zen vr7 stupid question !

TJ · 15th March 2004, 12:40 PM

hi, i like some expert can give me some answer for this questiions !! why the output voltage not stay at 0 volt ?in this circuit it stay at +20v ! how it work ?

hacknet · 15th March 2004, 12:59 PM

i guess thats because it is supposed to work in balanced mode. on idle, the both 20v are the same potentials and thus is safe for the driver.

stefanobilliani · 15th March 2004, 01:01 PM

It is just that the speaker does not see any voltage , and it is indifferent to it where the absolute voltage of the drains are ; the drain voltages just have to be equal .

TJ · 15th March 2004, 02:18 PM

i still confuse ! if we not talk about impedance, gain distortion ...etc ... that meant we can direct connect output to the speaker from a ... differential amplifier .... or phase splitter ! and i right ?

stefanobilliani · 15th March 2004, 02:37 PM

Quote:

Originally posted by TJ
why the output voltage not stay at 0 volt ?in this circuit it stay at +20v

No! The output is differential and stays at O volt.

Of course the +20 volts are not arbitrary , and set for best performance .

For your last question I think you are right.

TJ · 16th March 2004, 11:40 PM

thank ! i got another questions / eq tion i not sure right or wrong !! hope u guy help me solve !! im calculate the output transformer base on the voltage and output from the circuit zvr7T and im not sure is correct or not ............
From the circuit we know that 30v is the max audio voltage , since transformer waste power i decreace 10% on it . ~27v/1.414 = 19V rms . this circuit is design for 30w into 8 ohm then voltage =15.5v , turn ratio = 19/15.5 = 1.225 , primary Z = 8 * 1.225 = 9.8 . 9.8* 4 = 39.2 ohm !! so the transformer for this circuit will be ~ 40 ohm center tapped ? correct or not ?

Nelson Pass · 17th March 2004, 07:49 PM

Well, the transformer says 8 ohms on the four primary windings,
and 80,000 ohms on the secondary which gives 50 to 1 if you
series all the primaries to 32 ohms.

The amp does 30 volts rms into these in series, which produces
50 X this voltage, which is 1500 V RMS. The loss in the
transformer is very slight at mid band, as electrostatic panels
don't load it until the top octave or so.

In your calculation, you are assuming a 30V peak, but remember
that this circuit can swing quite a bit more than rail voltage.

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
Another stupid question!	Dxvideo	Chip Amps	7	20th May 2007 03:46 PM
ok, stupid question probably	the-eliti	Multi-Way	6	23rd January 2002 04:17 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

15th March 2004, 12:59 PM	#2
hacknet diyAudio Member Join Date: Nov 2002 Location: sg	i guess thats because it is supposed to work in balanced mode. on idle, the both 20v are the same potentials and thus is safe for the driver.

15th March 2004, 01:01 PM	#3
stefanobilliani diyAudio Member Join Date: Jun 2002 Location: Italy	It is just that the speaker does not see any voltage , and it is indifferent to it where the absolute voltage of the drains are ; the drain voltages just have to be equal .

15th March 2004, 02:18 PM	#4
TJ diyAudio Member Join Date: Sep 2001 Location: UK	i still confuse ! if we not talk about impedance, gain distortion ...etc ... that meant we can direct connect output to the speaker from a ... differential amplifier .... or phase splitter ! and i right ?

17th March 2004, 07:49 PM	#7
Nelson Pass The one and only Join Date: Mar 2001	Well, the transformer says 8 ohms on the four primary windings, and 80,000 ohms on the secondary which gives 50 to 1 if you series all the primaries to 32 ohms. The amp does 30 volts rms into these in series, which produces 50 X this voltage, which is 1500 V RMS. The loss in the transformer is very slight at mid band, as electrostatic panels don't load it until the top octave or so. In your calculation, you are assuming a 30V peak, but remember that this circuit can swing quite a bit more than rail voltage.

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