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Skunk
2006-04-19, 19:52
I know there's a lot of info on other sites, but this site is the only one I have toolbar-bookmarked...

I was hoping to get advice on chip amps, of around 10 wpc. My Fostex 206's sounded great with a PP tube amp, but that amp has issues worthy of another thread. I had been leaning towards modding a sonic impact, but really like the look of some of the point to point wired amps. A CB+parts list would be nice too I guess, as it would be a first project for me.

Any advice, plans, recommended kits, or opinions would be greatly appreciated.

Michaelwagner
2006-04-20, 05:28
:-)

I must have been tired last night when I read this posting. I couldn't figure out what a chimp amp was. Today in the light of day it's all clearer - chip amp. Gotta get the eyeglasses checked.

BeerCan
2006-04-20, 05:51
Charlize is a tripath based amp that gets good reviews
http://www.diyparadise.com/charlize.html

Also somthing based on the hypex UcD180AD might be good

Mark Lanctot
2006-04-20, 06:30
There was some buzz about L C Audio ZAPpulse:

http://www.lcaudio.com/

The power is much higher than what you were looking at though.

ChrisOwens
2006-04-20, 09:09
If you're willing to mod, maybe you're willing to build? There's a lot of people on the web who are making 'Gainclone' chip amps based on some 'Gaincard' amp by a Japanese company, 47 Laboratory.

I'm not sure I want to put in the time our lead engineer Mike has on his transistor amp, but I've been researching building one of these for a few weeks.

http://www.mhennessy.f9.co.uk/gainclone/

Skunk
2006-04-20, 11:28
If you're willing to mod, maybe you're willing to build?

Well I'm willing to *try* :-)

Actually that is the same site I stumbled upon where I saw the P2P wired chip I wanted to try copying [see /construction]. I didn't realize there was a Slim Devices connection. I started surfing the 'gainclone ring' and forgot to bookmark his most excellent site.

Hopefully I'll follow through, and post some pics here.

randytsuch
2006-04-20, 13:13
Here is another site with a lot on infomation
http://myweb.tiscali.co.uk/nuukspot/decdun/gaincloneindex.html

There is also a chip amp section at diyaudio.com where you can find information on the subject.

Randy

ezkcdude
2006-04-20, 16:54
Also, check out the chip-amp kits at www.audiosector.com.

Skunk
2006-04-20, 21:05
Charlize is a tripath based amp that gets good reviews
http://www.diyparadise.com/charlize.html


I read the tripath had natural synergy with fostex drivers, so I traded a friend some cookies (I make good cookies) for a SI T-amp tonight. It's certainly different from the Jolida, more fatiguing but closer to the recording I'd bet. It's really showing me how bad my speakers are, but I hope to add some bits* to counteract the glare. Charlize sure looks tempting.

* http://members.tripod.com/talkgarden/sonic_impact_5066.htm

BeerCan
2006-04-21, 06:34
Also, check out the chip-amp kits at www.audiosector.com.
I forgot about http://www.audiosector.com/ While I did not purchase a gainclone from peter I did purchase a DAC. He does fine work and is very helpfull. More importantly he contributes a wealth of information back to the DIY community. I think this fits more to the slim style of open source/open knowledge

ezkcdude
2006-04-21, 07:50
More importantly he contributes a wealth of information back to the DIY community. I think this fits more to the slim style of open source/open knowledge

Yeah, he's one of the most frequent posters at diyaudio.

tyler_durden
2006-04-21, 08:37
More importantly he contributes a wealth of information back to the DIY community.

Don't confuse the skills to make a pretty box with knowledge about the circuits. You'll get far more valuable and useful DIY information from the data sheet and applications notes related to the chip amps.

On the other hand, if you want help selecting materials to make a box that looks nice in a sort of industrial looking way, you've got the right guy/place.

TD

BeerCan
2006-04-21, 15:11
Don't confuse the skills to make a pretty box with knowledge about the circuits. You'll get far more valuable and useful DIY information from the data sheet and applications notes related to the chip amps.

On the other hand, if you want help selecting materials to make a box that looks nice in a sort of industrial looking way, you've got the right guy/place.

TD
I did not say he was an EE genius. I said he contributed back to his community. I appreciate that in a person no matter what level of knowledge they have. Mahap wealth was too strong of a word for you :)

Kim Schultz
2006-04-23, 01:35
If you like the Sonic Impact amp, try looking at the 41hz.com website. Really great amps, and they are cheap ;)

lostboy
2006-04-23, 02:02
I can second Kim's comments on the 41Hz amps. I'm very pleased with the sound and volume levels from an AMP3 driving a pair of inefficient 25 year old Jim Rogers bookshelves (same guy who designed the LS3 BBC monitors). If you're new to soldering have a look at the AMP6 which doesn't use surface mount components. Jan, the designer of the 41Hz kits, does not frequent his forum as much nowadays, victim of his own success I think, but the supply of kits seems OK. For me the hardest part of the construction was winding the toroids. The tips on the forum were very useful.

