Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: hylaphone on January 09, 2023, 02:16:23 pm

Title: Recording/Headphone outputs
Post by: hylaphone on January 09, 2023, 02:16:23 pm

Hi folks, I've looking at implementing something like the attached schematic from Kagliostro, in a little micro amp I've built.
Will this still work if I have NFB fed from the secondary?
And do the recording and headphone outs pass full audio frequency? I'm not sure how to calculate that. If not, how would I scale up the components?Thanks very much!

Title: Re: Recording/Headphone outputs
Post by: shooter on January 09, 2023, 04:01:26 pm

does your uAmp pass full audio?
I did the math 40yrs ago, not gonna happen again  :icon_biggrin:
Just looking, it'll probably pass whatever comes out of the amp

Title: Re: Recording/Headphone outputs
Post by: hylaphone on January 09, 2023, 05:30:32 pm

haha I don't blame you! :icon_biggrin: Yes it's for bass guitar, 30Hz - 15kHzIf I have NFB coming from the secondary, will that be affected?

Title: Re: Recording/Headphone outputs
Post by: nandrewjackson on January 09, 2023, 09:50:43 pm

I'm guessing the thick black line that r80 is connected to us a ground? I've never seen it drawn that way before.

Title: Re: Recording/Headphone outputs
Post by: shooter on January 10, 2023, 04:57:23 am

i seldom use NFB, so  :dontknow:


yes, ground

Title: Re: Recording/Headphone outputs
Post by: PRR on January 10, 2023, 05:08:38 pm

NFB should only make things better, why fear it? Though not a lot of NFB in a guitar amp.

The fat line between the jacks has to be Ground to work as expected.

Both output have high-cut filters. Raw/naked geetar has annoying highs. But you can switch-out the caps if you want "all of it", as when you have a fancier cab-sim in the system. (The coil won't make a lot of difference without the cap.)

Title: Re: Recording/Headphone outputs
Post by: hylaphone on January 11, 2023, 10:40:20 am

AH! I see it now, thanks guys.