Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: stringbender.dk on November 08, 2016, 03:54:16 am

Title: super reverb (glassy or cold sound)
Post by: stringbender.dk on November 08, 2016, 03:54:16 am
Hi folks :)

I got my super reverb amp home for some weeks ago. a tech fixed the tremolo for me, so it is working by the power tubes now, with some help from you guys :)
He adjust the bias to 35mA.  which should be normal after what I could see on the internet...

BUT, I think it has a bit cold sound. a bit steril. not like the sounds I hear from other people who use a super reverb.
Should the bias be higher?

All the tubes I'm using is from Tube amp doctor.
Some say I should buy NOS tubes, but what difference would that do to the cold sound I hear???

And should I then buy NOS preamp tubes and NOS power tubes???
Title: Re: super reverb (glassy or cold sound)
Post by: P Batty on November 08, 2016, 09:47:29 am
Hi folks :)

I got my super reverb amp home for some weeks ago. a tech fixed the tremolo for me, so it is working by the power tubes now, with some help from you guys :)
He adjust the bias to 35mA.  which should be normal after what I could see on the internet...


I assume that "working by the power tubes now" he converted it to bias-vary tremolo, which needs to be a little on the cold side to work well. You might want to change your negative feedback to a higher resistance to get a "warmer" response.
Title: Re: super reverb (glassy or cold sound)
Post by: sluckey on November 08, 2016, 10:11:55 am
Disregard the tremolo and turn it off. Now adjust the bias so the tubes run hotter for a warmer sound. Can you get the sound you want?
Title: Re: super reverb (glassy or cold sound)
Post by: stringbender.dk on November 08, 2016, 04:20:08 pm
Well, the tremolo got stronger after the mod. I don't know how to disconnect the tremolo.

and the bias should be as "normal" when it is at 35mA, right? 

Do you adjust it higher? 

Title: Re: super reverb (glassy or cold sound)
Post by: sluckey on November 08, 2016, 05:46:19 pm
Disregard the tremolo and turn it off. Now adjust the bias so the tubes run hotter for a warmer sound. Can you get the sound you want?