Canadian Crack!
- Thread starter Lar
- Start date
You kept the finish simple, I like it. Looks alot like mine 
http://www.bottlehead.com/smf/index.php/topic,2188.0.html
I was using a 6SN7 with adapter as well. I liked it. I built Foreplay III with 6SN7's and figured I would end up with the 12AU7 back in Crack afterwards. I have been favoring 12BH7's instead. But if Crack was all by itself again, I'd be using a 6SN7. What 6SN7 tube is that, is it a Tungsol? ... Nevermind, missed the EH 6SN7 part
http://www.bottlehead.com/smf/index.php/topic,2188.0.htmlI was using a 6SN7 with adapter as well. I liked it. I built Foreplay III with 6SN7's and figured I would end up with the 12AU7 back in Crack afterwards. I have been favoring 12BH7's instead. But if Crack was all by itself again, I'd be using a 6SN7. What 6SN7 tube is that, is it a Tungsol? ... Nevermind, missed the EH 6SN7 part
stereo_eyes
New member
Looks great! But what's the little blue thing between the jack and the input tube?
Grainger49
New member
Lar, remember that doesn't include changing the voltage to the tube heater.
Grainger49
New member
Hmmm, thinking. It is easy if the 12A?7 is already wired to work on 6.3V. Otherwise I don't see how it is going to work. And let's leave it an option that I'm wrong. I just took some pain medicine 1/2 hour ago and might not be calculating in my brain that well.
Anyone else see how it is done?
Anyone else see how it is done?
Laudanum said:
Yep, I built my own adapter for the 6sn7. If making your own adapter you'll just need to wire one heater pin from the octal base to pins 4 & 5 and the other to pin 9 on the noval base. This way no modifications are needed on the crack. Nice looking amp by the way, I'm also liking the sound of the 6sn7.
Grainger49
New member
Laudanum said:
Am I getting this straight. You are starting with a 12.6V tube and want to convert to a 6.3V tube? If so does it take the 12.6V and drop it with a resistor?
Paul Joppa
Moderator
The Crack has a 6.3v winding. The 12AU7 is configured for 6.3v, and the 6080/6AS7 has a 6.3v heater. No other voltage is available.
Grainger49
New member
Tony,
That doesn't really answer my question. If the converter relies on a folded heater configuration, 6.3V wiring of a 12.6V heater, it will only work for these instances.
Most Bottlehead kits are like this. The original Foreplay used 12.6V heater wiring, I don't remember another, and still could be wrong since I haven't built them all.
For instance there were many kits and production tube amps/preamps that, like my PAS-3X, had a 25V supply and put two tube heaters in series at ~12.5V each. In this case an adapter would be hard to use.
Edit: I have already taken too much space in someone else's thread but wanted to add this to this post. Since there is nothing in the auction about the heater wiring I contacted the seller. It turns out I was watching the same auction for another purpose. I asked the seller about adjusting the heater voltage since putting 12.6V on a 6SN7 would burn the heater open and ruin the tube. Here is his answer:
Dear Valued customer Grainger,
please kindly note the adaptor will not change voltage , the original voltage can only be 6.3V or parallel connection 6.3v , it cannot be used for 12.6 V
Best regards
Ricky
This is to say that in any Bottlehead equipment that already has a 12.6V tube wired to work with a 6.3V heater you can make this substitution with the linked adapter. But don't use it in a 12.6V wired socket in other equipment.
That doesn't really answer my question. If the converter relies on a folded heater configuration, 6.3V wiring of a 12.6V heater, it will only work for these instances.
Most Bottlehead kits are like this. The original Foreplay used 12.6V heater wiring, I don't remember another, and still could be wrong since I haven't built them all.
For instance there were many kits and production tube amps/preamps that, like my PAS-3X, had a 25V supply and put two tube heaters in series at ~12.5V each. In this case an adapter would be hard to use.
Edit: I have already taken too much space in someone else's thread but wanted to add this to this post. Since there is nothing in the auction about the heater wiring I contacted the seller. It turns out I was watching the same auction for another purpose. I asked the seller about adjusting the heater voltage since putting 12.6V on a 6SN7 would burn the heater open and ruin the tube. Here is his answer:
Dear Valued customer Grainger,
please kindly note the adaptor will not change voltage , the original voltage can only be 6.3V or parallel connection 6.3v , it cannot be used for 12.6 V
Best regards
Ricky
This is to say that in any Bottlehead equipment that already has a 12.6V tube wired to work with a 6.3V heater you can make this substitution with the linked adapter. But don't use it in a 12.6V wired socket in other equipment.
Paul Joppa
Moderator
Good point, Grainger. The Stereomour also has a 12-v heater winding and the 12AT7 is run on that supply.
