Six Moons review of Crack

[Doc B.]

Just in case you haven't seen it -

http://www.6moons.com/audioreviews2/bottlehead/1.html

[NightFlight]

Good read.

I'd like to point out to anyone who is researching the BH Crack to keep in mind that the 6moons review covers only the base unit without tube rolling, upgrade to speedball or component upgrades.  I think the majority of the weaknesses mentioned can be addressed that way.

[Doc B.]

Here's another nice review that tends to support your comments:

http://diy.koenigs.dk/2014/03/02/bottlehead-crack-and-speedball-review/

[JamieMcC]

Nice review thanks for the heads up.

I would add as a T1 owner myself a few basic and relatively inexpensive mods to the Crack can make a significant difference to the listening experience with the T1 over a stock Crack the cans just seem to get a kiss of life and come alive.

A stepped attenuator film caps and choke which can be done for perhaps $150 with audio rated films capacitors and well under half that if your not snobby using the Russian paper in oil and Teflon bypasses (my personal favourite combination)
 
Hopefully Sixmoons might do a follow up with Speedball a modded up Crack and better tubes.

[grausch]

@NightFlight: Does the stock Crack have weaknesses? It sound pretty damn good to my ears.

[Kris]

@NightFlight: Does the stock Crack have weaknesses? It sound pretty damn good to my ears.

I installed Speedball in my Crack about a month ago and as I really like more dynamics, better soundstage, overall clarity and less distortion that Speedball offers, I'm also lacking those "magical" mids that I used to hear before upgrade. It sounds to me like mids are rolled off towards the bass region. They are simply less clear and less present now.

Question to our experts: Is there any way (lets say components upgrade?) that can bring those mids from stack Crack back (without uninstalling Speedball ), keeping all goods  that Speedball brought to my crack?
I've already tried different tubes which helps a little but still can't get the mids clarity from before upgrade.
I've also tried to bypass 3rd electrolytic cap in power supply with 2.2uF film, but this made mids even worse, so I pulled it out.

Thanks in advance,
Kris
 

[NightFlight]

@NightFlight: Does the stock Crack have weaknesses? It sound pretty damn good to my ears.

It's laid out in the 6moons review. When I read it, I was a bit mixed but had to mostly agree that the stock crack has its limitations. But its simply just not the end of the story for the crack. There's so much more you can do.

As to getting back the sultry mids post speedball, I think perhaps the trade-off for clarity has always been one of those audio rules that can't be avoided. But it can be augmented.  I put some Russian polystyrene .3uF (x3) as a bypass on my last PS cap, which did some good in my case.  I also have mundorf films replacing the output caps, but my jury is on hiatus on weather that was worth the upgrade. 

Tonight, I'm poking around on ebay for E80CC's as per the impressions expressed in the Crack Tube Rolling thread.

Thinking on this further, I remember reading PIO caps are known for the their lush and sweet presentation. Getting those in the audio path might be a way to go if that is your preference. I may just try some for bypassing the output caps. 

[JamieMcC]

I installed Speedball in my Crack about a month ago and as I really like more dynamics, better soundstage, overall clarity and less distortion that Speedball offers, I'm also lacking those "magical" mids that I used to hear before upgrade. It sounds to me like mids are rolled off towards the bass region. They are simply less clear and less present now.

Question to our experts: Is there any way (lets say components upgrade?) that can bring those mids from stack Crack back (without uninstalling Speedball ), keeping all goods  that Speedball brought to my crack?
I've already tried different tubes which helps a little but still can't get the mids clarity from before upgrade.
I've also tried to bypass 3rd electrolytic cap in power supply with 2.2uF film, but this made mids even worse, so I pulled it out.

Thanks in advance,
Kris

For the price of a cup of coffee you could try adding a k75-10 Russian Mylar pio bypass capacitor to the 100uf coupling capacitors.

http://www.enjoythemusic.com/diy/0411/capacitor2.htm

[Kris]

For the price of a cup of coffee you could try adding a k75-10 Russian Mylar pio bypass capacitor to the 100uf coupling capacitors.

Jamie,

What capacitance of the bypass caps would you suggest for best results?

Thanks,
Kris

[Kris]

Thinking on this further, I remember reading PIO caps are known for the their lush and sweet presentation. Getting those in the audio path might be a way to go if that is your preference. I may just try some for bypassing the output caps.

Please post your impression if you decide to go this rout.

Kris

[JamieMcC]

Jamie,

What capacitance of the bypass caps would you suggest for best results?

Thanks,
Kris

I used the 2.2uf 250v ones they had quiet a noticeable impact on the sonic.

[Kris]

I used the 2.2uf 250v ones they had quiet a noticeable impact on the sonic.

Thanks Jamie