May 20, 2011

The Latest Updates - Bottlehead and MHDT

Like an artist may say that a painting is never done, or the guys at PIXAR saying a movie is never finished, some of us electronics nuts feel like a project is never done. There is always another tweak, another piece to be added, substituted or upgraded. In the interest of keeping all information on a particular project in one place, I regularly go back and edit existing posts to include updates.


The first update to cover is the MHDT Constantine NOS DAC. When I was placing an order for some nicer caps in the MHDT Paradisea, I opted to get a few for the older Constantine as well, replacing the four 0.10uF stock caps with Obbligatos. A little bit of drilling of the soldering eyelets was required for the thick leads. Luckily, the Constantine board is one sided and I didn't have to worry about the conductive shells of the Obbligatos touching any traces. I did opt to add Teflon sleeving to the leads so that they wouldn't short across the shell though.


A few more of those beautiful gold Obbligatos for the Constantine
You can find the rest of the story here:
http://www.diyaudioblog.com/2011/02/modifying-mhdt-constantine-nos-dac.html




The second update covers a few additional modifications for the Bottlehead Crack headphone amplifier.  I managed to squeeze in a Solen 220uF film cap in the final electrolytic power cap location, sitting on a pair of standoffs. I also took the time to bypass the other two power caps with a pair of low-cost Audiophiler 2.2uF film caps. A Triad C7X was selected with a rating of 270ohms to take the place of the final resistor in the power supply (also 270 ohms). Since pretty much all the real estate has been used up on the plate, two 2" aluminum standoffs were used to raise the choke above the capacitor near the RCA inputs. This required adding 1" spiked feet to the bottom of the wood base for adequate clearance, just like in the Bottlehead S.E.X. build.  

Large Solen power cap and Triad choke
You can find the rest of the story here:




Finally, just a few days ago a MHDT Paradisea NOS DAC modification project was finished up. A variety of nice items were installed including Takman and Kiwame carbon film resistors along with Obbligato and Mundorf Silver Oil film capacitors. Next on the list for this mod is a Burr Brown op-amp to replace the stock Analog Devices one. 

Some creative mounting of the Mundorf Silve Oil Caps

You can see the whole story here:

Be sure to keep an eye out on other posts for new updates. I hope to be finishing up the Millett Jonokuchi headphone amplifier in the next few weeks, along with casing up a completed AMB Mini Cubed portable headphone amplifier. Of course it will be unique looking like my other projects ;)



The Fine Print:
Please remember that building circuits and performing circuit modifications can be dangerous to you and/or your surroundings and should only be performed by a certified technician. The owner of this blog and all associated parties can not / will not be held responsible if you attempt a modification posted below and cause physical harm to yourself or your surroundings. Many electronics contain high voltages that can kill, and mods, if performed improperly, can be a fire hazard. Please keep this in mind. 


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