[ccschua]

FRANKENZERO DAC with buffer added.

 

[Pricklely Peete]

Quote:

Originally Posted by ccschua /img/forum/go_quote.gif FRANKENZERO DAC with buffer added.

Cool CC.......how are the Nover caps coming along (burn in) ? In fact how is your unit's SQ shaping up now compared to stock ?

What type of buffer ? Diamond ?

Peete.

 

[espressogeek]

I finally broke down and bought a Zero. It sounds really nice as is to my ears. I'm going to try to address the low hanging fruit on the headphone amp. I didn't realize it uses 2 DUAL opamps. I wonder how they are configured exactly. I really want to either draw the schematic for this headphone amp out and try to figure out why it is the way it is. If I don't maybe I'll junk it and try to slip a PIMETA into the chassis.

I swamped out the op amps in the headphone section with opa2132 for the time being and I have a LME49710 in the DAC. I will probably try the opa 2227 in the headphone amp section and maybe I will try an HDAM in the filter. I am trying to keep this thing transportable so everything has to button up well for transport. As a result I dont see how squeezing in 3 HDAMs and a power support for the headphone amp will work, even though that is what i want to do if I retain the headphone amp.

 

[ccschua]

Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif Cool CC.......how are the Nover caps coming along (burn in) ? In fact how is your unit's SQ shaping up now compared to stock ? What type of buffer ? Diamond ? Peete.

The Franken mod is already a big league jump. The nover cap is there more neutral.

The Buffer in fact is from Kingwa which is BU2. That is a JFET and BJT in push pull class B. First impression is the sound is so dynamic and smoother sound. But I still need to improve on the DC offset on the output. Look at the flying wires.

Finally I got it done. I have found the culprit that causes the DC shift. Kingwa is right again that the RC networks provides the necessary bias to the JFET in order for it to sound right and the 100uF decoupling cap remove the osccilations that causes the DC offset.

 

[espressogeek]

Can someone recommend a good 75 ohm bnc receptacle that I can purchase from mouser or digikey? I like the neutriks at partsexpress but I wont want to pay 20 dollars for two of them shipped.

 

[ccschua]

Try Farnell. Canare or AMP should be good enough, or u can get from audio-gd too if u buy the OPA.

 

[espressogeek]

Thanks but I already have an order that I am placing with digikey so if I could find good one there that would be great. I might just give in and pay the shipping from partsexpress as I want to pick up some rca connectors too.

If I wanted to use "snap in" style capacitors, such as the Nichicon KG's, would they fit the board or will I have to mount them off board and air wire them? Any advice here is appreciated.

Finally, Has anyone considered replacing the power supply 337 and 1117 regulators with something from Paul Hynes? TNT has a pretty good article, http://www.tnt-audio.com/sorgenti/mo...su_mods_e.html on upgrading the Monica 2 DAC with these. I thought they might clean up the highest frequency noise better.

http://www.paulhynesdesign.com/page6.html

 

[Coreyk78]

If you want some decent prices on Neutrik bits, try going to Dale Pro Audio - Broadcast & Field Audio, Live Sound + Install, Recording & Professional Parts I ordered a bunch of rca jacks from them, and they also carry the D series jacks like the BNC one your looking for.

 

[espressogeek]

Thanks for the heads up Coreyk78!

 

[goorackerelite]

would it be blasphemy if I asked some one to perform this upgrade for me? of course I would reciprocate with monetary funds

 

[isao2k8]

I replaced 18 resistors around the DAC opamp with "Takman REY25" and "TamaElectric LF" known as one of the best-for-audiophile metal-film resistors in Japan. They gave more noticeable SQ improvement than I expected. Now sounds are more powerful and clean.

 

[espressogeek]

I have installed the Neutrik BNC in place of the factory supplied RCA plug. I am using a Blue Jeans cable to connect this to a HagUSB and it sounds wonderful! I will be installing my own version of the FrankenMod soon! I will be sure to post plenty of pics as well. Thanks for everyone's help!

 

[green0153]

I could contribute to this thread telling that i have done the Lampizator mod and the difference is huge.
I have used a different tube stage with great results.
My Stax and Koss headphones now have a huge 3d sound stage and i have never heard the sound so real behind and over my head.

 

[mattcalf]

Gawd I need to get a job so I can buy this and mod it!

Also could someone directly link me to the Lampizator mods.

 

[espressogeek]

My ultimate goal is either to do one of the two output sections on that site. I am glad you like it. Post some pics!

Quote:

Originally Posted by green0153 /img/forum/go_quote.gif I could contribute to this thread telling that i have done the Lampizator mod and the difference is huge. I have used a different tube stage with great results. My Stax and Koss headphones now have a huge 3d sound stage and i have never heard the sound so real behind and over my head.