New chip amplifier

[hybridfiat]

Just finished making a new amp (class D tripath chip) from a kit supplied by 41Hz.
It works well Ive not had a chance to try it with a decent input source and speakers but vol and sound quality using an ipod and cheap TEAC speakers is encouraging.
Next job is to make a little enclosure for the amp and toroidal transformer.
:2tsup:

[Isaac Hunt]

Not bad little amps.They lack a bit of power though-so you need efficient speakers.A lot of Class D amps also do not image very well-a sort of hollow soundstage.Good left to right but they lack depth and cental imaging.

The Panasonic 3876T chip amp kits you can get at Jaycar are superb.They are not class D /digital .They are more like 40 watts but again need reasonably efficient 8 ohm [not so good with 4 ohm] speakers.These are a Gianclone type amp similar to the high end Japanese amps by 47 Labs.They sound very high end with the right speakers-and have really good imaging-almost up to Single Ended Triode valve amp standard.

[hybridfiat]

Cheers, Ill check them out. Ive got another amp kit on it's way from Canada. Its from Audio Sector, the basis for their Patek amp.

[Bonsa1]

Hi Hybridfiat,

I recently bought a Kingrex T20U from Coem Audio, I use it with a small pair of Tannoy book shelf speakers for my computer. It has a USB input, so bypasses the 'not so good' soundcard in the computer, overall I am very happy with set-up and with the sound quality.
The 6moons reviews of the unit recomend you run it for about 200 hours before critical listening, they also say use battery powering rather than the switchmode supply (supplied with the unit) or the optional PSU, I figure that I might build my own 12v SLA battery supply and charger. There was a suitable charger in Silicon Chip a few months ago, alternativley there are SLA chargers available from Jaycar.
6moons reckon that the pure 12v DC sounds better than rectified AC, I don't know if my old ears could tell the difference, but will try anyhow!
I am thinking of making my own speaker cables too, I can go a bit 'exotic' as the speakers are fairly close together, I thought that I might try a few runs of silver wire? (Soundlabs Group keep solid silver insulated wire in a couple of sizes)
:2tsup::2tsup:

[hybridfiat]

Yes Ive read that the consistency of supply from a battery is better, but like you Im not sure I could tell the difference. I have a small 12v battery that Im using to test power the amps. I definately will not be buying silver wire. Any peripheral that costs more than the main driving parts I am unable to justify. A bit like solid gold hinges and lock on a Jarrah blanket box:oo:.
Im happy to try a few of these amps because of their low cost.
The AMP6 and the AMP32ps that I am is next to make are for the kids, active speakers for their rooms. I dont suppose they will care about the finer points or fripperies such as the lack of silver cable and the like.
Im keen to listen and compare the Peter Daniels amp with my Rotel and Sony. But again if Im not happy with the sound reproduction Ill pass it on and try another.:2tsup:



Hi Hybridfiat,

I recently bought a Kingrex T20U from Coem Audio, I use it with a small pair of Tannoy book shelf speakers for my computer. It has a USB input, so bypasses the 'not so good' soundcard in the computer, overall I am very happy with set-up and with the sound quality.
The 6moons reviews of the unit recomend you run it for about 200 hours before critical listening, they also say use battery powering rather than the switchmode supply (supplied with the unit) or the optional PSU, I figure that I might build my own 12v SLA battery supply and charger. There was a suitable charger in Silicon Chip a few months ago, alternativley there are SLA chargers available from Jaycar.
6moons reckon that the pure 12v DC sounds better than rectified AC, I don't know if my old ears could tell the difference, but will try anyhow!
I am thinking of making my own speaker cables too, I can go a bit 'exotic' as the speakers are fairly close together, I thought that I might try a few runs of silver wire? (Soundlabs Group keep solid silver insulated wire in a couple of sizes)
:2tsup::2tsup:

[hybridfiat]

I meant to add that as a young boy I lived at a wireless station in the bush, the house adjoined the transmitter hall and the radio literally came through the mains.
Plug in a stereo and turn up the volume and 6WB radio station came through clear as a bell.
I made a crystal radio set and was able to dispense with the condensor as the radio blotted out all other stations.
This makes me a little more receptive to the idea that mains power can be "polluted" depending on where you live of course.

