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Crack;Bottlehead OTL - Page 308

post #4606 of 5557

Anything but lead-free (tin only) solder. That stuff doesn't melt.

post #4607 of 5557

Here's a good read on another reason why lead-free solder is bad. I found it really interesting. It's about "tin whiskers"

 

http://www.maximintegrated.com/app-notes/index.mvp/id/5250

 

 

 

Thanks for the input all :)


Edited by ridethespiral - 4/9/14 at 6:02pm
post #4608 of 5557

what do you guys think of crack vs project ember ? which is better? I can't find very much reviews on it.. 

post #4609 of 5557
Quote:
Originally Posted by atraf View Post
 

what do you guys think of crack vs project ember ? which is better? I can't find very much reviews on it.. 

They are completely different amps so there isn't much you can compare.  It honestly depends on what you are going to be powering.  

post #4610 of 5557
@ridethespiral, get at least a 40W iron. A 15W iron will only frustrate you. The terminals and components you deal with in these kits have much more mass and take a lot more energy to heat.
post #4611 of 5557

Hello everyone,

 

Just wanted to share my Crack build for those of you thinking about building or upgrading one... I myself was inspired by deltaunit (from the Bottlehead forum), HiGHFLYiN9 (from Head-Fi), and the design of the Decware CSP2 -- so my sincere thanks goes to all of them.

 

 

Here is my humble set-up: M-Audio 2496 -> GlowPower Zilence ICs -> Bottlehead Crack -> AKG K612

 

I

 

The sound: First of all, I'm in love with the AKG house sound: that open clarity in the mids and the spaciousness overall are traits I will never compromise. So, I wanted a tube amp to help with the K601's and K612's shortcomings: the modest bass and lack of weight. The Crack with my tweaks listed below really has kicked down the door between my music and my emotions, to the point where I really don't feel a need to upgrade anymore. The AKGs themselves are a bit cold and thin, but with my upgraded Crack, the sound transforms to a weighty, smooth, powerful, life-injecting experience. When listening to ( ) by Sigur Ros, the richness of tone and fluidity are hypnotic and seductive; the weight and air churn and tighten my insides so as to command me to take a deep breath. Without the amp, the sound is just sounds (incohesive and analytical) and doesn't feel like music is supposed to. My favorite piece is Nirvana's Unplugged in New York performance. It's raw, haunting, emotional, sincere and beautiful. Even at low volumes, Kurt Cobain's voice reaches deep into my soul, clenching it with an ironclad fist; during 'All Apologies', his vocals tear through the air unrestrainedly like a wolf howling in silhouette before a full moon as the cello, bass guitar, and drums act as the clouds, wind and shadows to round out this heavy yet enlightening atmosphere around my head. Notice my sentimentality and over-the-top descriptions? That's what it's all about. Before this, I just didn't feel the music. Point is: I hope you find or have a set-up that let's you gush like this too ;)

         

 

Tweaks: (ranked by most noticeable improvement in sound quality [n/a = indiscernible difference in sound quality])

 

* (2) Audio Note AN-100K pot $35

     - Not many people seem to talk about these pots (or even buy them); I can't find many opinions on them online. First thing you'll notice is the thick, caramel-like smoothness when rotating the knob -- it feels truly high class. Aurally, the biggest, and most appreciated, difference is that as you lower the volume slowly to the point of empty space, the sound is perfectly even on both speakers until it gets to that utter silence. Conversely, the stock pot tracks inferiorly, as one speaker will be louder than the other at these lower volumes.

 

* (n/a) Audio Note silver RCAs $20

     - Honestly, this is a comfort thing -- a nicety that adds class -- but not much else. Maybe there's an incremental increase in sound quality (I doubt it), but if there is, it's not easily noticed.

 

* (5) Nippon Chemi-Con KMH 470uF 250V power caps $7.99

     - Adds a bit of a cleaner, blacker background.

 

* (3) Roe Gold 1000uF 250V power cap $30

     - This upgrade gave a noticeable increase in power along with a blacker background. Also, the sound overall was less mechanical and more natural (smooth) sounding.

