Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: jewishjay on April 02, 2021, 11:24:15 am

Title: Dissimilar plate resistors in the LTP
Post by: jewishjay on April 02, 2021, 11:24:15 am

Blencowe 9:9 reads "However...if the tail resistance is more than 18k....the balance becomes worse...and the mismatching of the anode resistors is unnecessary."

If I understand him correctly  then, the 5f6a Bassman uses 82k and 100k because it's tail resistors are 470+10k= 10,470 ohms. BUT our beloved ab763 Vibroverb would be better off with matched 100k because its tail is 22k+470=22,470 ohms. Is that right?

If so, why change the plate Rs why not change the tail Rs? What other reasons are there for the "traditional values" in the long tail pair? And what can be gained or lost by tweaking here?

Title: Re: Dissimilar plate resistors in the LTP
Post by: SILVERGUN on April 02, 2021, 12:09:22 pm

The Long-Tail Pair (aikenamps.com) (https://www.aikenamps.com/index.php/the-long-tail-pair)