ohm) and divide by 5.45 and get a resistor of that value to insert in series with the speaker. I've heard 500w amps sound wimpier. It's worth a try if you know your driver is in the .30's QES.

pocomo 4
pistollero 2
jmc207 2
webber 2
wcwc 1
springnr 2
 
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Destroyer OS

Member
Paid Member
2005-11-14 11:09 pm
PNW
The new boards that fit the Jantzen red 1.5uf are nice. The sound of the Jantzen's while about 4x the price over the original spec'd units (unbeatable for the price) they are a nice little upgrade. Dave from PiAudio recommended them to me, actually.

XRK I hope those caps are 1.5uf or better, as anything less = less bass. I bet you'd really like the OSCON sound. The Pannies and Nichie's are pretty close despite price. The Nichie's are a little more open in a way but it's not "better" per se. Are you using the old or new TL431? The OnSemi makes the amp cleaner but not as warm. The TI works but the KMR section wasn't quiet up to par with some of the regulators seen around the DIYaudio, but with the OnSemi it's comparable with noise to things like some fancy SMD LDO's and such.

On, and twist your wires! Looks like a hooligan came in and wired the speakers outputs for you.