New PassDIY Headphone Amp (now available)

[jameshillj]

Are the values of the 22uF caps critical, especially the one to ground on the -ve input of the IC?

Any benefit in using bigger/polyester type caps here?

 

[wayne]

No the cap values are not that critical. Mostly just values we stock.

 

[Tix88]

Hi guys,
I'm starting to mount the board, I have some questions
I am using red led 3.5mm, r9-r10-r13-r14 empty, c10-c8 220uf, r16-22-29-32 10ohm, so is it correct?

 

[wayne]

Yes that is correct.

 

[Russellc]

Swapped the AD823 with a Sparkos SS3602. Has turned out to be a really nice match with the rest of the parts. Voices are pleasant, mids are present without being harsh, the highs are crystal clear and soft to the ears. Definitely worth a listen. To my ears really makes all of Wayne's work shine.

Who is a recommended source for the Sparkos SS3602 devices? Quick search turned up Ebay, who absent a trusted seller I do not trust.

I take it they are quite a bit larger than the AD823 units? Any pics of how you wired them?

Russellc

 

[drpro]

Straight from Home - SparkoS Labs Inc. Russell. I will take apart my HPA tomorrow and snap a pic. Sparkos sends a DIP spacer so it fits nicely above the two caps on either end of the socket.

 

[Tix88]

Yes that is correct.

Thank you for the reply. What does it mean to use a 17.4V instead of 15V power supply?

 

[wayne]

Thank you for the reply. What does it mean to use a 17.4V instead of 15V power supply?

Not much difference a bit more power output but hardly matters for headphones. The heat goes up in the output stage and less heat in the regulators. I like the LEDs as power indicators.

 

[Tix88]

Hi
Here's my board almost complete.
I have used dale resistor ptf65 and rn60 & rn 65,for capacitors panasonic fc , nichicon fine gold, and Mundorf supreme evo oil, resistors are all 0.1%, matched led.
I'm waiting for 2sk / 2sj matched and then we can go to the test.
For the op-amp try OPA2228PA and OPA2132PA and maybe later discrete OPA

 

[Russellc]

Straight from Home - SparkoS Labs Inc. Russell. I will take apart my HPA tomorrow and snap a pic. Sparkos sends a DIP spacer so it fits nicely above the two caps on either end of the socket.

Great, thanks for the info, I need to finish mine up!

Russellc

 

[BDP]

Finished the headphone amp and after testing some of the kids headphones I thought I would give it a try on my Sonido fullrange speakers. It drivers them nicely, even with the low gain it played louder than I would ever listen.

BDP

 

[drpro]

Russell, finally got some photos of the Sparkos.

 

[blackdod]

I'm interested in the Sparkos. I have used OPA627 all this time with excellent results, but it would not be wrong to listen something else.

Please, Could you comment how they sound?

 

[meldano]

I tested both.
The soundstage of the sparkos was closer. Not fresh details like 627.
In my opinion the 627 sound much more better.

 

[blackdod]

I tested both.
The soundstage of the sparkos was closer. Not fresh details like 627.
In my opinion the 627 sound much more better.

Thanks Meldano!!!

I´m glad to hear from you

The problem is that overcoming the sound of 627 is very difficult IMO

I am also thinking of the Muse as an option.

 

[2 picoDumbs]

6L6

It would be nice if the circuit was added to the first post.

 

[jameshillj]

Actually, wouldn't it be good to have a circuit for a balanced version, and possibly with X-feed too - the 'THAT Corporation' chips work pretty well

 

[2 picoDumbs]

Actually, wouldn't it be good to have a circuit for a balanced version, and possibly with X-feed too - the 'THAT Corporation' chips work pretty well

Papa did a diagram like that for the gain clone chips.

 

[jameshillj]

I wonder where I could find that?

 

[2 picoDumbs]

I wonder where I could find that?

GC SuperSymmetry