SRPP headphoneamp with E88CC

[Mr. Triatic]

Hi guys!
what do you think about this design?
i only approximated the values so i will need some input from you..
it's intended to drive 32 ohm cans..

[fdegrove]

Hi,

what do you think about this design?

Errrrrrrrrrrr.....That there isn't much left to call it SRPP?

Cheers,

[Sch3mat1c]

Yeah... you'd be a bit LOT better off seperating the first stage and using the remaining three sections as a CF...

Of course, just one section as CF would be enough for most listening in 32 ohms, but I digress.

Tim

[Yvesm]

Or, 2 sections in each side, in order have quite equal pull up and pull down capability ?

How many sections would be necessary to drive an 8 ohms load at, uuuh, 1 Watt ?

But I disgress too

[Sch3mat1c]

Originally posted by Yvesm
How many sections would be necessary to drive an 8 ohms load at, uuuh, 1 Watt ?

Just one, if you have a 10k 1W OPT.

Tim

[fscarpa58]

Hi Triatic,

Exchange the 330u and the 100u.
You'll have a better performance at low freqs.

Which max amplitude (peak to peak)
is expected from that circuit ?

Federico

[Geek]

I've made one of those before settling on other tubes

Lose the 4k7 to ground, up the B+ to 250V and add one more capacitor across the output caps, a 0.1 to 0.47uF poly.

If you get distortion at too low levels, add 68R in series with the phones.

Then yer shmokin'

[Mr. Triatic]

thanks for your replies guys!
..SRPP...well maybe i should call the circuit SEPP instead?

-> fscarpa58
do you really 100uf at the output is sufficient, i'd rather raise the value to 680uF than lower it to 100uF, as far as i recall the higher capacitance the lower will the -3dB point be..?!
(though not extremely low..)

->geek
and what is your opinion about the sound of circuits like this? could i get away with a total of only three triodes?

->Sch3mat1c
well... my thought was to do something different from the usual cathodefollower.. 8-)

-is it realistic to think that the output would swing about 1,5-2V p-p?

-my intention is to try this kind of topology and, of course, later on cannabilise
it for parts (like most of my projects..) if this project doesn't perform well enough.. *lol*

[Geek]

Originally posted by Mr. Triatic
->geek
and what is your opinion about the sound of circuits like this? could i get away with a total of only three triodes?

My opinion is....I never want to hear sound any other way again

You could if you have sensitive enough headphones. Build the circuit on a breadboard and give it a try. Is the sound to your liking? Is the volume enough? If yes, you have a winner

If the sound isn't OK, try different tubes (Paralleled 6N1P are pretty good too ). If the sound is OK, but not the volume, use more tubes.

[fdegrove]

Hi,

..SRPP...well maybe i should call the circuit SEPP instead?

Neither.
BTW, the top triodes aren't biased properly either, PSRR is virtually nonexistant too.

May I suggest a SRPP stage followed by a WCF a la John Broskie's Aikido circuit?

With a decent PS and a volume control on the input it could double as a superb little preamp as well.
It would do nicely with all the gain AND drive for any headphone, even the lowest input impedance and silliest interconnect capacitance could be driven from that, hands down.

Cheers,