Tripath Amp update

Wayne1 · « **on:** 18 Mar 2005, 04:48 pm »

I will be soon building Class T amplifiers using circuit boards produced by 41 Hz

I should be getting some of his AMP 3 boards within the next 2 weeks. These are a major improvement over the Sonic Impact and Tripath evaluation boards.

All the resistors will be precision Metal Film, surface mounts, used to keep noise low. The output inductors will be hand wound toroidals. The wire used to wind them will be 99.9999 % pure copper and cryo-treated. The toroidal inductors will be quite a step up from the inexpensive axials used on the SI and Tripath boards. The toroidals also control RFI better than an air core would.

Also, the other boards use several chokes on the input signal lines, to keep out the RFI (much of it from the output chokes). He has removed the chokes on the signal inputs. One reason is the lower RFI from the toroids and the other reason is that the suggested chokes have a impedance of about 60 ohms at a few megaherz. As these are in series with the input resistor of 20 kohms they do not do any good. A choke like this makes prefect sense in the low impedance power supply connection so he has kept this one but upgraded from a 2A to a 6A rating.

The T-amp uses a 0.33uF input cap with a 20 KRin. No wonder they are known for having poor bass... On the new boards there is a 2.2 uF capacitor giving a corner frequency of 3.6 Hz so low frequency response should be a lot better.

The amp will be built standard with Black Gate N series NP electrolytic caps for coupling. Sonicaps will be an option. Speaker connectors will be Vampire for standard and Eichmann Cable Pods for an upgrade. Cardas RCAs are standard. WBT NextGens are a option.

There will be options for the type of internal wiring used. A volume control and input selector switch will be options.

The battery power supply for the AMP 1 (50 watt per channel) looks like it will be very large and expensive. I am shelving that idea for a bit and I will be building a prototype of this amp with a linear power supply with a toroidal transformer, high speed rectifier diodes and a few Nichicon Super Through filter caps. I will also be using a very exact regulated 5 volt supply for the prototype.

The AMP 3 based product should be available for beta testing in about a month.

I am also very excited about Jim Hagerman's new ideas for a tube DAC. He is planning a product called the Chime
Chime DAC It will have a main board for the tube output and buffer stage and space for a couple of daughter boards for DAC and USB input. He says it may incorporate a selector switch and volume control. If I can squeeze a Tripath amp board in a chassis with this item, we could have a one box tube dac that can take signal from a transport or computer or from a phono stage and amplify it through a Tripath chip.

I am thinking about just offering the AMP 3 circuit boards as an assembled board. Right now they are only available as an empty board and a few bags of parts. There is some very fine surface mount work need to assemble these boards. Not everyone who would like to experiment with these boards have the skills to assmble one.

I will have to get the boards in and build a couple before I can determine a price I would charge for my labor. This would also include winding the coils. I am thinking in the ball park of $150.00-200.00 for an assembled board. What do all of you think?

mcgsxr · « **Reply #1 on:** 18 Mar 2005, 05:57 pm »

Wayne, the idea of incorporating the tripath amp WITHIN the Chime DAC is very interesting, and should provide a VERY high ROI for those that are able to get their hands on that!

Good luck with the project,

shelt59 · « **Reply #2 on:** 18 Mar 2005, 06:15 pm »

I for one was very interested in the AMP3 board. I LOVE my SLA powered SI amp. However, while I'm a pretty decent solderer, I am not comfortable at all attempting a full SMT board project, especially the IC!

I would definitely be interested in a clean assembled board (with quality leads attached!). I'm in the middle of building an SI amp into a beautiful box, and would love to pop it out and stick an assembled AMP3 in!

Rich

tianguis · « **Reply #3 on:** 19 Mar 2005, 04:10 pm »

Wayne:
I'd be interested in a board. My SMT skills are nil, which limits what I'm able to do with the T-Amps.

Regards,
Larry Welsh

Wayne1 · « **Reply #4 on:** 19 Mar 2005, 04:41 pm »

Thanks for the interest, guys.

when I get the first boards in, I will see how hard it is for these old eyes and hands to put them together.

I will then post a picture and firm up the price on the assembled boards.

Panelhead · « **Reply #5 on:** 19 Mar 2005, 05:28 pm »

Quote from: Wayne1

Thanks for the interest, guys.

when I get the first boards in, I will see how hard it is for these old eyes and hands to put them together.

I will then post a picture and firm up the price on the assembled boards.

