TSSA - The Simplest Symmetrical Amplifier - Page 141

Salas · 4th December 2012, 09:54 PM

Quote:

Originally Posted by sonnya

No it is not. It works very well. My protoamp has run for months with this configuration.

No need to worry.

By using 50R you do not lose feedback. Distortion is the same. Damping factor is the same.

Being a CFB amp, only the 1K Rf position changes the current injection to the input node so the voltage gain division ratio does not modify crucial parameters? Is that a right way to sum it up?

sonnya · 4th December 2012, 10:03 PM

More or less.

Salas · 4th December 2012, 10:06 PM

OK, clear. Thanx.

Esperado · 4th December 2012, 10:09 PM

Quote:

Originally Posted by sonnya

Damping factor is the same.

How is-it possible, while feedback is divided by 2 ?

sonnya · 4th December 2012, 10:19 PM

i will write up on this one tomorrow Cristophe.

R11 and C12 sets the bandwidth and R11 and R12 is an "emitter" resistor at lower frequencies.

By set emitter to 50R instead of 100R we raise the open loop gain by +6dB but at the same time we increases the closedloop gain by +6dB. => loopgain is untouched.

vgeorge · 6th January 2013, 09:08 AM

Hi Sonny,

one question, can we increase input impedance and if if yes, up to what value? Are there going to be any drawbacks to this?
If possible, it is going to be very helpful to my setup.

mikelm · 6th January 2013, 10:59 AM

Quote:

Originally Posted by sonnya

i will write up on this one tomorrow Cristophe . . .

Tomorrow never came

sonnya · 6th January 2013, 11:11 AM

Quote:

Originally Posted by mikelm

Tomorrow never came

Sorry.. We have just been to busy.

We work 7 days a week. Have hired an engineer and an assembly lady. Will maybe need a Technician also.....

sonnya · 6th January 2013, 11:13 AM

Quote:

Originally Posted by vgeorge

Hi Sonny,

one question, can we increase input impedance and if if yes, up to what value? Are there going to be any drawbacks to this?
If possible, it is going to be very helpful to my setup.

You could change R1 to 22 - 100K only there will be a offset step when you connect/unconnect you source.

vgeorge · 6th January 2013, 11:52 AM

Quote:

Originally Posted by sonnya

You could change R1 to 22 - 100K only there will be a offset step when you connect/unconnect you source.

That means no problem, as I never connect/unconnect live my sources.
Thanks Sonny.

6th January 2013, 09:08 AM	#1406
vgeorge diyAudio Member Join Date: Mar 2004 Location: poros island	Hi Sonny, one question, can we increase input impedance and if if yes, up to what value? Are there going to be any drawbacks to this? If possible, it is going to be very helpful to my setup. __________________ "Without deviations from the norm, progress is not possible" - Frank Zappa

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
simplest amplifier possible with BJT's?	rmgvs	Solid State	123	10th July 2008 03:05 AM
Symmetrical Phono Amplifier	seroxatmad	Solid State	3	6th August 2007 04:00 PM
Simplest class B Amplifier	PicancoNet	Solid State	42	8th June 2005 02:55 PM
Symmetrical amplifier conundrum	Kilentra	Solid State	22	31st January 2003 05:06 AM
Symmetrical 400W amplifier	Diogo	Solid State	30	28th October 2002 11:00 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


	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

4th December 2012, 10:03 PM	#1402
sonnya diyAudio Member Join Date: Oct 2001 Location: Denmark	More or less.

4th December 2012, 10:06 PM	#1403
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	OK, clear. Thanx.

4th December 2012, 10:19 PM	#1405
sonnya diyAudio Member Join Date: Oct 2001 Location: Denmark	i will write up on this one tomorrow Cristophe. R11 and C12 sets the bandwidth and R11 and R12 is an "emitter" resistor at lower frequencies. By set emitter to 50R instead of 100R we raise the open loop gain by +6dB but at the same time we increases the closedloop gain by +6dB. => loopgain is untouched.