L'Amp: A simple SIT Amp - Page 107

OlavHaal · 10th May 2012, 03:36 PM

Hi again.

No - and yes - I have two sources: Squeezbox Touch that feeds through a DacMagic. And a HD980 CD-player that also is connected to the DacMagic. So I run both through the B1. And I can run the pre-out from my HK980 which also is relative good. But I think the B1 is so good - so you really relieved me now Michael.

Just a couple of resistors and soon ready to go.....rock and roll!!!

Best to all

Olav

Roscoe Primrose · 10th May 2012, 05:12 PM

Sounds like a job for a BOZ or JBOZ... My battery powered J310 based JBOZ works quite well...

Roscoe

KASUMI · 10th May 2012, 05:21 PM

Hi,how do you guys get rid of the switch on thump,though I get no thump just the drivers cone popping out alarmingly

only just noticed today

ra7 · 10th May 2012, 05:37 PM

One of the simplest ways to get rid of turn on thump is to put an inductor in the power supply. It resists a change in current, and so, turns on the power supply slowly. Result = no turn on thump. As a bonus, you get a quieter supply compared to a standard CRC. Start with 2mh, 16ga. Read the Zen articles.

Another way is to disconnect the speaker before turn on. And then are more complicated ways.

Zen Mod · 10th May 2012, 05:45 PM

and another way is to put delayed shortie in paralel with spk

there is cap , so no harm

KASUMI · 10th May 2012, 11:16 PM

Hi thanks for that I still get the excursion when the amps have been switched on and then I reconnect the speakers

problem existed before the new caps.

Installed some new caps today,only one amp done at the mo

Zen Mod · 10th May 2012, 11:29 PM

do you have bleeder resistor , in parallel with speaker ?

KASUMI · 11th May 2012, 12:21 AM

Quote:

Originally Posted by Zen Mod

do you have bleeder resistor , in parallel with speaker ?

nope,just using the basic cct.

Michael Rothacher · 12:45 AM

A "bleeder" resistor across the speaker terminals will discharge the big output capacitor, which is a good idea. You could try a 3W 100 Ohm, for instance. A bigger value will discharge more slowly / smaller value more quickly.

As far as turn-on thump goes, my low-tech approach is to install a shorting banana plug across the speaker terminals, temporarily shorting the output to ground for a few seconds during power up, then I remove it. I may have mentioned this in the text.

Also, see the Zen Lite article for an automated version of the same idea.

Is that fancy square thing a capacitor?

Zen Mod · 11th May 2012, 08:07 AM

Quote:

Originally Posted by KASUMI

nope,just using the basic cct.

then put it

10th May 2012, 03:36 PM	#1061
OlavHaal diyAudio Member Join Date: Oct 2010 Location: Haugesund	Thanks Michael & all... Hi again. No - and yes - I have two sources: Squeezbox Touch that feeds through a DacMagic. And a HD980 CD-player that also is connected to the DacMagic. So I run both through the B1. And I can run the pre-out from my HK980 which also is relative good. But I think the B1 is so good - so you really relieved me now Michael. Just a couple of resistors and soon ready to go.....rock and roll!!! Best to all Olav

10th May 2012, 05:45 PM	#1065
Zen Mod diyAudio Member Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain	and another way is to put delayed shortie in paralel with spk there is cap , so no harm __________________ my Papa is smarter than your Nelson ! tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; Mighty ZM's Bloggg;I'm dumb

10th May 2012, 11:29 PM	#1067
Zen Mod diyAudio Member Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain	do you have bleeder resistor , in parallel with speaker ? __________________ my Papa is smarter than your Nelson ! tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; Mighty ZM's Bloggg;I'm dumb

11th May 2012, 12:42 AM	#1069
Michael Rothacher www.audiohobby.com diyAudio Member Join Date: May 2001 Blog Entries: 3	A "bleeder" resistor across the speaker terminals will discharge the big output capacitor, which is a good idea. You could try a 3W 100 Ohm, for instance. A bigger value will discharge more slowly / smaller value more quickly. As far as turn-on thump goes, my low-tech approach is to install a shorting banana plug across the speaker terminals, temporarily shorting the output to ground for a few seconds during power up, then I remove it. I may have mentioned this in the text. Also, see the Zen Lite article for an automated version of the same idea. Is that fancy square thing a capacitor? __________________ My Website, Projects, Sale Items Last edited by Michael Rothacher; 11th May 2012 at 12:45 AM.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search


	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

10th May 2012, 05:12 PM	#1062
Roscoe Primrose diyAudio Member Join Date: Jan 2004 Location: Virginia, USA	Sounds like a job for a BOZ or JBOZ... My battery powered J310 based JBOZ works quite well... Roscoe

10th May 2012, 05:21 PM	#1063
KASUMI diyAudio Member Join Date: May 2005 Location: UK	Hi,how do you guys get rid of the switch on thump,though I get no thump just the drivers cone popping out alarmingly only just noticed today

10th May 2012, 05:37 PM	#1064
ra7 diyAudio Member Join Date: Feb 2009 Blog Entries: 1	One of the simplest ways to get rid of turn on thump is to put an inductor in the power supply. It resists a change in current, and so, turns on the power supply slowly. Result = no turn on thump. As a bonus, you get a quieter supply compared to a standard CRC. Start with 2mh, 16ga. Read the Zen articles. Another way is to disconnect the speaker before turn on. And then are more complicated ways.

10th May 2012, 11:16 PM	#1066
KASUMI diyAudio Member Join Date: May 2005 Location: UK	Hi thanks for that I still get the excursion when the amps have been switched on and then I reconnect the speakers problem existed before the new caps. Installed some new caps today,only one amp done at the mo

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
L’Amp: A Simple SIT Amp: Part 1	Michael Rothacher	diyAudio.com Articles	20	2nd March 2013 08:26 PM
SIT Amp Article Out Now	Variac	Site Announcements	0	2nd December 2011 07:55 AM
Srajan has the 1st SIT amp for Une dégustation	vizion	Pass Labs	131	14th November 2011 11:41 PM
SIT-Preamp	VladimirK	Solid State	36	27th August 2011 08:36 PM
New SIT - old problem	StevenOH	Parts	2	13th June 2008 10:46 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read