Charisma's BH Crack Build

Colonl_Charisma · 1962

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Offline Colonl_Charisma

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on: January 16, 2021, 12:29:12 PM
First, I’d like to thank Paul Birkeland and all the BH members who helped me troubleshoot my Crack over the past few months. No way could I have made it this far without the help and the wealth of knowledge on this forum.

Pics of my current build are attached!

Short impressions of the sound from my various builds. Hopefully, this will help others on the forum if they are looking to mod their Crack.

Tubes used in builds #1 & #2 = Thomson 6080WA & Muller CV4003
Tubes used in builds #3, #4, and #5 = Thomson 6080WA & Raytheon VT-231 6SN7GT (Garage1217 adapter)

1. Stock Crack - The stock Crack sounds amazing, and I experienced many ‘wow’ moments during my time with it. The “tube sound” is definitely present which is a plus. Only reason I started modding was due to me breaking my volume pot.
2. Crack w/ Speedball + PEC potentiometer – Upgrading (only time I’ll use this word) the volume potentiometer is game-changing. Previously, I was barely able to move the knob before the volume was too loud. Upgrading the pot allowed for better volume control. Speedball mod was also great. It took me a couple of hours to get used to the new sound. It really cleaned up the tube distortion, added a little bit of gain, and seemed to really open the soundstage. I had more ‘wow’ moments after the Speedball. I did find the Speedball to add overwhelming bass which fatigued my ears, but this is the only ‘complaint’ that I can point to.
3. Replaced output caps w/ Dayton Audio 100uf/200v film caps + bypassed last PSU cap w/ a WIMA 2.2uf/250v + Cree diode rectifier added - This is currently tied with my current build as my favorite in terms of sound. First, the bass was tamed, and I no longer found it fatiguing. The amount of detail, soundstage, and overall depth to the music I experienced was impressive. For the first time, I was able to listen to Panopticon’s “Roads to the North” where it did not sound like a jumbled mess, and I could actually hear the vocalist.
4.  Choke + Dayton Audio 100uf/200v replacing last PSU cap + Dayton Audio 1.0uf/250 bypass caps on all large film caps + bypassed 2nd PSU cap with WIMA 2.2uf/250v – This created a very interesting effect, but it made music sound awful. Songs, in general, sounded recessed into the background with only very specific sounds being ‘projected’ towards me. I assumed it was the bypass capacitors on the film caps, and I was correct. I clipped them off, and that led to my current build.
5. Current Build – Clipping the bypass caps off the large film caps created a massive change in sound. The sound is more relaxed which I really like. I also feel as if the soundstage has been opened.

Currently thinking about experimenting with film cap rolling specifically in the last PSU spot, and rolling bypass caps on the large film caps. Any suggestions, feel free to post them!
« Last Edit: January 16, 2021, 12:56:29 PM by Colonl_Charisma »

Ross


Offline Paul Birkeland

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Reply #1 on: January 16, 2021, 03:02:58 PM
The red base looks nice.  I think you're out of space to do much more! 


Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline larcenasb

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Reply #2 on: January 16, 2021, 03:58:21 PM
Looks great! I tried rolling different bypass caps for the last PS cap--mine is an Audyn Q4 68uF 400V (same as the output caps).

I think the Jantzen Superior-Z (mine is 0.68uF 800V) is a great value at around $12-15, and isn't too large to be a problematic fit. Should be fun to listen and compare to your Wima, to see if you can hear any improvement or change.

Lowell B.


Offline Colonl_Charisma

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Reply #3 on: January 16, 2021, 05:51:35 PM
Thanks PB! The red base surprised me with how well it turned out.

I appreciate the recommendations larcenasb! I'll check out those two cap manufacturers.
« Last Edit: January 16, 2021, 05:53:16 PM by Colonl_Charisma »

Ross


Offline larcenasb

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Reply #4 on: January 18, 2021, 07:27:37 AM
Sorry, I wasn't very clear... I use Audyn Q4 68uF 400V caps for the two output caps, as well as the last PS cap. The Jantzen 0.68uF 800V is the bypass on the last PS cap.

I've never tried bypassing the output caps, please post your impressions here if you do it!

Lowell B.


Offline Colonl_Charisma

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Reply #5 on: January 18, 2021, 11:16:54 AM
No worries! I appreciate the clarification.

Currently, I have Dayton Audio 100uf/250v film caps as the last PS cap and my two output caps. I have tried bypassing all three with DA 1uf/250v film caps. The sound change was pretty awful haha. It was too quiet, and I lost so much detail in every song. Vocals were really recessed into the background along with other sounds.

However, I’m going to replace the last PS cap with a Mundorf 220uf/250v and see how that changes the sound. Then, if all is well, I’m going to experiment with bypassing the larger film caps with some Russian K75-10s.


Ross


Offline cddc

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Reply #6 on: January 21, 2021, 07:36:25 PM
Thanks PB! The red base surprised me with how well it turned out.

I appreciate the recommendations larcenasb! I'll check out those two cap manufacturers.

The red base does look great! What stain / oil did you use?

I think you are almost done with rolling components, time to roll tubes...LOL ;D



Offline Colonl_Charisma

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Reply #7 on: January 21, 2021, 08:37:01 PM
Thanks cddc! I used the oil-based Minwax Barn Red stain, and I applied two coats for a darker appearance. I still need to apply my polyurethane coat.

Haha yes, I'm nearly out of space. I just added a 220uf/250v cap to the last PSU cap position and removed my WIMA bypass on the 2nd PSU cap. I had to raise my amp's feet because the 220uf/250v film cap was quite large lol.


Ross


Offline cddc

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Reply #8 on: January 21, 2021, 09:28:51 PM
LOL...you've stuffed the Crack with too many goodies   ;D

Have you added the pair of twisted grounding diodes as per PB?
https://forum.bottlehead.com/index.php?topic=11676.0



Offline Colonl_Charisma

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Reply #9 on: January 22, 2021, 09:03:43 AM
It is stuffed for sure! Only thing I'm going to experiment with now is bypassing the last PSU cap that I added, but I'm waiting on the caps to be delivered. I have no room for anything else haha.

Yep, the twisted grounding diodes have been added. I guess you can't really see them in the pic that I posted due to the choke.

Ross