SI T-amp - bad hiss in one channel - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 27th November 2006, 03:31 PM   #1
toolkit is offline toolkit  United Kingdom
diyAudio Member
 
toolkit's Avatar
 
Join Date: Nov 2006
Location: Chesterfield, UK
Default SI T-amp - bad hiss in one channel

Just got one and powered it up, but there's a really bad hiss in the left channel. The music is there behind the hiss though so it's not a complete channel failure.

I've resoldered the input jack as one of the legs looked really badly done, no change. Some of the other soldering looks dodgy too.

Any ideas if there's an obvious component that could be the cause of this hiss?

Cheers
Chris
  Reply With Quote
Old 28th November 2006, 04:09 PM   #2
toolkit is offline toolkit  United Kingdom
diyAudio Member
 
toolkit's Avatar
 
Join Date: Nov 2006
Location: Chesterfield, UK
Oh great, and now the one channel that works is cutting out

I'd heard there were quality issues.

Another one now on order, let's hope this one works. At least I can use the duffer for test-fitting if I get round to re-boxing it.
  Reply With Quote
Old 29th November 2006, 08:56 PM   #3
v-bro is offline v-bro  Netherlands
diyAudio Member
 
v-bro's Avatar
 
Join Date: May 2006
Ther ARE quality issues, read the thread here:
SI nightmare

But I had a similar problem on an AMP32 build from 41hz.com (very similar kind of chip, very very similar) the bias capacitor needed changing...overheated it with soldering I guess, funny the SMD parts all went well on the eight AMP32 kits I've built so far....Great alternative by the way, the chip seems to be able to handle a lot more abuse.

But all my T-amps from sonic impact died (had three of them babies )

Here's some pictures of my AMP32 builds (just scroll down....)
Amp 32 Pics + Review
__________________
Max. cone displacement can be several foot on any speaker!Too bad it can be done only once......
  Reply With Quote
Old 29th November 2006, 10:12 PM   #4
toolkit is offline toolkit  United Kingdom
diyAudio Member
 
toolkit's Avatar
 
Join Date: Nov 2006
Location: Chesterfield, UK
Well, if I like the Tripath sound, I will either rebox the T-amp with some mods (got some Soniq caps for the input on order anyway) or combine that with an AMP6 build or buy an autocostruire kit anyway as they seem to last a bit better!
  Reply With Quote
Old 29th November 2006, 10:30 PM   #5
v-bro is offline v-bro  Netherlands
diyAudio Member
 
v-bro's Avatar
 
Join Date: May 2006
Autocostruire is quite a good bet, I have an MC4x100 they sell. A very nice four channel amp with plenty of power and very good sound.
Don't know about the Fenice though... probably a very fine amp too...

But I am very very satisfied with the quality of the cheapest 41hz.com amp (amp32) and have just ordered the 12V version of AMP9 which is also four channel (sharing the same chip as the MC4x100) This amp delivers a lot more current than the TA2020 based amps (AMP6) and has only a couple of relatively large surface mount components ("little component count and pretty easy to build") funny it only costs 49 EUR.

The TAA4100A chip has proven itself to me to be virtually indestructible.
Shorted it accidentally a lot of times (use in car, cable between chair... ) and used it on SLA batteries, NiCD, SMPS, tranny (MC4x100 has rectifier on board) connected it to ESLs...(TAA4100A can handle very tough loads)..
__________________
Max. cone displacement can be several foot on any speaker!Too bad it can be done only once......
  Reply With Quote
Old 30th November 2006, 12:15 AM   #6
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
It does seem to be very easy to kill the inputs of the Sonic Impact. Don't know why....

I have a whole drawer full of dead ones that I hope to call "Lazarus" some day.
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 30th November 2006, 12:28 AM   #7
v-bro is offline v-bro  Netherlands
diyAudio Member
 
v-bro's Avatar
 
Join Date: May 2006
Me too!

I still have them, and must say I liked the sound quite well. Especially after some modifications, but the AMP32 (maybe due to the inductors, which appear very nice to me...) sounds better out of the box ("from the workbench")...

The TA2020 chip seems fine to me (I think it's the same chip package as the TAA4100A, not?) if higher power requirements or bi-amping are not one your wishlist..

I chose the versatility of the TAA4100A based amp...

I once read the TA2024 chip has problems (called internal fuses, how useless if they don't self-recover...) I'm curious if anyone knows where this information can be read again...I forgot....
__________________
Max. cone displacement can be several foot on any speaker!Too bad it can be done only once......
  Reply With Quote
Old 30th November 2006, 12:47 AM   #8
v-bro is offline v-bro  Netherlands
diyAudio Member
 
v-bro's Avatar
 
Join Date: May 2006
And I do find the board layout of Jan's amps (41hz) very nice (much space for good input caps, on AMP32 even the choice between smd and trough-hole types).

I have a hunch the reliability of Jan's amps is more than good...I made a couple of small mistakes during the builds which would probably have killed an SI-amp several times...(good protection circuitry in both TA2021B and TAA4100A, almost no need for Jan to sell them separately)...

Jan has good eye for detail and has presented himself as quite a nice guy sofar...(very quick email response also, good support, his own forum, soon a picture gallery.....)

And last but not least, looooooowww price!

Stick your hands out of your sleeves diyers and build!

Attached Images
File Type: jpg amp32mini.jpg (70.1 KB, 70 views)
__________________
Max. cone displacement can be several foot on any speaker!Too bad it can be done only once......
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hiss but no hum... RockysDad Tubes / Valves 13 5th April 2009 05:35 PM
Hiss From An Ampli Channel Calamaro Solid State 13 20th September 2008 01:50 PM
Pre-amp hiss on 1 channel bulgin Solid State 1 5th August 2006 01:04 PM
T-Amp hiss/crackle in channel nehpets Class D 19 10th October 2005 06:34 PM
hiss jaudio Chip Amps 21 6th March 2005 05:02 PM


New To Site? Need Help?

All times are GMT. The time now is 10:17 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2