18w Stand alone power amp
Moderators: CurtissRobin, colossal, zaphod_phil, Daviedawg, Graydon
-
- Unrated
- Posts: 2
- Joined: Sat 12/07/19 1:34 pm
18w Stand alone power amp
Hello there.
I recently built a Soldano X88r preamp clone - quite a challenging undertaking but i managed to wrap it up...
Now i need to build a matching power amp.
I have a set of 18w transformers which I salvaged from my very first build (i reused the chassis and ither bits for other orojects along the years).
I figured i could blatantly copy the power section of the Marshall 18w, using only 1/2 of the first preamp stage and adding a negative fb loop.
Now the one thing i couldnt figure out is how to keep the response as linear as possible? I’m open to suggestions!
Thanks
I recently built a Soldano X88r preamp clone - quite a challenging undertaking but i managed to wrap it up...
Now i need to build a matching power amp.
I have a set of 18w transformers which I salvaged from my very first build (i reused the chassis and ither bits for other orojects along the years).
I figured i could blatantly copy the power section of the Marshall 18w, using only 1/2 of the first preamp stage and adding a negative fb loop.
Now the one thing i couldnt figure out is how to keep the response as linear as possible? I’m open to suggestions!
Thanks
0 x
- KagliostroAmpwww
- Unrated
- Posts: 23
- Joined: Mon 03/13/23 7:53 pm
Re: 18w Stand alone power amp
I'll try to add a an NFB with a pot + resistor instead of a simple resistor to be able to vary the NFB level at taste
K
K
2 x
-
- Unrated
- Posts: 2
- Joined: Sat 12/07/19 1:34 pm
Re: 18w Stand alone power amp
As in a “resonance” control? My SLO builds have exactly this arrangement but I wanted to keep it simple.KagliostroAmpwww wrote: ↑Sat 03/25/23 10:17 amI'll try to add a an NFB with a pot + resistor instead of a simple resistor to be able to vary the NFB level at taste
K
Thanks tho!
0 x
- KagliostroAmpwww
- Unrated
- Posts: 23
- Joined: Mon 03/13/23 7:53 pm
Re: 18w Stand alone power amp
No, simply a variabile resistor
The fixed resistor is to fix a max value for the NFB signal & the (in series) potentiometer is to be connected as rehostat to perform the reduction of the NFB signal of a desired level (use your ears as feedback instrument)
Nothing of complicated
K
The fixed resistor is to fix a max value for the NFB signal & the (in series) potentiometer is to be connected as rehostat to perform the reduction of the NFB signal of a desired level (use your ears as feedback instrument)
Nothing of complicated
K
1 x
- TriodeLuvr
- Frequent poster
- Posts: 616
- Joined: Tue 10/16/18 11:19 am
Re: 18w Stand alone power amp
I wouldn't use NFB in an amplifier with a Marshall-type LTP inverter. It will negate the desirable tone of the inverter and cause a coarser breakup at high volumes.
Jack
Jack
2 x
- Unit_1
- Newbie
- Posts: 32
- Joined: Sun 11/09/14 6:35 pm
Re: 18w Stand alone power amp
Although using NFB with LTP pi isn't unheard of
https://robrobinette.com/images/Guitar/ ... _small.png
https://robrobinette.com/images/Guitar/ ... _small.png
0 x
The ability to play/make music is a gift that not everyone gets. Those of us who have it should use it.
- Bieworm
- Verbose Moderator
- Posts: 2287
- Joined: Mon 02/10/20 8:24 am
- Location: Belgium
Re: 18w Stand alone power amp
auwch! You're referring to Fullerton type amps...not the sweet Marshall LTP PI overdrive you're eliminating with a NFB loop.Unit_1 wrote: ↑Wed 03/29/23 11:51 pmAlthough using NFB with LTP pi isn't unheard of
https://robrobinette.com/images/Guitar/ ... _small.png
FWIW the bassman without NFB loop sounds sweeter too IMHO
2 x
"THIS should be played at high volume..preferably in a residential area"