Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: MxT on April 26, 2011, 08:51:48 PM
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Hi Guys
I am awaiting my Crack kit and was thinking that afater looking at some photo's and reading up on the forum that the Speedball upgrade is the most suggested upgrade. Maybe I would like to tweak some other items. What would you suggest.
I was thinking on rolling the tubes- what drop in options would you suggest that are availble and doest cost more than the kit?
Wiring with some fancy wire-maybe some 19gauge Kimber copper for the signal and power path?? other options-is 19 g fine?
Popping in a blue Alps volume pot- or is there another suggestion in a similar price range.
Any suggestions on caps that I can put in as a drop in replacement for the stock Solens??
Maybe some Cardas or Vampire RCA connectors-I dont mind drilling the holes bigger if need be.
Any other options I could consider that does not need me to change the circuit wiring or that will take mayor landscaping on the top plate?
Thanks so much!!!
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Looks like you have read up well. Tube rolling is always good but your outcome might be different with the Speedball. So do it first.
I think that any capacitor in the amp could be upgraded. The output caps are in series with the music, so very important. I believe some folks have put in motor start caps (Oilers) here. Upgrading the last power supply cap with one that is lower ESR and higher value is always good.
I don't see any Solen caps in the Crack. There are 3 power supply caps and two output caps.
I would go with beefy copper for the power supply rather than designer wire. Designer wire of your choice is good for signals. Connectors, volume pot and headphone jack are often upgraded.
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Thanks
So far Im looking at the following changes.
Speedbal
Erse 100.0μF 250v PulseX -caps
Some Kimber 19g for the signal path
Neutrik locking Phono plug
Cardas RCA's
Alps Stereo Volume pot/or maybe the Audionote
Furutech IEC inlet
I think that should be decent without breaking the bank. Any other suggestions are welcome!
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Mxt,
If it were me, I'd go with something a bit finer for the signal wiring -- say 24 or 22 gauge, or even 26. Also, the furu iec will indeed require some surgery to get installed as there is very little room in that corner to work with and the iec inlet hole is specific to the type of iec/fuse holder that BH uses.
I use copper vampire jacks on all my bh gear and they are drop-ins and need no drilling to accomodate.
Other than that, everything loos good, and of course if you like cardas connectors, go ahead and use them. The locking Neutrik will also probably need some surgery to fit.
HTH,
Jim
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Thanks guys- Which model Vampire jacks do you use- im either or and any other suggestions on the caps?
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The ones with the inside nut and made of copper with direct gold plating. They only make one model like this.
-- Jim
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Hi Guys some options on the volume pots- which of these fits in hte crack with Speedball and which is the best bang for buck?
Blue Velvet - STEREO Conductive Plastic Potentiometer, 100K, audio/log taper volume controls
http://www.partsconnexion.com/product7382.html
TKD 2CP-2511 STEREO Potentiometer, 100K
http://www.partsconnexion.com/tkd_64187.html
Audio Note - 100K, Audio/Log Taper, Stereo, VOLUME Control
http://www.partsconnexion.com/anote_72544.html
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The TKD and Audionote are both smaller than the Alps so there should be enough space for any of them. Hificollective.co.uk has the dimensions if you need them.
No idea which is best though.
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I assume the Furutech IEC you're using is the FI-03, is it a direct drop in? I'd personally put that money toward a nicer potentiometer / attenuator than the Alps Blue, it's a difference that should be easy to notice. I haven't used the TKD myself, but I've heard nothing but good things.
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I went with the TKD pot. I read through many threads here and on other forums. Decided to take a chance on it. Don't know what it sounds like yet. I'm still a couple of weeks away from building my Crack.
The only other changes I plan to make are installing the speedball upgrade, a pilot light and a Neutrik locking stereo jack.
http://angela.com/genuinesylvaniapilotlightassemblyfortubeamps.aspx
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The only way to know what it sounds like is build with another pot first then change it. That is what Doc always suggests.
