Original Crack without Speedball with 6SN7

[hpleung]

I want to check here if it is electrically safe to use a 6SN7 tube (with Adapter) with the Original Crack without the Speedball upgrade.

[Paul Birkeland]

This will work, but some of those adapters can be a bit noisy.

[adeep42]

Many years ago, I ran my Crack with Speedball with a 6SN7 with an adapter. It was great. I still remember that the 6SN7 that I settled on was a National Union that I got from Brent Jesse.

[Gerry E.]

This is the adapter to get if they have the one you need (scroll down):

https://garage1217.com/g1217_011.htm

Very high quality.

Gerry

[Tom-s]

My top recommendation (after trying many) are handmade by a guy named Deyan.
He's a DIYer from Bulgaria and does this as a hobby like all of us.

If your Crack is black, he can make it black. If it's metal. He can make it out of metal etc.
If you want it 20mm tall, it's 20mm tall, if you want it 40mm tall it can be that way.

He's an active member on head-fi or just google Deyan tube adapters.

[Paul Birkeland]

If it's metal. He can make it out of metal etc.

I'd be very hesitant to use a tube adapter made out of metal. 

[Mucker]

FWIW, although the 6SN7 had decent sound, nothing I used beat an E80CC. The Crack/SB with that tube and a 5998 is what I have been using for the past couple of years and I have no desire to change it. The resistors on the Speedball have to be changed out which is easy. IMO adding the Speedball yields really good results without losing the tube sound.

I tried several different 6SN7 tubes and all of them had varying degrees of hum and it was with the Garage adapter. It does sound decent enough but I'll never go back to it.

[Tom-s]

I'd be very hesitant to use a tube adapter made out of metal.

Understand your point. It's a metal outer skin on an otherwise non conductive tube adapter.

[Paul Birkeland]

If a plate connection happens to touch the metal outer shell, there isn't really a good way to keep that shell earthed, so there's some concern there.