Bottlehead Crack

Anyone else find the crack (with speedball) has way to much gain? Using my hd650k, I keep it at 7 o'clock, maybe 8, 6 o'clock being silent/off.

Seems pretty good though, but not enough of an upgrade from my Valhalla to warent buying one, and too large, and too difficult to transport.

 

I believe there's a thread on the BottleHead forum about this. Adding inline resistors was the recommendation.

 

Get an Alps pot (~$10 on eBay). Something like this:
https://www.ebay.com/itm/Japan-ALPS...tiometer-Dual-100K-Slotted-Shaft/320816794126
I've used this one, and it works much better then the stock pot, specifically for the gain issue.

A little difficult to solder, but not impossible.

I got this one, with lugs. I haven't tried it yet, but it looks easier to solder.
https://www.ebay.com/itm/PC-1-ALPS-...tenuator-Stereo-RK27-100KA-100KA/272849485455

 

I'd be careful with ordering an ALPS pot on eBay, especially from China. I've read that there are tons of fakes out there, and based on the appearance, it may be difficult to tell if it's genuine. I think that they're pretty reasonable on Mouser and Parts Express, at least they were the last time that I checked.

 

I just have the loaner so...
But it's size and 2 pieces-ness make it a no go for me. Also, it just doesn't seem like a worthy upgrade from Valhalla.

 

Non-working crack on head-fi for $190. Bet the dude will take less. Probably not hard to fix. Good deal

https://www.head-fi.org/threads/none-working-bottlehead-crack-w-speedball.866614/

 

Sold already.

 

Actually curious to what he may have screwed up.

 

That is lovely. Feel free to post it to me when you tire of it

 

That's a good deal indeed.

 

The arrival of my HD6XX's motivated me to build my Crack. I was thinking about getting the plate powdercoated, and spending some time on the base... but in the end decided to just build it and make a pretty base later (perhaps one that matches the faux wood on the Marantz).




My DAC/Amp is a Marantz HD-DAC1. Signal path is:
Tidal -> Chromecast Audio -> HD-DAC1 "fixed" line outs -> Crack -> HD6XX

After comparing Crack to the headphone out of the HD-DAC1 (by simply moving the cable back and forth), I'm finding the Crack a bit underwhelming. Note that I have not yet added the Speedball.

Forgive my terminology, I'm new at this headphone thing...

I find it more difficult to track the bass guitar - things are a bit congested with a lot less detail. I understand the Speedball will clear this up specifically.

The Crack is definitely warmer, but there's also less detail in the mids. It's like my ears are hearing less, but louder, with the Crack.

All in all, the HD-DAC1 is just a lot more engaging, and not in a tiring way. When switching from Crack to HD-DAC1, it's like I'm taking cottonballs out of my ears or something. Everything just jumps out at me on the HD-DAC1, I find myself getting into the song rather than listening for the things I want to compare.

Primary comparison song is "Hey Floyd" by Jamiroquai. As the song picks up, the instruments continue layering. All are clear and identifiable on the HD-DAC1, and the big orchestral chorus intro just sounds fat and wide and amazing. On the Crack, it sounds more like a wall of noise.

So my questions are:

-How much will break-in help the Crack? I have about 2hrs on it now.
-How much will speedball help the Crack for overall sound quality (that is - not just "tighter bass" as is often described)
-How much would better tubes help?
-I don't have experience with, well, any other DACs or AMPs. I know the HD-DAC1 isn't common, but reviews are glowing where you can find them - so is it just unreasonable for me to think that a ~$400 crack will sound as good as the amp in a ~$1100USD DAC/AMP unit?

Thanks in advance for any tips/advice/criticisms

 

Speedball makes a big difference, especially with the “wall of noise”. Speedball, choke, and output capacitors were significant mods for my crack. It’s been a long time since I listened to a crack though, especially a stock one. Clean and tight bass isn’t one of the crack’s strengths

Tubes make a difference, but don’t waste money tube rolling if you have major issues with how the amp sounds

 

I'm not much of a believer in break-in, but I know others are.

Speedball will definitely make a significant difference. If you're on the fence at that point, a choke is worth trying. If you now like it, but are wondering if it could be better, capacitors and tube rolling are worth trying.

So I'm mostly in agreement with @Melvillian, with perhaps more of a continuous slope between speedball, choke, caps, and tube rolling.

 

From what I understand, a new tube might need 10-20 hours to burnoff coatings internally.

 

Installed Speedball today. Incredible improvement to all areas of concern that I had listed above. No more cottonballs in the ears, and soundstage/etc seems to be significantly better as well.

Now it's just different from my Marantz, in a good way.

So for those who are on the fence like I was (ie - "maybe I'll like the 'laid-back' sound"), just get the Speedball. I was prepared and ready to sell Crack before I did, but now it's going nowhere.

 

@Mngnt it’s a fun amp to mod for relatively cheap. Its by no means perfect, but It’s a very fun and engaging amp.

 

I'm just starting on my new Crack amp, but I thought I would make a little cable to turn the Crack into a pre-amp. Here it is.

The 4 wires are braided tightly to reject EMI and RFI.

• Canare F-16 1/4in TRS Phone Plug
• Rean NYS372P-BG Phono Jack w/Gold Plated Contacts & Black Plated Shell
• 24 AWG solid core 4N silver wire, sleeved in cotton
• Heat shrink

 

I think you might need to adjust the capacitors and resistor network to match the impedance if you are going to use as a pre-amp.

 

Nope, works great out of the box as a pre-amp. (More of a tube buffer for my purposes)

 

Got mine out of the cupboard as the wife and two year old are away!


My Crack and speedball has been modded and think I have gone about as far realistically as I can with it

there Isn’t a lot of room left and I’m considering moving it on and getting a Crackatwoa. Anyone using one?