You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
KG CFA3 headphone amp
- Thread starter RudeWolf
- Start date
Elysian
1000+ Head-Fier
- Joined
- Aug 14, 2011
- Posts
- 1,234
- Likes
- 74
I am super excited about this CFA3 build
It's been a long time since anything in audio has gotten my attention.
Big thank you to @Dukei for being an amazing source of information. He's helping me through a lot of the questions I've had while reading up on amplifier design.
I am a bit curious about the difference between the Toshiba and Linear inputs re @paradoxper's comment on mids, but probably a moot point given the lack of easy access to matched Toshiba JFETs.

Big thank you to @Dukei for being an amazing source of information. He's helping me through a lot of the questions I've had while reading up on amplifier design.
I am a bit curious about the difference between the Toshiba and Linear inputs re @paradoxper's comment on mids, but probably a moot point given the lack of easy access to matched Toshiba JFETs.
This looks fantastic! Subbing in hopes that someone makes a manual... or step by step guide on how to build one of these... and a BOM...
paradoxper
Headphoneus Supremus
Go look on HC for an overview. You could also send a PM for the BOM -- unsure of a step-by-step "guide" per se. @kevin gilmore, however, is more than gracious with his time and energy should you seek help.
Thanks! Making my way through the thread atm. Once I am done I will reach out to him and see if hes willing to help out. Thread is a bit difficult for someone like me who really has no electrical background and is used to having a manual. Shall see how it pans out!Go look on HC for an overview. You could also send a PM for the BOM -- unsure of a step-by-step "guide" per se. @kevin gilmore, however, is more than gracious with his time and energy should you seek help.
K3cT
Headphoneus Supremus
- Joined
- Apr 1, 2007
- Posts
- 2,723
- Likes
- 350
I'm late. Perhaps the CFA-3 would offer a good contrast over the Beta22 and Dynahi?
paradoxper
Headphoneus Supremus
Over the Beta22, yes. Over a Dynahi. Depends on the version. I also think you should consider what design parameters of CFA vs Dynahi. For planar drive, the CFA is pretty special.
If you're only using, say, an HD800, sure, still build the CFA with SuSy switch.
If you're only using, say, an HD800, sure, still build the CFA with SuSy switch.
MASantos
Headphoneus Supremus
- Joined
- Dec 21, 2004
- Posts
- 2,436
- Likes
- 38
I can say I have the CFA2 (single ended only) and the dynalo mini (pretty much a DIY GS-X ) and prefered the CFA2 for HD650. I haven't tried other headphones but based on reports many people prefer it over the Dyna series of amplifiers.
Progress is going slowly mainly because of the slow shipping/handling in EU. GRLV and amp boards are done. Next up is to case it.

RudeWolf
100+ Head-Fier
- Joined
- May 29, 2011
- Posts
- 448
- Likes
- 191
Cool! Any of the builds using Toshiba JFETs?
Will be using the Linear systems JFETs LSJ74 and LSK170.
paradoxper
Headphoneus Supremus
PASS vs Gilmore?
I drank both koolaid.
This will be a bit more succinct as their strengths/weakness are balanced.
To start, the Pass is a behemoth and is severe absurdity for headphone drive.
There is an apparent warmth that is inoffensive and welcomes long listens.
Bass feels effortlessly extended, lacking full punch-feel?
Nothing across the spectrum really sticks out.
The mids feel a bit more liquid without really drawing much attention in a commission of way.
The treble is the best I've heard; well extended and extremely smooth.
Vocals sound especially, uh, intoxicating. This reminds me of the DIY T2 TBH.
The CFA conversely flat out sounds more dynamic in punch and excitement.
Bass has more energy behind it making the Pass almost feel underpowered (WHAT.) Yup.
The CFA is clearly the more clean/pristine sounding amplifier with more focus on active engagement.
At times, I feel the Pass better retrieves low-level detail and other times I feel the Pass sounds smeary
compared to the CFA.
I'm perplexed by the Pass nature as it sounds both, let's say, congested (but not actually)
and effortlessly open.
I would love if Kevin could run some numbers on what the CFA can output. With gain, however,
the conversation becomes downright confusing as there are no real standards.
The CFA feels like it throws around its muscle much more readily.
I don't believe either amp will be going anywhere.
The Pass Gilmore Cult Long Lives!

I drank both koolaid.
This will be a bit more succinct as their strengths/weakness are balanced.
To start, the Pass is a behemoth and is severe absurdity for headphone drive.
There is an apparent warmth that is inoffensive and welcomes long listens.
Bass feels effortlessly extended, lacking full punch-feel?
Nothing across the spectrum really sticks out.
The mids feel a bit more liquid without really drawing much attention in a commission of way.
The treble is the best I've heard; well extended and extremely smooth.
Vocals sound especially, uh, intoxicating. This reminds me of the DIY T2 TBH.
The CFA conversely flat out sounds more dynamic in punch and excitement.
Bass has more energy behind it making the Pass almost feel underpowered (WHAT.) Yup.
The CFA is clearly the more clean/pristine sounding amplifier with more focus on active engagement.
At times, I feel the Pass better retrieves low-level detail and other times I feel the Pass sounds smeary
compared to the CFA.
I'm perplexed by the Pass nature as it sounds both, let's say, congested (but not actually)
and effortlessly open.
I would love if Kevin could run some numbers on what the CFA can output. With gain, however,
the conversation becomes downright confusing as there are no real standards.
The CFA feels like it throws around its muscle much more readily.
I don't believe either amp will be going anywhere.
The Pass Gilmore Cult Long Lives!

Last edited:
Ethereal Sound
500+ Head-Fier
That pass amp is a monster. How heavy is that thing?
paradoxper
Headphoneus Supremus
I believe I read around 70lbs. It unnecessarily feels so.That pass amp is a monster. How heavy is that thing?
RudeWolf
100+ Head-Fier
- Joined
- May 29, 2011
- Posts
- 448
- Likes
- 191
Ha, the CFA3 walks over the Pass amp in portability.
Users who are viewing this thread
Total: 8 (members: 5, guests: 3)