Crack as preamp

jimiclow · 14248

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Offline jimiclow

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on: March 08, 2012, 07:30:34 AM
Hello!
First post. I'm waiting for my crack kit to arrive. I would like to know if I could use the crack as a preamp.
Has anybody tried this?
Thank you in advance.

Bottlehead Stereomour with V-cap, Mundorf, Alps
SEX 2.1- Alps, Mundorf
Stock Crack
Reduction with Mundorf, Clarity caps
Schiit Asgard, Schiit Lyr
Technics SL1200mkII
Woo WA-6
Hoyt-Bedford speakers, Fostex T90A
LCD-2, HD600, ER4P, HF5, SR60i, DT990-600, DT770-32, HFI580


Offline Doc B.

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Reply #1 on: March 08, 2012, 08:01:25 AM
Yes it will work fine as a line level preamp. Of course you won't have the ability to switch sources except by plugging and unplugging cables and you would need an adapter to plug the amp into the headphone jack.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline jimiclow

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Reply #2 on: March 08, 2012, 04:27:07 PM
Thank you very much for the reply Doc.
So you mean that there would be no modification or addition of parts involved?

Bottlehead Stereomour with V-cap, Mundorf, Alps
SEX 2.1- Alps, Mundorf
Stock Crack
Reduction with Mundorf, Clarity caps
Schiit Asgard, Schiit Lyr
Technics SL1200mkII
Woo WA-6
Hoyt-Bedford speakers, Fostex T90A
LCD-2, HD600, ER4P, HF5, SR60i, DT990-600, DT770-32, HFI580


Offline grufti

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Reply #3 on: March 08, 2012, 04:32:28 PM
You will likely throw away a lot of gain in a chain of amps that uses the Crack as a preamp. Take a look at various discussions of "gain structure" by Paul Joppa among many others. Throwing away gain is generally not a good idea.



Offline Doc B.

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Reply #4 on: March 08, 2012, 07:44:06 PM
You will likely throw away a lot of gain in a chain of amps that uses the Crack as a preamp. Take a look at various discussions of "gain structure" by Paul Joppa among many others. Throwing away gain is generally not a good idea.

Gain is about 15dB. Rule of thumb is about 10dB for a line stage. So it's not that far off, actually pretty close to the original Foreplay. I think the output jack and lack of selectable inputs are the only real deterrents.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline grufti

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Reply #5 on: March 08, 2012, 08:59:49 PM
That really leaves just the lack of selectable inputs as a deterrent. Three dollars worth of HOSA cable takes care of the connector issue, if you want to be cheap.

http://www.google.com/products/catalog?hl=en&sugexp=llsin&gs_nf=1&tok=x_5nE6esEeu1SFr6wcNoIA&cp=8&gs_id=ej&xhr=t&q=trs+6.3+mm&safe=off&biw=1333&bih=1052&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.,cf.osb&um=1&ie=UTF-8&tbm=shop&cid=11057247404590733065&sa=X&ei=0rZZT9OMGMbaiQKJz_ioCw&sqi=2&ved=0CEkQ8wIwBQ


I have swapped out the original tubes in my Crack build and forgot that the original configuration has a lot less gain.



Offline dwilli852

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Reply #6 on: March 09, 2012, 02:24:50 PM
Ok, couldn't stand it any longer. Connected my Crack to my monoblocks tonight. Very nice sounding. Damn, now I'm going have to build a tube preamp. That means more tube rolling, upgrades and on and on. Will it ever stop?

David Williams


Offline Grainger49

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Reply #7 on: March 09, 2012, 02:27:13 PM
Will it ever stop?  No, it is Crack!



Offline jlschweiger

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Reply #8 on: March 09, 2012, 03:07:55 PM
Or if you want to use your own favorite interconnect cables:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=090-314&utm_source=googleps

John Schweiger
Chromcast Audio -> Paramounts -> Triad bookshelf
ADCOM-575 -> Smack -> HD800


Offline lextek

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Reply #9 on: March 09, 2012, 04:15:00 PM
Oh intersting.....

Bob Lasky


Offline jimiclow

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Reply #10 on: March 09, 2012, 06:23:42 PM
Thanks again for all the responses.
Actually, I plan of using the Crack with the Decware Taboo.
Can't wait for the Crack to arrive..

Bottlehead Stereomour with V-cap, Mundorf, Alps
SEX 2.1- Alps, Mundorf
Stock Crack
Reduction with Mundorf, Clarity caps
Schiit Asgard, Schiit Lyr
Technics SL1200mkII
Woo WA-6
Hoyt-Bedford speakers, Fostex T90A
LCD-2, HD600, ER4P, HF5, SR60i, DT990-600, DT770-32, HFI580


Offline grufti

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Reply #11 on: March 09, 2012, 08:21:29 PM
In that case you are going to want a fair amount of gain from your preamp. You might very well be hitting a home run with that pairing. Buy the Speedball ... consider a very good 5998 ... wow!



Offline BNAL

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Reply #12 on: March 10, 2012, 04:05:35 AM
Don't forget the driver tube. I would read through the Crack tube rolling thread. There is a lot of good information in there about different tubes for the Crack.

http://www.bottlehead.com/smf/index.php/topic,663.0.html

Brad Nalitt
Iron Upgraded S.E.X. Amp 2.0
Foreplay III
Quickie w/PJCCS
Eros Phono
Blumenstein Orca Speakers, Baby Benthic Subs
S.E.X.y Speakers W/FT17H Horn Tweeters
Thorens TD 125 MkII W/ Shure M97xE JICO SAS Stylus


Offline lextek

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Reply #13 on: March 10, 2012, 09:24:39 AM
So I had to try it.  Made up a cable from some Kimber speaker cable.  Hooked the Crack up to the little SS amp upstairs.  I really, love Crack.  Especially Speedballing.....

Bob Lasky


Offline jlschweiger

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Reply #14 on: March 10, 2012, 12:29:38 PM
Would anyone here be able to offer an opinion about using a speedball crack as a preamp for the Paramounts?  I'm interested in if the output/input impedence is compatible between the two.

John Schweiger
Chromcast Audio -> Paramounts -> Triad bookshelf
ADCOM-575 -> Smack -> HD800