TTVJ FET-A amp now shipping! - Head-Fi: Covering Headphones, Earphones and Portable Audio

Todd · #1 (**permalink**) 02-06-2009, 05:35 PM

HI All,

We are now shipping the TTVJ FET A amplifiers. They are going to be $649 for the first 10 and $729 for each thereafter. Order yours now and save.

The TTVJ Fet-A headphone amp is a slightly different take on the general-purpose desktop headphone amp. Instead of using opamps, it's circuitry consists of entirely single-ended, class-A discrete transistor circuitry. Precision, low-noise JFET transistors are used for voltage amplification, and power MOS transistors are used for the output stage. Bipolar transistors are used for biasing.

Since JFET transistors make very linear amplifiers, no overall feedback is used in the design - only local feedback around one stage to stabilize the gain. The result is excellent overload characteristics and unmeasurable high-order distortion products.

The single-ended power MOS output stage is DC-coupled to the headphones, providing low output impedance and a very flat frequency response. It is capable of driving any headphones, and can deliver up to 9V RMS into 100 ohms.

The result is a combination of the best characteristics of tube and solid-state circuits: very low noise, low distortion, wide frequency response, and low output impedance, along with the excellent overload response and, of course, excellent sound.

We look forward to hearing from you soon! Also look for a loaner program to appear here soon.

Todd

Voltron · #2 (**permalink**) 02-06-2009, 06:24 PM

Sweet! This design sounds great and I am really hoping the loaner amp gets to me before vacation week after next so I can spend some quality time with it!

Morph201 · #3 (**permalink**) 02-06-2009, 06:50 PM

Got any updated pics with the new case?

Todd · #4 (**permalink**) 02-07-2009, 06:41 PM

Hi Voltron,

Yes, one is on its way to you and will be used for the upcoming loaner program.

I will have new pics up n the site early next week. I think you will find it very nice.

Todd

recstar24 · #5 (**permalink**) 02-07-2009, 07:02 PM

Quote:

Originally Posted by Todd

Hi Voltron,

Yes, one is on its way to you and will be used for the upcoming loaner program.

I will have new pics up n the site early next week. I think you will find it very nice.

Todd

Todd and Al,

Remember who is next on the list for the upcoming loaner program

Ryan

Lamenthe · #6 (**permalink**) 02-07-2009, 08:14 PM

Can't wait to hear some impressions.

arrowmark · #7 (**permalink**) 02-07-2009, 09:00 PM

Todd, You told me I was third in line. Thank you, Arrowmark

Todd · #8 (**permalink**) 02-07-2009, 10:43 PM

HI recstar24 and arrowmark,

You two guys are the reason I have not yet put the loaner program into action. You are both in line for a listen and review. I look forward to your impressions.

Once it is in arrowmarks hands (3rd) I will be opening the loaner program up for 5 or 6 more auditions. Please wait until I post it in a separate thread before contacting me. Thanks.

Todd

Voltron · #9 (**permalink**) 02-11-2009, 06:46 PM

I just received the TTVJ FET-A and it looks and sounds great! I will try to post pics tonight or tomorrow, but I am already listening to it as a preamp and the initial impression is very favorable. The sound is detailed, rich and full in my desktop setup, and the background / idle state is completely quiet. I am taking the output from my HeadRoom Desktop Amp into the TTVJ FET-A, and then into my HeadRoom Desktop Power Amps, out the Harbeths and into my ears. Because the amp has about 1 hour of burn-in, this will be a good way to log some hours while at work. I don't have headphones in my office, but I will see if somebody has some or just check that out tonight.

Nice work Pete and Todd!

Voltron · #10 (**permalink**) 02-12-2009, 06:08 PM

Didn't have much time to listen with headphones last night, but I liked what I heard with the HD600s (Blue Dragon) and HF1s. Here are some pics for the time being:

chris_ah1 · #11 (**permalink**) 02-13-2009, 01:30 AM

does anyone have the specs for this unit? power output at 300ohm, output impedance and voltage swing? it does look very sweet - if only we could see the internals.

Brighten · #12 (**permalink**) 02-23-2009, 10:29 PM

Yes, I'd love to see some of the internals too. I love the "no op-amp" sign on the front of the amp.

Todd · #13 (**permalink**) 02-23-2009, 11:50 PM

HI All,

I will try to get a shot of a loaded board in a day or two.

Todd

Voltron · #14 (**permalink**) 02-24-2009, 09:54 AM

I have posted a review of the FET-A in the amp forum, but I guess I should paste it in here too. If that seems lame, Todd, just cut it and leave the link.