Wayne,
You most likely already have one, but this will be a lot easier if you get a SM soldering station. The hot air soldering will prevent 90% of the problems from dealing with these small components.
At work we one off protypes, since going from through hole to SM the circuits have gotten much smaller. Very few problems with construction also.
Look on ebay if you need one, they sell at big discounts.

George

BradJudy · « **Reply #6 on:** 19 Mar 2005, 06:17 pm »

I haven't been following the T-path stuff closely, so this may be a dumb question. Is this AMP 3 board a single channel or two channels?

tianguis · « **Reply #7 on:** 19 Mar 2005, 06:22 pm »

Brad:
It uses the 2021B chip and puts out 25 w into two channels.

Regards,
Larry Welsh

doggie · « **Reply #8 on:** 29 Mar 2005, 02:43 am »

Hi Wayne,

Having worked on a couple SI boards but balked at reworking the smd parts I would also be interested in a model 3 board if it came in at the lower end of that price range. I am looking forward to hearing your comments about it's performance relative to the Tripath eval boards...

I am running an SI board in a new chassis with SLA power right now to drive some AKG K-1000 phones. Quite amazing...

Best,

Paul

Christopher Witmer · « **Reply #9 on:** 4 Apr 2005, 01:53 pm »

I would be very much interested in pre-assembled boards, especially with Litz wire toroidals.

Here is another option you might consider -- if it would be practical:

Partially assembled boards; in other words, boards that have the tiniest and most difficult-to-solder components installed. If there are any components that can be installed without mastery of SMT board soldering techniques, let the purchaser install just those. The reason why I mention this is because IF the toroidals fall into the category of components that the purchaser could self-install, then maybe winding and soldering of the toroidals could be left to to the purchaser. It's just a thought. (If the price difference would be negligible then the only rationale for the non-SMT-solderer to go that route would be the fun of DIY.)

Christopher Witmer

Wayne1 · « **Reply #10 on:** 4 Apr 2005, 02:10 pm »

I am not sure what wire Jan might be sending along with the toroidals. I have some solid core 99.9999% pure copper wire that I am planning to use for winding the toroidals I will use in the finished product

The value you get does depend on how tight you wind the coil. I do have an impedance meter, so any coils I will wind will be the exact value spec'ed and matched to the other coil.

I really do not want to get into the parts business or do too much custom work on these boards for the DIY crowd. My initial thoughts were just to offer assembled boards. The end user would be responsible for all wiring, hook-up, cases, etc. I would not be selling a kit. There would be no warranty on assembled boards. They would be tested before they leave Colorado. Too much can go wrong afterwards to warranty. If DC power is hooked up backwards, even for just a moment, it can blow the chip.

doggie · « **Reply #11 on:** 4 Apr 2005, 02:55 pm »

Quote from: Wayne1

I am not sure what wire Jan might be sending along with the toroidals. I have some solid core 99.9999% pure copper wire that I am planning to use for winding the toroidals I will use in the finished product

The value you get does depend on how tight you wind the coil. I do have an impedance meter, so any coils I will wind will be the exact value spec'ed and matched to the other coil.

I really do not want to get into the parts business or do too much custom work on these boards for the DIY crowd. My in ...

Sounds good. Let us know when they are ready...

Christopher Witmer · « **Reply #12 on:** 4 Apr 2005, 03:27 pm »

What you propose will surely sound great; I'll keep checking to see what you eventually decide. Thanks!

Christopher Witmer

Wayne1 · « **Reply #13 on:** 4 Apr 2005, 07:39 pm »

I just received word that the circuit boards and parts should ship tomorrow!

With any luck, I should have one put together by the end of next week.

doggie · « **Reply #14 on:** 14 Apr 2005, 03:39 pm »

Hi Wayne,

I am seeing some posts on DIYAudio that mention folks getting their 41MZ boards over the past few days. Just wondering if yours came and how they look?

Best,

Paul

Wayne1 · « **Reply #15 on:** 14 Apr 2005, 04:03 pm »

The circuit boards showed up Tuesday. I started work on one of them yesterday.

The board is laid out very nicely. I would not suggest that anyone attemp to assemble one without a very good magnifying lens and a very small pair of tweezers

I have some other projects to work on, but I hope to have one of the amps up and working next week.

I also received a couple of DACs from DIYParadise.

This is a NOS DAC with a 80 mhz reclocking circuit. It uses the 1545 DAC.

You can buy a complete assembled DAC for $115.00 US and put it in your own case.

I have one running now and I will comment more on it after a week or so. Right away it does seem a bit lacking in dynamics and low and high extension compared to my Mensa Plus DI/O

If it works out, I may offer this DAC in a case, battery powered, with a few mods and parts upgrades.