CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS

Lobby => DIY => Topic started by: MisterRogers on July 11, 2015, 12:35:58 AM

Title: Hummingbird Verita Dual Mono AK 4495S XMOS
Post by: MisterRogers on July 11, 2015, 12:35:58 AM

Hey Mates,

We're finally ready to release the dual mono AK4485S DAC many of you heard at the Denver week a few weeks ago. This DAC is the result of a collaboration between JLSounds and myself, so I intend to make it available here in the states. I intend to price out a matching case for those who simply want to install components and begin enjoying one of the best DS DAC's I've ever heard.

I'll post some new photos soon, but I thought I'd get this up.

The final design took a little longer than anticipated - resulting in several stages:

First stage, the analogue circuit was designed for ‘through hole’ components.
Second stage, the analogue circuit was reworked for SMD components.
The idea was to compare both designs sonically. Many different listeners at different gatherings verified the SMD design to be as good, or better than the first stage through-hole design. Corrections or tweaks were identified during testing to insure the best possible sonic performance.
Third stage, apply these changes to our SMD board.

We’ve also designed a control LCD indicator board, along with the firmware needed to provide complete control of all DAC chip features.

Specifications

USB (XMOS based) input: up to 384kHz 32 bit, up to DSD128 AES/EBU up to 192kHz, 24 bit, S/PDIF up to 192kHz, 24 bit, Optical up to 192kHz, 24 bit

Outputs: RCA (Single Ended) & XLR (Balanced)
All available features of the DAC are accessible via indicator board / firmware
5 different sonic filters
DSD mode - volume bypass and normal path
5 different sound quality settings
Volume control
Phase inverting
De-emphasis

Realization

Two AK4495S DAC chips are used in a Dual Mono configuration
Discrete power supplies - one per channel
Pre-regulator / LDO for digital circuit
ADM7150 LDO is used for oscillators
NDK NZ2520SD oscillators, optionally Crystek CCHD 957’s can be used
All inputs are Galvanically Isolated
In the analogue circuit we’ve only used PPS Film capacitors, no ceramic ones. All signal path resistors are Susumu.
To power this board one will need three transformers: 2x22V and 1x12V.

Vitals

Dimensions: 230.18mm x 171.6mm

Misc.

https://translate.google.es/translate?hl=es&sl=bg&tl=en&u=http%3A%2F%2Fwww.myhifi.org%2Fкакво-слушахме%2F209-нещо-интересно-на-хоризонта (https://translate.google.es/translate?hl=es&sl=bg&tl=en&u=http%3A%2F%2Fwww.myhifi.org%2Fкакво-слушахме%2F209-нещо-интересно-на-хоризонта)
http://www.prettygoodsoftware.net/DIY/VeritasFlyer.pdf (http://www.prettygoodsoftware.net/DIY/VeritasFlyer.pdf)

Price for USB input board, DAC board and LCD indicator board: $600

Estimation for ready boards: late August 2015.
All signup’s on or before 7/31/15 receive free shipping.

(http://www.prettygoodsoftware.net/DIY/Hummingbird_stage_2_smd.jpg)

Title: Re: Hummingbird Verita Dual Mono AK 4495S XMOS
Post by: Hands on July 11, 2015, 03:03:51 AM

Looking forward to being able to really listen to this extensively and compare with other DACs!

Title: Re: Hummingbird Verita Dual Mono AK 4495S XMOS
Post by: Hroðulf on July 11, 2015, 08:51:07 AM

Didn'tchya hear? Delta Sigma is dead!

Patiently waiting for photos...

Also - are digital inputs reclocked in any way?

Title: Re: Hummingbird Verita Dual Mono AK 4495S XMOS
Post by: audiofrk on July 11, 2015, 02:50:05 PM

Interesting, what will the dimesions be?

I wanna post this in the cavalli dac options thread on head-fi.

Title: Re: Hummingbird Verita Dual Mono AK 4495S XMOS
Post by: MisterRogers on July 11, 2015, 02:55:58 PM

Just need to dig up my mechanical drawings - I'll post dimensions in a few. POSTED ABOVE.

Title: Re: Hummingbird Verita Dual Mono AK 4495S XMOS
Post by: OJneg on July 11, 2015, 04:52:56 PM

Looks snazzy. Details on output stage? I'm guessing OPA16xx?

Title: Re: Hummingbird Verita Dual Mono AK 4495S XMOS
Post by: MisterRogers on July 15, 2015, 12:05:54 PM

After each 4495S we're using the LME49724 for balanced out, and the LME49710 for SE out. When we stared our design cycle, the intent was to use discrete output. As we evolved / tuned the board, we were pretty amazed at how well these sounded. Very natural, dynamic & organic.

I'll be bringing a prototype to our upcoming mini-meet in the Boulder area; everyone there will get some extended listening.

Title: Re: Hummingbird Verita Dual Mono AK 4495S XMOS
Post by: MisterRogers on July 15, 2015, 12:10:02 PM

For those of you considering a build of this DAC, I also have a couple of custom made SUMR transformers that are specifically designed for this DAC. Just add a case, and you'll have one of the best DS DAC's I've ever heard.

For casing - that's often a personal preference. I am going to reach out to my case builder in Montana to see what his price would be for a small number of cases. He built the case my prototype's in, and did a stellar job. Casing can be expensive though, and he's a woodworker; not everyone's cup of tea.