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Make sure you use a LED conversion with that particular pilot light, otherwise you'll overtax the 6.3V winding if you use a standard incandescent (~30V versus 150-300V). Earlier in my "audiophile" career, I rolled a Alps Blue, a Chinese $50 stepper, and a DACT CT3. There was a major difference between the alps blue and the stepped attenuators, and a very small difference between the CT3 and Chinese stepper. I think it's worth it to experience these differences, that way you know why you're spending a little more here and there.
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Make sure you use a LED conversion with that particular pilot light, otherwise you'll overtax the 6.3V winding if you use a standard incandescent (~30V versus 150-300V). Earlier in my "audiophile" career, I rolled a Alps Blue, a Chinese $50 stepper, and a DACT CT3. There was a major difference between the alps blue and the stepped attenuators, and a very small difference between the CT3 and Chinese stepper. I think it's worth it to experience these differences, that way you know why you're spending a little more here and there.
Oh boy. I feel like I just got in over my head here with the pilot light idea... Did a quick google for LED conversion and found this: http://www.sears.com/shc/s/p_10153_12605_SPM188183368P?sid=IDx20101019x00001a&ci_src=14110944&ci_sku=SPM188183368
And, as for the actual installation I planned to go by this thread.
http://www.bottlehead.com/smf/index.php/topic,972.0.html
One wire will go to pin 9 on the 9 pin socket, the other wire will go to pin 5 on the 9 pin socket.
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Thanks guys- VERY valuble input- Dropped the IEC and got the tkd pot. So the changes will be as follows
Speedbal
New signal Caps
Fancy Signal wire
New Stereo Pot
New RCA's
Locking Phono input
EAR feet
Will post pics of the build once I start- will be doing a Red root London oil finish on the wood with a hammered silver top plate and transformer plate finish.
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MxT, All very good choices :)
Mr. Davis, A bayonet mount LED should only run about $5 at most. Find out the size used by the pilot light you purchased and run a search in Google or eBay for the size.
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Concerning fit: view the Alps pot here
http://www.bottlehead.com/smf/index.php/topic,1508.0.html
Perfect with the speedball upgrade. Since others stated your other selections are smaller they should work as well.
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Mr. Davis, A bayonet mount LED should only run about $5 at most. Find out the size used by the pilot light you purchased and run a search in Google or eBay for the size.
I was able to find an #47 6.3 volt LED bayonet base pinball machine light that I think will work.
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I just received my kit and I'm also considering adding a pilot light. Found a nice looking 6.3V light, similar to the lights I've seen enterprising folks deploy, here:
http://angela.com/redjewel63vtubeamppilotlightassembly.aspx
What's the best way to make a hole in the plate? Just drill it out and round file it? This particular light requires a 0.620" hole. Thanks!
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Use a step drill. Something like this: http://www.harborfreight.com/catalogsearch/result?q=step+drill
Just remember to drill a pilot hole first.
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Thanks, Mr Davis, and also for the warning to first drill a pilot. I've seen those types of bits before but never investigated what they are for. Looks like one that can go as large as 5/8" will do the trick.
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Is a "pilot light" just for aesthetic reasons or does it serve a function?
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I think it is a "classic look" that goes with tube equipment. I don't know the available heater current for the Crack but if you get a 120V pilot light it could go on the AC side and not make any difference.
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Is a "pilot light" just for aesthetic reasons or does it serve a function?
I would imagine it would dramatically upgrade the ability to determine whether the amp is turned on or off.
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I'm adding it mostly for aesthetic reasons but I suppose it is more obvious an indicator at quick glance that the amp is on than trying to discern tube glow, in a bright environment.
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Just a follow-up thank you again to Mr Davis re: the step drill bit. I picked one up at Home Depot -- expensive relative to the online set -- and had no problems whatsoever making the 5/8" hole I need. Seeing as it is this easy to make nice holes in aluminum, I'm not going to have any qualms about further mods that need drilling!
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For those of you who used the Neutrik jack, what size does the hole need to be and is there any benefit from drilling in one direction or the other?