F4 power amplifier

Jump to Latest
F

flocchini

Member
Joined 2004
With my balanced F4 headphone amp could I use Jack Ellianos PVA2-N from Electra Print (Electra-Print.com PVA Passive Audio Pre-Amplifier) as my input transformer? I would wire XLR pins 2 and 3 to the xformer inputs and xformer out to the + and - F4 boards

I would then have CD - Transformer - Balanced F4 headphone amp _ headphones

Thanks
 
flg

flg

Member
Joined 2005
Maybe this is interesting? :D
 

Attachments

  • lundahl Hybrid circ.jpg
    lundahl Hybrid circ.jpg
    119 KB · Views: 494
Zen Mod

Zen Mod

Official Court Jester
Joined 2003
zenmod.in.rs/
Paid Member
flocchini said:
With my balanced F4 headphone amp could I use Jack Ellianos PVA2-N from Electra Print (Electra-Print.com PVA Passive Audio Pre-Amplifier) as my input transformer? I would wire XLR pins 2 and 3 to the xformer inputs and xformer out to the + and - F4 boards

I would then have CD - Transformer - Balanced F4 headphone amp _ headphones

Thanks
Click to expand...

link to xformer data ?


flg said:
Maybe this is interesting? :D
Click to expand...


it is , generally
 
Zen Mod

Zen Mod

Official Court Jester
Joined 2003
zenmod.in.rs/
Paid Member
flocchini said:
Zen Mod said:
link to xformer data ?


Electra-Print.com PVA Passive Audio Pre-Amplifier
Electra-Print.com Special Use Transformers

Sorry
Click to expand...


no need to sorry

anyway - try to find some xformer with 1:1+1 ratio ,where primary impedance is marked for line level duty ( loading in range of 10K)

dual secondary (or one , center tapped ) is necessity , to have phase splitting function of xformer

tip - for better behavior in freq. domain , you can wire xformer as aoutoformer ....... in other words - as center tapped choke with multiple taps

dunno ..... on your side of Big Splash which xformers you can try

so - there is possible candidate , as example :
http://www.lundahl.se/pdf/1592.pdf

look at "Phase splitting 1:1+1 input " connection picture ; it's interesting for unbalanced to balanced conversion

in your case , as you already have balanced source , you can use it as 1+1 : 1+1 , where both primary and secondary center taps must be grounded , for perfect balanced function


conclusion - you can't use electra print , because of lack of dual secondaries ......... and low impedance primary
Click to expand...
 
Last edited:
R

regal

Member
Joined 2004
flocchini said:
I have been listening to my balanced F4 driven by Pass X10 and fed by my Mc through a Buffalo II for about 3 weeks now. Running with 300mA bias at 15V.

I have to say this setup is absolutely superb with my HiFi Man 500s and with modded Denon 2000s, The bass is low and tight. There is very nice detail and the female vocalists (Etta James, Eva Cassidy, Jacintha, Nora Jones ) sound incredible. Why did I wait so long to do this. Highly recommended.

Thanks Choky and all who contributed to this thread/project.

I wonder what it would sound like with a MAGMA front end :D

Best

Bob
Click to expand...

I have a pair of Hifiman HE-HLE (I think the sucessor to the HE-500), been following this thread as they need an unusual amount of power (~1=2W) for headphones.

I really think you will have a big improvement with a gain stage, no mater how big your F4 without at least a 6Vrms voltage swing these phones can sound better, at least for music with a bigger dynamic range.

Does the Magma include a VAS (or other gain) ?
 
R

regal

Member
Joined 2004
Yes for the hifimans the lundhal 1+1:1+1 won't give the gain. A 1+1:1+1+1+1 may be a good compromise, just know from my experience with these ortho headphones perform best with 6Vrms swing headroom (measurements taken listening to my lowest level recording with the highest dynamics volume pot left in same position then running a 0dbs 1khz sine wave for measurement.) I've found typical recording listening level around 3-4rms (at 0dbs). Obviously most of the music content is lower but these thing want that headroom. They are rated at 87db/mW but I think at higher levels their efficiency drops. They are oddballs, but sound amazing and I've been considering the F4 buffer just for them (ethusiastic to see others thinking along the same lines.) Currently I am using a commercial hybrid + p-p mosfet output class A-B design.
 
Last edited:
F

flocchini

Member
Joined 2004
I have used a Aleph 30 with the HiFi Man 500s. Sounds extremely good.

In my opinion and I will continue to listen the balanced F4 driven by a Pass Xp -10 is right there with the Aleph 30.

I would like to try a Buffalo II with Volumite and Legato drive the F4 directly.

I am bit confused about transformers. Does the Lundahl 1592 have no voltage gain?
Would a Lundahl1674(1+1:4+4)http://www.lundahl.se/pdfs/datash/1674.pdf
have gain?

If someone could point me to a place to read more I will do my homework

Thanks

Bob
 
You must log in or register to reply here.
Top Bottom