[hybridfiat]

Got the speakers ready to take the Amp They are the inside pair.
They are John Krutke's (zaphaudio.com) design for a small single driver system. They sound HUGE! They perform way above their weight and Id strongly recommend this project (3" Hivi B3S or B3N found at darcheraudio.com.au) to anyone thinking about making speakers as a beginner project.:2tsup:

http://i252.photobucket.com/albums/hh36/savage99-2007/Hivis.jpg

[Zaphod]

Just finished making a new amp (class D tripath chip) from a kit supplied by 41Hz.
It works well Ive not had a chance to try it with a decent input source and speakers but vol and sound quality using an ipod and cheap TEAC speakers is encouraging.
Next job is to make a little enclosure for the amp and toroidal transformer.
:2tsup:

The Tripath™ amps are severely crippled. Good thing the company went belly-up. If you want to build a really good amp, then look to one of the Silicon Chip designs. Their Class A amp, or, even better, their ULD amp (100 Watts) is the best you'll do in the kit world. Great value for money.

BTW: I don't consider ALL switching amps as bad, just the Tripath™ ones.

[Bonsa1]

[quote=hybridfiat;788189]Got the speakers ready to take the Amp They are the inside pair.
They are John Krutke's (zaphaudio.com) design for a small single driver system. They sound HUGE! They perform way above their weight and Id strongly recommend this project (3" Hivi B3S or B3N found at darcheraudio.com.au) to anyone thinking about making speakers as a beginner project.:2tsup:

http://i252.photobucket.com/albums/hh36/savage99-2007/Hivis.jpgNice looking speakers! I hope they sound as good as they look! Nice woodgrain too, are they solid or veneered?:2tsup::2tsup:

[hybridfiat]

The Tripath™ amps are severely crippled. Good thing the company went belly-up. If you want to build a really good amp, then look to one of the Silicon Chip designs. Their Class A amp, or, even better, their ULD amp (100 Watts) is the best you'll do in the kit world. Great value for money.

BTW: I don't consider ALL switching amps as bad, just the Tripath™ ones.


Im happy with the sound and as Ive said they are for the kids to use as desktop monitors.
Ill check out the Silicon Chip site

The wood is solid Chestnut, milled from a tree felled in a friends garden.

[Zaphod]

Im happy with the sound and as Ive said they are for the kids to use as desktop monitors.
Ill check out the Silicon Chip site

The wood is solid Chestnut, milled from a tree felled in a friends garden.

I realised the size limitations AFTER I posted my reply. I hate Tripath™ stuff. BIg time. It's over-priced, under-performing and over-hyped. Having said all that, it is efficient and compact. For the purpose you have, they may well be an appropriate choice. IMO, however, there are better chip amps, using conventional A/B technology for a whole lot less money and they offer much better sound quality. Unfortunately, they do get hotter and heat sink requirements are somewhat greater.

[hybridfiat]

I finished the active speakers yesterday. I put the 41Hz Amp6 into the Rt speaker and screwed the filters to the inside back wall of each box. They sound good but the amp is clipping at 75% VOL. I think Ive made a mistake in the filter. Nothing else has been changed. Im back at work now so theyll have to wait. Im sure my daughter will be rapt at Christmas when she sees them.:2tsup:
Next job is the little Amp32PS and then the gainclone from Peter Daniels.
Ive got a friend who has asked me to make an amp to fit in his old set of B&W DW4s.
Ill do a 60w/channel amp for that.

[V-bro]

The Tripath™ amps are severely crippled. Good thing the company went belly-up. If you want to build a really good amp, then look to one of the Silicon Chip designs. Their Class A amp, or, even better, their ULD amp (100 Watts) is the best you'll do in the kit world. Great value for money.

BTW: I don't consider ALL switching amps as bad, just the Tripath™ ones.

Can you please elaborate? I doubt there is any profound technical knowledge behind these statements. Neither experience with anything better than the small Tripath amps. If it is just your opinion, fine, I would only say it's perhaps better to stick to woodworking then. :~

Want to know my opinion? One of my friends has the ULD amp and is selling it. It sounds lifeless, metalic and uninspiring. Ever tried a good TK2050 amp? Speaking of Ultra Low Distortion AND great sound!!

