TDA7297 - What are you looking to see, for DIY?

Folsom · « **on:** 23 Nov 2014, 08:13 pm »

Hi guys,

I've been getting some questions about my boards.

Right now I've got a board that I'm making a few changes on before having printed again. It does not include a power supply section of any sort (yet).

TDA7297 -
*Features capacitor mounting for Panasonic/Nichicon 330uf 25v Organic Polymer capacitors (the good ones, I'm using Panasonic ATM)
*They're arranged in my manner for reductions in magnetic resonance
*Has a variety of input capacitor selection, with options for lots of film caps like Wima including solder pads for strangely sized caps
*Hole to connect wire to heatsink to ground RF
*Currently just has V+ and PG input holes for power

Do you guys want to buy w/ parts? If you do, and a GB/crowd fun option happens I can provide you with the parts saving you a little $, especially on shipping.

I've got a PSU in the works, but I haven't ordered prototype boards to test yet. It does not include a transformer but that could become an option. I'm currently using for unregulated a 10v hammond low profile 4.8A that ends up rectified at 16v. The chip may sound better with a little less voltage than it's max.

Here's some pictures (yes, I need to change my name, I've been talked out of Salis, which is ok since nothing has ever had it engraved/printed on it, I Just had to come up with something when I became an "Industry Participant")

*Switching to just film caps

ejfud · « **Reply #1 on:** 24 Nov 2014, 04:14 am »

Nice!

I'd love to get everything needed in one spot. It seems that is the way I get things done these days. If I need to chase parts, the projects usually die.

JDUBS · « **Reply #2 on:** 24 Nov 2014, 04:28 am »

Sweet! Definitely interested in trying one of the out.

Including everything would be ideal, IMO.

How much gain will it have and is it changeable?

Thanks,
Jim

S Clark · « **Reply #3 on:** 24 Nov 2014, 04:30 am »

Quote from: ejfud on 24 Nov 2014, 04:14 am

Nice!

I'd love to get everything needed in one spot. It seems that is the way I get things done these days. If I need to chase parts, the projects usually die.

I agree. If it's all there, it's a lot more likely to get done. Are you using the Texas Inst. chips out of China?

Folsom · « **Reply #4 on:** 24 Nov 2014, 05:14 am »

ST chips. I'm not going to deal with rejects and counterfeits.

Would you guys want a PSU with it? The PSU would cost a lot more than the amp itself. However I'll tell ya, this thing is unique with some good power. The condition here is there's no way I could consider not doing a GB/crowd fund.

It's not that I want to constrain you on parts but... If you want to have a new main amplifier you got to use the right stuff

S Clark · « **Reply #5 on:** 24 Nov 2014, 06:01 am »

Excellent. That's the answer I was looking for.

Folsom · « **Reply #6 on:** 24 Nov 2014, 06:07 am »

Clark I'm very curious if this new version could drive your line arrays. I know that's a tall order

shadowlight · « **Reply #7 on:** 24 Nov 2014, 02:34 pm »

Would be interested in all parts and power supply. Any tweaks that needs to be done to make them work with 16ohm speakers?

Folsom · « **Reply #8 on:** 24 Nov 2014, 05:29 pm »

I haven't tried. What sensitivity?

shadowlight · « **Reply #9 on:** 24 Nov 2014, 06:47 pm »

Quote from: Salis Audio on 24 Nov 2014, 05:29 pm

I haven't tried. What sensitivity?

Assuming the question is directed towards me. The speakers in question are Zu Druid V which are 16ohm and 101db sensitive.

Folsom · « **Reply #10 on:** 24 Nov 2014, 06:53 pm »

I don't think you'll have any issues. My speakers are 87db at 8ohm. You'll get more power than I do.

Now I want come hear one at your place. The Druids should be giving one hell of a performance with this amp.

I'll get some pricing together for the full monty.

shadowlight · « **Reply #11 on:** 24 Nov 2014, 07:31 pm »

Quote from: Salis Audio on 24 Nov 2014, 06:53 pm

I don't think you'll have any issues. My speakers are 87db at 8ohm. You'll get more power than I do.

Now I want come hear one at your place. The Druids should be giving one hell of a performance with this amp.

I'll get some pricing together for the full monty.

If you are ever in NY/NJ/PA/DE area give me a buzz and we can setup something up. I am located in Princeton, NJ area. My current setup is

PC running W2K12 server with jRiver (everything is currently converted to DSD) --> usb --> Lampizator 4.5 with DSD option --> Dodd 6H30 preamp (in couple of weeks I will also have a 4p1l DHT based preamp) --> Triodelab 2a3 amp. I also have a B&O 125asx2 based Ghent amp and modified by rhing YJ tpa3116 with laptop power supply that we can try.

ejfud · « **Reply #12 on:** 24 Nov 2014, 08:11 pm »

I'd like the power supply included.

dnewcomer · « **Reply #13 on:** 24 Nov 2014, 11:42 pm »

i would be interested in a full kit also

Folsom · « **Reply #14 on:** 28 Nov 2014, 08:52 pm »

Working on getting it done ASAP. The amp board is done. The PSU and transformer boards are next. I have to prototype them, so I can come up with revisions before you get them.

Folsom · « **Reply #15 on:** 10 Dec 2014, 12:09 am »

Here's the transformer board.

barrows · « **Reply #16 on:** 10 Dec 2014, 01:25 am »

Salis: please keep the option of buying the amp board only, full kit with parts is fine with me, but I would rather build my own power supply as long as you provide appropriate specs (needed Vin and current draw to achieve maximum output).

So to confirm: this single ended input only, yes?

You decouple with the large array of organic polymer caps there, but I presume that if using an unregulated supply there will be an advantage to using CRC or CLC filtering in the raw DC supply... yes?

Folsom · « **Reply #17 on:** 10 Dec 2014, 01:49 am »

I plan to offer separate PCB's as well. The kits are a group buy, and limited by number.

Single ended input, balanced out. I know, it's ironic. The PSU board has an LC on it, not in the DC. That's intentional.

When all said and done I'll be very impressed if anyone makes a nicer power supply. Most likely I envision people trying to use SMPS units for laptops, Astrons, etc. That's fine, but the PSU and transformer board I'm supplying make this amp true hifi. The transformer is dampened on the primary, the CMC's are dampened, capacitors are in a special orientation, everything is featured on very low inductance that you can't create with just wire, and the noise attenuation doesn't present a trade off some are familiar with in things like traditional snubbers etc. There's a great many deliberate choices.

My goal is to get a unit on tour, to entice people into the GB. I can't imagine anyone not being impressed.

OzarkTom · « **Reply #18 on:** 10 Dec 2014, 01:56 am »

Quote from: Salis Audio on 10 Dec 2014, 01:49 am

My goal is to get a unit on tour, to entice people into the GB. I can't imagine anyone not being impressed.

ME, ME, ME, first.

mboxler · « **Reply #19 on:** 10 Dec 2014, 05:03 pm »

I'm currently bi-amping my Klipshorns with a pair of these $6 amps using a 12V brick.

Could your power supply drive two (or more) of your amps, or would you suggest separate power supplies per amp?

Mike