Bridged option for 2x F4 MonoBlock's ???
Hi all, i am in for listning to my F4 right away. So i have this quistion :
If i bridge the F4, what will actually happend ? lower distortion, and nothing more, ofcause the capacity of currency will double, but voltagesving stays the same ? I will stay at the same listning level right ?.
I simply can't understand why the distortion will be lowered, could someone explain ?
I will just short the input and output and give it a try later, but i like to know what happens CAN SOMETHING go wrong here ???
...
Jesper.
Hi all, i am in for listning to my F4 right away. So i have this quistion :
If i bridge the F4, what will actually happend ? lower distortion, and nothing more, ofcause the capacity of currency will double, but voltagesving stays the same ? I will stay at the same listning level right ?.
I simply can't understand why the distortion will be lowered, could someone explain ?
I will just short the input and output and give it a try later, but i like to know what happens CAN SOMETHING go wrong here ???
...Jesper.
Attachments
When bridging you must drive one F4 with an inverted signal related to the other F4, e.g. any balanced preamp does just that.
The load - that is, the loudspeaker - will be connected between "hot" on both F4s (normally the RED binding post).
The output transistor of each F4 will still have the same current capacity. No increase in current capacity. But as the two F4s swing in different direction, the output voltage is doubled.
So the "U" in that formula P=U^2/2R is doubled.
If you do not have a balanced output preamplifier you can use
1. an audio transformer
2. an op amp configured in the inverting configuration
Regds
Rolv-Karsten
The load - that is, the loudspeaker - will be connected between "hot" on both F4s (normally the RED binding post).
The output transistor of each F4 will still have the same current capacity. No increase in current capacity. But as the two F4s swing in different direction, the output voltage is doubled.
So the "U" in that formula P=U^2/2R is doubled.
If you do not have a balanced output preamplifier you can use
1. an audio transformer
2. an op amp configured in the inverting configuration
Regds
Rolv-Karsten
lykkedk said:
I guess the setup you are refering to is to simply run the two channels of each "box" in parallel as monoblocks. With that you'll most likely get the ability to drive lower impedance, but besides that I doubt you'll get much improvement. I guess you can get better performance in this aspect simply by turning up the current (provideded you have sufficient heatsinking and psu capability).
Running the output stages of F4s in parallell is something completly different than balanced mode.
This will surely give more juice for difficult loads like old Quads (but NP said it sounded good on these already, or was that the F3?) Instead of parallelling F4s one could make a F4 with more output transistors, but of course there's a limit to that (driving their gates) which NP probably can inform us about.
If I was going the F4 route I would first listen carefuly if one plain F4 circuit per speaker would do. If more swing is needed I would bridge F4s. A >20 V swing balanced preamp would then be needed. Look to www.passlabs.com or for DIY follow the Curl BlowTorch thread or look to Erno (www.borbelyaudio.com).
RK
This will surely give more juice for difficult loads like old Quads (but NP said it sounded good on these already, or was that the F3?) Instead of parallelling F4s one could make a F4 with more output transistors, but of course there's a limit to that (driving their gates) which NP probably can inform us about.
If I was going the F4 route I would first listen carefuly if one plain F4 circuit per speaker would do. If more swing is needed I would bridge F4s. A >20 V swing balanced preamp would then be needed. Look to www.passlabs.com or for DIY follow the Curl BlowTorch thread or look to Erno (www.borbelyaudio.com).
RK
Hey... CViller... having a good time out there ?
Well, that was my bellive too, I guess i will have to wait to get more out off them, until i have made some balanced out of whatever pre it might be Good then, the sound is amazing anyway. This is my first class A project till now, and i am really glad with the sound. What 'really' suprised me, was that there is absolutely no hum at all, not even from my pearl-phonostage (i used to have a little hum here)... Well it has been very excitited to make them... I guess the weekend will be in for hour's of listning !!!
Jesper.
Well, that was my bellive too, I guess i will have to wait to get more out off them, until i have made some balanced out of whatever pre it might be
Good then, the sound is amazing anyway. This is my first class A project till now, and i am really glad with the sound. What 'really' suprised me, was that there is absolutely no hum at all, not even from my pearl-phonostage (i used to have a little hum here)... Well it has been very excitited to make them... I guess the weekend will be in for hour's of listning !!!Jesper.
jacco vermeulen said:
Yes, I do, or else I would not have proposed it
That infinite BlowTorch (BT) reverse engineering thread has revealed it has balanced outputs and runs off cirka +/- 24 Volt rails.
So me thinks the hot pin on ts XLR output swings to almost +24 Volts while the cold XLR pin swings down to -24 Volts simultaneously, so between hot and cold more than 40 Volts of undistorted music appears!!!
Remember the hot pin of the XLR is connected to one F4 input and the cold one to the other F4 input. So these swings between the 24 Volts rails of the BT. The F4 runs off 22 Volt rails, so this should be a nice fit. The BT should possibly be able to even overload the F4.
So put the BT and the F4 in the same chassis boyz, and get the worlds best integrated amp!
RK
lykkedk said:
Have a look here http://www.lundahl.se/pdfs/datash/5402.pdf
The Lundahl LL5402 is intended for unbalanced drive, e.g. a single opamp as shown, or probably more or less any decent preamplifier. But read carefully through the data sheet.
Attachments
R-K Rønningstad said:
Yes, I do, or else I would not have proposed it
That infinite BlowTorch (BT) reverse engineering thread has revealed it has balanced outputs and runs off cirka +/- 24 Volt rails.
So me thinks the hot pin on ts XLR output swings to almost +24 Volts while the cold XLR pin swings down to -24 Volts simultaneously, so between hot and cold more than 40 Volts of undistorted music appears!!!
Remember the hot pin of the XLR is connected to one F4 input and the cold one to the other F4 input. So these swings between the 24 Volts rails of the BT. The F4 runs off 22 Volt rails, so this should be a nice fit. The BT should possibly be able to even overload the F4.
So put the BT and the F4 in the same chassis boyz, and get the worlds best integrated amp!
RK
naah......
is better
(anyway- who needs that UGSish (Pass's)/BT/Borbely simplicity ?
Re: Variac,
what a question!!??
of course- where da is.........
http://www.diyaudio.com/forums/showthread.php?s=&threadid=106844
chrismercurio said:
what a question!!??
of course- where da
is.........http://www.diyaudio.com/forums/showthread.php?s=&threadid=106844
Chris,
It is now at Ft. Mason, in San Francisco, right on the bay.. right where Robot Wars and other tech-geek events happen-but off to the side in a separate building.
Unfortunately, it will cost a lot to rent , so we would appreciate people contacting AR2 and telling him that you will make it. AND please get like minded friends to attend..and sign up..
Magura will be coming in person!!
Zen Mod by proxy -he's sending a Pumpkin preamp.
SY is finishing his tube preamp with balanced outs for the F4
I'm desperately working on my pair of F4's
So it's going to be an F4 Fest!!! In fact, we may need more..
Variac
It is now at Ft. Mason, in San Francisco, right on the bay.. right where Robot Wars and other tech-geek events happen-but off to the side in a separate building.
Unfortunately, it will cost a lot to rent , so we would appreciate people contacting AR2 and telling him that you will make it. AND please get like minded friends to attend..and sign up..
Magura will be coming in person!!
Zen Mod by proxy -he's sending a Pumpkin preamp.
SY is finishing his tube preamp with balanced outs for the F4
I'm desperately working on my pair of F4's
So it's going to be an F4 Fest!!! In fact, we may need more..
Variac