Damn that’s a good deal. All the one’s I’ve seen go for more than $500. I will need to keep an eye on Ebay
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This is the example, you can see a little ding in the frame on the rear corner, but other than that, everything looks very solidly built.
I actually have an upgraded ALPS pot in my possession. Is it worth it to start with that?
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Then again, there’s stuff like this. IMPRESSIVE. I may wind up going to “upgrade” route but I’ll do those myself.
Replacing the output caps made a pretty significant difference for me. I used Solen caps. Bass particularly improved in every way - extension, definition, impact. That mod along with replacing the factory attenuator and doing the Speedball will give you the most improvement.
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What’s a reputable go to source for parts? Would not be wanting to trust ebay for high end caps.
Digikey is often good for small quantities
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I’d do the speedball first then you can look at things like output caps and replacement pots.
All your really looking for in a Pot is no crackling when turning and channel matching, so it wouldn’t be high on my list things to change.
Generally Electrolytic caps are considered to be compromises, and a lot of the improvements you see in higher end amps are better Caps, and higher tolerance resistors.
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Parts Connexion in canada is pretty well regarded too
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get the power cord upgrade kit before speedball or upgrading caps. even bottlehead says makes the biggest sonic improvement. easy to build with a drill(or hand twisting but more time consuming).
edit: well maybe not before the speedball lol. but definitely before upgrading caps.
edit 2: and while i love my crack, once you get to a certain point in $$, your better off getting a better tube amp. and those large mundorf caps are pricey and start putting you into that point.
They actually say the power cord will make it sound better? I can understand potentially getting an improvement with a conditioner. But I’m skeptical about there being any real improvement with just the cord
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Here’s where I got the caps https://solen.ca/products/capacitors/fast-capacitors-250v-pa-series-metallized-polypropylene/solen-pa10000/
The standard pot upgrade is the Alps Blue which you can get from Digikey, Mouser and, a bunch of other places.
P.S.
Space in the Crack is limited so you can’t just go with any output cap. Gotta make sure it’s going to fit.
Thanks guys, this is going to be a nice little hands on project for me. I’m going to use it simply as a headphone amp for those times I can’t use my speakers in the living room. I won’t be looking to upgrade from this. (famous last words right?)
When I bought my Zu speakers, I sprung for the “clarity caps” it was a $100 dollar upgrade. Going by the link you shared @A_Jedi it wasn’t highway robbery.
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yes, right on the website. i got mine in a couple weeks ago, have not had a chance to build it yet. i forget the guys name that builds them. anyways he was the same. they had a bunch of extra wire from a mis-order. he decided to use some to create a power cord for the crack amp just expecting a better cord and no real benefit. to his surprise, it made the amp sound better.
from bottlehead website:
Serendipity The reason this power cord came about was that we accidentally ordered several thousand feet of 20 gauge stranded wire instead of solid core wire for hookup wire in our kits. The mistake wasn’t caught until after some wire had been cut from each spool, so we were stuck with it. PB suggested we try making a power cord with it. I realized that we would need to use a couple lengths of wire for each conductor in the cord or it would really only be good for very low current applications, so we came up with a cord using twisted pairs that are braided together. It makes for a very flexible cord. We built a couple cords and I figured that would be that, they wouldn’t make the system sound any different than stock. I simply had three big spools of wire that would end up sitting in the lab forever. But then this most unexpected and puzzling thing happened, this cord actually made our gear sound better than our stock cords.
We listened for about an hour the day we built the production protoype, comparing this new power cord to another prototype cord done with solid core rather than stranded wire, a sample of one of the upgrade power cords we previously sold, and one of the stock black molded cords we include with Bottlehead kits. We put one new cord on our prototype preamp, and then put another into my Tube Repro on my Nagra, and then swapped back and forth between the new cord and the other cords on both pieces of gear while listening to the same track. As I said, I expected to hear no difference and thus I have no explanation for this, but Shawn and I both thought the new power cord gave the music more bass clarity and depth, a sense of better image scale and depth, and less glare. Might be sort of a tone control effect, but it seems like there is more going on than just that. At any rate I can’t figure out why it would make a diff, but the difference is audible. Rather than trying to come up with some far fetched theory like most cable manufacturers I will simply state that I find that it makes our gear sound better than the stock power cord and leave it at that. So now I find myself saying shoot, it worked. Now we have to make up about 20 of them for my system…
edit: a review from the wesbite as well:
I had to leave a review for the power cord because simply put, this is the best upgrade I’ve made on a Bottlehead amp. With a stock Crack and Speedball this has surpassed all the upgrades I’ve made on it before, including high end caps, pot, and tube upgrades. To me the cord has made the biggest difference in sound quality, with more emphasis on the bass and a major increase in clarity. The music sounds amazingly life-like. I was skeptical as to how much improvement I would hear but I now can never go back to using a stock cable. This is just too good of a sound I am hearing. It was without a doubt worth every penny. Well done Bottlehead!
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Had my crack for 3 + years…upgrades were to chcnge our the pot for a genuine ALPS 27, only reason I had slight channel imbalance in the low end. you can get a PCN to solder the pot in and wire it into the circuit. The Alps pots are buttery smooth…no sonic change IMO. Got mine for about $15 or so I think parts connexion.
The only other cange was to add the diodes for noise suppression as indicated at the BH crack forum. NO sonic change IMO.
Great little amp. legandary with senns…the HD600’s are a magical pairing for sure.
Doc and Paul at BH the “guys” often state the circuit is more important than the upgrades lots of us put int this amp…and its really with speedball pretty much optimized…but hey its nice to muck around …part of the DIY spirit.
To me the speedball upgrade is really worth it…adding a constant current source for stability and accurate bass reproduction.
Enjoy the amp!
Alex
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Not a great believer in power cords in normal situations, the cord from the wall is the last 6 feet of 10,000’s of feet of copper running back to your local transformer, it would have to be truly terrible to make a difference.
That changes a lot IF your using a power regenerator, where it can have a significant effect on the impedance, but most of us aren’t running regenerators.
I do know people who swear power cables made a significant difference but they were running PS Audio regenerators.
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to each their own. i don’t want to replace caps or anything, and i figured for about 95$ after shipping, easy way to potentially improve the sound quality. and its right angle. that’s the biggest reason i got the kit. will be way less pressure on the ac jack then a traditional cord tugging on it. if it adds what people say, even better!
Unlike the discussion in the USB cable thread that’s active now, power is the one thing that would most likely vary in our setups. We live in different areas in buildings built in different eras in grids that feed different quality to our home and varying voltages.
I think what’s missed most in the power cable discussion is not the sable itself but the shielding. The specific twist and 99% shielding used in cabling does cut out errant EMF noise. If your line is not noisy to begin with, not much gained.
Not judging at all, I keep some $200 interconnects on my D10 just because they weren’t doing anything, and I find it amusing that the interconnects cost more than twice what the DAC did.
A 90 degree is a nice to have on the Crack.
Mine has the speedball, my pot sounds fine so I have no interest in replacing it, and I don’t really feel the need to start changing components.
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