Quick newb question, couldn't find the answer.

[handrewmoore]

I have a Crack on the way, should be here Tues. Hopefully I'll have it built and running for the weekend. I have all of my sources running through a Mcintosh 6200 integrated amp right now. I have two options as I see it. I can run a line out of the tape output on the 6200 to the Crack and control the volume with the Crack. This option bypasses the volume control and 5 band equalizer on the Mcintosh. Or I could put a line selector on the preamp output and select between the main amp for my speakers and the Crack for my headphones. This option leaves me the ability to use the 5 band (rarely do) if I wanted but adds another volume pot in the path. I use the headphone jack on the 6200 to run my RS1i, I love it, but I do find on some tracks I lift the bottom end a bit. I just picked up some Senns and the headphone out is pretty useless with high impedance cans hence the reason for the Crack. If I were to go with option 2 and use the 6200 as a preamp, would I set the volume of the Crack on max? 12:00? I tried a search but came up with nothing.

[Grainger49]

You have laid out the pros and cons pretty well.  I would go with the record out.  Much of the sweetness of SET is the simplicity. 

[kgoss]

If you max out the volume on the crack you will essentially remove it from the circuit path.  However you might overdrive the Crack from the Mac preamp tape outputs and need to back off the crack volume.  Its an easy experiment to conduct.  You should also read Paul Joppa's excellent article on signals and signal to noise ratios.  You will find it on the Bottlehead Community page.  The Community page is under the "More" header on the BH home page.

[handrewmoore]

I'm sure I'll test it out both ways. I was just unsure about volume matching between the preamp and crack. I'll check out that article directly, thanks!

[Nathan]

In terms of signal path, simple is better. I would say that unless you find you absolutely need the EQ, use the tape out. I really would not want to run a signal through two volume pots.

[handrewmoore]

In terms of signal path, simple is better. I would say that unless you find you absolutely need the EQ, use the tape out. I really would not want to run a signal through two volume pots.

I honestly don't know yet, I rarely use eq with my other headphones. I haven't auditioned the Crack before, I just purchased it on the mountains of praise. Though the Senns dig a bit deeper than the Grados, so you may be right, I may not need the eq.

[handrewmoore]

I just finished up my Crack, everything measured right first time around, no problems. Listening to it now and it's awesome. I'm using it with the preamp now, sounds great, but I'm about to switch it over to the tape out to bypass the Mcintosh. I don't believe I'll be needing any eq.

[Adrian]

I started like you.  I connected my Crack to the Monitor (Line) out of my Marantz 2325 receiver and this separated everything but the input selector on the Marantz from the Crack.  If I want to run the phono input then I must turn on the receiver to access the internal phono stage there.

I have left behind any EQ adjustment many years ago.  Its fun to mess with but I decided to let my system play without it and then I can check and adjust with changes to the components within the signal path (from input to ears).

[Grainger49]

Congratulations! ! !

That's nice neat work.  That would make troubleshooting easier.  And it will make modifications so much easier.

[Paul Birkeland]

Squeaky clean! That's how you twist and braid, well done!

[handrewmoore]

Squeaky clean! That's how you twist and braid, well done!

Congratulations! ! !

That's nice neat work.  That would make troubleshooting easier.  And it will make modifications so much easier.

Thanks guys, I hadn't soldered anything since I was a kid. I took my sweet time. I was originally going to get it with the speedball, but I read multiple times to build it stock first. I really do like how it sounds stock and I'm even debating if I should build the speedball. I figure I'll run the Crack stock a while and get a good feel for it before I decide what I need to upgrade, if anything. I should note that I'm using it with the 150ohm HD700, not one of the 300ohm Senns. I know they're not the most loved cans, but I really do like its sound. I was concerned about the lower impedance with the Crack and almost got the Sex, but I read that a few people really liked the Crack with the HD700 so I gave it a shot. And I'm glad I did. I am thinking of giving the HD650s another go, I didn't care for them when I first auditioned them, but everyone goes on and on about the pairing.

I do have another question. I read that using a 5998 will lower the output impedance, does that mean it would better suit the 150ohm Senns over the 6080? Not that I'm having a noticeable problem with the sound. I'm no EE and figured I'd get your thoughts. Thanks again!

[Paul Joppa]

...
I do have another question. I read that using a 5998 will lower the output impedance, does that mean it would better suit the 150ohm Senns over the 6080? Not that I'm having a noticeable problem with the sound. I'm no EE and figured I'd get your thoughts. Thanks again!

It's true, but it's a modest effect - 20% to 30% impedance reduction, based on the published curves in the tube specifications.