Originally Posted by Aeolus Kratos
I'm just wondering a question, how would be the comparison between the fully upgraded Crack ( with Speedball + GEC Brown Base + best input tubes + bunch of Mundorfs / Teflon film caps + Stepped Attenuator ) and the stock Mainline??? Because the price of a fully upgraded Crack maybe is even greater than the price for a Mainline.
Like this auction which is near to the deadline, and the price now is just ridiculous : http://www.ebay.co.uk/itm/141259960898?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649
I haven't had any chance listening to an upgraded Crack, I just listened to the speedballed Crack and Mainline, and the Mainline is clearly better.
Crack certainly improves nicely with upgrades and is a tremendous value and performer compared to competing commercially manufactured OTL's, but I'll echo the others above in recommending a jump straight to the mainline for those with the requisite budget who are looking to drive high end dynamic cans (and who are comfortable with a more sophisticated build).
The tinkering and tweaking is really an end in and of itself and a whole lot of fun. Also, a lot of us got into modding our cracks and tube rolling before the mainline was available. My crack, built back in 2011, for example, has a rather nice tkd pot, 100 uf obbligato coupling caps, and an axon bypassing the 3rd psu cap, in addition to the speedball. I also have a pretty solid set of tube options, including all the usual suspects - various mullard, bugle boy, rca, tungsol 12au7/12bh7's and several 5998's, a GEC 6as7g, a 7802, various 6080's (previously a nos 7236) etc. I still get lots of listening enjoyment out of my crack every day in the office. It is a very nice amp in its own right, but even with my hd650's (x10 with my hd800's), my ears instantly pick up on the fact that the mainline is a totally different and more sophisticated animal than the modded crack, irrespective of its tube complement. Put on a good Decca recording or the like (e.g. Schiff's Goldberg Variations), and the mainline's refinement, details and speed become all the more apparent.
This is why I occasionally wave my arms in the air and try to discourage folks from investing $200 in a GEC tube when its 1/6 the price of the mainline (and really may or may not be any more enjoyable than a good 6080 or 5998 depending on a multitude of factors). I picked up my GEC when they cost half that, and I know others have found reasonable deals on rebrands in particular on occasion. But as you correctly imply, modding and tube rolling should not be with the expectation that the crack will overcome mainline in technical proficiency.