Sakuma inspired headphone amp

Andrew · Post by **Andrew** » Wed Jan 14, 2009 9:40 pm

Blummin 'eck. Sure beats my ideas of an Aikido using 6H30s, well at least it does on size.

Reminiscent of Stephen's (izzywizzy) 813 push pull amp I believe you had to walk around it to work on it

-- Andrew

Post by **Nick** » Wed Jan 14, 2009 10:22 pm

Interesting thing I have found tonight, connecting headphones the big problem was noise (white) not hum as I expected, and the source of noise seems to be the DC heater supply for the first 211. I have added a hum pot which lets me null it a bit, but it will need a better solution. So I need a heater supply that sounds good, and is quieter than a tent labs supply. (and does 10v @ 3.25A)

Andrew · Post by **Andrew** » Wed Jan 14, 2009 10:34 pm

So its broadband noise produced by the regs in the tent supply?

simon · Post by **simon** » Wed Jan 14, 2009 10:48 pm

Probably not related at all but I found when I was playing around with the Aikido headphone amp that listening with headphones I was a aware of all sorts of sound issues that I don't think I would have been with an amp used through speakers. There seems to be something very "dialled in" about headphones.

Post by **Nick** » Wed Jan 14, 2009 11:32 pm

Andrew wrote:So its broadband noise produced by the regs in the tent supply?

I can only assume so, it nulls in the same way as AC would.

Andrew · Post by **Andrew** » Wed Jan 14, 2009 11:41 pm

Have you 'scoped it? Will it filter out with a low pass filter? I tried a cap multiiplier of the LCR and I think it has improved things but that might screw up the Tent modules, I haven't studied the circuit on those things.

Just random late night thoughts....

-- Andrew

Post by **Nick** » Wed Jan 14, 2009 11:43 pm

Andrew wrote:Have you 'scoped it? Will it filter out with a low pass filter? I tried a cap multiiplier of the LCR and I think it has improved things but that might screw up the Tent modules, I haven't studied the circuit on those things.

Just random late night thoughts....

-- Andrew

I have been having similar thoughts. I was wondering about a choke or too as well.

Andrew · Post by **Andrew** » Wed Jan 14, 2009 11:49 pm

Did you mean a CLC supply and not use the Tent modules, or a ferrites to knock out the HF? Both came to my mind.

-- Andrew

Post by **Nick** » Thu Jan 15, 2009 7:51 am

Hmm, both also. I was also thinking aboiut a seres VR followed by a emmiter follower, then a choke in each lead.

andrew Ivimey · Post by **andrew Ivimey** » Thu Jan 15, 2009 8:16 am

Of course VR valves have their own tuppence of noise too, but tameable, surely!

Andrew · Post by **Andrew** » Thu Jan 15, 2009 9:24 am

andrew Ivimey wrote:Of course VR valves have their own tuppence of noise too, but tameable, surely!

I think Nick meant a series reg LM317 type thingy, but I'm not certain.

-- Andrew

Post by **Nick** » Thu Jan 15, 2009 9:25 am

My mistake I meand VR = voltage reg, I was thinking of a three pin reg, then the VBE to reduce noise.

andrew Ivimey · Post by **andrew Ivimey** » Thu Jan 15, 2009 9:29 am

yeah that might do it! I just like the flashy glow! - nb, I too have a pair of 866s glowing nicely in the wings!

audio-talk

Sakuma inspired headphone amp

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