     - At first, duct tape held the power cap in place! But then I fashioned myself a holder using an extra plastic dinner-table placemat I had, and zip ties (see picture below). I cut into two strips of placemat holes the size, circumferentially, of the other two power caps, then I simply fit the strips on those two caps, sandwiching the large cap, and finally disallowing the strips to fall or move by blocking them with the zip ties. It works perfectly and fares much better with heat than duct tape!

 

 

* (2) Roe Gold 470uF 160V output caps $25

     - Here is my most obvious experience of "break in"... Upon first installing these caps the sound was thinner, more veiled, harsh, and less dynamic than the stock Pannys... literally everything I didn't want! After listening for much of the day, my conclusive thought was "Ughhh, I'll solder the Pannys back in tomorrow..." Meanwhile, I still needed my music. So, I fell asleep with my headphones on. Not so curiously, happiness tends to catch us off guard, and we're most off guard catching zZzZzZZZs. To the point, I woke up aware that the sound was clearly different. No placebo, no wishful-thinking (I'm skeptical and rational), I was simply aware that there were less of the bad traits than before. The sound was still lacking in bass and weight, but the harshness smoothed out and the dynamics puffed its chest out. I then realized I was in the middle of an experiment! So for the next few days, I allowed the caps to break in, playing music for hours and hours. The sound had thickened after these three days, and evolved closer towards my idea of audio bliss: bass was there in equal presence with the mids and highs, there was zero harshness but still had the welcome bite needed for music like punk rock, the thinness blossomed into weight and spaciousness, dynamics were powerful ...YAY! It really seemed like frozen maple syrup that needed some time to thaw in the sun before it could flow and express itself.

 

LESSON: give audio equipment some time before any frustration-motivated damnation(!), especially if they're decades old NOS parts like mine are ;]

 

P.S. My roommate's headphones (Dr. Dre Beats) have deeper bass with the 470uF Roes, but there is still some hum with these low impedance phones.

 

* (3) Mundorf M-CAP EVO 10uF 450V oil bypass cap [for Roe power cap] $19

     - Adds a noticeable improvement in terms of smoothness and naturalness.

    

* (n/a) QQQ phenolic + tin-plated phosphorus bronze tube sockets $9

     - Another nicety, though the ease of inputting and removing tubes and the tightness of the pins' contact to the sockets is the best I've experienced.

 

* (1) Tung-Sol 7236 power tube $100-ish (got mine for $35, keep eBay hunting!)

     - Yeah, the improvement is not small... headroom, dynamics, and bass weight all increase to eye-popping levels. With the Tung-Sol, low level listening is not only now an option, but a pleasure. If you can get one for <$50, then this is a no-brainer.

 

* (2) Mullard 12AU7 square-getter [K61 date code] $100-ish (got mine for $40 :P)

     - For me, the Mullard is perfect: weight, tone, an even presence from the bass to the highs; just really allows the sounds to grab me emotionally so I can simply enjoy my music.

     - To compare, the RCA clear top's sound is too bright with my K612s. The Sylvania 12AU7 grey plates is likewise too bright. The Brimar CV4003's sound is powerful and has a bit more weight and a lot more bass presence than the previous two, but the treble can make me cringe ...like chewing aluminum foil with a mouthful of fillings, EEEEEK! With the 1950's RCA black plates, the sound is smooth (no harshness whatsoever) but the sound lacks that bit of welcome bite I mentioned before needed to give me the chills and excitement ...whereas the Mullard focuses on this: producing goosebumps, releasing adrenaline and dopamine; this lets the music ignite an inner-revolution of self-awareness and clarity. Is that too dramatic again? Well, again, that's the power of music for you.

 

* (3) Signal Cable MagicPower power cord $67

     - Adds a noticeable improvement in terms of weight and bass presence, but still, this was a tough $67 to spend for me.

 

* (4) Kimber Kable TCSS 19AWG input wires <$5

     - A minor increase in smoothness and tone.

 

* (n/a) silver spikes (from eBay) $20

     - These are the screw-in type spikes. I went to Home Depot and found hammer-in threadings for the spikes, then glued small wood blocks for them ...and voila!

