[JamieMcC]

thanks! thats actually what i did is cast a larger rectangle and then cut it down into "slices" and then ill polish it all once assembled. its not really hard honestly to work with. once they get here ill get started and update.

Please takes some pics of your progress its an unusual approach I am sure plenty would be intrigued to see.

I had good results casting large blocks 400mm x 150mm x 150mm of resin in moulds made out of HDPE plastic which releases easily (I used the white plastic hdpe cutting boards which work out a lot less expensive than buying it in sheet form).

 

[Paladin79]

I am always fascinated by your builds Jamie, I may be using a similar design that you used on some Amp camp amps, I have large heat sinks on the way out of China and once those hit I will probably start shopping for either burled walnut or burled maple for the tops and fronts.

 

[bigfatpaulie]

So you said.

Paul I found a pic of a Crack showing the scale of the 400V Mundorfs your Clarity caps are only a few mm larger I think you should be ok maybe just some higher feet to get a little extra ground clearance. I remember using some 25mm rubber door stops on mine.

Thanks! I used to have the 400v in my last one. I feel like the Clarity caps are bigger, however. That's just from memory, not measuring so I could be wrong. Time will tell I supposed.

 

[R-Oak]

the skill level displayed in a few of those crack's build on this thread is really inspiring,
i was wondering:
what are the few upgrades that people tend to do the most??, (i'm guessing either because they are easy to implement, cheap and does a difference)

i have seen alot of the velvet blue volume pot

 

[Paladin79]

Rolling tubes is one upgrade of course, lots of people do replace the pots with Alps blue velvet.
Most of my changes were a bit radical and expensive to talk about as common upgrades so I will defer to others to talk about caps.

 

[Allanmarcus]

the skill level displayed in a few of those crack's build on this thread is really inspiring,
i was wondering:
what are the few upgrades that people tend to do the most??, (i'm guessing either because they are easy to implement, cheap and does a difference)

i have seen alot of the velvet blue volume pot

Most popular, and effective, is tube rolling. Until you have tubes you really like, there isn’t much of a point in changing anything else. In terms of effect on sounds, tubes have an enormous effect compared to any other change.

The next is probably to pot. The blue velvet or other pots give better balance at low volumes, and more even co tell of the volume at moderate volumes.

A choke is common for the vest mod, and more and more, the rectifier mod. They are relatively easy.

Finally, caps.

A few folks will “upgrade”the rca and trs jacks, it that is really cosmetic also, a few will use difference tube sockets.

Biggest bang for buck for sound is tubes. All other mods are pretty much for fun and will have a fraction of sound impact as the tubes.

 

[Kitchener]

the skill level displayed in a few of those crack's build on this thread is really inspiring,
i was wondering:
what are the few upgrades that people tend to do the most??, (i'm guessing either because they are easy to implement, cheap and does a difference)

i have seen alot of the velvet blue volume pot

Only mod I can recommend is the Speedball.
I’ve done Mundorf caps, choke, TKD pot and power bypass cap. And I can’t say any of them made a noticeable difference.
-then again, I can’t tell a Mullard from a Gold Lion from a Clear Top so what do I know?

 

[Paladin79]

You are honest in your appraisal of changes.

As far as microphonics I have added a copper top, front, and back plates to mine and the sheer weight of the amp along with one inch thick quartered oak makes mine very very stable and not susceptible to vibrations but it is not something i would recommend to others. I also like single gang pots but that is a personal preference. I did locate some made by Alps that are amazing but you have to have room for them, and know where to find them.

 

[Kitchener]

I can only tell what I hear

I must point out that I’m not dismissing other mods. Some people have sharper ears that others.
And, I did all mods at once, not taking the time to appreciate each one, so there’s that.
The best way to find out is to try for yourself, sadly!

 

[Paladin79]

I did most all mods with a stock Crack next to the one being modified so I could listen and test each as I went along but I knew I would be starting with two. It is hard for me to say ok I made a bunch of changes and I "remember" what the Crack sounded like before I changed things lol. It is not something for everyone but I like to be able to readily switch between amps, dacs, headphones, solid state, tubes, balanced, unbalanced and even headphone cables and try different combinations to achieve the sound I like. I still go back to the Crack though just for the tube sound.

 

[Kitchener]

I wish I could have done that!
I wasn’t in a hurry exactly, but once I start a project I devote as much as I can to getting it done.
When I was into DIY handwired mechanical keyboards, I worked on them in the garage until 6 in the morning before heading to work. -with a two year old in the house!
I guess it’s a form of mania.

I recently got a Stax earspeaker set and discovered I’m more of a neutral, analytical sort of guy! Still use the Crack for bedside listening though.

 

[Paladin79]

I believe you showed one of your keyboards before, it was amazing. Right now I am looking at old school typewriter keyboards with bluetooth for an Ipad Pro I just got but a lot of them are $400 up.

I am also building class A monoblock speaker amps and coaster hybrid headphone amps and am considering doing an Elekit preamp or Marantz M7.

 

[Maxhawk]

Another useful mod is the ability to change the bias resistor in the anode of the signal tube to optimize the current for other tube types such as the E80CC and 12BH7. I used to offer a PCB with a switch that allowed easy switch of this resistor. I currently have no more boards but would be willing to get more if there's enough interest.

 

[bloodhawk]

Another useful mod is the ability to change the bias resistor in the anode of the signal tube to optimize the current for other tube types such as the E80CC and 12BH7. I used to offer a PCB with a switch that allowed easy switch of this resistor. I currently have no more boards but would be willing to get more if there's enough interest.

This is how @Maxhawk 's awesome PCB's look in my crack - https://imgur.com/a/g3zkf4e

Im overhauling things today and moving everything to a 10"x10" Panel, it will look even better on that.

 

[Paladin79]

Very nice and additions like that are one of the reasons I went with a larger cabinet to begin with. Of course I used VU meters and their circuit board and dual pots so my builds would have been tough to do in a standard box no matter what. I did finally use a 12 by 12 inch top copper plate but with all the changes I made there, I hesitate to call it a Crack amp. A few components were recognizable but not many.