Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: ernie_jr on February 20, 2015, 04:11:38 pm

Title: 5f6-a
Post by: ernie_jr on February 20, 2015, 04:11:38 pm: Has any one built a 5f6-a with octals instead of 12__7's, and if so what did you use 6sl7's or 6sn7's and how did it sound?
Thanks,
Ernie
Title: Re: 5f6-a
Post by: HotBluePlates on February 20, 2015, 05:13:52 pm: Quote from: ernie_jr on February 20, 2015, 04:11:38 pm
Has any one built a 5f6-a with octals instead of 12__7's ...

Ampgeek has. You might wish to PM him if he doesn't see this.
Title: Re: 5f6-a
Post by: labb on February 20, 2015, 05:25:35 pm: I have built a couple of 5c3's which use the octals. Had a lot of trouble with them being microphonic.
Title: Re: 5f6-a
Post by: HotBluePlates on February 20, 2015, 05:28:46 pm: Quote from: labb on February 20, 2015, 05:25:35 pm
I have built a couple of 5c3's which use the octals. Had a lot of trouble with them being microphonic.

With the 6SC7's?

I used to have a '54 Princeton with a 6SL7 and had no issues with microphonics, but that is a much smaller (and quieter) amp.
Title: Re: 5f6-a
Post by: labb on February 20, 2015, 05:47:02 pm: I have used both 6SC7 and 6SL7. NOS for the 6SC7 and NOS, Sovtek and Tung-Sol new issue for the 6SL7. More problems with the SC's. Will say this though, when you get quiet ones they really sound good IMO. I would check the price for each. They have really gotten expensive lately.
Title: Re: 5f6-a
Post by: shooter on February 20, 2015, 05:49:27 pm: I used Sluckey's Rock-ola build as a basis for a SE build using a 6550, I love the 6sN7 tubes, I have a pair of NOS rca's that add warmth and stay very clean. I also used 1 6SN7 as a PI but didn't really like it there. FWIW
Title: Re: 5f6-a
Post by: mresistor on February 20, 2015, 06:03:20 pm: I've been using Russian 6H9C's and they seem to be pretty good tubes. The ones made in the Reflektor factory.