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:

http://www.diyaudioblog.com/2011/02/bottlehead-crack-otl-headphone.html

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:

http://www.diyaudioblog.com/2011/05/modifying-mhdt-paradisea-nos-dac.html  

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. 

A List of My Favorite Parts Suppliers

So I tend to get a few emails here and there asking me where I find my parts for builds / cables / etc. so I decided that it would be worthwhile to come up with a small list that describes my favorites and what you can expect from them.

PartsConnexion (Boutique): If you have a laundry list of boutique parts to purchase, these guys will likely have the vast majority of what's on your list. The selection of film caps is especially impressive. The prices are typically MSRP, but you really can't beat the selection so you'll save $$ on shipping getting all your parts from one place. They do run sales from time to time; March's happened to be film caps at 15% off. PCX does a lot of business and the time between ordering and shipping is a little longer than some competitors, so be sure to allot a couple of extra days for your order.

PercyAudio (Boutique): Michael Percy has been offering boutique audio parts out of California for as long as I can remember. Selection isn't as vast as PartsConnexion, and it's lacking newer parts like Furutech and various film caps. Pricing is fairly competitive however. The way to order through Percy Audio is to tally up what you want from the Adobe PDF list and send him a payment.

Handmade (Boutique / General): Selection is further reduced compared to PartsConnexion and PercyAudio, but the prices are either on par or better than PercyAudio for what they have. Nice source for silver mica caps, Elna and Nichicon audiophile electrolytics, Cardas RCAs and binding posts. Shipping tends to be pretty quick.

Soniccraft (Boutique): Soniccraft's main attraction is their Sonicap line of capacitors. These are reasonably priced, nice sounding film capacitors that aren't overly large, so you can fit them into some designs that might not necessarily fit a big fat AmpOhm capacitor. They also carry a halfway decent selection of other boutique parts for MSRP and run sales from time to time.

Homegrown Audio (Boutique): Great selection of the companies own spades, bananas and RCAs in gold, silver and rhodium plate. This is actually my preferred source for them, they are well made and priced right. Homegrown also carries a variety of silver and copper wire and other cable building supplies.

Antique Electronics Supply (Vintage): Great selection of vintage-type electronics, good prices on tubes and accessories. If you're building a tube amplifier, you'll likely find some stuff you'll want here (ie: Hammond transformers, chassis, knobs, pilot lights, vintage caps, etc.) You'll also find guitar amp related paraphernalia.

Angela Instruments (Vintage): Great prices on Hammond chassis and transformers. Pretty similar to AES in that they have a number of vintage parts for tube amps. Customer service seems to be on par with other resellers.

Triode Electronics (Vintage): Similar to the above two, good place to check out if you are rebuilding a Dynaco. They have brand new chassis and replacement boards depending on your tastes.

Dynakit Parts (Vintage): Dynakit Parts has an awesome selection of everything you need to rebuild a Dynaco to stock specs. If you'd rather not mess with those new boards out there and want to listen as it was originally built, check these guys out.

RadioDaze (Vintage): Great little shop for vintage parts. I was able to locate some hard to find items here when restoring my Dynaco PAS. Nice prices on pretty much everything. If you like carbon comp resistors, they have great package prices. They are currently rebuilding the website, so if you don't see what you're after, give em a call or email. Customer service is excellent.

Mouser (General): If you've ever build an amplifier, chances are you used Mouser. They are a one stop shop for pretty much all the general parts (read non-boutique) you need. They also have Kiwame resistors branded as Koa Speers on the cheap (16-40 cents versus $1.10 elsewhere). Shipping is quick and fulfillment is accurate.

Digikey (General): Prices are generally a little higher than Mouser, but they tend to keep more capacitors in stock and the shipping isn't as expensive for small orders. Between Mouser and Digikey, you can usually handle most of your BoM (Bill of Materials). Like Mouser, shipping is quick and fulfillment is accurate.

Allied Electronics / Newark (General): Use these guys if you still can't find something between Mouser and Digikey ;)

I'll update this list once I find some more good suppliers.