Chris

cplus
2006-04-24, 21:06
If you're willing to DIY, there are several PCB + parts kits you can look into. Despite being dissed above, Peter Daniels (http://www.audiosector.com/) appears to put out a solid kit, especially the premium version where he's done a lot to select upgraded parts (resisters, caps, etc). Another alternative is BrianGT's chipamp kits (http://www.chipamp.com/); these are somewhat more complex and include snubberized power supplies. Going another step up in complexity, you can also look at Twisted Pear's kit based on Mauro Penasa's My Reference 3886 "RevC" - http://www.twistedpearaudio.com/ - which IIRC have robust power supplies, soft-start circuits, speaker protection and some other features. Personally, I'm kind of waiting for them to finish up the Super-Symmetrical 3886 kit which I understand to be a bridged 3886 setup based on an idea Nelson Pass put up on DIYAudio. That, plus a Twisted X-BoSoZ preamp and SB3 might be a killer setup.

Skunk
2006-04-27, 05:21
I finally got the sonic impact to beat out the jolida 102b in overall presentation of the music. I can't believe how good some of the discs I had completely written off are sounding. The two most notable examples are Fishbone's Truth and Soul, and Tool's AEnima. Both sounded great on past systems, and in the car- but very thin and extremely bright through the jolida.

The key seemed to be adding 30db of attenuation at the server, and cranking the volume on the SI to max (my speakers are effecient) Only then did everything gel. Also- with necessity being the mother of invention- I got a RCA piggyback cable* from RS ($11) to act as a sub out from the SB, and attached the rca-->headphone adapter that feeds the SI to the piggy's back. I wonder if there are sonic consequences to this, other than the physical connection itself?

At any rate, I'm convinced I need to build one of these little amps. I can only imagine how much better it can get, and starting from scratch seems the way to go. The audiosector amps seem to be at the front of the pack. Maybe it's just the usable Web site making me think that.

EDIT: after experimenting further, the sound out of the t amp is much better after eliminating all server attenuation, and using the t amp potentiometer to attenuate the signal. Sorry for any inconvenience :-)

*

ezkcdude
2006-04-27, 10:00
Also somthing based on the hypex UcD180AD might be good

I think this is an interesting option. After reading the following article, I think I will build this eventually:
http://www.hardwareanalysis.com/content/article/1822/

dwc
2006-04-27, 23:34
I'd like to build a hypex amp. Dusty at Channel Islands builds with those, and people love them.

http://www.ciaudio.com/

mfieger
2006-04-28, 09:49
Skunk,

With a goal of 10wpc, have you considered chip amps made for car stereo applications such as the TDA8563? Available on Digikey (568-1145-5-ND) for $5.40. It's stereo, has very few external components, operates from a single supply (12V to 18V wall wart), and has a wide pin pitch. The THD+N specs for these car stereo amps are not so great, raising to over 0.5% at 30W, and much higher... Should be fine at 10W.

There are a couple other chip amps similar to tda8563. You could use an old 12V wall wart, some perf board, and a used heat sink from a cpu. Cheap and easy to build.

Skunk
2006-04-28, 13:13
Skunk,

With a goal of 10wpc, have you considered chip amps made for car stereo applications such as the TDA8563?

I hadn't considered it, but I think with this type of amp I'll need more than 10 watts. The sonic impact seems to compress/distort pretty badly after 1 watt- which makes me feel wrong for saying it sounds better than the jolida, which could put out most of it's rated power (20W) without audible distortion.

I've been thinking a lot about the LM3875, which audio sector makes a kit for, as I believe it was the gaincard chip. I would like to get as close in audio quality to that 'ideal' as I can, otherwise I would probably stick with the jolida.

Tyler is absolutely right; If I weren't such an electrical dunce I would take his advice and design straight from the application notes/data sheet- which seems like what you're suggesting as well.

mfieger
2006-04-28, 16:41
Skunk,

$50/$85 for the LM3875 kit from audiosector is a great price. That is going to be really tough to beat. You could study the datasheet for the LM3875 while building the kit, no harm there.

Also, if you are just starting out in electronics, and wish to get more hands on experience, I would highly recommend getting one of those 50in1 electronics labs (with the springs and the wires). I had one as a kid, everybody has to start somewhere!

Michaelwagner
2006-04-28, 16:51
I had one of these, either this one or a similar one. It's great for trying stuff out.

http://www.thesourcecc.com/estore/Product.aspx?language=en-CA&catalog=Online&category=PC+board%2fSockets&product=2760169

I think mine came with a kit of common resistors and common capacitors and a bunch of wire wrap wire and jumpers but it's the same idea.