Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: Dr. Toobz on April 09, 2010, 11:15:06 AM
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With the Queen being out of commission for a few days, and the fact that you guys had to double the order of chassis plates, I was wondering how close we are to seeing the first kits ship out?
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Just need to do a little final editing of the assembly manual. The first run will begin shipping next week. The second run is between a third and halfway sold out. I think we sold 4 just today. Second run chassis plates are on order and the second run will probably begin shipping in about three weeks. That will pretty much consume the old stock American 6080s and 6AS7s I have on hand. We will then begin to purchase new Eastern European tubes, and so by the third production run the price will probably go up a bit, to maybe $219 or so.
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The Crack manual is complete as of this afternoon. We ran into one error in our inventory - we ended up with stranded wire rather than solid core for the hookup wire. The correct wire should be here in a day or two and the kits will begin shipping.
In the meantime PB and I got the production prototype of the C4S active load upgrade for Crack built and photographed. As if the name Crack didn't bother some folks enough, I've decided the appropriate name for the upgrade kit is Speedball. We should have parts and manual pulled together and an order page active for the upgrade kit not too long after we begin shipping the amp kits. Price for the upgrade will be around $100 -$120.
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If I ordered Crack today, will I be able to get in on the second run? and will the upgrade be available before it ships so I can get a Speedball with the Crack?
Bryon
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Yes we still have a few kits left in the second run. The upgrade kit is a separate kit, and I can't say exactly when it will begin shipping. But we will do our best to feed your addictions.
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Awesome. I haven't been this excited since....well, my last BH project! Sounds like some of us who bought the kit the day it was released may have them up and running by the end of April.
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For the inexperienced... what is an "C4S active load upgrade"?
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If I ordered Crack today, will I be able to get in on the second run? and will the upgrade be available before it ships so I can get a Speedball with the Crack?
Bryon
Do ya think the DEA is monitoring the internet? Are they having fun with all the Bottleheads on Crack?
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What, no rock and roll, asks Ian Drury?
Doc, how did the Axon caps work out and will they be part of the upgrade kit? Will the upgrade include active loads for both the gain and output tubes as you had been playing with?
-- Jim
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Hi Jim,
We're going to let folks buy their own caps, as we can't get enough of a price break to make it feasible for us to offer them. The upgrade will indeed include C4S boards for both the input voltage amps and the output cathode followers
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For the inexperienced... what is an "C4S active load upgrade"?
This upgrade replacing loading resistors with a high impedance "stack" of bipolar junction transistors. For the first stage of the Crack, this will result in greatly reduced distortion, a lower noise floor, and increased gain. Most users also report an increase of fine detail, along with other positive qualities. For the output stage, the distortion is vastly reduced, but noise rejection remains about the same. (This isn't a huge issue since the second stage is a current amplifier, not a voltage amplifier)
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Doc,
Can you give me an idea of how much vertical height inside the chassis the speedball upgrade will require? Or are the Axon caps the taller of the options? Just trying to figure out how tall to make the base if I want to get started on a different one.
Thanks,
Jim
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The Speedball upgrade uses all but 1/8" of the height available in the base. Going shorter isn't really an option, going taller is certainly an acceptable possibility.
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I'm curious, does this include the feet on the bottom of the base, presuming it comes with feet?
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The kit includes the feet. The Speedball upgrade is not so tall that it is visible between the ground and wood base when the feet are installed, but it is pretty close.
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Thanks, Paul. How much room is there in the corner by the volume pot? Enough to get one of the TKDs in there -- maybe with a little creative metalwork on the top plate?
-- Jim
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When do you think the Speedball will be ready to ship?
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I would guess that the Speedball will be ready in 30-90 days.
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Actually I'm shooting for the 30 day end of that estimate, or sooner. We just need to order some PC boards and a few other parts and get the manual written. I'll try to get a pre-order page up on the shopping cart next week.
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How much was it supposed to cost?
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Regarding the C4S upgrades, if you had to choose one would it be the voltage amp tube or the cathode follower? Which one makes the most difference?
Thanks,
Jim
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Regarding the C4S upgrades, if you had to choose one would it be the voltage amp tube or the cathode follower? Which one makes the most difference?
Until someone does the experiment, all we can do is guess.
Normally, I'd say the cathode follower, but that's based on experience with preamps where the load impedance is high. Since the Crack has a low-impedance (headphone) load, the C4S won't increase the net load impedance very much at all. So I'd guess the voltage amp stage C4S will have the greater effect.
But what you hear does not always correspond to your theories, so I'd rather withhold judgment until we have some actual experience.
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Paul,
Thanks. Guess we'll just have to wait though I wonder how many folks would try one without the other.
I'm trying to keep things running as cool as possible, and if the CF CCS isn't a huge improvement over the VA alone, then I may just skip it.
-- Jim
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In the first example I built I think the VA load had a little more impact than the CF load, but using both sounded best. As for heat, whether it's cathode and plate resistors or active loads there will be more or less the same amount of heat under the hood. Going from one to the other doesn't really increase the current draw enough to make a big difference, not like adding a shunt regulator with a bunch of additional current draw and increased B+ might.
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Thanks, Paul. How much room is there in the corner by the volume pot? Enough to get one of the TKDs in there -- maybe with a little creative metalwork on the top plate?
-- Jim
I put one of the conductive plastic TKD's in mine and with just a little time with a rat tail file, it fit the stock hole no problem. Unfortunately, the pot that I used was from an old project of mine and it was history so I need to order another one. Be advised, the length of the shaft is much longer but with the application of some spacers on the bottom, the knob sits just a little higher than it did originally.
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Doc,
Thanks, and as long as the heat is roughly the same, no need to worry here.
Steve, Thanks, I did some fiddling with this yesterday and came to the same conclusion -- that I could either drill or file out the existing hole and then file a notch for the index tab. I'd also cut the shaft down a bit and use a nice quilted maple knob I have, or leave it as-is and use one of the big audio note gold knobs I also have.
-- Jim