Commercial Gainclone kit- building instructions - Page 101

Peter Daniel · 5th February 2010, 03:33 PM

Yes, thermal compound is required with supplied isolation pad.

Wavne · 5th February 2010, 06:32 PM

Quote:

Originally Posted by etoiledusoir

You can ask Richard if he have surplus stock. I ordered from him two 300va 22-22 for 40$ each about two month ago. Check also for Antek, for more competitive price.

He had 1 left for $40 so I ordered it. They would be $95 + tax and shipping. They are built per order even if it's just one, so that may explain if it's a little pricey.

etoiledusoir · 6th February 2010, 02:24 PM

Quote:

Originally Posted by Wavne

He had 1 left for $40 so I ordered it. They would be $95 + tax and shipping. They are built per order even if it's just one, so that may explain if it's a little pricey.

Don't forget to test it. It is rated at 22v but when I test mine I got 24v.

Peter Daniel · 6th February 2010, 06:30 PM

Quote:

Originally Posted by etoiledusoir

Don't forget to test it. It is rated at 22v but when I test mine I got 24v.

That is caused by regulation margin (transformers are rated at full load) and by variations of AC from a wall which sometimes can be another 6-8%

Wavne · 11th February 2010, 08:31 PM

Hi Peter;
I got the kit the other day, thanks for the fast delivery. I have a question regarding running each board in bridged mode as my speakers are 8ohm. I have the toroid mentioned above (got it yesterday). So i use one rectifier board to drive both boards run in bridged mode...correct? So i will be using R0 and which IN/OUT do I use?

Regards,

Wayne

Peter Daniel · 11th February 2010, 08:56 PM

Yes, one rectifier board.

The bridged configuration has been explained here: AudioSector-chip amp kits, dacs, chassis

You'll be using R0 and and both IN and OUT connections as you need both positive and negative inputs/outputs. You will also need SG (signal ground) but no OG connection.

Bridged setup can be compared to both amps connected in series, where you feed each amp section with opposite polarity signal and the output is taken from "between" the amps with no reference to ground. Read page 7 of this manual for more info: http://www.firstwatt.com/downloads/f4_om.pdf

Wavne · 12th February 2010, 12:10 AM

Sorry for these basic questions. Looking at the LM4780 bridged schematic from Nationals site. The input positive is split between the inputs and uses common signal ground. The output from each (3886) is put across the speaker, thus like you said no 'OG' ....correct?

Which output goes to which lead on the speaker?

Thanks for your help!

Peter Daniel · 12th February 2010, 02:05 AM

National's bridged schematic is different from mine; with their setup you can connect unbalanced source and still get balanced output.

With my kit, to get balanced output, you need to connect balanced input.

The + from a speaker is connected on a same side where positive input (of a balanced signal) is hooked up..

To use unbalanced signal with this bridged amp you can simply use an input transformer: Commercial Gainclone kit- building instructions

Wavne · 12th February 2010, 05:06 PM

So, if I run it in stereo or parallel I can used unbalanced inputs? I know parallel is recommended for 4ohm speakers but can it be run this way with an 8ohm load? That was my only reason for using bridged mode is my speakers are 8ohms.

littlerick · 12th February 2010, 08:19 PM

Ok I know this is a long way back in the thread but the volume pot with 8 pins on the square pot. Are all pots of this type wired the same.. I have a ALPS pot i got from a dead amp rated at 60k x 2. Would it be wired the same?

5th February 2010, 03:33 PM	#1001
Peter Daniel diyAudio Member Join Date: Jul 2002 Location: Toronto, Canada	Yes, thermal compound is required with supplied isolation pad. __________________ www.audiosector.com “Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC

11th February 2010, 08:56 PM	#1006
Peter Daniel diyAudio Member Join Date: Jul 2002 Location: Toronto, Canada	Yes, one rectifier board. The bridged configuration has been explained here: AudioSector-chip amp kits, dacs, chassis You'll be using R0 and and both IN and OUT connections as you need both positive and negative inputs/outputs. You will also need SG (signal ground) but no OG connection. Bridged setup can be compared to both amps connected in series, where you feed each amp section with opposite polarity signal and the output is taken from "between" the amps with no reference to ground. Read page 7 of this manual for more info: http://www.firstwatt.com/downloads/f4_om.pdf __________________ www.audiosector.com “Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC

12th February 2010, 02:05 AM	#1008
Peter Daniel diyAudio Member Join Date: Jul 2002 Location: Toronto, Canada	National's bridged schematic is different from mine; with their setup you can connect unbalanced source and still get balanced output. With my kit, to get balanced output, you need to connect balanced input. The + from a speaker is connected on a same side where positive input (of a balanced signal) is hooked up.. To use unbalanced signal with this bridged amp you can simply use an input transformer: Commercial Gainclone kit- building instructions __________________ www.audiosector.com “Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC

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

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Commercial complete Gainclone kit for a beginner?	gychang	Chip Amps	365	4th October 2011 08:19 AM

11th February 2010, 08:31 PM	#1005
Wavne diyAudio Member Join Date: Oct 2007 Location: Chatham ON	Hi Peter; I got the kit the other day, thanks for the fast delivery. I have a question regarding running each board in bridged mode as my speakers are 8ohm. I have the toroid mentioned above (got it yesterday). So i use one rectifier board to drive both boards run in bridged mode...correct? So i will be using R0 and which IN/OUT do I use? Regards, Wayne

12th February 2010, 12:10 AM	#1007
Wavne diyAudio Member Join Date: Oct 2007 Location: Chatham ON	Sorry for these basic questions. Looking at the LM4780 bridged schematic from Nationals site. The input positive is split between the inputs and uses common signal ground. The output from each (3886) is put across the speaker, thus like you said no 'OG' ....correct? Which output goes to which lead on the speaker? Thanks for your help!

12th February 2010, 05:06 PM	#1009
Wavne diyAudio Member Join Date: Oct 2007 Location: Chatham ON	So, if I run it in stereo or parallel I can used unbalanced inputs? I know parallel is recommended for 4ohm speakers but can it be run this way with an 8ohm load? That was my only reason for using bridged mode is my speakers are 8ohms.

12th February 2010, 08:19 PM	#1010
littlerick diyAudio Member Join Date: Nov 2009 Location: Lincolnshire UK	Ok I know this is a long way back in the thread but the volume pot with 8 pins on the square pot. Are all pots of this type wired the same.. I have a ALPS pot i got from a dead amp rated at 60k x 2. Would it be wired the same?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

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