Paul Joppa
Moderator
6FQ7 and 6CG7 are 6SN7s in 9-pin mini bottles. For what it's worth.
Tube Rolling w/Crack
- Thread starter Dr. Toobz
- Start date
Colonl_Charisma
New member
Thanks Paul! So, could I use my 6SN7 adapter on a 6FQ7 tube if I wanted to try out of one of those?
Thermioniclife
Member
The 6fq7 is a nine pin tube so no adaptor needed but I will check the pinouts and get back. Stand by.
Thermioniclife
Member
Only one snag, the heater wiring is different but it can be done.
First remove jumper between pin 4 and 5 on the 9 pin socket.
Second remove green wire from pin 9.
lastly solder green wire to pin 4.
Be advised that if want to go back to a 12au and its variants or use a 6sn7 in an adaptor you will need to change this back to the original wiring.
First remove jumper between pin 4 and 5 on the 9 pin socket.
Second remove green wire from pin 9.
lastly solder green wire to pin 4.
Be advised that if want to go back to a 12au and its variants or use a 6sn7 in an adaptor you will need to change this back to the original wiring.
If you rewire for 6CG7s, you can use a 7AU7 instead of a 12AU7 without reverting the socket to stock wiring.
Colonl_Charisma
New member
Thanks guys! If I re-wire my Crack for a 6FQ7 tube, does that mean I wouldn’t have to use an adapter for 6SN7 tubes in the future?
Thermioniclife
Member
You are always going to need an adaptor of some sort because the 6sn7 is an 8 pin tube that fits in an octal socket and the 6fq7 and 7au7 are 9 pin tubes that fits in a noval socket.
Mucker
Member
I enjoy the 6SN7 variants very much, but I also love the Tung Sol 12AU7. Both are outstanding tube types. The garage adapter works perfectly and keeps the original design intact. However, I am all for the "have it your way" option if that is what you desire. That is the best thing about Bottlehead engineering. Solid if left as is with the flexibility to do many customization's to the electronics and chassis. Win, win.
Colonl_Charisma
New member
I appreciate all the help! Before I start re-wiring, I will check out the Tung Sol 12AU7. They are pretty cheap on eBay.
Mucker
Member
Colonl_Charisma said:
I REALLY like that tube. Try to get a NOS tube or at least one with matching sides. Made in USA tube and not the reissue ones although I hear the reissues are not bad at all. The NOS may be slightly higher in price but I think they are worth it.
Something like these:
https://www.ebay.com/itm/143923491451?hash=item218282327b:g:Z1IAAOSwNjxgCGAP
https://www.ebay.com/itm/353519882921?hash=item524f6d52a9:g:HN0AAOSwUTxgt-pP
Enjoy!
Colonl_Charisma
New member
Thanks, Mucker! I picked up one of the NOS versions, and I appreciate the links. Excited to try out the Tung Sol 12AU7.
watonwak
New member
There have been a ton of complaints about the Thomson 6080s being sold on eBay, so I would temper your expectations a little bit until you receive the tubes and try them out.
They are not fakes, but rather they don't seem to work properly and were possibly intended to be discarded when they were manufactured, but made it out of the plant somehow.
Colonl_Charisma
New member
I'm enjoying the Tung Sol 12AU7! I had been using the 6SN7 for so long that I forgot how quiet the Crack is. I always had some tube noises with the 6SN7, but I cannot even tell that the Crack is turned on with a 12AU7 in with no music playing haha.
Mucker
Member
Colonl_Charisma said:
That's really great feedback and my experience as well. I could only get certain 6SN7's to be quiet when using 6080 tubes. With a 5998 all of the 6SN7 I tried have some hum, and some more than others.
However, the 12AU7 was always quiet, and the Tung Sol really performed well. I do like the 6SN7GT Channel Master tall tube with a Chatham 5998 but if I throw the TS 12AU7 in there, I am equally happy. Just great tubes both of them. Glad to hear it is working out for you!
Mucker
Member
Paul Birkeland said:
Very interesting! I purchased a pair of these Thompson's from "Tube Maze Store" on eBay and they turned out to be be complete garbage after a few hours use. They actually sounded very good in my Woo WA2 until they just outright quit with no signs of trying to fight death. I could never get them to work in the Crack. I could hear audio but it was whisper quiet. They are quite an attractive buy because they do sound pretty good but I would never again buy them because of their wretched history.