Sure there are overpriced specimen of Tripath amps, but there are at least just as many of any other technology. Sure there have been overhyped and unrealistic raves and reviews on Tripath amps. But there's no reason to go so blunt on it saying it's a good thing they went belly-up. Neither is there any reason to powerfully state that Tripath amplifiers are severely crippled. To me and many others I'm afraid your opinion is rather severely crippled! What use is it anyway to advise a Class A amplifier and start moaning about high prices?! After a few years even a severely overpriced Tripath amp will have paid itself back on the electricity bill! LOL!

I'm sorry, but I just needed this straigtened out...:B

By the way, very nice little speakers there Hybridfiat!!

[Bonsa1]

+1


I have three Tripath amplifiers in different stages of modification, main modifications being input caps, filter inductors, tank caps and various power supplies.
I have shared my experiences on the diyAudio site where there are a stack of other contributors doing similar things. I have found these units extremely easy and pleaseant to listen to, even in there non-modified state.


I agree that there are some fantastic class D designs, kit's and pre-made modules available, I always drool when I look at Peter Daniel's Audio Sector site


With regard to Silicon Chip designs, from what I have read, the amplifiers end up with fabulously low distortion figures, but the amplifiers as published do not normally exhibit a very wide soundstage, or a great deal of depth to the stereo image. The designers look at the figures too much and don't rely on their ears and how 'musical' the amplifier is. What is the point of very high THD performance, when it sound like crap!


I have owned a variety of amplifiers over the years, and yes, class A (Peter Stein ME amp) PP valve amps etc., so I have a good understanding of how different amplifiers sound and what their advantages / disadvantages are.


So Zaphod, I think your comments about Tripath amps are a bit narrow minded!

[soundman]

For years i have been fascinated at the hype surrounding these..." gainclone" amps built from cheap generic amp chips.
None of them are very powerful, and the "off sheet" spec's simply do not look impressive too me.


But hey retail HIFI these days is pretty low end.

Possibly the reason people think these things sound so good is that they are not surrounded by the trappings of retail HIFI.... which has definitely gone down hill since the 80's

On the matter of battery being better than AC supply... all I can say is the AC supply must be pretty poor.......if you drop from 15 volts to 12 volts you drop your available power output considerably for starters.
You are behind to start with if you are running on a single rail supply.

this might also account for the lack of channel seperation and the soo called poor sound stage.

Any power amplifier is only as good as its power supply... in fact I would say the power supply design is at least as important as the output stage

back when I was young and building power amps was a viable thing.......we always built bigger and better power supplies than those specified....and with better results.

running sererate power supplies for each output module is definitely a good start.

having a power supply that does not sag with load is a good step too... but this means a PSU that is over rated in comparison to the load it must deliver.....

Then we start looking at "filter capacitors"... all the big name brand amps of the time (crown, phase linear)...... had very big capacitors.......likewise we found that bigger caps were always better
The other issue was/is the big electrolytic caps have considerable self inductance.....so we paralelled them with some smaller value caps.....right down to .1uF blue chips.

This gave the PSU a far better ability to deliver current and provide far better smoothing at all frequencies.

And then do not forget your earthing hygeen........poor earth structure can bugger up your cross talk badly.


One thing that is good about these chip amps is thay are easy particularly is someone else has designed and supplied the board for you.....and most of them quote reasonable power supply rejection.

Remember all of these chip amps are layout critical....so someone with better design skills will produce a better amp with the same components on a different PCB.

Remember the electronics magazine amp boards are not cutting edge designs and the electronic magazine market is nowhere near as competitive and well funded as it was back in the 80's...so you can only expect soo much.... and these guys were never up with the commercial designers and never will be.

If you want to try a good cheap little amp... see if you can track down the Elector headphone amp from back then...it was an op amp afterburner design with a single op amps followed by a BD139 and a BD140.....it was wee ripper on dual 15 volt rails....and capable of a few watts with the right heatsinks.........total component cost these days without PCB would be arround $10.


cheers
cheers

[Bonsa1]

Thanks for your wise words Soundman :) Just to clarify a few things;


Battery supplies: I have built a sealed lead acid battery supply with inbuilt charger and monitor LEDs, the battery when fully charged = 13.4 volts with the LED illuminating at about 12volts, that equates to about six hour running. Note that a TA2020 Tripath chip maximum input voltage is 14.6volts with destruction at ~16volts


I to, with a lot of success and dabbled with passive power supplies, I am currently using a David Dalton design PS Sonic/Tripath (http://www.michael.mardis.com/sonic/start.html) I have also increased the capacitance across the PS into the amps, much increasing the lower end bass response. :2tsup:



Hey I built Elektor Class A headphone amp (fully descrete, no IC's) back in the early 80's I still have it and use it! It's a little gem!


