Increasing gain on the Crack

wullymc · 6808

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Offline wullymc

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Reply #15 on: January 26, 2013, 08:13:10 AM
I am in Ottawa.

I don't know if it would be a good idea to recheck the voltages?  What component would possibly cause the volume problem if there is one?

Thanks!

Dave
Project RPM5.1 with 2M Bronze/Graham Slee Era Gold V/Quickie with PJCSS/Paramount 1.1 300B/Woden Valiant

ODAC/Crack/DT880 600ohm

Current Project:  Beepre!!!


Offline Doc B.

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Reply #16 on: January 26, 2013, 08:14:51 AM
I'm still a bit lost here. "12 and 2" doesn't really translate to anything when we don't know how the knob was oriented when installed. The knob can turn through 3/4 of a clock face. Some people have the knob at its lowest setting at 7:30, some at 6:00 and some at 12:00.  Is the knob at lowest volume at 7:30 and between 12 and 2 is like turned up halfway to 2/3 of the way, or is the lowest volume setting point of reference something else?

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


Offline STURMJ

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Reply #17 on: January 26, 2013, 08:15:32 AM
I have confirmed on my crack, with 600 ohm phones, the volume turned to 12:00-01:00 is where I normally listen. I never looked closely at the stock pot, is it log tapered? I know that the alps I have in there now is. I wonder if this is the situation, the attenuation decreasing at a log rate as it is turned up? (meaning there is no problem).



Offline wullymc

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Reply #18 on: January 26, 2013, 08:25:16 AM
Thanks.

Sorry, I have the volume pot installed so that 0 is at 7 o'clock.  It is the stock pot that came with the kit.


Dave
Project RPM5.1 with 2M Bronze/Graham Slee Era Gold V/Quickie with PJCSS/Paramount 1.1 300B/Woden Valiant

ODAC/Crack/DT880 600ohm

Current Project:  Beepre!!!


Offline Grainger49

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Reply #19 on: January 26, 2013, 09:18:03 AM
Dave,

You have your volume control installed as I would.  That is pretty much standard.  But Dan had to ask because who knows where the screw gets set on the knob.

Your situation is odd.  Maybe a recheck of the voltages and posting anything over 15% high or low would help clarify it.

The stock pot is log or audio taper.  Linear tapers act really funny in an audio application.  

Oh, I'm in Knoxville TN, so I'm no help.  We do have a number of Canadian Bottleheads.



Offline STURMJ

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Reply #20 on: January 26, 2013, 09:27:12 AM
Sorry i forgot to take into account the preamp i was using with the crack.  Without it comfortable levels are more around the 10:00 position. (with 600 ohm phones)



Offline wullymc

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Reply #21 on: January 26, 2013, 10:30:13 AM
I will try to take the voltage reading tomorrow.

STURMJ, what headphones are you using?  Would you say that you have a lot of volume if you go up to 2 or 3pm?  You have the Speedball upgrade eh?  Can you describe your audio layout.

Thanks.  Sorry for staying on this but I really want to be sure that my Crack is fine.

Dave
Project RPM5.1 with 2M Bronze/Graham Slee Era Gold V/Quickie with PJCSS/Paramount 1.1 300B/Woden Valiant

ODAC/Crack/DT880 600ohm

Current Project:  Beepre!!!


Offline Doc B.

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Reply #22 on: January 26, 2013, 01:08:55 PM
If your pot is at 7 for 0 volume that means it will travel to about 4 before reaching full output. If you are running the amp at 12-2 for typical listening I am afraid that I don't understand why you are concerned. Will the headphones play louder than you want to listen when turned past 2?

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


Offline STURMJ

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Reply #23 on: January 26, 2013, 04:07:43 PM
I usually use a fpII as a pre.  It has been modified to lose lots of signal and I never got that to work quite right, but works great on the crack.  I have Beyer dt990s (600ohm) and dt880s (250ohm). On a speedballed crack there is plenty of volume at 10:00 then earsplitting starts at about 01:00.

 I do have  a non-speedballed crack that I didn't think to try until your last question.  Using the non-speedballed crack I would say comfortable level is at about 11:30 and getting loud at about 12:00.  (I do consider my ears to be sensitive; others may not ;D )

My understanding is that the dt990 and dt880 have the same drivers, so our phones should perform about the same.  But there are many more variables; mains line voltage, specific tube outputs (a tube output may vary slightly from others), actual source levels, different peoples ears, and even variability in recording levels between listening materials.  There are others here that know much more than I, but I suspect the difference between our two setups are within the normal range of variability.



Offline 2wo

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Reply #24 on: January 26, 2013, 06:19:06 PM
I have a ODAC and I find it to have the lowest output of any of the DACs I have. I think that having your volume control at the high end rather then the low end, is a good thing. As long as you have a little more to go...John

John S.


Offline wullymc

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Reply #25 on: January 27, 2013, 01:18:33 AM
Thanks guys for the input.

Thanks STURMJ for taking the time to test.  I really appreciate it.

It is not that I need earsplitting volume but I just think there might be something up.

I will wait until I get my turntable and phono box and try it out.  I really hope that everything works well and I can stay with the volume around 12 -2.

I will update when I get my Turntable and if there are problems I will post my voltages.

Thanks again!

Dave
Project RPM5.1 with 2M Bronze/Graham Slee Era Gold V/Quickie with PJCSS/Paramount 1.1 300B/Woden Valiant

ODAC/Crack/DT880 600ohm

Current Project:  Beepre!!!


Offline wullymc

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Reply #26 on: February 02, 2013, 03:27:19 PM
Thanks everyone for all the feedback.

I received my TT and phono preamp today.

I ended up going with a Pro-ject RPM 5.1 with Ortofone Bronze feeding to a Graham Slee Era Gold V to my Crack to DT880 600ohms.

With this combo I was happy to find out that I have to have my volume at 2 - 3:30.  This is perfectly fine with me!  I have never heard my Crack sound better than through this combo!!!!  I love records again!!

I will wait awhile and probably end up upgrading my Crack with the Speedball upgrade.

Thanks to everyone.   I am a happy camper. Take care...Dave

Dave
Project RPM5.1 with 2M Bronze/Graham Slee Era Gold V/Quickie with PJCSS/Paramount 1.1 300B/Woden Valiant

ODAC/Crack/DT880 600ohm

Current Project:  Beepre!!!


Offline wullymc

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Reply #27 on: February 03, 2013, 10:25:34 AM

Now I am thinking about a summer project being the Quickie.

I am just wondering if this would work as such.  I think it would work and it would be a fun project:


turntable -- > phono preamp   \
                                              \
                                             Quickie  ------>  Crack
                                            /
laptop  ------------->   dac    /



Is my thinking correct.  I could have 2 switchable inputs to 1 output thereby allowing me not to not to unplug my interconnects to my Crack?

What other benefits would I see by adding a Quickie other than having 2 inputs?

Thanks and I am sorry for all the neophyte questions.

Dave
Project RPM5.1 with 2M Bronze/Graham Slee Era Gold V/Quickie with PJCSS/Paramount 1.1 300B/Woden Valiant

ODAC/Crack/DT880 600ohm

Current Project:  Beepre!!!