Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Oddvar on November 12, 2017, 04:32:15 pm

Title: Soldano Sloo without the poweramp section?
Post by: Oddvar on November 12, 2017, 04:32:15 pm
Hi.  Is there a way to build this Slo without the power section?
Title: Re: Soldano Sloo without the poweramp section?
Post by: 92Volts on November 12, 2017, 04:55:45 pm
Sure, but a schematic is a better starting point than a layout to figure out/make changes like that.

Usually everything past the Master Volume control is considered part of the poweramp. Often this includes 1 additional "preamp tube" which is used as the phase inverter. Different poweramp designs would use different phase inverters, and single-ended poweramps don't even have one, which is why it's not considered part of the preamp.

What are you using it for? Driving a different vacuum-tube poweramp design? Easy. Take everything before the Master Volume of this amp and hook it to everything after the Master Volume of a different design.

Driving headphones? Not so easy, you still need a "poweramp"-- a smaller one-- to do this. You'll also want to reduce treble to simulate the changes a guitar speaker makes to the sound.

A recording interface or the input of another amp? Probably easier than headphones, but you'll still want a lower voltage signal and maybe the ability to supply more current.
Title: Re: Soldano Sloo without the poweramp section?
Post by: shooter on November 12, 2017, 05:32:11 pm
here's how I would do it-ish.  read the footnote
Title: Re: Soldano Sloo without the poweramp section?
Post by: Oddvar on November 13, 2017, 01:11:48 am
Thanks for this.  I am thinking of using it for the Reload Torpedo Loadbox, direct to daw.
Title: Re: Soldano Sloo without the poweramp section?
Post by: guitardude57 on November 13, 2017, 01:01:57 pm
The diagram shown would work. 


You could even place a level pot before the FX/output jack...
Title: Re: Soldano Sloo without the poweramp section?
Post by: 92Volts on November 13, 2017, 05:02:08 pm
Thanks for this.  I am thinking of using it for the Reload Torpedo Loadbox, direct to daw.

I don't think the direct-in function of that loadbox simulates the effect a speaker would have on the sound. If it's not doing that, you might as well hook this preamp straight to the DAW.

Now, you probably do want a device that simulates the effect a speaker would have on the sound... that loadbox can do that but only using the 4, 8, or 16 ohm impedance settings which need to be driven by a poweramp!

You could build a significantly smaller, cheaper poweramp to go with the SLO preamp. Or if you don't have that loadbox already, make sure you get one that will do speaker/cab simulation starting with a line-level signal.

If you can (and want to) do speaker/cab simulation digitally, there should be no problem hooking this preamp straight to the DAW. I would lower the value of that resistor as described on the schematic to keep the signal low and not overdrive the DAW.
Title: Re: Soldano Sloo without the poweramp section?
Post by: shooter on November 13, 2017, 06:18:29 pm
I 'm missing something, is the OD side 180 out from the normal at the mix R's? 
guessing it works, just seems odd :dontknow:
Title: Re: Soldano Sloo without the poweramp section?
Post by: DummyLoad on November 13, 2017, 06:37:52 pm
I 'm missing something, is the OD side 180 out from the normal at the mix R's? 
guessing it works, just seems odd :dontknow:

yes, does it matter? with VR1 and VR2 seems like only one path is active at any given time.

--pete
Title: Re: Soldano Sloo without the poweramp section?
Post by: shooter on November 13, 2017, 07:17:54 pm
 :think1: I was just looking at my cropped version, which don't have notes!!
resume normal programing, n Thx Sir.
Title: Re: Soldano Sloo without the poweramp section?
Post by: Tone Junkie on November 13, 2017, 07:19:02 pm
Look at the soldano X88 its what your wanting with a better crunch channel.
Bill