Happy new year!


Cheers!

[hybridfiat]

I agree with most of the comments here. I have made several Tripath and gainclone amps of various types since posting originally but Id put the Peter Daniels at the top but not by much. I set out to do a ULD amp but the cost of good components was going to break the bank. Im not that obsessed with low distortion to want to spend a thou or more on an experiment.
Power supplies are alway critical, but with the gainclones overdoing the smoothing caps leads to losses in sound quality down the track. Ive tried quite a few combinations and a gain in bass (big bully buster caps) is usually accompanied by a loss of mid and treble. :doh:
If you go the Audiosector route be advised to use what Peter gives you.

[soundman]

In this situation where you have increased filter capacitor size...have you just used big electrolytic caps...or have you added smaller caps in paralell to them.

Large electrolytic caps have quite some self inductance....their low frequecy filtering ability will be great... but their capacity to deliver mid and high frequency demand will be poor.

so putting some much smaller value caps in paralell, perhaps in steps right down to .1uF I expect would restore the mid and high performance and still maintain that low frequency improvement.

cheers

[hybridfiat]

Cheers Soundman

[FreakyShotGlass]

Get an lm3886 and be done with it.

[soundman]

Mate regardless of the chip that is used, the quality of the result is still very much dependent on the design, PCB layout and the quality of the power supply.

Even then it is still only a chip amplifier....something designed for consumer electronics.

cheers

[Zaphod]

Can you please elaborate?


Certainly. Tripath™ amps are SPECIFICALLY designed with the following features in mind:

* Compact.
* Cheap to manufacture.
* Tough.
* Minimal heat sink requirements.
* Adequate sound quality, when driving resistive loads.

The Tripath™ amps meet all these requirements. At NO STAGE, were Tripath™ amps ever designed to be the best sounding amps available. Worse, because they use a relatively low switching frequency, they will experience significant difficulties when driving any load impedance less than 8 Ohms.



I doubt there is any profound technical knowledge behind these statements.


Doubt all you wish. You'd be wrong. My business is electronics, specifically focussed on audio. I know the Tripath™ products very well indeed. They tend to be significantly less reliable than the manufacturer's stated design goals and certainly less reliable than most chip amps.



Neither experience with anything better than the small Tripath amps. If it is just your opinion, fine, I would only say it's perhaps better to stick to woodworking then. :~


Hmmm. I suggest you ascertain your facts, before you make silly statements.



Want to know my opinion? One of my friends has the ULD amp and is selling it. It sounds lifeless, metalic and uninspiring. Ever tried a good TK2050 amp? Speaking of Ultra Low Distortion AND great sound!!


If your friend prefers a Tripath™ amp to the ULD amp, then he has rocks in his head, or socks in his ears. The ULD amp is VERY, VERY good indeed. It has no obvious audible, or measureable defects. The Tripath™ amps, OTOH, can easily be goaded into exhibiting severe problems.



Sure there are overpriced specimen of Tripath amps, but there are at least just as many of any other technology. Sure there have been overhyped and unrealistic raves and reviews on Tripath amps. But there's no reason to go so blunt on it saying it's a good thing they went belly-up.


The chip-sets were nonsensically over-priced on release and they didn't get much better.



Neither is there any reason to powerfully state that Tripath amplifiers are severely crippled.


I deal in facts, not hyperbole. There are other products, available for the same or less money, that offers superior performance. EXCEPT, I might add, in the area of efficiency and heat sink use.



To me and many others I'm afraid your opinion is rather severely crippled!


Fair enough. My problem is that I am constantly exposed to the very finest audio equipment available. When I compare products, I inevitably compare them to very high quality ones. The Tripath™ stuff does not rate.



What use is it anyway to advise a Class A amplifier and start moaning about high prices?!


The ULD amp is not a Class A amp.



After a few years even a severely overpriced Tripath amp will have paid itself back on the electricity bill! LOL!


Nonsense.



I'm sorry, but I just needed this straigtened out...:B


Your opinions are duly noted.


By the way, very nice little speakers there Hybridfiat!![/QUOTE]

Indeed they are.