[Folsom]

Hey guys!

I need 44 people to purchase one in order to get this ball rolling! All the work is done, and I want to get kit parts ordered ASAP!

igg.me/at/DIY7297KIT

[Folsom]

Here's some stuff that's on the IGOGO page. Feel free to ask any questions!

The finished PCB's.





The PSU without the AC filter caps.

[poseidonsvoice]

Do you have a link to some simple specs? It may be useful for some as the link above tells you nothing about power output, etc...(even though you recommend 91dB speakers).

Best,
Anand.

[Folsom]

Here's the datasheet.

[TF1216]

Cool!  Who is Folsom Audio?  That's my last name.

[Folsom]

The name that should be my profile name  . It's my middle name.

Salis came about prematurely because I had to make an industry name.

[JDUBS]

So, just to verify, this is $200 and doesn't come with an enclosure?

-Jim

[Folsom]

So, just to verify, this is $200 and doesn't come with an enclosure?

-Jim

No it does not. I wouldn't mind having one ready to go, but it'd be hard to buy in bulk since it's much more of a gamble for people to want. The complete PSU and transformer have made the cost go up but it's a very good, complete, package. I'll point it out now, were you to buy everything separate you wouldn't save any money, if not spend more by about $5 or so. Yup, I've actually closed that gap and extra!

To recap, you get:

TDA7297 PCB - featuring copper pours (planes), star grounding, surface pad for rolling film caps w/ multiple vias (holes), and CFC (capacitor field cancellation) for DC caps.

TDA7297 chip (not factory seconds)

Input capacitors PHE450 (Rifa, now Kemet)

Mute/Stdby network

12x SEPF Panasonic Oscon 330uf capacitors

Kmultiplier featuring several parts including two transistors, one with a heatsink and TL431 voltage regulator


Antipole PCB - featuring copper pours, diode laydown room for proximity with ground pour (plane), CFC, and auxillary taps

Nichicon's best CK version of the KG capacitor for ripple/filter power supply caps

Coilcraft Common and Differential Mode choke with dampening resistors

EPCOS naked MKT capacitors for the AC filtration with the Coilcraft CMC on a specially arranged array of vias (holes)


Hammond 185 Dual Bobbin chassis mount transformer, 80va 16v

[Folsom]

Here's the demo, playing music.

[Folsom]

I had to overnight some resistors, right  before I send the unit out... so get the regulated voltage up. I forgot I only had values for 16v.

It's still a huge upgrade from even my test rig that everything has been based on, the box, better PCB's, etc. I'm very excited for everyone to go from, "I dunno it's like $150 more than the one I'm using" to "what?! it's only $200 SHIPPED?!" 

I've spent around $2k to get to this point, with a demo, and I realized it's money well spent because at the end if I still have the demo I'm ahead of the game since I got an amp that's easily worth the price.

[Folsom]

First stop on the tour.  Yes, one of the kits is going to replace the Bryston. "No question, I prefer your amp overall" - Craig. Maybe I'll get him to produce a better review, but that's not a bad one!

[ejfud]

Nice! Would be fun to hear about the differences with the Bryston.

Where can one sign up for the tour?

[Folsom]

Send me a PM.

The Bryston has some more umph according to Craig; but at regular listening levels it's hard to say till Rhing puts in the convection holes with the top on (I play with it off at home). However the clarity of snapping on drums, some track of Dave Mathews Band, sold him for certain. He claims it's significantly quieter. I myself can't tell when it's on, but he means in general the clarity is so much higher, where all sounds are more obvious. Comparatively voices and tone are better according to Craig; I'd describe it as much more organic. Craig said that whether or not more low end comes through (better cables, and cooling primarily will be done for his), he'd take it anyway. Previously he tried some Bel Canto class D that had a similar clarity, but he claims flat out lacked life. The 7297 has brought the clarity and life to a point where he, a junky for sheer force, prefers it.

 

[Folsom]

Playing on the Totem flagships here. They aren't super efficient but Nirvana unplugged into the McIntosh turntable and tube preamp was pretty amazing. The guy that works at Acoustic Visions, Missoula MT, said it was definitely every bit as good as anything in the store and more revealing. We didn't have time to AB with the other amps, but I can confidently say the treble area on the DIY7297 is much friendlier with more weight. It really can do a nice little dance on your ear drums, especially with something like Tool, without being fatiguing or offensive.

The worst part was the huge chain of equipment for digital starting from an iPad to a server, across two rooms. It was a clear veil to the sound. The vinyl was much better. We played a local band's vinyl and it was really fun, but you could hear which instrument tracks had dumpier microphones or something; it was obvious when it wasn't the same recording level as another instrument track.

We also listened with some Paradigm bookshelves that were a discontinued model that's right below the flagship bookshelves I think, but they just weren't that good. They were sorta thin and too tight for me.

[Folsom]

Do any of you have any questions? Is the idea of having a high end piece of equipment intimidating for a DIY person?

[Folsom]

The IndieGoGo is currently down. Feel free to contact me. Perhaps I'll just do PCB's, but it costs more in order to buy all the parts on your own if you use the PSU, as well. If you are not using it, then you still have to have high enough voltage for the regulator. It can be adjusted down but the amp is much better at 18v.

[Odal3]

Is the Salis Audio chip amp used for the Vapor review your design?
http://www.audiocircle.com/index.php?topic=135924.msg1444677;topicseen#new

Either way, I find your amp very interesting. Perhaps the price was too high for people to experiment with??? Maybe an idea would be to have a cheap version with multiple upgrade versions? That seems to be a winning strategy by some mfg.

[Folsom]

Yes it is, and the name is actually Folsom (it needs to get changed).

You can buy the Chinese version and follow my modifications in The Lab circle, if you want a cheap one.

The one in the review has almost nothing particularly high in price in it. But at the same time there's almost zero substitutions that work with it. The main thing that can be changed is rolling input capacitors. You could build your own PSU and provide your own transformer; but I can't tell you what I'm about to if you do... (and I have a few PCB's for sale, discounted, for people that want to do it)

I'd like to point out that for $200, your chassis, your wire, you're connectors, is the entry price point for a piece of equipment that was used on $27k speakers and was viewed favorably and comparably with things that cost $13.5k.

[Odal3]

I remember that you wrote about the name change. Like the Folsom better. 

Congratulations on getting the nice press.  Well deserved! I'm very impressed by your technical skills and generosity to post detailed build threads at the same time you are trying to sell your own amp. I really hope that you can get some sales to fund this and future projects! If I had the skills I would buy one of your PCBs. Need to practice and learn some first. 

[Folsom]

I plan to always release some DIY fun. Right now I've got a volume control and selector switch that's extremely affordable and easy to work with, in the works. It also greatly reduces ground noise. Aspects of it may be used later inside of more high end devices.

Also, once you get a taste of the 7297, you might understand how going high-end with it has appeal.