     - These are supposed to be noise-isolating, though I never had a problem with noise or vibrations -- so I don't really notice a difference. However, the amp is raised considerably higher compared to the stock rubber feet, so this should be better against heat build-up. And of course this is another classy nicety xD

 

 

Summary: As you can see, I don't like to spend more than $50 per upgrade. Every few weeks I bought one of these parts, improving my amp little by little at what I think of as a reasonable cost. This is why I didn't buy the Speedball upgrade ($125), though I keep hearing it's the biggest improvement that can be made to the Crack. So, I'll save a few months and hopefully place my order for the Speedball this summer. Lastly, maybe I'll re-cable my cans as the cherry on top later down the road. I want to stress that the Tung-Sol 7236 was the pivotal replacement so far, my reaction was the most drastic with that upgrade -- so, along with being the easiest part to change -- I'd advise you find the right tubes before doing any other upgrade. I am so happy with my music, and so proud to have built it. Good luck to any future builders.

 

Cheers music lovers,

 

larcenasb


Edited by larcenasb - 4/10/14 at 12:39am
post #4612 of 5557
The TS 7236 is my favourite power cap for the Crack. Clarity and tight, fast bass in spades.

Brilliant work and great impressions for those looking to upgrade.

If you like the 7236, you will love what Speedball does.
post #4613 of 5557

AH! I can't imagine the sound getting much better ...so I really am curious about the Speedball now. If and when I do get it, I'll be sure to update my post with my impressions. Thank you for the kind words. Take care and enjoy the music.

post #4614 of 5557
Quote:
Originally Posted by larcenasb View Post
 

Hello everyone,

 

Just wanted to share my Crack build for those of you thinking about building or upgrading one... I myself was inspired by deltaunit (from the Bottlehead forum), HiGHFLYiN9 (from Head-Fi), and the design of the Decware CSP2 -- so my sincere thanks goes to all of them.

 

 

I

 

 

larcenasb

 

Congrats a nice build and I like the white top it gives it a nice clean n fresh look and can clearly see the heritage from your inspiration coming through.


Edited by JamieMcC - 4/10/14 at 1:37am
post #4615 of 5557
Quote:
Originally Posted by Zashoomin View Post
 

They are completely different amps so there isn't much you can compare.  It honestly depends on what you are going to be powering.  

HD650 I also have an IEM gr07BE but I guess I will have to pass on that since it won't work with low impedance HP's (42ohm)

post #4616 of 5557
Thanks JamieMcC,

I just looked through your gallery of recent Crack pics... That all black/carbon fiber look is sleeeeek, especially with those dark glass tubes. What kind of tubes are those? If it's not too much trouble, could you state your favorite 12AU7s for the Crack? Have you tried the Mullard square getter (date code: k61)?

Happy listening,

larcenasb
post #4617 of 5557
Get Mullard E80CC you will never regret it
post #4618 of 5557
Have a look in the cables, accessories for sale thread wink.gif
post #4619 of 5557
Quote:
Originally Posted by larcenasb View Post

Thanks JamieMcC,

I just looked through your gallery of recent Crack pics... That all black/carbon fiber look is sleeeeek, especially with those dark glass tubes. What kind of tubes are those? If it's not too much trouble, could you state your favorite 12AU7s for the Crack? Have you tried the Mullard square getter (date code: k61)?

Happy listening,

larcenasb

 

Hi thanks for the kind comments details on the Crack Noir tubes here

 

http://bottlehead.com/smf/index.php/topic,6010.0.html

 

My build log

 

http://bottlehead.com/smf/index.php?topic=5284.msg50967#msg50967

 

My favourite 12au7's are the Mullards the standard ecc82 and the 4003 box-plates closely followed by the Tung-sol 12au7 black glass and the 1950's Tung sol 12au7 jtl. The E80cc is also a nice tube very much on par with the best of the 12au7/eec82 I have tried and a option if you have a speedball fitted.


Edited by JamieMcC - 4/11/14 at 2:16am
post #4620 of 5557

My postman dropped off a little brown package this morning inside a Tung-sol/Bendix 6080wb :atsmile: I had been curious to try a graphite tube for a while now.

 

 

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